commit a53ce18cac upstream.
Commit 829c1651e9 ("sched/fair: sanitize vruntime of entity being placed")
fixes an overflowing bug, but ignore a case that se->exec_start is reset
after a migration.
For fixing this case, we delay the reset of se->exec_start after
placing the entity which se->exec_start to detect long sleeping task.
In order to take into account a possible divergence between the clock_task
of 2 rqs, we increase the threshold to around 104 days.
Fixes: 829c1651e9 ("sched/fair: sanitize vruntime of entity being placed")
Originally-by: Zhang Qiao <zhangqiao22@huawei.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Zhang Qiao <zhangqiao22@huawei.com>
Link: https://lore.kernel.org/r/20230317160810.107988-1-vincent.guittot@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 829c1651e9 upstream.
When a scheduling entity is placed onto cfs_rq, its vruntime is pulled
to the base level (around cfs_rq->min_vruntime), so that the entity
doesn't gain extra boost when placed backwards.
However, if the entity being placed wasn't executed for a long time, its
vruntime may get too far behind (e.g. while cfs_rq was executing a
low-weight hog), which can inverse the vruntime comparison due to s64
overflow. This results in the entity being placed with its original
vruntime way forwards, so that it will effectively never get to the cpu.
To prevent that, ignore the vruntime of the entity being placed if it
didn't execute for much longer than the characteristic sheduler time
scale.
[rkagan: formatted, adjusted commit log, comments, cutoff value]
Signed-off-by: Zhang Qiao <zhangqiao22@huawei.com>
Co-developed-by: Roman Kagan <rkagan@amazon.de>
Signed-off-by: Roman Kagan <rkagan@amazon.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230130122216.3555094-1-rkagan@amazon.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b416514054 ]
RCU sometimes needs to perform a delayed wake up for specific kthreads
handling offloaded callbacks (RCU_NOCB). These wakeups are performed
by timers and upon entry to idle (also to guest and to user on nohz_full).
However the delayed wake-up on kernel exit is actually performed after
the thread flags are fetched towards the fast path check for work to
do on exit to user. As a result, and if there is no other pending work
to do upon that kernel exit, the current task will resume to userspace
with TIF_RESCHED set and the pending wake up ignored.
Fix this with fetching the thread flags _after_ the delayed RCU-nocb
kthread wake-up.
Fixes: 47b8ff194c ("entry: Explicitly flush pending rcuog wakeup before last rescheduling point")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230315194349.10798-3-joel@joelfernandes.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6ce895128b ]
Some thread flags can be set remotely, and so even when IRQs are disabled,
the flags can change under our feet. Generally this is unlikely to cause a
problem in practice, but it is somewhat unsound, and KCSAN will
legitimately warn that there is a data race.
To avoid such issues, a snapshot of the flags has to be taken prior to
using them. Some places already use READ_ONCE() for that, others do not.
Convert them all to the new flag accessor helpers.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20211129130653.2037928-3-mark.rutland@arm.com
Stable-dep-of: b416514054 ("entry/rcu: Check TIF_RESCHED _after_ delayed RCU wake-up")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 10ec8ca8ec ]
We've seen recent AWS EKS (Kubernetes) user reports like the following:
After upgrading EKS nodes from v20230203 to v20230217 on our 1.24 EKS
clusters after a few days a number of the nodes have containers stuck
in ContainerCreating state or liveness/readiness probes reporting the
following error:
Readiness probe errored: rpc error: code = Unknown desc = failed to
exec in container: failed to start exec "4a11039f730203ffc003b7[...]":
OCI runtime exec failed: exec failed: unable to start container process:
unable to init seccomp: error loading seccomp filter into kernel:
error loading seccomp filter: errno 524: unknown
However, we had not been seeing this issue on previous AMIs and it only
started to occur on v20230217 (following the upgrade from kernel 5.4 to
5.10) with no other changes to the underlying cluster or workloads.
We tried the suggestions from that issue (sysctl net.core.bpf_jit_limit=452534528)
which helped to immediately allow containers to be created and probes to
execute but after approximately a day the issue returned and the value
returned by cat /proc/vmallocinfo | grep bpf_jit | awk '{s+=$2} END {print s}'
was steadily increasing.
I tested bpf tree to observe bpf_jit_charge_modmem, bpf_jit_uncharge_modmem
their sizes passed in as well as bpf_jit_current under tcpdump BPF filter,
seccomp BPF and native (e)BPF programs, and the behavior all looks sane
and expected, that is nothing "leaking" from an upstream perspective.
The bpf_jit_limit knob was originally added in order to avoid a situation
where unprivileged applications loading BPF programs (e.g. seccomp BPF
policies) consuming all the module memory space via BPF JIT such that loading
of kernel modules would be prevented. The default limit was defined back in
2018 and while good enough back then, we are generally seeing far more BPF
consumers today.
Adjust the limit for the BPF JIT pool from originally 1/4 to now 1/2 of the
module memory space to better reflect today's needs and avoid more users
running into potentially hard to debug issues.
Fixes: fdadd04931 ("bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K")
Reported-by: Stephen Haynes <sh@synk.net>
Reported-by: Lefteris Alexakis <lefteris.alexakis@kpn.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://github.com/awslabs/amazon-eks-ami/issues/1179
Link: https://github.com/awslabs/amazon-eks-ami/issues/1219
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230320143725.8394-1-daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 08697bca9b ]
The hwlatd tracer will end up starting multiple per-cpu threads with
the following script:
#!/bin/sh
cd /sys/kernel/debug/tracing
echo 0 > tracing_on
echo hwlat > current_tracer
echo per-cpu > hwlat_detector/mode
echo 100000 > hwlat_detector/width
echo 200000 > hwlat_detector/window
echo 1 > tracing_on
To fix the issue, check if the hwlatd thread for the cpu is already
running, before starting a new one. Along with the previous patch, this
avoids running multiple instances of the same CPU thread on the system.
Link: https://lore.kernel.org/all/20230302113654.2984709-1-tero.kristo@linux.intel.com/
Link: https://lkml.kernel.org/r/20230310100451.3948583-3-tero.kristo@linux.intel.com
Cc: stable@vger.kernel.org
Fixes: f46b16520a ("trace/hwlat: Implement the per-cpu mode")
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 800977f6f3 ]
Add a new helper function kthread_run_on_cpu(), which includes
kthread_create_on_cpu/wake_up_process().
In some cases, use kthread_run_on_cpu() directly instead of
kthread_create_on_node/kthread_bind/wake_up_process() or
kthread_create_on_cpu/wake_up_process() or
kthreadd_create/kthread_bind/wake_up_process() to simplify the code.
[akpm@linux-foundation.org: export kthread_create_on_cpu to modules]
Link: https://lkml.kernel.org/r/20211022025711.3673-2-caihuoqing@baidu.com
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Cc: Bernard Metzler <bmt@zurich.ibm.com>
Cc: Cai Huoqing <caihuoqing@baidu.com>
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 08697bca9b ("trace/hwlat: Do not start per-cpu thread if it is already running")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 71c7a30442 ]
There is a problem with the behavior of hwlat in a container,
resulting in incorrect output. A warning message is generated:
"cpumask changed while in round-robin mode, switching to mode none",
and the tracing_cpumask is ignored. This issue arises because
the kernel thread, hwlatd, is not a part of the container, and
the function sched_setaffinity is unable to locate it using its PID.
Additionally, the task_struct of hwlatd is already known.
Ultimately, the function set_cpus_allowed_ptr achieves
the same outcome as sched_setaffinity, but employs task_struct
instead of PID.
Test case:
# cd /sys/kernel/tracing
# echo 0 > tracing_on
# echo round-robin > hwlat_detector/mode
# echo hwlat > current_tracer
# unshare --fork --pid bash -c 'echo 1 > tracing_on'
# dmesg -c
Actual behavior:
[573502.809060] hwlat_detector: cpumask changed while in round-robin mode, switching to mode none
Link: https://lore.kernel.org/linux-trace-kernel/20230316144535.1004952-1-costa.shul@redhat.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: 0330f7aa8e ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit baf1b12a67 ]
Time readers rely on perf_event_context->[time|timestamp|timeoffset] to get
accurate time_enabled and time_running for an event. The difference between
ctx->timestamp and ctx->time is the among of time when the context is not
enabled. __update_context_time(ctx, false) is used to increase timestamp,
but not time. Therefore, it should only be called in ctx_sched_in() when
EVENT_TIME was not enabled.
Fixes: 09f5e7dc7a ("perf: Fix perf_event_read_local() time")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/r/20230313171608.298734-1-song@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit fd0815f632 upstream.
Events should only be added to a groups rb tree if they have not been
removed from their context by list_del_event(). Since remove_on_exec
made it possible to call list_del_event() on individual events before
they are detached from their group, perf_group_detach() should check each
sibling's attach_state before calling add_event_to_groups() on it.
Fixes: 2e498d0a74 ("perf: Add support for event removal on exec")
Signed-off-by: Budimir Markovic <markovicbudimir@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/ZBFzvQV9tEqoHEtH@gentoo
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ee92fa4433 upstream.
KASAN reported follow problem:
BUG: KASAN: use-after-free in lookup_rec
Read of size 8 at addr ffff000199270ff0 by task modprobe
CPU: 2 Comm: modprobe
Call trace:
kasan_report
__asan_load8
lookup_rec
ftrace_location
arch_check_ftrace_location
check_kprobe_address_safe
register_kprobe
When checking pg->records[pg->index - 1].ip in lookup_rec(), it can get a
pg which is newly added to ftrace_pages_start in ftrace_process_locs().
Before the first pg->index++, index is 0 and accessing pg->records[-1].ip
will cause this problem.
Don't check the ip when pg->index is 0.
Link: https://lore.kernel.org/linux-trace-kernel/20230309080230.36064-1-chenzhongjin@huawei.com
Cc: stable@vger.kernel.org
Fixes: 9644302e33 ("ftrace: Speed up search by skipping pages by address")
Suggested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9f116f76fa upstream.
The function hist_field_name() cannot handle being passed a NULL field
parameter. It should never be NULL, but due to a previous bug, NULL was
passed to the function and the kernel crashed due to a NULL dereference.
Mark Rutland reported this to me on IRC.
The bug was fixed, but to prevent future bugs from crashing the kernel,
check the field and add a WARN_ON() if it is NULL.
Link: https://lkml.kernel.org/r/20230302020810.762384440@goodmis.org
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Fixes: c6afad49d1 ("tracing: Add hist trigger 'sym' and 'sym-offset' modifiers")
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e400be674a upstream.
Since the commit 36e2c7421f ("fs: don't allow splice read/write
without explicit ops") is applied to the kernel, splice() and
sendfile() calls on the trace file (/sys/kernel/debug/tracing
/trace) return EINVAL.
This patch restores these system calls by initializing splice_read
in file_operations of the trace file. This patch only enables such
functionalities for the read case.
Link: https://lore.kernel.org/linux-trace-kernel/20230314013707.28814-1-sfoon.kim@samsung.com
Cc: stable@vger.kernel.org
Fixes: 36e2c7421f ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Sung-hun Kim <sfoon.kim@samsung.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 03e1d60e17 ]
The watch_queue_set_size() allocation error paths return the ret value
set via the prior pipe_resize_ring() call, which will always be zero.
As a result, IOC_WATCH_QUEUE_SET_SIZE callers such as "keyctl watch"
fail to detect kernel wqueue->notes allocation failures and proceed to
KEYCTL_WATCH_KEY, with any notifications subsequently lost.
Fixes: c73be61ced ("pipe: Add general notification queue support")
Signed-off-by: David Disseldorp <ddiss@suse.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 601363cc08 ]
Parallel probing of devices that share interrupts (e.g. when a driver
uses asynchronous probing) can currently result in two mappings for the
same hardware interrupt to be created due to missing serialisation.
Make sure to hold the irq_domain_mutex when creating mappings so that
looking for an existing mapping before creating a new one is done
atomically.
Fixes: 765230b5f0 ("driver-core: add asynchronous probing support for drivers")
Fixes: b62b2cf575 ("irqdomain: Fix handling of type settings for existing mappings")
Link: https://lore.kernel.org/r/YuJXMHoT4ijUxnRb@hovoldconsulting.com
Cc: stable@vger.kernel.org # 4.8
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-7-johan+linaro@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9b459804ff ]
btf_datasec_resolve contains a bug that causes the following BTF
to fail loading:
[1] DATASEC a size=2 vlen=2
type_id=4 offset=0 size=1
type_id=7 offset=1 size=1
[2] INT (anon) size=1 bits_offset=0 nr_bits=8 encoding=(none)
[3] PTR (anon) type_id=2
[4] VAR a type_id=3 linkage=0
[5] INT (anon) size=1 bits_offset=0 nr_bits=8 encoding=(none)
[6] TYPEDEF td type_id=5
[7] VAR b type_id=6 linkage=0
This error message is printed during btf_check_all_types:
[1] DATASEC a size=2 vlen=2
type_id=7 offset=1 size=1 Invalid type
By tracing btf_*_resolve we can pinpoint the problem:
btf_datasec_resolve(depth: 1, type_id: 1, mode: RESOLVE_TBD) = 0
btf_var_resolve(depth: 2, type_id: 4, mode: RESOLVE_TBD) = 0
btf_ptr_resolve(depth: 3, type_id: 3, mode: RESOLVE_PTR) = 0
btf_var_resolve(depth: 2, type_id: 4, mode: RESOLVE_PTR) = 0
btf_datasec_resolve(depth: 1, type_id: 1, mode: RESOLVE_PTR) = -22
The last invocation of btf_datasec_resolve should invoke btf_var_resolve
by means of env_stack_push, instead it returns EINVAL. The reason is that
env_stack_push is never executed for the second VAR.
if (!env_type_is_resolve_sink(env, var_type) &&
!env_type_is_resolved(env, var_type_id)) {
env_stack_set_next_member(env, i + 1);
return env_stack_push(env, var_type, var_type_id);
}
env_type_is_resolve_sink() changes its behaviour based on resolve_mode.
For RESOLVE_PTR, we can simplify the if condition to the following:
(btf_type_is_modifier() || btf_type_is_ptr) && !env_type_is_resolved()
Since we're dealing with a VAR the clause evaluates to false. This is
not sufficient to trigger the bug however. The log output and EINVAL
are only generated if btf_type_id_size() fails.
if (!btf_type_id_size(btf, &type_id, &type_size)) {
btf_verifier_log_vsi(env, v->t, vsi, "Invalid type");
return -EINVAL;
}
Most types are sized, so for example a VAR referring to an INT is not a
problem. The bug is only triggered if a VAR points at a modifier. Since
we skipped btf_var_resolve that modifier was also never resolved, which
means that btf_resolved_type_id returns 0 aka VOID for the modifier.
This in turn causes btf_type_id_size to return NULL, triggering EINVAL.
To summarise, the following conditions are necessary:
- VAR pointing at PTR, STRUCT, UNION or ARRAY
- Followed by a VAR pointing at TYPEDEF, VOLATILE, CONST, RESTRICT or
TYPE_TAG
The fix is to reset resolve_mode to RESOLVE_TBD before attempting to
resolve a VAR from a DATASEC.
Fixes: 1dc9285184 ("bpf: kernel side support for BTF Var and DataSec")
Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/r/20230306112138.155352-2-lmb@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d55f7f4c58 ]
Refactor __irq_domain_alloc_irqs() so that it can be called internally
while holding the irq_domain_mutex.
This will be used to fix a shared-interrupt mapping race, hence the
Fixes tag.
Fixes: b62b2cf575 ("irqdomain: Fix handling of type settings for existing mappings")
Cc: stable@vger.kernel.org # 4.8
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-6-johan+linaro@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a402f1e353 upstream.
Currently, calling clone3() with CLONE_NEWTIME in clone_args->flags
fails with -EINVAL. This is because CLONE_NEWTIME intersects with
CSIGNAL. However, CSIGNAL was deprecated when clone3 was introduced in
commit 7f192e3cd3 ("fork: add clone3"), allowing re-use of that part
of clone flags.
Fix this by explicitly allowing CLONE_NEWTIME in clone3_args_valid. This
is also in line with the respective check in check_unshare_flags which
allow CLONE_NEWTIME for unshare().
Fixes: 769071ac9f ("ns: Introduce Time Namespace")
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2bb3669f57 ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Yang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20230202151633.2310897-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 55bf243c51 ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Chris Down <chris@chrisdown.name>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230202151411.2308576-1-gregkh@linuxfoundation.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3e4272b995 ]
In a previous commit 7433632c9f, buffer, buffer->buffers and
buffer->buffers[cpu] in ring_buffer_wake_waiters() can be NULL,
and thus the related checks are added.
However, in the same call stack, these variables are also used in
ring_buffer_free_read_page():
tracing_buffers_release()
ring_buffer_wake_waiters(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> Add checks by previous commit
ring_buffer_free_read_page(iter->array_buffer->buffer)
cpu_buffer = buffer->buffers[cpu] -> No check
Thus, to avod possible null-pointer derefernces, the related checks
should be added.
These results are reported by a static tool designed by myself.
Link: https://lkml.kernel.org/r/20230113125501.760324-1-baijiaju1990@gmail.com
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8843e06f67 upstream.
It seems a data race between ring_buffer writing and integrity check.
That is, RB_FLAG of head_page is been updating, while at same time
RB_FLAG was cleared when doing integrity check rb_check_pages():
rb_check_pages() rb_handle_head_page():
-------- --------
rb_head_page_deactivate()
rb_head_page_set_normal()
rb_head_page_activate()
We do intergrity test of the list to check if the list is corrupted and
it is still worth doing it. So, let's refactor rb_check_pages() such that
we no longer clear and set flag during the list sanity checking.
[1] and [2] are the test to reproduce and the crash report respectively.
1:
``` read_trace.sh
while true;
do
# the "trace" file is closed after read
head -1 /sys/kernel/tracing/trace > /dev/null
done
```
``` repro.sh
sysctl -w kernel.panic_on_warn=1
# function tracer will writing enough data into ring_buffer
echo function > /sys/kernel/tracing/current_tracer
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
```
2:
------------[ cut here ]------------
WARNING: CPU: 9 PID: 62 at kernel/trace/ring_buffer.c:2653
rb_move_tail+0x450/0x470
Modules linked in:
CPU: 9 PID: 62 Comm: ksoftirqd/9 Tainted: G W 6.2.0-rc6+
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:rb_move_tail+0x450/0x470
Code: ff ff 4c 89 c8 f0 4d 0f b1 02 48 89 c2 48 83 e2 fc 49 39 d0 75 24
83 e0 03 83 f8 02 0f 84 e1 fb ff ff 48 8b 57 10 f0 ff 42 08 <0f> 0b 83
f8 02 0f 84 ce fb ff ff e9 db
RSP: 0018:ffffb5564089bd00 EFLAGS: 00000203
RAX: 0000000000000000 RBX: ffff9db385a2bf81 RCX: ffffb5564089bd18
RDX: ffff9db281110100 RSI: 0000000000000fe4 RDI: ffff9db380145400
RBP: ffff9db385a2bf80 R08: ffff9db385a2bfc0 R09: ffff9db385a2bfc2
R10: ffff9db385a6c000 R11: ffff9db385a2bf80 R12: 0000000000000000
R13: 00000000000003e8 R14: ffff9db281110100 R15: ffffffffbb006108
FS: 0000000000000000(0000) GS:ffff9db3bdcc0000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005602323024c8 CR3: 0000000022e0c000 CR4: 00000000000006e0
Call Trace:
<TASK>
ring_buffer_lock_reserve+0x136/0x360
? __do_softirq+0x287/0x2df
? __pfx_rcu_softirq_qs+0x10/0x10
trace_function+0x21/0x110
? __pfx_rcu_softirq_qs+0x10/0x10
? __do_softirq+0x287/0x2df
function_trace_call+0xf6/0x120
0xffffffffc038f097
? rcu_softirq_qs+0x5/0x140
rcu_softirq_qs+0x5/0x140
__do_softirq+0x287/0x2df
run_ksoftirqd+0x2a/0x30
smpboot_thread_fn+0x188/0x220
? __pfx_smpboot_thread_fn+0x10/0x10
kthread+0xe7/0x110
? __pfx_kthread+0x10/0x10
ret_from_fork+0x2c/0x50
</TASK>
---[ end trace 0000000000000000 ]---
[ crash report and test reproducer credit goes to Zheng Yejian]
Link: https://lore.kernel.org/linux-trace-kernel/1676376403-16462-1-git-send-email-quic_mojha@quicinc.com
Cc: <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 1039221cc2 ("ring-buffer: Do not disable recording when there is an iterator")
Reported-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e686c32590 upstream.
While experimenting with CXL region removal the following corruption of
/proc/iomem appeared.
Before:
f010000000-f04fffffff : CXL Window 0
f010000000-f02fffffff : region4
f010000000-f02fffffff : dax4.0
f010000000-f02fffffff : System RAM (kmem)
After (modprobe -r cxl_test):
f010000000-f02fffffff : **redacted binary garbage**
f010000000-f02fffffff : System RAM (kmem)
...and testing further the same is visible with persistent memory
assigned to kmem:
Before:
480000000-243fffffff : Persistent Memory
480000000-57e1fffff : namespace3.0
580000000-243fffffff : dax3.0
580000000-243fffffff : System RAM (kmem)
After (ndctl disable-region all):
480000000-243fffffff : Persistent Memory
580000000-243fffffff : ***redacted binary garbage***
580000000-243fffffff : System RAM (kmem)
The corrupted data is from a use-after-free of the "dax4.0" and "dax3.0"
resources, and it also shows that the "System RAM (kmem)" resource is
not being removed. The bug does not appear after "modprobe -r kmem", it
requires the parent of "dax4.0" and "dax3.0" to be removed which
re-parents the leaked "System RAM (kmem)" instances. Those in turn
reference the freed resource as a parent.
First up for the fix is release_mem_region_adjustable() needs to
reliably delete the resource inserted by add_memory_driver_managed().
That is thwarted by a check for IORESOURCE_SYSRAM that predates the
dax/kmem driver, from commit:
65c7878413 ("kernel, resource: check for IORESOURCE_SYSRAM in release_mem_region_adjustable")
That appears to be working around the behavior of HMM's
"MEMORY_DEVICE_PUBLIC" facility that has since been deleted. With that
check removed the "System RAM (kmem)" resource gets removed, but
corruption still occurs occasionally because the "dax" resource is not
reliably removed.
The dax range information is freed before the device is unregistered, so
the driver can not reliably recall (another use after free) what it is
meant to release. Lastly if that use after free got lucky, the driver
was covering up the leak of "System RAM (kmem)" due to its use of
release_resource() which detaches, but does not free, child resources.
The switch to remove_resource() forces remove_memory() to be responsible
for the deletion of the resource added by add_memory_driver_managed().
Fixes: c2f3011ee6 ("device-dax: add an allocation interface for device-dax instances")
Cc: <stable@vger.kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/167653656244.3147810.5705900882794040229.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8932c32c30 upstream.
Hierarchical domains created using irq_domain_create_hierarchy() are
currently added to the domain list before having been fully initialised.
This specifically means that a racing allocation request might fail to
allocate irq data for the inner domains of a hierarchy in case the
parent domain pointer has not yet been set up.
Note that this is not really any issue for irqchip drivers that are
registered early (e.g. via IRQCHIP_DECLARE() or IRQCHIP_ACPI_DECLARE())
but could potentially cause trouble with drivers that are registered
later (e.g. modular drivers using IRQCHIP_PLATFORM_DRIVER_BEGIN(),
gpiochip drivers, etc.).
Fixes: afb7da83b9 ("irqdomain: Introduce helper function irq_domain_add_hierarchy()")
Cc: stable@vger.kernel.org # 3.19
Signed-off-by: Marc Zyngier <maz@kernel.org>
[ johan: add commit message ]
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-8-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e3b7ab025e upstream.
In case a newly allocated IRQ ever ends up not having any associated
struct irq_data it would not even be possible to dispose the mapping.
Replace the bogus disposal with a WARN_ON().
This will also be used to fix a shared-interrupt mapping race, hence the
CC-stable tag.
Fixes: 1e2a7d7849 ("irqdomain: Don't set type when mapping an IRQ")
Cc: stable@vger.kernel.org # 4.8
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-4-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6e6f75c9c9 upstream.
Avoid looking for an existing mapping twice when creating a new mapping
using irq_create_fwspec_mapping() by factoring out the actual allocation
which is shared with irq_create_mapping_affinity().
The new helper function will also be used to fix a shared-interrupt
mapping race, hence the Fixes tag.
Fixes: b62b2cf575 ("irqdomain: Fix handling of type settings for existing mappings")
Cc: stable@vger.kernel.org # 4.8
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-5-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3f883c38f5 upstream.
The global irq_domain_mutex is held when mapping interrupts from
non-hierarchical domains but currently not when disposing them.
This specifically means that updates of the domain mapcount is racy
(currently only used for statistics in debugfs).
Make sure to hold the global irq_domain_mutex also when disposing
mappings from non-hierarchical domains.
Fixes: 9dc6be3d41 ("genirq/irqdomain: Add map counter")
Cc: stable@vger.kernel.org # 4.13
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-3-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b06730a571 upstream.
The sanity check for an already mapped virq is done outside of the
irq_domain_mutex-protected section which means that an (unlikely) racing
association may not be detected.
Fix this by factoring out the association implementation, which will
also be used in a follow-on change to fix a shared-interrupt mapping
race.
Fixes: ddaf144c61 ("irqdomain: Refactor irq_domain_associate_many()")
Cc: stable@vger.kernel.org # 3.11
Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230213104302.17307-2-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f1c97a1b4e upstream.
When arch_prepare_optimized_kprobe calculating jump destination address,
it copies original instructions from jmp-optimized kprobe (see
__recover_optprobed_insn), and calculated based on length of original
instruction.
arch_check_optimized_kprobe does not check KPROBE_FLAG_OPTIMATED when
checking whether jmp-optimized kprobe exists.
As a result, setup_detour_execution may jump to a range that has been
overwritten by jump destination address, resulting in an inval opcode error.
For example, assume that register two kprobes whose addresses are
<func+9> and <func+11> in "func" function.
The original code of "func" function is as follows:
0xffffffff816cb5e9 <+9>: push %r12
0xffffffff816cb5eb <+11>: xor %r12d,%r12d
0xffffffff816cb5ee <+14>: test %rdi,%rdi
0xffffffff816cb5f1 <+17>: setne %r12b
0xffffffff816cb5f5 <+21>: push %rbp
1.Register the kprobe for <func+11>, assume that is kp1, corresponding optimized_kprobe is op1.
After the optimization, "func" code changes to:
0xffffffff816cc079 <+9>: push %r12
0xffffffff816cc07b <+11>: jmp 0xffffffffa0210000
0xffffffff816cc080 <+16>: incl 0xf(%rcx)
0xffffffff816cc083 <+19>: xchg %eax,%ebp
0xffffffff816cc084 <+20>: (bad)
0xffffffff816cc085 <+21>: push %rbp
Now op1->flags == KPROBE_FLAG_OPTIMATED;
2. Register the kprobe for <func+9>, assume that is kp2, corresponding optimized_kprobe is op2.
register_kprobe(kp2)
register_aggr_kprobe
alloc_aggr_kprobe
__prepare_optimized_kprobe
arch_prepare_optimized_kprobe
__recover_optprobed_insn // copy original bytes from kp1->optinsn.copied_insn,
// jump address = <func+14>
3. disable kp1:
disable_kprobe(kp1)
__disable_kprobe
...
if (p == orig_p || aggr_kprobe_disabled(orig_p)) {
ret = disarm_kprobe(orig_p, true) // add op1 in unoptimizing_list, not unoptimized
orig_p->flags |= KPROBE_FLAG_DISABLED; // op1->flags == KPROBE_FLAG_OPTIMATED | KPROBE_FLAG_DISABLED
...
4. unregister kp2
__unregister_kprobe_top
...
if (!kprobe_disabled(ap) && !kprobes_all_disarmed) {
optimize_kprobe(op)
...
if (arch_check_optimized_kprobe(op) < 0) // because op1 has KPROBE_FLAG_DISABLED, here not return
return;
p->kp.flags |= KPROBE_FLAG_OPTIMIZED; // now op2 has KPROBE_FLAG_OPTIMIZED
}
"func" code now is:
0xffffffff816cc079 <+9>: int3
0xffffffff816cc07a <+10>: push %rsp
0xffffffff816cc07b <+11>: jmp 0xffffffffa0210000
0xffffffff816cc080 <+16>: incl 0xf(%rcx)
0xffffffff816cc083 <+19>: xchg %eax,%ebp
0xffffffff816cc084 <+20>: (bad)
0xffffffff816cc085 <+21>: push %rbp
5. if call "func", int3 handler call setup_detour_execution:
if (p->flags & KPROBE_FLAG_OPTIMIZED) {
...
regs->ip = (unsigned long)op->optinsn.insn + TMPL_END_IDX;
...
}
The code for the destination address is
0xffffffffa021072c: push %r12
0xffffffffa021072e: xor %r12d,%r12d
0xffffffffa0210731: jmp 0xffffffff816cb5ee <func+14>
However, <func+14> is not a valid start instruction address. As a result, an error occurs.
Link: https://lore.kernel.org/all/20230216034247.32348-3-yangjihong1@huawei.com/
Fixes: f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 868a6fc0ca upstream.
Since the following commit:
commit f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")
modified the update timing of the KPROBE_FLAG_OPTIMIZED, a optimized_kprobe
may be in the optimizing or unoptimizing state when op.kp->flags
has KPROBE_FLAG_OPTIMIZED and op->list is not empty.
The __recover_optprobed_insn check logic is incorrect, a kprobe in the
unoptimizing state may be incorrectly determined as unoptimizing.
As a result, incorrect instructions are copied.
The optprobe_queued_unopt function needs to be exported for invoking in
arch directory.
Link: https://lore.kernel.org/all/20230216034247.32348-2-yangjihong1@huawei.com/
Fixes: f66c0447cc ("kprobes: Set unoptimized flag after unoptimizing code")
Cc: stable@vger.kernel.org
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b613c7f314 upstream.
A non-first waiter can potentially spin in the for loop of
rwsem_down_write_slowpath() without sleeping but fail to acquire the
lock even if the rwsem is free if the following sequence happens:
Non-first RT waiter First waiter Lock holder
------------------- ------------ -----------
Acquire wait_lock
rwsem_try_write_lock():
Set handoff bit if RT or
wait too long
Set waiter->handoff_set
Release wait_lock
Acquire wait_lock
Inherit waiter->handoff_set
Release wait_lock
Clear owner
Release lock
if (waiter.handoff_set) {
rwsem_spin_on_owner(();
if (OWNER_NULL)
goto trylock_again;
}
trylock_again:
Acquire wait_lock
rwsem_try_write_lock():
if (first->handoff_set && (waiter != first))
return false;
Release wait_lock
A non-first waiter cannot really acquire the rwsem even if it mistakenly
believes that it can spin on OWNER_NULL value. If that waiter happens
to be an RT task running on the same CPU as the first waiter, it can
block the first waiter from acquiring the rwsem leading to live lock.
Fix this problem by making sure that a non-first waiter cannot spin in
the slowpath loop without sleeping.
Fixes: d257cc8cb8 ("locking/rwsem: Make handoff bit handling more consistent")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Mukesh Ojha <quic_mojha@quicinc.com>
Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230126003628.365092-2-longman@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a0e8c13ccd ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5b268d8aba ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic at
once.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230202151214.2306822-1-gregkh@linuxfoundation.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b7082cdfc4 ]
Bugs have been reported on 8 sockets x86 machines in which the TSC was
wrongly disabled when the system is under heavy workload.
[ 818.380354] clocksource: timekeeping watchdog on CPU336: hpet wd-wd read-back delay of 1203520ns
[ 818.436160] clocksource: wd-tsc-wd read-back delay of 181880ns, clock-skew test skipped!
[ 819.402962] clocksource: timekeeping watchdog on CPU338: hpet wd-wd read-back delay of 324000ns
[ 819.448036] clocksource: wd-tsc-wd read-back delay of 337240ns, clock-skew test skipped!
[ 819.880863] clocksource: timekeeping watchdog on CPU339: hpet read-back delay of 150280ns, attempt 3, marking unstable
[ 819.936243] tsc: Marking TSC unstable due to clocksource watchdog
[ 820.068173] TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.
[ 820.092382] sched_clock: Marking unstable (818769414384, 1195404998)
[ 820.643627] clocksource: Checking clocksource tsc synchronization from CPU 267 to CPUs 0,4,25,70,126,430,557,564.
[ 821.067990] clocksource: Switched to clocksource hpet
This can be reproduced by running memory intensive 'stream' tests,
or some of the stress-ng subcases such as 'ioport'.
The reason for these issues is the when system is under heavy load, the
read latency of the clocksources can be very high. Even lightweight TSC
reads can show high latencies, and latencies are much worse for external
clocksources such as HPET or the APIC PM timer. These latencies can
result in false-positive clocksource-unstable determinations.
These issues were initially reported by a customer running on a production
system, and this problem was reproduced on several generations of Xeon
servers, especially when running the stress-ng test. These Xeon servers
were not production systems, but they did have the latest steppings
and firmware.
Given that the clocksource watchdog is a continual diagnostic check with
frequency of twice a second, there is no need to rush it when the system
is under heavy load. Therefore, when high clocksource read latencies
are detected, suspend the watchdog timer for 5 minutes.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Waiman Long <longman@redhat.com>
Cc: John Stultz <jstultz@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Feng Tang <feng.tang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9f76d59173 ]
The nanosleep syscalls use the restart_block mechanism, with a quirk:
The `type` and `rmtp`/`compat_rmtp` fields are set up unconditionally on
syscall entry, while the rest of the restart_block is only set up in the
unlikely case that the syscall is actually interrupted by a signal (or
pseudo-signal) that doesn't have a signal handler.
If the restart_block was set up by a previous syscall (futex(...,
FUTEX_WAIT, ...) or poll()) and hasn't been invalidated somehow since then,
this will clobber some of the union fields used by futex_wait_restart() and
do_restart_poll().
If userspace afterwards wrongly calls the restart_syscall syscall,
futex_wait_restart()/do_restart_poll() will read struct fields that have
been clobbered.
This doesn't actually lead to anything particularly interesting because
none of the union fields contain trusted kernel data, and
futex(..., FUTEX_WAIT, ...) and poll() aren't syscalls where it makes much
sense to apply seccomp filters to their arguments.
So the current consequences are just of the "if userspace does bad stuff,
it can damage itself, and that's not a problem" flavor.
But still, it seems like a hazard for future developers, so invalidate the
restart_block when partly setting it up in the nanosleep syscalls.
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230105134403.754986-1-jannh@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ea5c8987fe ]
The synchronize_rcu_tasks_rude() function invokes rcu_tasks_rude_wait_gp()
to wait one rude RCU-tasks grace period. The rcu_tasks_rude_wait_gp()
function in turn checks if there is only a single online CPU. If so, it
will immediately return, because a call to synchronize_rcu_tasks_rude()
is by definition a grace period on a single-CPU system. (We could
have blocked!)
Unfortunately, this check uses num_online_cpus() without synchronization,
which can result in too-short grace periods. To see this, consider the
following scenario:
CPU0 CPU1 (going offline)
migration/1 task:
cpu_stopper_thread
-> take_cpu_down
-> _cpu_disable
(dec __num_online_cpus)
->cpuhp_invoke_callback
preempt_disable
access old_data0
task1
del old_data0 .....
synchronize_rcu_tasks_rude()
task1 schedule out
....
task2 schedule in
rcu_tasks_rude_wait_gp()
->__num_online_cpus == 1
->return
....
task1 schedule in
->free old_data0
preempt_enable
When CPU1 decrements __num_online_cpus, its value becomes 1. However,
CPU1 has not finished going offline, and will take one last trip through
the scheduler and the idle loop before it actually stops executing
instructions. Because synchronize_rcu_tasks_rude() is mostly used for
tracing, and because both the scheduler and the idle loop can be traced,
this means that CPU0's prematurely ended grace period might disrupt the
tracing on CPU1. Given that this disruption might include CPU1 executing
instructions in memory that was just now freed (and maybe reallocated),
this is a matter of some concern.
This commit therefore removes that problematic single-CPU check from the
rcu_tasks_rude_wait_gp() function. This dispenses with the single-CPU
optimization, but there is no evidence indicating that this optimization
is important. In addition, synchronize_rcu_tasks_generic() contains a
similar optimization (albeit only for early boot), which also splats.
(As in exactly why are you invoking synchronize_rcu_tasks_rude() so
early in boot, anyway???)
It is OK for the synchronize_rcu_tasks_rude() function's check to be
unsynchronized because the only times that this check can evaluate to
true is when there is only a single CPU running with preemption
disabled.
While in the area, this commit also fixes a minor bug in which a
call to synchronize_rcu_tasks_rude() would instead be attributed to
synchronize_rcu_tasks().
[ paulmck: Add "synchronize_" prefix and "()" suffix. ]
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2d7f00b2f0 ]
The normal grace period's RCU CPU stall warnings are invoked from the
scheduling-clock interrupt handler, and can thus invoke smp_processor_id()
with impunity, which allows them to directly invoke dump_cpu_task().
In contrast, the expedited grace period's RCU CPU stall warnings are
invoked from process context, which causes the dump_cpu_task() function's
calls to smp_processor_id() to complain bitterly in debug kernels.
This commit therefore causes synchronize_rcu_expedited_wait() to disable
preemption around its call to dump_cpu_task().
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 83e8864fee ]
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230202141956.2299521-1-gregkh@linuxfoundation.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d384dce281 ]
KPROBE program's user-facing context type is defined as typedef
bpf_user_pt_regs_t. This leads to a problem when trying to passing
kprobe/uprobe/usdt context argument into global subprog, as kernel
always strip away mods and typedefs of user-supplied type, but takes
expected type from bpf_ctx_convert as is, which causes mismatch.
Current way to work around this is to define a fake struct with the same
name as expected typedef:
struct bpf_user_pt_regs_t {};
__noinline my_global_subprog(struct bpf_user_pt_regs_t *ctx) { ... }
This patch fixes the issue by resolving expected type, if it's not
a struct. It still leaves the above work-around working for backwards
compatibility.
Fixes: 91cc1a9974 ("bpf: Annotate context types")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230216045954.3002473-2-andrii@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 28319d6dc5 ]
RCU Tasks and PID-namespace unshare can interact in do_exit() in a
complicated circular dependency:
1) TASK A calls unshare(CLONE_NEWPID), this creates a new PID namespace
that every subsequent child of TASK A will belong to. But TASK A
doesn't itself belong to that new PID namespace.
2) TASK A forks() and creates TASK B. TASK A stays attached to its PID
namespace (let's say PID_NS1) and TASK B is the first task belonging
to the new PID namespace created by unshare() (let's call it PID_NS2).
3) Since TASK B is the first task attached to PID_NS2, it becomes the
PID_NS2 child reaper.
4) TASK A forks() again and creates TASK C which get attached to PID_NS2.
Note how TASK C has TASK A as a parent (belonging to PID_NS1) but has
TASK B (belonging to PID_NS2) as a pid_namespace child_reaper.
5) TASK B exits and since it is the child reaper for PID_NS2, it has to
kill all other tasks attached to PID_NS2, and wait for all of them to
die before getting reaped itself (zap_pid_ns_process()).
6) TASK A calls synchronize_rcu_tasks() which leads to
synchronize_srcu(&tasks_rcu_exit_srcu).
7) TASK B is waiting for TASK C to get reaped. But TASK B is under a
tasks_rcu_exit_srcu SRCU critical section (exit_notify() is between
exit_tasks_rcu_start() and exit_tasks_rcu_finish()), blocking TASK A.
8) TASK C exits and since TASK A is its parent, it waits for it to reap
TASK C, but it can't because TASK A waits for TASK B that waits for
TASK C.
Pid_namespace semantics can hardly be changed at this point. But the
coverage of tasks_rcu_exit_srcu can be reduced instead.
The current task is assumed not to be concurrently reapable at this
stage of exit_notify() and therefore tasks_rcu_exit_srcu can be
temporarily relaxed without breaking its constraints, providing a way
out of the deadlock scenario.
[ paulmck: Fix build failure by adding additional declaration. ]
Fixes: 3f95aa81d2 ("rcu: Make TASKS_RCU handle tasks that are almost done exiting")
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Suggested-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Eric W . Biederman <ebiederm@xmission.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4475709295 ]
Ever since the following commit:
5a41344a3d ("srcu: Simplify __srcu_read_unlock() via this_cpu_dec()")
SRCU doesn't rely anymore on preemption to be disabled in order to
modify the per-CPU counter. And even then it used to be done from the API
itself.
Therefore and after checking further, it appears to be safe to remove
the preemption disablement around __srcu_read_[un]lock() in
exit_tasks_rcu_start() and exit_tasks_rcu_finish()
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Suggested-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Stable-dep-of: 28319d6dc5 ("rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e4e1e8089c ]
Make sure we don't need to look again into the depths of git blame in
order not to miss a subtle part about how rcu-tasks is dealing with
exiting tasks.
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Suggested-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Stable-dep-of: 28319d6dc5 ("rcu-tasks: Fix synchronize_rcu_tasks() VS zap_pid_ns_processes()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7c4a5b89a0 ]
Commit 326587b840 ("sched: fix goto retry in pick_next_task_rt()")
removed any path which could make pick_next_rt_entity() return NULL.
However, BUG_ON(!rt_se) in _pick_next_task_rt() (the only caller of
pick_next_rt_entity()) still checks the error condition, which can
never happen, since list_entry() never returns NULL.
Remove the BUG_ON check, and instead emit a warning in the only
possible error condition here: the queue being empty which should
never happen.
Fixes: 326587b840 ("sched: fix goto retry in pick_next_task_rt()")
Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20230128-list-entry-null-check-sched-v3-1-b1a71bd1ac6b@diag.uniroma1.it
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3f5245538a ]
Commit:
91d2a812df ("locking/rwsem: Make handoff writer optimistically spin on owner")
... assumes that when the owner field is changed to NULL, the lock will
become free soon. But commit:
48dfb5d256 ("locking/rwsem: Disable preemption while trying for rwsem lock")
... disabled preemption when acquiring rwsem for write.
However, preemption has not yet been disabled when acquiring a read lock
on a rwsem. So a reader can add a RWSEM_READER_BIAS to count without
setting owner to signal a reader, got preempted out by a RT task which
then spins in the writer slowpath as owner remains NULL leading to live lock.
One easy way to fix this problem is to disable preemption at all the
down_read*() and up_read() code paths as implemented in this patch.
Fixes: 91d2a812df ("locking/rwsem: Make handoff writer optimistically spin on owner")
Reported-by: Mukesh Ojha <quic_mojha@quicinc.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230126003628.365092-3-longman@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 14c2404884 ]
We found that a process with 10 thousnads threads has been encountered
a regression problem from Linux-v4.14 to Linux-v5.4. It is a kind of
workload which will concurrently allocate lots of memory in different
threads sometimes. In this case, we will see the down_read_trylock()
with a high hotspot. Therefore, we suppose that rwsem has a regression
at least since Linux-v5.4. In order to easily debug this problem, we
write a simply benchmark to create the similar situation lile the
following.
```c++
#include <sys/mman.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sched.h>
#include <cstdio>
#include <cassert>
#include <thread>
#include <vector>
#include <chrono>
volatile int mutex;
void trigger(int cpu, char* ptr, std::size_t sz)
{
cpu_set_t set;
CPU_ZERO(&set);
CPU_SET(cpu, &set);
assert(pthread_setaffinity_np(pthread_self(), sizeof(set), &set) == 0);
while (mutex);
for (std::size_t i = 0; i < sz; i += 4096) {
*ptr = '\0';
ptr += 4096;
}
}
int main(int argc, char* argv[])
{
std::size_t sz = 100;
if (argc > 1)
sz = atoi(argv[1]);
auto nproc = std:🧵:hardware_concurrency();
std::vector<std::thread> thr;
sz <<= 30;
auto* ptr = mmap(nullptr, sz, PROT_READ | PROT_WRITE, MAP_ANON |
MAP_PRIVATE, -1, 0);
assert(ptr != MAP_FAILED);
char* cptr = static_cast<char*>(ptr);
auto run = sz / nproc;
run = (run >> 12) << 12;
mutex = 1;
for (auto i = 0U; i < nproc; ++i) {
thr.emplace_back(std::thread([i, cptr, run]() { trigger(i, cptr, run); }));
cptr += run;
}
rusage usage_start;
getrusage(RUSAGE_SELF, &usage_start);
auto start = std::chrono::system_clock::now();
mutex = 0;
for (auto& t : thr)
t.join();
rusage usage_end;
getrusage(RUSAGE_SELF, &usage_end);
auto end = std::chrono::system_clock::now();
timeval utime;
timeval stime;
timersub(&usage_end.ru_utime, &usage_start.ru_utime, &utime);
timersub(&usage_end.ru_stime, &usage_start.ru_stime, &stime);
printf("usr: %ld.%06ld\n", utime.tv_sec, utime.tv_usec);
printf("sys: %ld.%06ld\n", stime.tv_sec, stime.tv_usec);
printf("real: %lu\n",
std::chrono::duration_cast<std::chrono::milliseconds>(end -
start).count());
return 0;
}
```
The functionality of above program is simply which creates `nproc`
threads and each of them are trying to touch memory (trigger page
fault) on different CPU. Then we will see the similar profile by
`perf top`.
25.55% [kernel] [k] down_read_trylock
14.78% [kernel] [k] handle_mm_fault
13.45% [kernel] [k] up_read
8.61% [kernel] [k] clear_page_erms
3.89% [kernel] [k] __do_page_fault
The highest hot instruction, which accounts for about 92%, in
down_read_trylock() is cmpxchg like the following.
91.89 │ lock cmpxchg %rdx,(%rdi)
Sice the problem is found by migrating from Linux-v4.14 to Linux-v5.4,
so we easily found that the commit ddb20d1d3a ("locking/rwsem: Optimize
down_read_trylock()") caused the regression. The reason is that the
commit assumes the rwsem is not contended at all. But it is not always
true for mmap lock which could be contended with thousands threads.
So most threads almost need to run at least 2 times of "cmpxchg" to
acquire the lock. The overhead of atomic operation is higher than
non-atomic instructions, which caused the regression.
By using the above benchmark, the real executing time on a x86-64 system
before and after the patch were:
Before Patch After Patch
# of Threads real real reduced by
------------ ------ ------ ----------
1 65,373 65,206 ~0.0%
4 15,467 15,378 ~0.5%
40 6,214 5,528 ~11.0%
For the uncontended case, the new down_read_trylock() is the same as
before. For the contended cases, the new down_read_trylock() is faster
than before. The more contended, the more fast.
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20211118094455.9068-1-songmuchun@bytedance.com
Stable-dep-of: 3f5245538a ("locking/rwsem: Disable preemption in all down_read*() and up_read() code paths")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f3dd0c5337 upstream.
Commit 74e19ef0ff ("uaccess: Add speculation barrier to
copy_from_user()") built fine on x86-64 and arm64, and that's the extent
of my local build testing.
It turns out those got the <linux/nospec.h> include incidentally through
other header files (<linux/kvm_host.h> in particular), but that was not
true of other architectures, resulting in build errors
kernel/bpf/core.c: In function ‘___bpf_prog_run’:
kernel/bpf/core.c:1913:3: error: implicit declaration of function ‘barrier_nospec’
so just make sure to explicitly include the proper <linux/nospec.h>
header file to make everybody see it.
Fixes: 74e19ef0ff ("uaccess: Add speculation barrier to copy_from_user()")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Viresh Kumar <viresh.kumar@linaro.org>
Reported-by: Huacai Chen <chenhuacai@loongson.cn>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 74e19ef0ff upstream.
The results of "access_ok()" can be mis-speculated. The result is that
you can end speculatively:
if (access_ok(from, size))
// Right here
even for bad from/size combinations. On first glance, it would be ideal
to just add a speculation barrier to "access_ok()" so that its results
can never be mis-speculated.
But there are lots of system calls just doing access_ok() via
"copy_to_user()" and friends (example: fstat() and friends). Those are
generally not problematic because they do not _consume_ data from
userspace other than the pointer. They are also very quick and common
system calls that should not be needlessly slowed down.
"copy_from_user()" on the other hand uses a user-controller pointer and
is frequently followed up with code that might affect caches. Take
something like this:
if (!copy_from_user(&kernelvar, uptr, size))
do_something_with(kernelvar);
If userspace passes in an evil 'uptr' that *actually* points to a kernel
addresses, and then do_something_with() has cache (or other)
side-effects, it could allow userspace to infer kernel data values.
Add a barrier to the common copy_from_user() code to prevent
mis-speculated values which happen after the copy.
Also add a stub for architectures that do not define barrier_nospec().
This makes the macro usable in generic code.
Since the barrier is now usable in generic code, the x86 #ifdef in the
BPF code can also go away.
Reported-by: Jordy Zomer <jordyzomer@google.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Daniel Borkmann <daniel@iogearbox.net> # BPF bits
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d125d1349a upstream.
syzbot reported a RCU stall which is caused by setting up an alarmtimer
with a very small interval and ignoring the signal. The reproducer arms the
alarm timer with a relative expiry of 8ns and an interval of 9ns. Not a
problem per se, but that's an issue when the signal is ignored because then
the timer is immediately rearmed because there is no way to delay that
rearming to the signal delivery path. See posix_timer_fn() and commit
58229a1899 ("posix-timers: Prevent softirq starvation by small intervals
and SIG_IGN") for details.
The reproducer does not set SIG_IGN explicitely, but it sets up the timers
signal with SIGCONT. That has the same effect as explicitely setting
SIG_IGN for a signal as SIGCONT is ignored if there is no handler set and
the task is not ptraced.
The log clearly shows that:
[pid 5102] --- SIGCONT {si_signo=SIGCONT, si_code=SI_TIMER, si_timerid=0, si_overrun=316014, si_int=0, si_ptr=NULL} ---
It works because the tasks are traced and therefore the signal is queued so
the tracer can see it, which delays the restart of the timer to the signal
delivery path. But then the tracer is killed:
[pid 5087] kill(-5102, SIGKILL <unfinished ...>
...
./strace-static-x86_64: Process 5107 detached
and after it's gone the stall can be observed:
syzkaller login: [ 79.439102][ C0] hrtimer: interrupt took 68471 ns
[ 184.460538][ C1] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
...
[ 184.658237][ C1] rcu: Stack dump where RCU GP kthread last ran:
[ 184.664574][ C1] Sending NMI from CPU 1 to CPUs 0:
[ 184.669821][ C0] NMI backtrace for cpu 0
[ 184.669831][ C0] CPU: 0 PID: 5108 Comm: syz-executor192 Not tainted 6.2.0-rc6-next-20230203-syzkaller #0
...
[ 184.670036][ C0] Call Trace:
[ 184.670041][ C0] <IRQ>
[ 184.670045][ C0] alarmtimer_fired+0x327/0x670
posix_timer_fn() prevents that by checking whether the interval for
timers which have the signal ignored is smaller than a jiffie and
artifically delay it by shifting the next expiry out by a jiffie. That's
accurate vs. the overrun accounting, but slightly inaccurate
vs. timer_gettimer(2).
The comment in that function says what needs to be done and there was a fix
available for the regular userspace induced SIG_IGN mechanism, but that did
not work due to the implicit ignore for SIGCONT and similar signals. This
needs to be worked on, but for now the only available workaround is to do
exactly what posix_timer_fn() does:
Increase the interval of self-rearming timers, which have their signal
ignored, to at least a jiffie.
Interestingly this has been fixed before via commit ff86bf0c65
("alarmtimer: Rate limit periodic intervals") already, but that fix got
lost in a later rework.
Reported-by: syzbot+b9564ba6e8e00694511b@syzkaller.appspotmail.com
Fixes: f2c45807d3 ("alarmtimer: Switch over to generic set/get/rearm routine")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/87k00q1no2.ffs@tglx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c2dbe32d5d upstream.
If a non-root cgroup gets removed when there is a thread that registered
trigger and is polling on a pressure file within the cgroup, the polling
waitqueue gets freed in the following path:
do_rmdir
cgroup_rmdir
kernfs_drain_open_files
cgroup_file_release
cgroup_pressure_release
psi_trigger_destroy
However, the polling thread still has a reference to the pressure file and
will access the freed waitqueue when the file is closed or upon exit:
fput
ep_eventpoll_release
ep_free
ep_remove_wait_queue
remove_wait_queue
This results in use-after-free as pasted below.
The fundamental problem here is that cgroup_file_release() (and
consequently waitqueue's lifetime) is not tied to the file's real lifetime.
Using wake_up_pollfree() here might be less than ideal, but it is in line
with the comment at commit 42288cb44c ("wait: add wake_up_pollfree()")
since the waitqueue's lifetime is not tied to file's one and can be
considered as another special case. While this would be fixable by somehow
making cgroup_file_release() be tied to the fput(), it would require
sizable refactoring at cgroups or higher layer which might be more
justifiable if we identify more cases like this.
BUG: KASAN: use-after-free in _raw_spin_lock_irqsave+0x60/0xc0
Write of size 4 at addr ffff88810e625328 by task a.out/4404
CPU: 19 PID: 4404 Comm: a.out Not tainted 6.2.0-rc6 #38
Hardware name: Amazon EC2 c5a.8xlarge/, BIOS 1.0 10/16/2017
Call Trace:
<TASK>
dump_stack_lvl+0x73/0xa0
print_report+0x16c/0x4e0
kasan_report+0xc3/0xf0
kasan_check_range+0x2d2/0x310
_raw_spin_lock_irqsave+0x60/0xc0
remove_wait_queue+0x1a/0xa0
ep_free+0x12c/0x170
ep_eventpoll_release+0x26/0x30
__fput+0x202/0x400
task_work_run+0x11d/0x170
do_exit+0x495/0x1130
do_group_exit+0x100/0x100
get_signal+0xd67/0xde0
arch_do_signal_or_restart+0x2a/0x2b0
exit_to_user_mode_prepare+0x94/0x100
syscall_exit_to_user_mode+0x20/0x40
do_syscall_64+0x52/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
</TASK>
Allocated by task 4404:
kasan_set_track+0x3d/0x60
__kasan_kmalloc+0x85/0x90
psi_trigger_create+0x113/0x3e0
pressure_write+0x146/0x2e0
cgroup_file_write+0x11c/0x250
kernfs_fop_write_iter+0x186/0x220
vfs_write+0x3d8/0x5c0
ksys_write+0x90/0x110
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Freed by task 4407:
kasan_set_track+0x3d/0x60
kasan_save_free_info+0x27/0x40
____kasan_slab_free+0x11d/0x170
slab_free_freelist_hook+0x87/0x150
__kmem_cache_free+0xcb/0x180
psi_trigger_destroy+0x2e8/0x310
cgroup_file_release+0x4f/0xb0
kernfs_drain_open_files+0x165/0x1f0
kernfs_drain+0x162/0x1a0
__kernfs_remove+0x1fb/0x310
kernfs_remove_by_name_ns+0x95/0xe0
cgroup_addrm_files+0x67f/0x700
cgroup_destroy_locked+0x283/0x3c0
cgroup_rmdir+0x29/0x100
kernfs_iop_rmdir+0xd1/0x140
vfs_rmdir+0xfe/0x240
do_rmdir+0x13d/0x280
__x64_sys_rmdir+0x2c/0x30
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: 0e94682b73 ("psi: introduce psi monitor")
Signed-off-by: Munehisa Kamata <kamatam@amazon.com>
Signed-off-by: Mengchi Cheng <mengcc@amazon.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/lkml/20230106224859.4123476-1-kamatam@amazon.com/
Link: https://lore.kernel.org/r/20230214212705.4058045-1-kamatam@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9c89bb8e32 ]
This clean up the error/notification messages in kprobes related code.
Basically this defines 'pr_fmt()' macros for each files and update
the messages which describes
- what happened,
- what is the kernel going to do or not do,
- is the kernel fine,
- what can the user do about it.
Also, if the message is not needed (e.g. the function returns unique
error code, or other error message is already shown.) remove it,
and replace the message with WARN_*() macros if suitable.
Link: https://lkml.kernel.org/r/163163036568.489837.14085396178727185469.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Stable-dep-of: eb7423273c ("riscv: kprobe: Fixup misaligned load text")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit db370a8b9f upstream.
Let L1 and L2 be two spinlocks.
Let T1 be a task holding L1 and blocked on L2. T1, currently, is the top
waiter of L2.
Let T2 be the task holding L2.
Let T3 be a task trying to acquire L1.
The following events will lead to a state in which the wait queue of L2
isn't empty, but no task actually holds the lock.
T1 T2 T3
== == ==
spin_lock(L1)
| raw_spin_lock(L1->wait_lock)
| rtlock_slowlock_locked(L1)
| | task_blocks_on_rt_mutex(L1, T3)
| | | orig_waiter->lock = L1
| | | orig_waiter->task = T3
| | | raw_spin_unlock(L1->wait_lock)
| | | rt_mutex_adjust_prio_chain(T1, L1, L2, orig_waiter, T3)
spin_unlock(L2) | | | |
| rt_mutex_slowunlock(L2) | | | |
| | raw_spin_lock(L2->wait_lock) | | | |
| | wakeup(T1) | | | |
| | raw_spin_unlock(L2->wait_lock) | | | |
| | | | waiter = T1->pi_blocked_on
| | | | waiter == rt_mutex_top_waiter(L2)
| | | | waiter->task == T1
| | | | raw_spin_lock(L2->wait_lock)
| | | | dequeue(L2, waiter)
| | | | update_prio(waiter, T1)
| | | | enqueue(L2, waiter)
| | | | waiter != rt_mutex_top_waiter(L2)
| | | | L2->owner == NULL
| | | | wakeup(T1)
| | | | raw_spin_unlock(L2->wait_lock)
T1 wakes up
T1 != top_waiter(L2)
schedule_rtlock()
If the deadline of T1 is updated before the call to update_prio(), and the
new deadline is greater than the deadline of the second top waiter, then
after the requeue, T1 is no longer the top waiter, and the wrong task is
woken up which will then go back to sleep because it is not the top waiter.
This can be reproduced in PREEMPT_RT with stress-ng:
while true; do
stress-ng --sched deadline --sched-period 1000000000 \
--sched-runtime 800000000 --sched-deadline \
1000000000 --mmapfork 23 -t 20
done
A similar issue was pointed out by Thomas versus the cases where the top
waiter drops out early due to a signal or timeout, which is a general issue
for all regular rtmutex use cases, e.g. futex.
The problematic code is in rt_mutex_adjust_prio_chain():
// Save the top waiter before dequeue/enqueue
prerequeue_top_waiter = rt_mutex_top_waiter(lock);
rt_mutex_dequeue(lock, waiter);
waiter_update_prio(waiter, task);
rt_mutex_enqueue(lock, waiter);
// Lock has no owner?
if (!rt_mutex_owner(lock)) {
// Top waiter changed
----> if (prerequeue_top_waiter != rt_mutex_top_waiter(lock))
----> wake_up_state(waiter->task, waiter->wake_state);
This only takes the case into account where @waiter is the new top waiter
due to the requeue operation.
But it fails to handle the case where @waiter is not longer the top
waiter due to the requeue operation.
Ensure that the new top waiter is woken up so in all cases so it can take
over the ownerless lock.
[ tglx: Amend changelog, add Fixes tag ]
Fixes: c014ef69b3 ("locking/rtmutex: Add wake_state to rt_mutex_waiter")
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230117172649.52465-1-wander@redhat.com
Link: https://lore.kernel.org/r/20230202123020.14844-1-wander@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3e46d910d8 upstream.
poll() and select() on per_cpu trace_pipe and trace_pipe_raw do not work
since kernel 6.1-rc6. This issue is seen after the commit
42fb0a1e84 ("tracing/ring-buffer: Have
polling block on watermark").
This issue is firstly detected and reported, when testing the CXL error
events in the rasdaemon and also erified using the test application for poll()
and select().
This issue occurs for the per_cpu case, when calling the ring_buffer_poll_wait(),
in kernel/trace/ring_buffer.c, with the buffer_percent > 0 and then wait until the
percentage of pages are available. The default value set for the buffer_percent is 50
in the kernel/trace/trace.c.
As a fix, allow userspace application could set buffer_percent as 0 through
the buffer_percent_fops, so that the task will wake up as soon as data is added
to any of the specific cpu buffer.
Link: https://lore.kernel.org/linux-trace-kernel/20230202182309.742-2-shiju.jose@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <mchehab@kernel.org>
Cc: <linux-edac@vger.kernel.org>
Cc: stable@vger.kernel.org
Fixes: 42fb0a1e84 ("tracing/ring-buffer: Have polling block on watermark")
Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d3178e8a43 upstream.
The verifier skips invalid kfunc call in check_kfunc_call(), which
would be captured in fixup_kfunc_call() if such insn is not eliminated
by dead code elimination. However, this can lead to the following
warning in backtrack_insn(), also see [1]:
------------[ cut here ]------------
verifier backtracking bug
WARNING: CPU: 6 PID: 8646 at kernel/bpf/verifier.c:2756 backtrack_insn
kernel/bpf/verifier.c:2756
__mark_chain_precision kernel/bpf/verifier.c:3065
mark_chain_precision kernel/bpf/verifier.c:3165
adjust_reg_min_max_vals kernel/bpf/verifier.c:10715
check_alu_op kernel/bpf/verifier.c:10928
do_check kernel/bpf/verifier.c:13821 [inline]
do_check_common kernel/bpf/verifier.c:16289
[...]
So make backtracking conservative with this by returning ENOTSUPP.
[1] https://lore.kernel.org/bpf/CACkBjsaXNceR8ZjkLG=dT3P=4A8SBsg0Z5h5PWLryF5=ghKq=g@mail.gmail.com/
Reported-by: syzbot+4da3ff23081bafe74fc2@syzkaller.appspotmail.com
Signed-off-by: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20230104014709.9375-1-sunhao.th@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f30d4968e9 upstream.
Below is a simplified case from a report in bcc [0]:
r4 = 20
*(u32 *)(r10 -4) = r4
*(u32 *)(r10 -8) = r4 /* r4 state is tracked */
r4 = *(u64 *)(r10 -8) /* Read more than the tracked 32bit scalar.
* verifier rejects as 'corrupted spill memory'.
*/
After commit 354e8f1970 ("bpf: Support <8-byte scalar spill and refill"),
the 8-byte aligned 32bit spill is also tracked by the verifier and the
register state is stored.
However, if 8 bytes are read from the stack instead of the tracked 4 byte
scalar, then verifier currently rejects the program as "corrupted spill
memory". This patch fixes this case by allowing it to read but marks the
register as unknown.
Also note that, if the prog is trying to corrupt/leak an earlier spilled
pointer by spilling another <8 bytes register on top, this has already
been rejected in the check_stack_write_fixed_off().
[0] https://github.com/iovisor/bcc/pull/3683
Fixes: 354e8f1970 ("bpf: Support <8-byte scalar spill and refill")
Reported-by: Hengqi Chen <hengqi.chen@gmail.com>
Reported-by: Yonghong Song <yhs@gmail.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Hengqi Chen <hengqi.chen@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20211102064535.316018-1-kafai@fb.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 345e004d02 upstream.
Commit 354e8f1970 ("bpf: Support <8-byte scalar spill and refill")
introduced support in the verifier to track <8B spill/fills of scalars.
The backtracking logic for the precision bit was however skipping
spill/fills of less than 8B. That could cause state pruning to consider
two states equivalent when they shouldn't be.
As an example, consider the following bytecode snippet:
0: r7 = r1
1: call bpf_get_prandom_u32
2: r6 = 2
3: if r0 == 0 goto pc+1
4: r6 = 3
...
8: [state pruning point]
...
/* u32 spill/fill */
10: *(u32 *)(r10 - 8) = r6
11: r8 = *(u32 *)(r10 - 8)
12: r0 = 0
13: if r8 == 3 goto pc+1
14: r0 = 1
15: exit
The verifier first walks the path with R6=3. Given the support for <8B
spill/fills, at instruction 13, it knows the condition is true and skips
instruction 14. At that point, the backtracking logic kicks in but stops
at the fill instruction since it only propagates the precision bit for
8B spill/fill. When the verifier then walks the path with R6=2, it will
consider it safe at instruction 8 because R6 is not marked as needing
precision. Instruction 14 is thus never walked and is then incorrectly
removed as 'dead code'.
It's also possible to lead the verifier to accept e.g. an out-of-bound
memory access instead of causing an incorrect dead code elimination.
This regression was found via Cilium's bpf-next CI where it was causing
a conntrack map update to be silently skipped because the code had been
removed by the verifier.
This commit fixes it by enabling support for <8B spill/fills in the
bactracking logic. In case of a <8B spill/fill, the full 8B stack slot
will be marked as needing precision. Then, in __mark_chain_precision,
any tracked register spilled in a marked slot will itself be marked as
needing precision, regardless of the spill size. This logic makes two
assumptions: (1) only 8B-aligned spill/fill are tracked and (2) spilled
registers are only tracked if the spill and fill sizes are equal. Commit
ef979017b8 ("bpf: selftest: Add verifier tests for <8-byte scalar
spill and refill") covers the first assumption and the next commit in
this patchset covers the second.
Fixes: 354e8f1970 ("bpf: Support <8-byte scalar spill and refill")
Signed-off-by: Paul Chaignon <paul@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d83d7ed260 upstream.
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable <stable@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230202151554.2310273-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 71f656a501 ]
Register range information is copied in several places. The intent is
to transfer range/id information from one register/stack spill to
another. Currently this is done using direct register assignment, e.g.:
static void find_equal_scalars(..., struct bpf_reg_state *known_reg)
{
...
struct bpf_reg_state *reg;
...
*reg = *known_reg;
...
}
However, such assignments also copy the following bpf_reg_state fields:
struct bpf_reg_state {
...
struct bpf_reg_state *parent;
...
enum bpf_reg_liveness live;
...
};
Copying of these fields is accidental and incorrect, as could be
demonstrated by the following example:
0: call ktime_get_ns()
1: r6 = r0
2: call ktime_get_ns()
3: r7 = r0
4: if r0 > r6 goto +1 ; r0 & r6 are unbound thus generated
; branch states are identical
5: *(u64 *)(r10 - 8) = 0xdeadbeef ; 64-bit write to fp[-8]
--- checkpoint ---
6: r1 = 42 ; r1 marked as written
7: *(u8 *)(r10 - 8) = r1 ; 8-bit write, fp[-8] parent & live
; overwritten
8: r2 = *(u64 *)(r10 - 8)
9: r0 = 0
10: exit
This example is unsafe because 64-bit write to fp[-8] at (5) is
conditional, thus not all bytes of fp[-8] are guaranteed to be set
when it is read at (8). However, currently the example passes
verification.
First, the execution path 1-10 is examined by verifier.
Suppose that a new checkpoint is created by is_state_visited() at (6).
After checkpoint creation:
- r1.parent points to checkpoint.r1,
- fp[-8].parent points to checkpoint.fp[-8].
At (6) the r1.live is set to REG_LIVE_WRITTEN.
At (7) the fp[-8].parent is set to r1.parent and fp[-8].live is set to
REG_LIVE_WRITTEN, because of the following code called in
check_stack_write_fixed_off():
static void save_register_state(struct bpf_func_state *state,
int spi, struct bpf_reg_state *reg,
int size)
{
...
state->stack[spi].spilled_ptr = *reg; // <--- parent & live copied
if (size == BPF_REG_SIZE)
state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
...
}
Note the intent to mark stack spill as written only if 8 bytes are
spilled to a slot, however this intent is spoiled by a 'live' field copy.
At (8) the checkpoint.fp[-8] should be marked as REG_LIVE_READ but
this does not happen:
- fp[-8] in a current state is already marked as REG_LIVE_WRITTEN;
- fp[-8].parent points to checkpoint.r1, parentage chain is used by
mark_reg_read() to mark checkpoint states.
At (10) the verification is finished for path 1-10 and jump 4-6 is
examined. The checkpoint.fp[-8] never gets REG_LIVE_READ mark and this
spill is pruned from the cached states by clean_live_states(). Hence
verifier state obtained via path 1-4,6 is deemed identical to one
obtained via path 1-6 and program marked as safe.
Note: the example should be executed with BPF_F_TEST_STATE_FREQ flag
set to force creation of intermediate verifier states.
This commit revisits the locations where bpf_reg_state instances are
copied and replaces the direct copies with a call to a function
copy_register_state(dst, src) that preserves 'parent' and 'live'
fields of the 'dst'.
Fixes: 679c782de1 ("bpf/verifier: per-register parent pointers")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230106142214.1040390-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 354e8f1970 ]
The verifier currently does not save the reg state when
spilling <8byte bounded scalar to the stack. The bpf program
will be incorrectly rejected when this scalar is refilled to
the reg and then used to offset into a packet header.
The later patch has a simplified bpf prog from a real use case
to demonstrate this case. The current work around is
to reparse the packet again such that this offset scalar
is close to where the packet data will be accessed to
avoid the spill. Thus, the header is parsed twice.
The llvm patch [1] will align the <8bytes spill to
the 8-byte stack address. This can simplify the verifier
support by avoiding to store multiple reg states for
each 8 byte stack slot.
This patch changes the verifier to save the reg state when
spilling <8bytes scalar to the stack. This reg state saving
is limited to spill aligned to the 8-byte stack address.
The current refill logic has already called coerce_reg_to_size(),
so coerce_reg_to_size() is not called on state->stack[spi].spilled_ptr
during spill.
When refilling in check_stack_read_fixed_off(), it checks
the refill size is the same as the number of bytes marked with
STACK_SPILL before restoring the reg state. When restoring
the reg state to state->regs[dst_regno], it needs
to avoid the state->regs[dst_regno].subreg_def being
over written because it has been marked by the check_reg_arg()
earlier [check_mem_access() is called after check_reg_arg() in
do_check()]. Reordering check_mem_access() and check_reg_arg()
will need a lot of changes in test_verifier's tests because
of the difference in verifier's error message. Thus, the
patch here is to save the state->regs[dst_regno].subreg_def
first in check_stack_read_fixed_off().
There are cases that the verifier needs to scrub the spilled slot
from STACK_SPILL to STACK_MISC. After this patch the spill is not always
in 8 bytes now, so it can no longer assume the other 7 bytes are always
marked as STACK_SPILL. In particular, the scrub needs to avoid marking
an uninitialized byte from STACK_INVALID to STACK_MISC. Otherwise, the
verifier will incorrectly accept bpf program reading uninitialized bytes
from the stack. A new helper scrub_spilled_slot() is created for this
purpose.
[1]: https://reviews.llvm.org/D109073
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210922004941.625398-1-kafai@fb.com
Stable-dep-of: 71f656a501 ("bpf: Fix to preserve reg parent/live fields when copying range info")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bdb7fdb0ac ]
In current bpf_send_signal() and bpf_send_signal_thread() helper
implementation, irq_work is used to handle nmi context. Hao Sun
reported in [1] that the current task at the entry of the helper
might be gone during irq_work callback processing. To fix the issue,
a reference is acquired for the current task before enqueuing into
the irq_work so that the queued task is still available during
irq_work callback processing.
[1] https://lore.kernel.org/bpf/20230109074425.12556-1-sunhao.th@gmail.com/
Fixes: 8b401f9ed2 ("bpf: implement bpf_send_signal() helper")
Tested-by: Hao Sun <sunhao.th@gmail.com>
Reported-by: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230118204815.3331855-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a3d81bc1ea ]
The following kernel panic can be triggered when a task with pid=1 attaches
a prog that attempts to send killing signal to itself, also see [1] for more
details:
Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
CPU: 3 PID: 1 Comm: systemd Not tainted 6.1.0-09652-g59fe41b5255f #148
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x100/0x178 lib/dump_stack.c:106
panic+0x2c4/0x60f kernel/panic.c:275
do_exit.cold+0x63/0xe4 kernel/exit.c:789
do_group_exit+0xd4/0x2a0 kernel/exit.c:950
get_signal+0x2460/0x2600 kernel/signal.c:2858
arch_do_signal_or_restart+0x78/0x5d0 arch/x86/kernel/signal.c:306
exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203
__syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd
So skip task with pid=1 in bpf_send_signal_common() to avoid the panic.
[1] https://lore.kernel.org/bpf/20221222043507.33037-1-sunhao.th@gmail.com
Signed-off-by: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230106084838.12690-1-sunhao.th@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8b152e9150 upstream.
Function 'create_hist_field' is called recursively at
trace_events_hist.c:1954 and can return NULL-value that's why we have
to check it to avoid null pointer dereference.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lkml.kernel.org/r/20230111120409.4111-1-n.petrova@fintech.ru
Cc: stable@vger.kernel.org
Fixes: 30350d65ac ("tracing: Add variable support to hist triggers")
Signed-off-by: Natalia Petrova <n.petrova@fintech.ru>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3bb06eb6e9 upstream.
Currently trace_printk() can be used as soon as early_trace_init() is
called from start_kernel(). But if a crash happens, and
"ftrace_dump_on_oops" is set on the kernel command line, all you get will
be:
[ 0.456075] <idle>-0 0dN.2. 347519us : Unknown type 6
[ 0.456075] <idle>-0 0dN.2. 353141us : Unknown type 6
[ 0.456075] <idle>-0 0dN.2. 358684us : Unknown type 6
This is because the trace_printk() event (type 6) hasn't been registered
yet. That gets done via an early_initcall(), which may be early, but not
early enough.
Instead of registering the trace_printk() event (and other ftrace events,
which are not trace events) via an early_initcall(), have them registered at
the same time that trace_printk() can be used. This way, if there is a
crash before early_initcall(), then the trace_printk()s will actually be
useful.
Link: https://lkml.kernel.org/r/20230104161412.019f6c55@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: e725c731e3 ("tracing: Split tracing initialization into two for early initialization")
Reported-by: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Tested-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0254127ab9 upstream.
During a system boot, it can happen that the kernel receives a burst of
requests to insert the same module but loading it eventually fails
during its init call. For instance, udev can make a request to insert
a frequency module for each individual CPU when another frequency module
is already loaded which causes the init function of the new module to
return an error.
Since commit 6e6de3dee5 ("kernel/module.c: Only return -EEXIST for
modules that have finished loading"), the kernel waits for modules in
MODULE_STATE_GOING state to finish unloading before making another
attempt to load the same module.
This creates unnecessary work in the described scenario and delays the
boot. In the worst case, it can prevent udev from loading drivers for
other devices and might cause timeouts of services waiting on them and
subsequently a failed boot.
This patch attempts a different solution for the problem 6e6de3dee5
was trying to solve. Rather than waiting for the unloading to complete,
it returns a different error code (-EBUSY) for modules in the GOING
state. This should avoid the error situation that was described in
6e6de3dee5 (user space attempting to load a dependent module because
the -EEXIST error code would suggest to user space that the first module
had been loaded successfully), while avoiding the delay situation too.
This has been tested on linux-next since December 2022 and passes
all kmod selftests except test 0009 with module compression enabled
but it has been confirmed that this issue has existed and has gone
unnoticed since prior to this commit and can also be reproduced without
module compression with a simple usleep(5000000) on tools/modprobe.c [0].
These failures are caused by hitting the kernel mod_concurrent_max and can
happen either due to a self inflicted kernel module auto-loead DoS somehow
or on a system with large CPU count and each CPU count incorrectly triggering
many module auto-loads. Both of those issues need to be fixed in-kernel.
[0] https://lore.kernel.org/all/Y9A4fiobL6IHp%2F%2FP@bombadil.infradead.org/
Fixes: 6e6de3dee5 ("kernel/module.c: Only return -EEXIST for modules that have finished loading")
Co-developed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: Petr Mladek <pmladek@suse.com>
[mcgrof: enhance commit log with testing and kmod test result interpretation ]
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7535b832c6 upstream.
Use a temporary variable to take full advantage of READ_ONCE() behavior.
Without this, the report (and even the test) might be out of sync with
the initial test.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/Y5x7GXeluFmZ8E0E@hirez.programming.kicks-ass.net
Fixes: 9fc9e278a5 ("panic: Introduce warn_limit")
Fixes: d4ccd54d28 ("exit: Put an upper limit on how often we can oops")
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jann Horn <jannh@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Marco Elver <elver@google.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8b05aa2633 upstream.
Since Warn count is now tracked and is a fairly interesting signal, add
the entry /sys/kernel/warn_count to expose it to userspace.
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-6-keescook@chromium.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 9fc9e278a5 upstream.
Like oops_limit, add warn_limit for limiting the number of warnings when
panic_on_warn is not set.
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-doc@vger.kernel.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-5-keescook@chromium.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 79cc1ba7ba upstream.
Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll
their own warnings, and each check "panic_on_warn". Consolidate this
into a single function so that future instrumentation can be added in
a single location.
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Gow <davidgow@google.com>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: kasan-dev@googlegroups.com
Cc: linux-mm@kvack.org
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@chromium.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 9db89b4111 upstream.
Since Oops count is now tracked and is a fairly interesting signal, add
the entry /sys/kernel/oops_count to expose it to userspace.
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jann Horn <jannh@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-3-keescook@chromium.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d4ccd54d28 upstream.
Many Linux systems are configured to not panic on oops; but allowing an
attacker to oops the system **really** often can make even bugs that look
completely unexploitable exploitable (like NULL dereferences and such) if
each crash elevates a refcount by one or a lock is taken in read mode, and
this causes a counter to eventually overflow.
The most interesting counters for this are 32 bits wide (like open-coded
refcounts that don't use refcount_t). (The ldsem reader count on 32-bit
platforms is just 16 bits, but probably nobody cares about 32-bit platforms
that much nowadays.)
So let's panic the system if the kernel is constantly oopsing.
The speed of oopsing 2^32 times probably depends on several factors, like
how long the stack trace is and which unwinder you're using; an empirically
important one is whether your console is showing a graphical environment or
a text console that oopses will be printed to.
In a quick single-threaded benchmark, it looks like oopsing in a vfork()
child with a very short stack trace only takes ~510 microseconds per run
when a graphical console is active; but switching to a text console that
oopses are printed to slows it down around 87x, to ~45 milliseconds per
run.
(Adding more threads makes this faster, but the actual oops printing
happens under &die_lock on x86, so you can maybe speed this up by a factor
of around 2 and then any further improvement gets eaten up by lock
contention.)
It looks like it would take around 8-12 days to overflow a 32-bit counter
with repeated oopsing on a multi-core X86 system running a graphical
environment; both me (in an X86 VM) and Seth (with a distro kernel on
normal hardware in a standard configuration) got numbers in that ballpark.
12 days aren't *that* short on a desktop system, and you'd likely need much
longer on a typical server system (assuming that people don't run graphical
desktop environments on their servers), and this is a *very* noisy and
violent approach to exploiting the kernel; and it also seems to take orders
of magnitude longer on some machines, probably because stuff like EFI
pstore will slow it down a ton if that's active.
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20221107201317.324457-1-jannh@google.com
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-2-keescook@chromium.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 9360d035a5 upstream.
In preparation for adding more sysctls directly in kernel/panic.c, split
CONFIG_SMP from the logic that adds sysctls.
Cc: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: tangmeng <tangmeng@uniontech.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221117234328.594699-1-keescook@chromium.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0e25498f8c upstream.
There are two big uses of do_exit. The first is it's design use to be
the guts of the exit(2) system call. The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.
Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure. In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.
Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.
As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 1a2383e8b8 upstream.
In the current code, the following three places need to unset
panic_on_warn before calling panic() to avoid recursive panics:
kernel/kcsan/report.c: print_report()
kernel/sched/core.c: __schedule_bug()
mm/kfence/report.c: kfence_report_error()
In order to avoid copy-pasting "panic_on_warn = 0" all over the places,
it is better to move it inside panic() and then remove it from the other
places.
Link: https://lkml.kernel.org/r/1644324666-15947-4-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Xuefeng Li <lixuefeng@loongson.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 9df9186984 upstream.
kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.
To help with this maintenance let's start by moving sysctls to places
where they actually belong. The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we
just care about the core logic.
All filesystem syctls now get reviewed by fs folks. This commit
follows the commit of fs, move the oops_all_cpu_backtrace sysctl to
its own file, kernel/panic.c.
Signed-off-by: tangmeng <tangmeng@uniontech.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5b24ac2dfd ]
Size of the 'expect' array in the __report_matches is 1536 bytes, which
is exactly the default frame size warning limit of the xtensa
architecture.
As a result allmodconfig xtensa kernel builds with the gcc that does not
support the compiler plugins (which otherwise would push the said
warning limit to 2K) fail with the following message:
kernel/kcsan/kcsan_test.c:257:1: error: the frame size of 1680 bytes
is larger than 1536 bytes
Fix it by dynamically allocating the 'expect' array.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Marco Elver <elver@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e4f4db4779 ]
To mitigate Spectre v4, 2039f26f3a ("bpf: Fix leakage due to
insufficient speculative store bypass mitigation") inserts lfence
instructions after 1) initializing a stack slot and 2) spilling a
pointer to the stack.
However, this does not cover cases where a stack slot is first
initialized with a pointer (subject to sanitization) but then
overwritten with a scalar (not subject to sanitization because
the slot was already initialized). In this case, the second write
may be subject to speculative store bypass (SSB) creating a
speculative pointer-as-scalar type confusion. This allows the
program to subsequently leak the numerical pointer value using,
for example, a branch-based cache side channel.
To fix this, also sanitize scalars if they write a stack slot
that previously contained a pointer. Assuming that pointer-spills
are only generated by LLVM on register-pressure, the performance
impact on most real-world BPF programs should be small.
The following unprivileged BPF bytecode drafts a minimal exploit
and the mitigation:
[...]
// r6 = 0 or 1 (skalar, unknown user input)
// r7 = accessible ptr for side channel
// r10 = frame pointer (fp), to be leaked
//
r9 = r10 # fp alias to encourage ssb
*(u64 *)(r9 - 8) = r10 // fp[-8] = ptr, to be leaked
// lfence added here because of pointer spill to stack.
//
// Ommitted: Dummy bpf_ringbuf_output() here to train alias predictor
// for no r9-r10 dependency.
//
*(u64 *)(r10 - 8) = r6 // fp[-8] = scalar, overwrites ptr
// 2039f26f3aca: no lfence added because stack slot was not STACK_INVALID,
// store may be subject to SSB
//
// fix: also add an lfence when the slot contained a ptr
//
r8 = *(u64 *)(r9 - 8)
// r8 = architecturally a scalar, speculatively a ptr
//
// leak ptr using branch-based cache side channel:
r8 &= 1 // choose bit to leak
if r8 == 0 goto SLOW // no mispredict
// architecturally dead code if input r6 is 0,
// only executes speculatively iff ptr bit is 1
r8 = *(u64 *)(r7 + 0) # encode bit in cache (0: slow, 1: fast)
SLOW:
[...]
After running this, the program can time the access to *(r7 + 0) to
determine whether the chosen pointer bit was 0 or 1. Repeat this 64
times to recover the whole address on amd64.
In summary, sanitization can only be skipped if one scalar is
overwritten with another scalar. Scalar-confusion due to speculative
store bypass can not lead to invalid accesses because the pointer
bounds deducted during verification are enforced using branchless
logic. See 979d63d50c ("bpf: prevent out of bounds speculation on
pointer arithmetic") for details.
Do not make the mitigation depend on !env->allow_{uninit_stack,ptr_leaks}
because speculative leaks are likely unexpected if these were enabled.
For example, leaking the address to a protected log file may be acceptable
while disabling the mitigation might unintentionally leak the address
into the cached-state of a map that is accessible to unprivileged
processes.
Fixes: 2039f26f3a ("bpf: Fix leakage due to insufficient speculative store bypass mitigation")
Signed-off-by: Luis Gerhorst <gerhorst@cs.fau.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Henriette Hofmeier <henriette.hofmeier@rub.de>
Link: https://lore.kernel.org/bpf/edc95bad-aada-9cfc-ffe2-fa9bb206583c@cs.fau.de
Link: https://lore.kernel.org/bpf/20230109150544.41465-1-gerhorst@cs.fau.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit ef01f4e25c upstream.
When changing the ebpf program put() routines to support being called
from within IRQ context the program ID was reset to zero prior to
calling the perf event and audit UNLOAD record generators, which
resulted in problems as the ebpf program ID was bogus (always zero).
This patch addresses this problem by removing an unnecessary call to
bpf_prog_free_id() in __bpf_prog_offload_destroy() and adjusting
__bpf_prog_put() to only call bpf_prog_free_id() after audit and perf
have finished their bpf program unload tasks in
bpf_prog_put_deferred(). For the record, no one can determine, or
remember, why it was necessary to free the program ID, and remove it
from the IDR, prior to executing bpf_prog_put_deferred();
regardless, both Stanislav and Alexei agree that the approach in this
patch should be safe.
It is worth noting that when moving the bpf_prog_free_id() call, the
do_idr_lock parameter was forced to true as the ebpf devs determined
this was the correct as the do_idr_lock should always be true. The
do_idr_lock parameter will be removed in a follow-up patch, but it
was kept here to keep the patch small in an effort to ease any stable
backports.
I also modified the bpf_audit_prog() logic used to associate the
AUDIT_BPF record with other associated records, e.g. @ctx != NULL.
Instead of keying off the operation, it now keys off the execution
context, e.g. '!in_irg && !irqs_disabled()', which is much more
appropriate and should help better connect the UNLOAD operations with
the associated audit state (other audit records).
Cc: stable@vger.kernel.org
Fixes: d809e134be ("bpf: Prepare bpf_prog_put() to be called from irq context.")
Reported-by: Burn Alting <burn.alting@iinet.net.au>
Reported-by: Jiri Olsa <olsajiri@gmail.com>
Suggested-by: Stanislav Fomichev <sdf@google.com>
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230106154400.74211-1-paul@paul-moore.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7397906057 upstream.
do_prlimit() adds the user-controlled resource value to a pointer that
will subsequently be dereferenced. In order to help prevent this
codepath from being used as a spectre "gadget" a barrier needs to be
added after checking the range.
Reported-by: Jordy Zomer <jordyzomer@google.com>
Tested-by: Jordy Zomer <jordyzomer@google.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 87ca4f9efb upstream.
Since commit 07ec77a1d4 ("sched: Allow task CPU affinity to be
restricted on asymmetric systems"), the setting and clearing of
user_cpus_ptr are done under pi_lock for arm64 architecture. However,
dup_user_cpus_ptr() accesses user_cpus_ptr without any lock
protection. Since sched_setaffinity() can be invoked from another
process, the process being modified may be undergoing fork() at
the same time. When racing with the clearing of user_cpus_ptr in
__set_cpus_allowed_ptr_locked(), it can lead to user-after-free and
possibly double-free in arm64 kernel.
Commit 8f9ea86fdf ("sched: Always preserve the user requested
cpumask") fixes this problem as user_cpus_ptr, once set, will never
be cleared in a task's lifetime. However, this bug was re-introduced
in commit 851a723e45 ("sched: Always clear user_cpus_ptr in
do_set_cpus_allowed()") which allows the clearing of user_cpus_ptr in
do_set_cpus_allowed(). This time, it will affect all arches.
Fix this bug by always clearing the user_cpus_ptr of the newly
cloned/forked task before the copying process starts and check the
user_cpus_ptr state of the source task under pi_lock.
Note to stable, this patch won't be applicable to stable releases.
Just copy the new dup_user_cpus_ptr() function over.
Fixes: 07ec77a1d4 ("sched: Allow task CPU affinity to be restricted on asymmetric systems")
Fixes: 851a723e45 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()")
Reported-by: David Wang 王标 <wangbiao3@xiaomi.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221231041120.440785-2-longman@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ff4837f7fe upstream.
The maximum number of synthetic fields supported is defined as
SYNTH_FIELDS_MAX which value currently is 64, but it actually fails
when try to generate a synthetic event with 64 fields by executing like:
# echo "my_synth_event int v1; int v2; int v3; int v4; int v5; int v6;\
int v7; int v8; int v9; int v10; int v11; int v12; int v13; int v14;\
int v15; int v16; int v17; int v18; int v19; int v20; int v21; int v22;\
int v23; int v24; int v25; int v26; int v27; int v28; int v29; int v30;\
int v31; int v32; int v33; int v34; int v35; int v36; int v37; int v38;\
int v39; int v40; int v41; int v42; int v43; int v44; int v45; int v46;\
int v47; int v48; int v49; int v50; int v51; int v52; int v53; int v54;\
int v55; int v56; int v57; int v58; int v59; int v60; int v61; int v62;\
int v63; int v64" >> /sys/kernel/tracing/synthetic_events
Correct the field counting to fix it.
Link: https://lore.kernel.org/linux-trace-kernel/20221207091557.3137904-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: c9e759b1e8 ("tracing: Rework synthetic event command parsing")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
[Fix conflict due to lack of c24be24aed]
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c1ac03af6e upstream.
print_trace_line may overflow seq_file buffer. If the event is not
consumed, the while loop keeps peeking this event, causing a infinite loop.
Link: https://lkml.kernel.org/r/20221129113009.182425-1-yangjihong1@huawei.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 088b1e427d ("ftrace: pipe fixes")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 575b76cb88 upstream.
When creating probe names, a check is done to make sure it matches basic C
standard variable naming standards. Basically, starts with alphabetic or
underline, and then the rest of the characters have alpha-numeric or
underline in them.
But system names do not have any true naming conventions, as they are
created by the TRACE_SYSTEM macro and nothing tests to see what they are.
The "xhci-hcd" trace events has a '-' in the system name. When trying to
attach a eprobe to one of these trace points, it fails because the system
name does not follow the variable naming convention because of the
hyphen, and the eprobe checks fail on this.
Allow hyphens in the system name so that eprobes can attach to the
"xhci-hcd" trace events.
Link: https://lore.kernel.org/all/Y3eJ8GiGnEvVd8%2FN@macondo/
Link: https://lore.kernel.org/linux-trace-kernel/20221122122345.160f5077@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 5b7a962209 ("tracing/probe: Check event/group naming rule at parsing")
Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e25e43a4e5 upstream.
Both CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER partially enables the
CONFIG_TRACER_MAX_TRACE code, but that is complicated and has
introduced a bug; It declares tracing_max_lat_fops data structure outside
of #ifdefs, but since it is defined only when CONFIG_TRACER_MAX_TRACE=y
or CONFIG_HWLAT_TRACER=y, if only CONFIG_OSNOISE_TRACER=y, that
declaration comes to a definition(!).
To fix this issue, and do not repeat the similar problem, makes
CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER enables the
CONFIG_TRACER_MAX_TRACE always. It has there benefits;
- Fix the tracing_max_lat_fops bug
- Simplify the #ifdefs
- CONFIG_TRACER_MAX_TRACE code is fully enabled, or not.
Link: https://lore.kernel.org/linux-trace-kernel/167033628155.4111793.12185405690820208159.stgit@devnote3
Fixes: 424b650f35 ("tracing: Fix missing osnoise tracer on max_latency")
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: stable@vger.kernel.org
Reported-by: David Howells <dhowells@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/all/166992525941.1716618.13740663757583361463.stgit@warthog.procyon.org.uk/ (original thread and v1)
Link: https://lore.kernel.org/all/202212052253.VuhZ2ulJ-lkp@intel.com/T/#u (v1 error report)
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d5f30a7da8 upstream.
The flag that tells the event to call its triggers after reading the event
is set for eprobes after the eprobe is enabled. This leads to a race where
the eprobe may be triggered at the beginning of the event where the record
information is NULL. The eprobe then dereferences the NULL record causing
a NULL kernel pointer bug.
Test for a NULL record to keep this from happening.
Link: https://lore.kernel.org/linux-trace-kernel/20221116192552.1066630-1-rafaelmendsr@gmail.com/
Link: https://lore.kernel.org/all/20221117214249.2addbe10@gandalf.local.home/
Cc: stable@vger.kernel.org
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0a041ebca4 upstream.
It passes the attr struct to the security_perf_event_open() but it's
not initialized yet.
Fixes: da97e18458 ("perf_event: Add support for LSM and SELinux checks")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20221220223140.4020470-1-namhyung@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 82470f7d90 upstream.
When generate a synthetic event with many params and then create a trace
action for it [1], kernel panic happened [2].
It is because that in trace_action_create() 'data->n_params' is up to
SYNTH_FIELDS_MAX (current value is 64), and array 'data->var_ref_idx'
keeps indices into array 'hist_data->var_refs' for each synthetic event
param, but the length of 'data->var_ref_idx' is TRACING_MAP_VARS_MAX
(current value is 16), so out-of-bound write happened when 'data->n_params'
more than 16. In this case, 'data->match_data.event' is overwritten and
eventually cause the panic.
To solve the issue, adjust the length of 'data->var_ref_idx' to be
SYNTH_FIELDS_MAX and add sanity checks to avoid out-of-bound write.
[1]
# cd /sys/kernel/tracing/
# echo "my_synth_event int v1; int v2; int v3; int v4; int v5; int v6;\
int v7; int v8; int v9; int v10; int v11; int v12; int v13; int v14;\
int v15; int v16; int v17; int v18; int v19; int v20; int v21; int v22;\
int v23; int v24; int v25; int v26; int v27; int v28; int v29; int v30;\
int v31; int v32; int v33; int v34; int v35; int v36; int v37; int v38;\
int v39; int v40; int v41; int v42; int v43; int v44; int v45; int v46;\
int v47; int v48; int v49; int v50; int v51; int v52; int v53; int v54;\
int v55; int v56; int v57; int v58; int v59; int v60; int v61; int v62;\
int v63" >> synthetic_events
# echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="bash"' >> \
events/sched/sched_waking/trigger
# echo "hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(\
pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,\
pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,\
pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,pid,\
pid,pid,pid,pid,pid,pid,pid,pid,pid)" >> events/sched/sched_switch/trigger
[2]
BUG: unable to handle page fault for address: ffff91c900000000
PGD 61001067 P4D 61001067 PUD 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 2 PID: 322 Comm: bash Tainted: G W 6.1.0-rc8+ #229
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:strcmp+0xc/0x30
Code: 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee
c3 cc cc cc cc 0f 1f 00 31 c0 eb 08 48 83 c0 01 84 d2 74 13 <0f> b6 14
07 3a 14 06 74 ef 19 c0 83 c8 01 c3 cc cc cc cc 31 c3
RSP: 0018:ffff9b3b00f53c48 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffffba958a68 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffff91c943d33a90 RDI: ffff91c900000000
RBP: ffff91c900000000 R08: 00000018d604b529 R09: 0000000000000000
R10: ffff91c9483eddb1 R11: ffff91ca483eddab R12: ffff91c946171580
R13: ffff91c9479f0538 R14: ffff91c9457c2848 R15: ffff91c9479f0538
FS: 00007f1d1cfbe740(0000) GS:ffff91c9bdc80000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff91c900000000 CR3: 0000000006316000 CR4: 00000000000006e0
Call Trace:
<TASK>
__find_event_file+0x55/0x90
action_create+0x76c/0x1060
event_hist_trigger_parse+0x146d/0x2060
? event_trigger_write+0x31/0xd0
trigger_process_regex+0xbb/0x110
event_trigger_write+0x6b/0xd0
vfs_write+0xc8/0x3e0
? alloc_fd+0xc0/0x160
? preempt_count_add+0x4d/0xa0
? preempt_count_add+0x70/0xa0
ksys_write+0x5f/0xe0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f1d1d0cf077
Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e
fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00
f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74
RSP: 002b:00007ffcebb0e568 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000143 RCX: 00007f1d1d0cf077
RDX: 0000000000000143 RSI: 00005639265aa7e0 RDI: 0000000000000001
RBP: 00005639265aa7e0 R08: 000000000000000a R09: 0000000000000142
R10: 000056392639c017 R11: 0000000000000246 R12: 0000000000000143
R13: 00007f1d1d1ae6a0 R14: 00007f1d1d1aa4a0 R15: 00007f1d1d1a98a0
</TASK>
Modules linked in:
CR2: ffff91c900000000
---[ end trace 0000000000000000 ]---
RIP: 0010:strcmp+0xc/0x30
Code: 75 f7 31 d2 44 0f b6 04 16 44 88 04 11 48 83 c2 01 45 84 c0 75 ee
c3 cc cc cc cc 0f 1f 00 31 c0 eb 08 48 83 c0 01 84 d2 74 13 <0f> b6 14
07 3a 14 06 74 ef 19 c0 83 c8 01 c3 cc cc cc cc 31 c3
RSP: 0018:ffff9b3b00f53c48 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffffba958a68 RCX: 0000000000000000
RDX: 0000000000000010 RSI: ffff91c943d33a90 RDI: ffff91c900000000
RBP: ffff91c900000000 R08: 00000018d604b529 R09: 0000000000000000
R10: ffff91c9483eddb1 R11: ffff91ca483eddab R12: ffff91c946171580
R13: ffff91c9479f0538 R14: ffff91c9457c2848 R15: ffff91c9479f0538
FS: 00007f1d1cfbe740(0000) GS:ffff91c9bdc80000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff91c900000000 CR3: 0000000006316000 CR4: 00000000000006e0
Link: https://lore.kernel.org/linux-trace-kernel/20221207035143.2278781-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: d380dcde9a ("tracing: Fix now invalid var_ref_vals assumption in trace action")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 96017bf903 upstream.
Currently, trc_wait_for_one_reader() atomically increments
the trc_n_readers_need_end counter before sending the IPI
invoking trc_read_check_handler(). All failure paths out of
trc_read_check_handler() and also from the smp_call_function_single()
within trc_wait_for_one_reader() must carefully atomically decrement
this counter. This is more complex than it needs to be.
This commit therefore simplifies things and saves a few lines of
code by dispensing with the atomic decrements in favor of having
trc_read_check_handler() do the atomic increment only in the success case.
In theory, this represents no change in functionality.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7c201739be upstream.
With Clang version 16+, -fsanitize=thread will turn
memcpy/memset/memmove calls in instrumented functions into
__tsan_memcpy/__tsan_memset/__tsan_memmove calls respectively.
Add these functions to the core KCSAN runtime, so that we (a) catch data
races with mem* functions, and (b) won't run into linker errors with
such newer compilers.
Cc: stable@vger.kernel.org # v5.10+
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
[ elver@google.com: adjust check_access() call for v5.15 and earlier. ]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e96b95c2b7 upstream.
In GCC version 12.1 a checksum field was added.
This patch fixes a kernel crash occurring during boot when using
gcov-kernel with GCC version 12.2. The crash occurred on a system running
on i.MX6SX.
Link: https://lkml.kernel.org/r/20221220102318.3418501-1-rickaran@axis.com
Fixes: 977ef30a7d ("gcov: support GCC 12.1 and newer compilers")
Signed-off-by: Rickard x Andersson <rickaran@axis.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Tested-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Martin Liska <mliska@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c5f31c655b ]
The integer overflow is descripted with following codes:
> 317 static comp_t encode_comp_t(u64 value)
> 318 {
> 319 int exp, rnd;
......
> 341 exp <<= MANTSIZE;
> 342 exp += value;
> 343 return exp;
> 344 }
Currently comp_t is defined as type of '__u16', but the variable 'exp' is
type of 'int', so overflow would happen when variable 'exp' in line 343 is
greater than 65535.
Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Jinhao <zhangjinhao2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ceb1c8c9b8 ]
Running rcutorture with non-zero fqs_duration module parameter in a
kernel built with CONFIG_PREEMPTION=y results in the following splat:
BUG: using __this_cpu_read() in preemptible [00000000]
code: rcu_torture_fqs/398
caller is __this_cpu_preempt_check+0x13/0x20
CPU: 3 PID: 398 Comm: rcu_torture_fqs Not tainted 6.0.0-rc1-yoctodev-standard+
Call Trace:
<TASK>
dump_stack_lvl+0x5b/0x86
dump_stack+0x10/0x16
check_preemption_disabled+0xe5/0xf0
__this_cpu_preempt_check+0x13/0x20
rcu_force_quiescent_state.part.0+0x1c/0x170
rcu_force_quiescent_state+0x1e/0x30
rcu_torture_fqs+0xca/0x160
? rcu_torture_boost+0x430/0x430
kthread+0x192/0x1d0
? kthread_complete_and_exit+0x30/0x30
ret_from_fork+0x22/0x30
</TASK>
The problem is that rcu_force_quiescent_state() uses __this_cpu_read()
in preemptible code instead of the proper raw_cpu_read(). This commit
therefore changes __this_cpu_read() to raw_cpu_read().
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 608c6ed333 ]
When input some constructed invalid 'trigger' command, command info
in 'error_log' are lost [1].
The root cause is that there is a path that event_hist_trigger_parse()
is recursely called once and 'last_cmd' which save origin command is
cleared, then later calling of hist_err() will no longer record origin
command info:
event_hist_trigger_parse() {
last_cmd_set() // <1> 'last_cmd' save origin command here at first
create_actions() {
onmatch_create() {
action_create() {
trace_action_create() {
trace_action_create_field_var() {
create_field_var_hist() {
event_hist_trigger_parse() { // <2> recursely called once
hist_err_clear() // <3> 'last_cmd' is cleared here
}
hist_err() // <4> No longer find origin command!!!
Since 'glob' is empty string while running into the recurse call, we
can trickly check it and bypass the call of hist_err_clear() to solve it.
[1]
# cd /sys/kernel/tracing
# echo "my_synth_event int v1; int v2; int v3;" >> synthetic_events
# echo 'hist:keys=pid' >> events/sched/sched_waking/trigger
# echo "hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(\
pid,pid1)" >> events/sched/sched_switch/trigger
# cat error_log
[ 8.405018] hist:sched:sched_switch: error: Couldn't find synthetic event
Command:
hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(pid,pid1)
^
[ 8.816902] hist:sched:sched_switch: error: Couldn't find field
Command:
hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(pid,pid1)
^
[ 8.816902] hist:sched:sched_switch: error: Couldn't parse field variable
Command:
hist:keys=next_pid:onmatch(sched.sched_waking).my_synth_event(pid,pid1)
^
[ 8.999880] : error: Couldn't find field
Command:
^
[ 8.999880] : error: Couldn't parse field variable
Command:
^
[ 8.999880] : error: Couldn't find field
Command:
^
[ 8.999880] : error: Couldn't create histogram for field
Command:
^
Link: https://lore.kernel.org/linux-trace-kernel/20221207135326.3483216-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <zanussi@kernel.org>
Fixes: f404da6e1d ("tracing: Add 'last error' error facility for hist triggers")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 57ddfecc72 ]
list_for_each_entry_reverse() assumes that the iterated list is nonempty
and that every list_head is embedded in the same type, but its use in
padata_do_serial() breaks both rules.
This doesn't cause any issues now because padata_priv and padata_list
happen to have their list fields at the same offset, but we really
shouldn't be relying on that.
Fixes: bfde23ce20 ("padata: unbind parallel jobs from specific CPUs")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 34c3a47d20 ]
A deadlock can happen when an overloaded system runs ->parallel() in the
context of the current task:
padata_do_parallel
->parallel()
pcrypt_aead_enc/dec
padata_do_serial
spin_lock(&reorder->lock) // BHs still enabled
<interrupt>
...
__do_softirq
...
padata_do_serial
spin_lock(&reorder->lock)
It's a bug for BHs to be on in _do_serial as Steffen points out, so
ensure they're off in the "current task" case like they are in
padata_parallel_worker to avoid this situation.
Reported-by: syzbot+bc05445bc14148d51915@syzkaller.appspotmail.com
Fixes: 4611ce2246 ("padata: allocate work structures for parallel jobs from a pool")
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d35af0a7fe ]
In BPF all global functions, and BPF helpers return a 64-bit
value. For kfunc calls, this is not the case, and they can return
e.g. 32-bit values.
The return register R0 for kfuncs calls can therefore be marked as
subreg_def != DEF_NOT_SUBREG. In general, if a register is marked with
subreg_def != DEF_NOT_SUBREG, some archs (where bpf_jit_needs_zext()
returns true) require the verifier to insert explicit zero-extension
instructions.
For kfuncs calls, however, the caller should do sign/zero extension
for return values. In other words, the compiler is responsible to
insert proper instructions, not the verifier.
An example, provided by Yonghong Song:
$ cat t.c
extern unsigned foo(void);
unsigned bar1(void) {
return foo();
}
unsigned bar2(void) {
if (foo()) return 10; else return 20;
}
$ clang -target bpf -mcpu=v3 -O2 -c t.c && llvm-objdump -d t.o
t.o: file format elf64-bpf
Disassembly of section .text:
0000000000000000 <bar1>:
0: 85 10 00 00 ff ff ff ff call -0x1
1: 95 00 00 00 00 00 00 00 exit
0000000000000010 <bar2>:
2: 85 10 00 00 ff ff ff ff call -0x1
3: bc 01 00 00 00 00 00 00 w1 = w0
4: b4 00 00 00 14 00 00 00 w0 = 0x14
5: 16 01 01 00 00 00 00 00 if w1 == 0x0 goto +0x1 <LBB1_2>
6: b4 00 00 00 0a 00 00 00 w0 = 0xa
0000000000000038 <LBB1_2>:
7: 95 00 00 00 00 00 00 00 exit
If the return value of 'foo()' is used in the BPF program, the proper
zero-extension will be done.
Currently, the verifier correctly marks, say, a 32-bit return value as
subreg_def != DEF_NOT_SUBREG, but will fail performing the actual
zero-extension, due to a verifier bug in
opt_subreg_zext_lo32_rnd_hi32(). load_reg is not properly set to R0,
and the following path will be taken:
if (WARN_ON(load_reg == -1)) {
verbose(env, "verifier bug. zext_dst is set, but no reg is defined\n");
return -EFAULT;
}
A longer discussion from v1 can be found in the link below.
Correct the verifier by avoiding doing explicit zero-extension of R0
for kfunc calls. Note that R0 will still be marked as a sub-register
for return values smaller than 64-bit.
Fixes: 83a2881903 ("bpf: Account for BPF_FETCH in insn_has_def32()")
Link: https://lore.kernel.org/bpf/20221202103620.1915679-1-bjorn@kernel.org/
Suggested-by: Yonghong Song <yhs@meta.com>
Signed-off-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221207103540.396496-1-bjorn@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f596da3efa ]
When the blk_classic option is enabled, non-blktrace events must be
filtered out. Otherwise, events of other types are output in the blktrace
classic format, which is unexpected.
The problem can be triggered in the following ways:
# echo 1 > /sys/kernel/debug/tracing/options/blk_classic
# echo 1 > /sys/kernel/debug/tracing/events/enable
# echo blk > /sys/kernel/debug/tracing/current_tracer
# cat /sys/kernel/debug/tracing/trace_pipe
Fixes: c71a896154 ("blktrace: add ftrace plugin")
Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20221122040410.85113-1-yangjihong1@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 529409ea92 ]
When equivalent completed state is found and it has additional precision
restrictions, BPF verifier propagates precision to
currently-being-verified state chain (i.e., including parent states) so
that if some of the states in the chain are not yet completed, necessary
precision restrictions are enforced.
Unfortunately, right now this happens only for the last frame (deepest
active subprogram's frame), not all the frames. This can lead to
incorrect matching of states due to missing precision marker. Currently
this doesn't seem possible as BPF verifier forces everything to precise
when validated BPF program has any subprograms. But with the next patch
lifting this restriction, this becomes problematic.
In fact, without this fix, we'll start getting failure in one of the
existing test_verifier test cases:
#906/p precise: cross frame pruning FAIL
Unexpected success to load!
verification time 48 usec
stack depth 0+0
processed 26 insns (limit 1000000) max_states_per_insn 3 total_states 17 peak_states 17 mark_read 8
This patch adds precision propagation across all frames.
Fixes: a3ce685dd0 ("bpf: fix precision tracking")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221104163649.121784-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 27113c59b6 ]
Every 8 bytes of the stack is tracked by a bpf_stack_state.
Within each bpf_stack_state, there is a 'u8 slot_type[8]' to track
the type of each byte. Verifier tests slot_type[0] == STACK_SPILL
to decide if the spilled reg state is saved. Verifier currently only
saves the reg state if the whole 8 bytes are spilled to the stack,
so checking the slot_type[7] is the same as checking slot_type[0].
The later patch will allow verifier to save the bounded scalar
reg also for <8 bytes spill. There is a llvm patch [1] to ensure
the <8 bytes spill will be 8-byte aligned, so checking
slot_type[7] instead of slot_type[0] is required.
While at it, this patch refactors the slot_type[0] == STACK_SPILL
test into a new function is_spilled_reg() and change the
slot_type[0] check to slot_type[7] check in there also.
[1] https://reviews.llvm.org/D109073
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210922004934.624194-1-kafai@fb.com
Stable-dep-of: 529409ea92 ("bpf: propagate precision across all frames, not just the last one")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a3b666bfa9 ]
When processing ALU/ALU64 operations (apart from BPF_MOV, which is
handled correctly already; and BPF_NEG and BPF_END are special and don't
have source register), if destination register is already marked
precise, this causes problem with potentially missing precision tracking
for the source register. E.g., when we have r1 >>= r5 and r1 is marked
precise, but r5 isn't, this will lead to r5 staying as imprecise. This
is due to the precision backtracking logic stopping early when it sees
r1 is already marked precise. If r1 wasn't precise, we'd keep
backtracking and would add r5 to the set of registers that need to be
marked precise. So there is a discrepancy here which can lead to invalid
and incompatible states matched due to lack of precision marking on r5.
If r1 wasn't precise, precision backtracking would correctly mark both
r1 and r5 as precise.
This is simple to fix, though. During the forward instruction simulation
pass, for arithmetic operations of `scalar <op>= scalar` form (where
<op> is ALU or ALU64 operations), if destination register is already
precise, mark source register as precise. This applies only when both
involved registers are SCALARs. `ptr += scalar` and `scalar += ptr`
cases are already handled correctly.
This does have (negative) effect on some selftest programs and few
Cilium programs. ~/baseline-tmp-results.csv are veristat results with
this patch, while ~/baseline-results.csv is without it. See post
scriptum for instructions on how to make Cilium programs testable with
veristat. Correctness has a price.
$ ./veristat -C -e file,prog,insns,states ~/baseline-results.csv ~/baseline-tmp-results.csv | grep -v '+0'
File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF)
----------------------- -------------------- --------------- --------------- ------------------ ---------------- ---------------- -------------------
bpf_cubic.bpf.linked1.o bpf_cubic_cong_avoid 997 1700 +703 (+70.51%) 62 90 +28 (+45.16%)
test_l4lb.bpf.linked1.o balancer_ingress 4559 5469 +910 (+19.96%) 118 126 +8 (+6.78%)
----------------------- -------------------- --------------- --------------- ------------------ ---------------- ---------------- -------------------
$ ./veristat -C -e file,prog,verdict,insns,states ~/baseline-results-cilium.csv ~/baseline-tmp-results-cilium.csv | grep -v '+0'
File Program Total insns (A) Total insns (B) Total insns (DIFF) Total states (A) Total states (B) Total states (DIFF)
------------- ------------------------------ --------------- --------------- ------------------ ---------------- ---------------- -------------------
bpf_host.o tail_nodeport_nat_ingress_ipv6 4448 5261 +813 (+18.28%) 234 247 +13 (+5.56%)
bpf_host.o tail_nodeport_nat_ipv6_egress 3396 3446 +50 (+1.47%) 201 203 +2 (+1.00%)
bpf_lxc.o tail_nodeport_nat_ingress_ipv6 4448 5261 +813 (+18.28%) 234 247 +13 (+5.56%)
bpf_overlay.o tail_nodeport_nat_ingress_ipv6 4448 5261 +813 (+18.28%) 234 247 +13 (+5.56%)
bpf_xdp.o tail_lb_ipv4 71736 73442 +1706 (+2.38%) 4295 4370 +75 (+1.75%)
------------- ------------------------------ --------------- --------------- ------------------ ---------------- ---------------- -------------------
P.S. To make Cilium ([0]) programs libbpf-compatible and thus
veristat-loadable, apply changes from topmost commit in [1], which does
minimal changes to Cilium source code, mostly around SEC() annotations
and BPF map definitions.
[0] https://github.com/cilium/cilium/
[1] https://github.com/anakryiko/cilium/commits/libbpf-friendliness
Fixes: b5dc0163d8 ("bpf: precise scalar_value tracking")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221104163649.121784-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f5e477a861 ]
For the case where allow_ptr_leaks is false, code is checking whether
slot type is STACK_INVALID and STACK_SPILL and rejecting other cases.
This is a consequence of incorrectly checking for register type instead
of the slot type (NOT_INIT and SCALAR_VALUE respectively). Fix the
check.
Fixes: 01f810ace9 ("bpf: Allow variable-offset stack access")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221103191013.1236066-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4d8586e046 ]
The 'padding' field of the 'rchan_buf' structure is an array of 'size_t'
elements, but the memory is allocated for an array of 'size_t *' elements.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Link: https://lkml.kernel.org/r/20221129092002.3538384-1-Ilia.Gavrilov@infotecs.ru
Fixes: b86ff981a8 ("[PATCH] relay: migrate from relayfs to a generic relay API")
Signed-off-by: Ilia.Gavrilov <Ilia.Gavrilov@infotecs.ru>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: wuchi <wuchi.zero@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6f855b39e4 ]
The DYING/STARTING callbacks are not expected to fail. However, as reported
by Derek, buggy drivers such as tboot are still free to return errors
within those sections, which halts the hot(un)plug and leaves the CPU in an
unrecoverable state.
As there is no rollback possible, only log the failures and proceed with
the following steps.
This restores the hotplug behaviour prior to commit 453e410851
("cpu/hotplug: Add cpuhp_invoke_callback_range()")
Fixes: 453e410851 ("cpu/hotplug: Add cpuhp_invoke_callback_range()")
Reported-by: Derek Dolney <z23@posteo.net>
Signed-off-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Derek Dolney <z23@posteo.net>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215867
Link: https://lore.kernel.org/r/20220927101259.1149636-1-vdonnefort@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 64ea6e44f8 ]
Writing the current state back in hotplug/target calls cpu_down()
which will set cpu dying even when it isn't and then nothing will
ever clear it. A stress test that reads values and writes them back
for all cpu device files in sysfs will trigger the BUG() in
select_fallback_rq once all cpus are marked as dying.
kernel/cpu.c::target_store()
...
if (st->state < target)
ret = cpu_up(dev->id, target);
else
ret = cpu_down(dev->id, target);
cpu_down() -> cpu_set_state()
bool bringup = st->state < target;
...
if (cpu_dying(cpu) != !bringup)
set_cpu_dying(cpu, !bringup);
Fix this by letting state==target fall through in the target_store()
conditional. Also make sure st->target == target in that case.
Fixes: 757c989b99 ("cpu/hotplug: Make target state writeable")
Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20221117162329.3164999-2-pauld@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 90d7588967 ]
Commit ca16d5bee5 ("futex: Prevent robust futex exit race") addressed
two cases when tasks waiting on a robust non-PI futex remained blocked
despite the futex not being owned anymore:
* if the owner died after writing zero to the futex word, but before
waking up a waiter
* if a task waiting on the futex was woken up, but died before updating
the futex word (effectively swallowing the notification without acting
on it)
In the second case, the task could be woken up either by the previous
owner (after the futex word was reset to zero) or by the kernel (after
the OWNER_DIED bit was set and the TID part of the futex word was reset
to zero) if the previous owner died without the resetting the futex.
Because the referenced commit wakes up a potential waiter only if the
whole futex word is zero, the latter subcase remains unaddressed.
Fix this by looking only at the TID part of the futex when deciding
whether a wake up is needed.
Fixes: ca16d5bee5 ("futex: Prevent robust futex exit race")
Signed-off-by: Alexey Izbyshev <izbyshev@ispras.ru>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221111215439.248185-1-izbyshev@ispras.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9049e1ca41 ]
Fault injection tests trigger warnings like this:
kernfs: can not remove 'chip_name', no directory
WARNING: CPU: 0 PID: 253 at fs/kernfs/dir.c:1616 kernfs_remove_by_name_ns+0xce/0xe0
RIP: 0010:kernfs_remove_by_name_ns+0xce/0xe0
Call Trace:
<TASK>
remove_files.isra.1+0x3f/0xb0
sysfs_remove_group+0x68/0xe0
sysfs_remove_groups+0x41/0x70
__kobject_del+0x45/0xc0
kobject_del+0x29/0x40
free_desc+0x42/0x70
irq_free_descs+0x5e/0x90
The reason is that the interrupt descriptor sysfs handling does not roll
back on a failing kobject_add() during allocation. If the descriptor is
freed later on, kobject_del() is invoked with a not added kobject resulting
in the above warnings.
A proper rollback in case of a kobject_add() failure would be the straight
forward solution. But this is not possible due to the way how interrupt
descriptor sysfs handling works.
Interrupt descriptors are allocated before sysfs becomes available. So the
sysfs files for the early allocated descriptors are added later in the boot
process. At this point there can be nothing useful done about a failing
kobject_add(). For consistency the interrupt descriptor allocation always
treats kobject_add() failures as non-critical and just emits a warning.
To solve this problem, keep track in the interrupt descriptor whether
kobject_add() was successful or not and make the invocation of
kobject_del() conditional on that.
[ tglx: Massage changelog, comments and use a state bit. ]
Fixes: ecb3f394c5 ("genirq: Expose interrupt information through sysfs")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20221128151612.1786122-1-yangyingliang@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e8d7a90c08 ]
In pmu_dev_alloc(), when dev_set_name() failed, it will goto free_dev
and call put_device(pmu->dev) to release it.
However pmu->dev->release is assigned after this, which makes warning
and memleak.
Call dev_set_name() after pmu->dev->release = pmu_dev_release to fix it.
Device '(null)' does not have a release() function...
WARNING: CPU: 2 PID: 441 at drivers/base/core.c:2332 device_release+0x1b9/0x240
...
Call Trace:
<TASK>
kobject_put+0x17f/0x460
put_device+0x20/0x30
pmu_dev_alloc+0x152/0x400
perf_pmu_register+0x96b/0xee0
...
kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
unreferenced object 0xffff888014759000 (size 2048):
comm "modprobe", pid 441, jiffies 4294931444 (age 38.332s)
backtrace:
[<0000000005aed3b4>] kmalloc_trace+0x27/0x110
[<000000006b38f9b8>] pmu_dev_alloc+0x50/0x400
[<00000000735f17be>] perf_pmu_register+0x96b/0xee0
[<00000000e38477f1>] 0xffffffffc0ad8603
[<000000004e162216>] do_one_initcall+0xd0/0x4e0
...
Fixes: abe4340057 ("perf: Sysfs enumeration")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221111103653.91058-1-chenzhongjin@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6e5d7300cb ]
The actual maximum image size formula in hibernate_preallocate_memory()
is as follows:
max_size = (count - (size + PAGES_FOR_IO)) / 2
- 2 * DIV_ROUND_UP(reserved_size, PAGE_SIZE);
but the one in the kerneldoc comment of the function is different and
incorrect.
Fixes: ddeb648708 ("PM / Hibernate: Add sysfs knob to control size of memory for drivers")
Signed-off-by: xiongxin <xiongxin@kylinos.cn>
[ rjw: Subject and changelog rewrite ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a2e7f03ed2 ]
Use the new util_fits_cpu() to ensure migration margin and capacity
pressure are taken into account correctly when uclamp is being used
otherwise we will fail to consider CPUs as fitting in scenarios where
they should.
s/asym_fits_capacity/asym_fits_cpu/ to better reflect what it does now.
Fixes: b4c9c9f156 ("sched/fair: Prefer prev cpu in asymmetric wakeup path")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220804143609.515789-6-qais.yousef@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 740cf8a760 ]
Create an inline helper for conditional code to be only executed on
asymmetric CPU capacity systems. This makes these (currently ~10 and
future) conditions a lot more readable.
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20220729111305.1275158-2-dietmar.eggemann@arm.com
Stable-dep-of: a2e7f03ed2 ("sched/uclamp: Make asym_fits_capacity() use util_fits_cpu()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a7ba894821 ]
Since commit 89aafd67f2 ("sched/fair: Use prev instead of new target as recent_used_cpu"),
p->recent_used_cpu is unconditionnaly set with prev.
Fixes: 89aafd67f2 ("sched/fair: Use prev instead of new target as recent_used_cpu")
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/20210928103544.27489-1-vincent.guittot@linaro.org
Stable-dep-of: a2e7f03ed2 ("sched/uclamp: Make asym_fits_capacity() use util_fits_cpu()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b759caa1d9 ]
Use the new util_fits_cpu() to ensure migration margin and capacity
pressure are taken into account correctly when uclamp is being used
otherwise we will fail to consider CPUs as fitting in scenarios where
they should.
Fixes: b4c9c9f156 ("sched/fair: Prefer prev cpu in asymmetric wakeup path")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220804143609.515789-5-qais.yousef@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b48e16a697 ]
So that the new uclamp rules in regard to migration margin and capacity
pressure are taken into account correctly.
Fixes: a7008c07a5 ("sched/fair: Make task_fits_capacity() consider uclamp restrictions")
Co-developed-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220804143609.515789-3-qais.yousef@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 48d5e9daa8 ]
fits_capacity() verifies that a util is within 20% margin of the
capacity of a CPU, which is an attempt to speed up upmigration.
But when uclamp is used, this 20% margin is problematic because for
example if a task is boosted to 1024, then it will not fit on any CPU
according to fits_capacity() logic.
Or if a task is boosted to capacity_orig_of(medium_cpu). The task will
end up on big instead on the desired medium CPU.
Similar corner cases exist for uclamp and usage of capacity_of().
Slightest irq pressure on biggest CPU for example will make a 1024
boosted task look like it can't fit.
What we really want is for uclamp comparisons to ignore the migration
margin and capacity pressure, yet retain them for when checking the
_actual_ util signal.
For example, task p:
p->util_avg = 300
p->uclamp[UCLAMP_MIN] = 1024
Will fit a big CPU. But
p->util_avg = 900
p->uclamp[UCLAMP_MIN] = 1024
will not, this should trigger overutilized state because the big CPU is
now *actually* being saturated.
Similar reasoning applies to capping tasks with UCLAMP_MAX. For example:
p->util_avg = 1024
p->uclamp[UCLAMP_MAX] = capacity_orig_of(medium_cpu)
Should fit the task on medium cpus without triggering overutilized
state.
Inlined comments expand more on desired behavior in more scenarios.
Introduce new util_fits_cpu() function which encapsulates the new logic.
The new function is not used anywhere yet, but will be used to update
various users of fits_capacity() in later patches.
Fixes: af24bde8df ("sched/uclamp: Add uclamp support to energy_compute()")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220804143609.515789-2-qais.yousef@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ef8df9798d ]
task_util and capacity are comparable unsigned long values. There is no
need for an intermidiate implicit signed cast.
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20211207095755.859972-1-vincent.donnefort@arm.com
Stable-dep-of: 48d5e9daa8 ("sched/uclamp: Fix relationship between uclamp and migration margin")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 517e6a301f ]
Per syzbot it is possible for perf_pending_task() to run after the
event is free()'d. There are two related but distinct cases:
- the task_work was already queued before destroying the event;
- destroying the event itself queues the task_work.
The first cannot be solved using task_work_cancel() since
perf_release() itself might be called from a task_work (____fput),
which means the current->task_works list is already empty and
task_work_cancel() won't be able to find the perf_pending_task()
entry.
The simplest alternative is extending the perf_event lifetime to cover
the task_work.
The second is just silly, queueing a task_work while you know the
event is going away makes no sense and is easily avoided by
re-arranging how the event is marked STATE_DEAD and ensuring it goes
through STATE_OFF on the way down.
Reported-by: syzbot+9228d6098455bb209ec8@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Marco Elver <elver@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ed29b0b4fd ]
In preparation for splitting io_uring up a bit, move it into its own
top level directory. It didn't really belong in fs/ anyway, as it's
not a file system only API.
This adds io_uring/ and moves the core files in there, and updates the
MAINTAINERS file for the new location.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 998b30c394 ("io_uring: Fix a null-ptr-deref in io_tctx_exit_cb()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4a7ba45b1a upstream.
memcg_write_event_control() accesses the dentry->d_name of the specified
control fd to route the write call. As a cgroup interface file can't be
renamed, it's safe to access d_name as long as the specified file is a
regular cgroup file. Also, as these cgroup interface files can't be
removed before the directory, it's safe to access the parent too.
Prior to 347c4a8747 ("memcg: remove cgroup_event->cft"), there was a
call to __file_cft() which verified that the specified file is a regular
cgroupfs file before further accesses. The cftype pointer returned from
__file_cft() was no longer necessary and the commit inadvertently dropped
the file type check with it allowing any file to slip through. With the
invarients broken, the d_name and parent accesses can now race against
renames and removals of arbitrary files and cause use-after-free's.
Fix the bug by resurrecting the file type check in __file_cft(). Now that
cgroupfs is implemented through kernfs, checking the file operations needs
to go through a layer of indirection. Instead, let's check the superblock
and dentry type.
Link: https://lkml.kernel.org/r/Y5FRm/cfcKPGzWwl@slm.duckdns.org
Fixes: 347c4a8747 ("memcg: remove cgroup_event->cft")
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org> [3.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bce9332220 upstream.
proc_skip_spaces() seems to think it is working on C strings, and ends
up being just a wrapper around skip_spaces() with a really odd calling
convention.
Instead of basing it on skip_spaces(), it should have looked more like
proc_skip_char(), which really is the exact same function (except it
skips a particular character, rather than whitespace). So use that as
inspiration, odd coding and all.
Now the calling convention actually makes sense and works for the
intended purpose.
Reported-and-tested-by: Kyle Zeng <zengyhkyle@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e6cfaf34be upstream.
proc_get_long() is passed a size_t, but then assigns it to an 'int'
variable for the length. Let's not do that, even if our IO paths are
limited to MAX_RW_COUNT (exactly because of these kinds of type errors).
So do the proper test in the rigth type.
Reported-by: Kyle Zeng <zengyhkyle@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4313e5a613 upstream.
After 65536 dynamic events have been added and removed, the "type" field
of the event then uses the first type number that is available (not
currently used by other events). A type number is the identifier of the
binary blobs in the tracing ring buffer (known as events) to map them to
logic that can parse the binary blob.
The issue is that if a dynamic event (like a kprobe event) is traced and
is in the ring buffer, and then that event is removed (because it is
dynamic, which means it can be created and destroyed), if another dynamic
event is created that has the same number that new event's logic on
parsing the binary blob will be used.
To show how this can be an issue, the following can crash the kernel:
# cd /sys/kernel/tracing
# for i in `seq 65536`; do
echo 'p:kprobes/foo do_sys_openat2 $arg1:u32' > kprobe_events
# done
For every iteration of the above, the writing to the kprobe_events will
remove the old event and create a new one (with the same format) and
increase the type number to the next available on until the type number
reaches over 65535 which is the max number for the 16 bit type. After it
reaches that number, the logic to allocate a new number simply looks for
the next available number. When an dynamic event is removed, that number
is then available to be reused by the next dynamic event created. That is,
once the above reaches the max number, the number assigned to the event in
that loop will remain the same.
Now that means deleting one dynamic event and created another will reuse
the previous events type number. This is where bad things can happen.
After the above loop finishes, the kprobes/foo event which reads the
do_sys_openat2 function call's first parameter as an integer.
# echo 1 > kprobes/foo/enable
# cat /etc/passwd > /dev/null
# cat trace
cat-2211 [005] .... 2007.849603: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196
cat-2211 [005] .... 2007.849620: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196
cat-2211 [005] .... 2007.849838: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196
cat-2211 [005] .... 2007.849880: foo: (do_sys_openat2+0x0/0x130) arg1=4294967196
# echo 0 > kprobes/foo/enable
Now if we delete the kprobe and create a new one that reads a string:
# echo 'p:kprobes/foo do_sys_openat2 +0($arg2):string' > kprobe_events
And now we can the trace:
# cat trace
sendmail-1942 [002] ..... 530.136320: foo: (do_sys_openat2+0x0/0x240) arg1= cat-2046 [004] ..... 530.930817: foo: (do_sys_openat2+0x0/0x240) arg1="������������������������������������������������������������������������������������������������"
cat-2046 [004] ..... 530.930961: foo: (do_sys_openat2+0x0/0x240) arg1="������������������������������������������������������������������������������������������������"
cat-2046 [004] ..... 530.934278: foo: (do_sys_openat2+0x0/0x240) arg1="������������������������������������������������������������������������������������������������"
cat-2046 [004] ..... 530.934563: foo: (do_sys_openat2+0x0/0x240) arg1="������������������������������������������������������������������������������������������������"
bash-1515 [007] ..... 534.299093: foo: (do_sys_openat2+0x0/0x240) arg1="kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk���������@��4Z����;Y�����U
And dmesg has:
==================================================================
BUG: KASAN: use-after-free in string+0xd4/0x1c0
Read of size 1 at addr ffff88805fdbbfa0 by task cat/2049
CPU: 0 PID: 2049 Comm: cat Not tainted 6.1.0-rc6-test+ #641
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
Call Trace:
<TASK>
dump_stack_lvl+0x5b/0x77
print_report+0x17f/0x47b
kasan_report+0xad/0x130
string+0xd4/0x1c0
vsnprintf+0x500/0x840
seq_buf_vprintf+0x62/0xc0
trace_seq_printf+0x10e/0x1e0
print_type_string+0x90/0xa0
print_kprobe_event+0x16b/0x290
print_trace_line+0x451/0x8e0
s_show+0x72/0x1f0
seq_read_iter+0x58e/0x750
seq_read+0x115/0x160
vfs_read+0x11d/0x460
ksys_read+0xa9/0x130
do_syscall_64+0x3a/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc2e972ade2
Code: c0 e9 b2 fe ff ff 50 48 8d 3d b2 3f 0a 00 e8 05 f0 01 00 0f 1f 44 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 0f 05 <48> 3d 00 f0 ff ff 77 56 c3 0f 1f 44 00 00 48 83 ec 28 48 89 54 24
RSP: 002b:00007ffc64e687c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000020000 RCX: 00007fc2e972ade2
RDX: 0000000000020000 RSI: 00007fc2e980d000 RDI: 0000000000000003
RBP: 00007fc2e980d000 R08: 00007fc2e980c010 R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000020f00
R13: 0000000000000003 R14: 0000000000020000 R15: 0000000000020000
</TASK>
The buggy address belongs to the physical page:
page:ffffea00017f6ec0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5fdbb
flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0000000 0000000000000000 ffffea00017f6ec8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88805fdbbe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88805fdbbf00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805fdbbf80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88805fdbc000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88805fdbc080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
This was found when Zheng Yejian sent a patch to convert the event type
number assignment to use IDA, which gives the next available number, and
this bug showed up in the fuzz testing by Yujie Liu and the kernel test
robot. But after further analysis, I found that this behavior is the same
as when the event type numbers go past the 16bit max (and the above shows
that).
As modules have a similar issue, but is dealt with by setting a
"WAS_ENABLED" flag when a module event is enabled, and when the module is
freed, if any of its events were enabled, the ring buffer that holds that
event is also cleared, to prevent reading stale events. The same can be
done for dynamic events.
If any dynamic event that is being removed was enabled, then make sure the
buffers they were enabled in are now cleared.
Link: https://lkml.kernel.org/r/20221123171434.545706e3@gandalf.local.home
Link: https://lore.kernel.org/all/20221110020319.1259291-1-zhengyejian1@huawei.com/
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Depends-on: e18eb8783e ("tracing: Add tracing_reset_all_online_cpus_unlocked() function")
Depends-on: 5448d44c38 ("tracing: Add unified dynamic event framework")
Depends-on: 6212dd2968 ("tracing/kprobes: Use dyn_event framework for kprobe events")
Depends-on: 065e63f951 ("tracing: Only have rmmod clear buffers that its events were active in")
Depends-on: 575380da8b ("tracing: Only clear trace buffer on module unload if event was traced")
Fixes: 77b44d1b7c ("tracing/kprobes: Rename Kprobe-tracer to kprobe-event")
Reported-by: Zheng Yejian <zhengyejian1@huawei.com>
Reported-by: Yujie Liu <yujie.liu@intel.com>
Reported-by: kernel test robot <yujie.liu@intel.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef38c79a52 upstream.
commit 94eedf3dde ("tracing: Fix race where eprobes can be called before
the event") fixed an issue where if an event is soft disabled, and the
trigger is being added, there's a small window where the event sees that
there's a trigger but does not see that it requires reading the event yet,
and then calls the trigger with the record == NULL.
This could be solved with adding memory barriers in the hot path, or to
make sure that all the triggers requiring a record check for NULL. The
latter was chosen.
Commit 94eedf3dde set the eprobe trigger handle to check for NULL, but
the same needs to be done with histograms.
Link: https://lore.kernel.org/linux-trace-kernel/20221118211809.701d40c0f8a757b0df3c025a@kernel.org/
Link: https://lore.kernel.org/linux-trace-kernel/20221123164323.03450c3a@gandalf.local.home
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Reported-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 022632f6c4 upstream.
The duration type is a 64 long value, not an int. This was
causing some long noise to report wrong values.
Change the duration to a 64 bits value.
Link: https://lkml.kernel.org/r/a93d8a8378c7973e9c609de05826533c9e977939.1668692096.git.bristot@kernel.org
Cc: stable@vger.kernel.org
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Fixes: bce29ac9ce ("trace: Add osnoise tracer")
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 836e49e103 ]
bpf_selem_alloc function is used by inode_storage, sk_storage and
task_storage maps to set map value, for these map types, there may
be a spin lock in the map value, so if we use memcpy to copy the whole
map value from user, the spin lock field may be initialized incorrectly.
Since the spin lock field is zeroed by kzalloc, call copy_map_value
instead of memcpy to skip copying the spin lock field to fix it.
Fixes: 6ac99e8f23 ("bpf: Introduce bpf sk local storage")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/r/20221114134720.1057939-2-xukuohai@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 47df8a2f78 ]
Since commit bfea9a8574 ("bpf: Add name to struct bpf_ksym"), when
reporting subprog ksymbol to perf, prog name instead of subprog name is
used. The backtrace of bpf program with subprogs will be incorrect as
shown below:
ffffffffc02deace bpf_prog_e44a3057dcb151f8_overwrite+0x66
ffffffffc02de9f7 bpf_prog_e44a3057dcb151f8_overwrite+0x9f
ffffffffa71d8d4e trace_call_bpf+0xce
ffffffffa71c2938 perf_call_bpf_enter.isra.0+0x48
overwrite is the entry program and it invokes the overwrite_htab subprog
through bpf_loop, but in above backtrace, overwrite program just jumps
inside itself.
Fixing it by using subprog name when reporting subprog ksymbol. After
the fix, the output of perf script will be correct as shown below:
ffffffffc031aad2 bpf_prog_37c0bec7d7c764a4_overwrite_htab+0x66
ffffffffc031a9e7 bpf_prog_c7eb827ef4f23e71_overwrite+0x9f
ffffffffa3dd8d4e trace_call_bpf+0xce
ffffffffa3dc2938 perf_call_bpf_enter.isra.0+0x48
Fixes: bfea9a8574 ("bpf: Add name to struct bpf_ksym")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20221114095733.158588-1-houtao@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
From: Marc Zyngier <maz@kernel.org>
commit c48c8b829d upstream.
Although setting the affinity of an interrupt to a set of CPUs that doesn't
have any online CPU is generally frowned apon, there are a few limited
cases where such affinity is set from a CPUHP notifier, setting the
affinity to a CPU that isn't online yet.
The saving grace is that this is always done using the 'force' attribute,
which gives a hint that the affinity setting can be outside of the online
CPU mask and the callsite set this flag with the knowledge that the
underlying interrupt controller knows to handle it.
This restores the expected behaviour on Marek's system.
Fixes: 33de0aa4ba ("genirq: Always limit the affinity to online CPUs")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/4b7fc13c-887b-a664-26e8-45aed13f048a@samsung.com
Link: https://lore.kernel.org/r/20220414140011.541725-1-maz@kernel.org
Signed-off-by: Luiz Capitulino <luizcap@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Marc Zyngier <maz@kernel.org>
commit 33de0aa4ba upstream.
[ Fixed small conflicts due to the HK_FLAG_MANAGED_IRQ flag been
renamed on upstream ]
When booting with maxcpus=<small number> (or even loading a driver
while most CPUs are offline), it is pretty easy to observe managed
affinities containing a mix of online and offline CPUs being passed
to the irqchip driver.
This means that the irqchip cannot trust the affinity passed down
from the core code, which is a bit annoying and requires (at least
in theory) all drivers to implement some sort of affinity narrowing.
In order to address this, always limit the cpumask to the set of
online CPUs.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220405185040.206297-3-maz@kernel.org
Signed-off-by: Luiz Capitulino <luizcap@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Marc Zyngier <maz@kernel.org>
commit d802057c7c upstream.
[ This commit is almost a rewrite because it conflicts with Thomas
Gleixner's refactoring of this code in v5.17-rc1. I wasn't sure if
I should drop all the s-o-bs (including Mark's), but decided
to keep as the original commit ]
When booting with maxcpus=<small number>, interrupt controllers
such as the GICv3 ITS may not be able to satisfy the affinity of
some managed interrupts, as some of the HW resources are simply
not available.
The same thing happens when loading a driver using managed interrupts
while CPUs are offline.
In order to deal with this, do not try to activate such interrupt
if there is no online CPU capable of handling it. Instead, place
it in shutdown state. Once a capable CPU shows up, it will be
activated.
Reported-by: John Garry <john.garry@huawei.com>
Reported-by: David Decotigny <ddecotig@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: John Garry <john.garry@huawei.com>
Link: https://lore.kernel.org/r/20220405185040.206297-2-maz@kernel.org
Signed-off-by: Luiz Capitulino <luizcap@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 5dd7caf0bd ]
In __unregister_kprobe_top(), if the currently unregistered probe has
post_handler but other child probes of the aggrprobe do not have
post_handler, the post_handler of the aggrprobe is cleared. If this is
a ftrace-based probe, there is a problem. In later calls to
disarm_kprobe(), we will use kprobe_ftrace_ops because post_handler is
NULL. But we're armed with kprobe_ipmodify_ops. This triggers a WARN in
__disarm_kprobe_ftrace() and may even cause use-after-free:
Failed to disarm kprobe-ftrace at kernel_clone+0x0/0x3c0 (error -2)
WARNING: CPU: 5 PID: 137 at kernel/kprobes.c:1135 __disarm_kprobe_ftrace.isra.21+0xcf/0xe0
Modules linked in: testKprobe_007(-)
CPU: 5 PID: 137 Comm: rmmod Not tainted 6.1.0-rc4-dirty #18
[...]
Call Trace:
<TASK>
__disable_kprobe+0xcd/0xe0
__unregister_kprobe_top+0x12/0x150
? mutex_lock+0xe/0x30
unregister_kprobes.part.23+0x31/0xa0
unregister_kprobe+0x32/0x40
__x64_sys_delete_module+0x15e/0x260
? do_user_addr_fault+0x2cd/0x6b0
do_syscall_64+0x3a/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...]
For the kprobe-on-ftrace case, we keep the post_handler setting to
identify this aggrprobe armed with kprobe_ipmodify_ops. This way we
can disarm it correctly.
Link: https://lore.kernel.org/all/20221112070000.35299-1-lihuafei1@huawei.com/
Fixes: 0bc11ed5ab ("kprobes: Allow kprobes coexist with livepatch")
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 31029a8b2c ]
The function ring_buffer_nr_dirty_pages() was created to find out how many
pages are filled in the ring buffer. There's two running counters. One is
incremented whenever a new page is touched (pages_touched) and the other
is whenever a page is read (pages_read). The dirty count is the number
touched minus the number read. This is used to determine if a blocked task
should be woken up if the percentage of the ring buffer it is waiting for
is hit.
The problem is that it does not take into account dropped pages (when the
new writes overwrite pages that were not read). And then the dirty pages
will always be greater than the percentage.
This makes the "buffer_percent" file inaccurate, as the number of dirty
pages end up always being larger than the percentage, event when it's not
and this causes user space to be woken up more than it wants to be.
Add a new counter to keep track of lost pages, and include that in the
accounting of dirty pages so that it is actually accurate.
Link: https://lkml.kernel.org/r/20221021123013.55fb6055@gandalf.local.home
Fixes: 2c2b0a78b3 ("ring-buffer: Add percentage of ring buffer full to wake up reader")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bb88f96954 ]
To catch missing SIGTRAP we employ a WARN in __perf_event_overflow(),
which fires if pending_sigtrap was already set: returning to user space
without consuming pending_sigtrap, and then having the event fire again
would re-enter the kernel and trigger the WARN.
This, however, seemed to miss the case where some events not associated
with progress in the user space task can fire and the interrupt handler
runs before the IRQ work meant to consume pending_sigtrap (and generate
the SIGTRAP).
syzbot gifted us this stack trace:
| WARNING: CPU: 0 PID: 3607 at kernel/events/core.c:9313 __perf_event_overflow
| Modules linked in:
| CPU: 0 PID: 3607 Comm: syz-executor100 Not tainted 6.1.0-rc2-syzkaller-00073-g88619e77b33d #0
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
| RIP: 0010:__perf_event_overflow+0x498/0x540 kernel/events/core.c:9313
| <...>
| Call Trace:
| <TASK>
| perf_swevent_hrtimer+0x34f/0x3c0 kernel/events/core.c:10729
| __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
| __hrtimer_run_queues+0x1c6/0xfb0 kernel/time/hrtimer.c:1749
| hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
| local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline]
| __sysvec_apic_timer_interrupt+0x17c/0x640 arch/x86/kernel/apic/apic.c:1113
| sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1107
| asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
| <...>
| </TASK>
In this case, syzbot produced a program with event type
PERF_TYPE_SOFTWARE and config PERF_COUNT_SW_CPU_CLOCK. The hrtimer
manages to fire again before the IRQ work got a chance to run, all while
never having returned to user space.
Improve the WARN to check for real progress in user space: approximate
this by storing a 32-bit hash of the current IP into pending_sigtrap,
and if an event fires while pending_sigtrap still matches the previous
IP, we assume no progress (false negatives are possible given we could
return to user space and trigger again on the same IP).
Fixes: ca6c21327c ("perf: Fix missing SIGTRAPs")
Reported-by: syzbot+b8ded3e2e2c6adde4990@syzkaller.appspotmail.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221031093513.3032814-1-elver@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 94eedf3dde upstream.
The flag that tells the event to call its triggers after reading the event
is set for eprobes after the eprobe is enabled. This leads to a race where
the eprobe may be triggered at the beginning of the event where the record
information is NULL. The eprobe then dereferences the NULL record causing
a NULL kernel pointer bug.
Test for a NULL record to keep this from happening.
Link: https://lore.kernel.org/linux-trace-kernel/20221116192552.1066630-1-rafaelmendsr@gmail.com/
Link: https://lore.kernel.org/linux-trace-kernel/20221117214249.2addbe10@gandalf.local.home
Cc: Linux Trace Kernel <linux-trace-kernel@vger.kernel.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reported-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 42fb0a1e84 upstream.
Currently the way polling works on the ring buffer is broken. It will
return immediately if there's any data in the ring buffer whereas a read
will block until the watermark (defined by the tracefs buffer_percent file)
is hit.
That is, a select() or poll() will return as if there's data available,
but then the following read will block. This is broken for the way
select()s and poll()s are supposed to work.
Have the polling on the ring buffer also block the same way reads and
splice does on the ring buffer.
Link: https://lkml.kernel.org/r/20221020231427.41be3f26@gandalf.local.home
Cc: Linux Trace Kernel <linux-trace-kernel@vger.kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Primiano Tucci <primiano@google.com>
Cc: stable@vger.kernel.org
Fixes: 1e0d6714ac ("ring-buffer: Do not wake up a splice waiter when page is not full")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 56f4ca0a79 upstream.
rb_head_page_deactivate() expects cpu_buffer to contain a valid list of
->pages, so verify that the list is actually present before calling it.
Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.
Link: https://lkml.kernel.org/r/20221114143129.3534443-1-d-tatianin@yandex-team.ru
Cc: stable@vger.kernel.org
Fixes: 77ae365eca ("ring-buffer: make lockless")
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 19ba6c8af9 upstream.
The @ftrace_mod is allocated by kzalloc(), so both the members {prev,next}
of @ftrace_mode->list are NULL, it's not a valid state to call list_del().
If kstrdup() for @ftrace_mod->{func|module} fails, it goes to @out_free
tag and calls free_ftrace_mod() to destroy @ftrace_mod, then list_del()
will write prev->next and next->prev, where null pointer dereference
happens.
BUG: kernel NULL pointer dereference, address: 0000000000000008
Oops: 0002 [#1] PREEMPT SMP NOPTI
Call Trace:
<TASK>
ftrace_mod_callback+0x20d/0x220
? do_filp_open+0xd9/0x140
ftrace_process_regex.isra.51+0xbf/0x130
ftrace_regex_write.isra.52.part.53+0x6e/0x90
vfs_write+0xee/0x3a0
? __audit_filter_op+0xb1/0x100
? auditd_test_task+0x38/0x50
ksys_write+0xa5/0xe0
do_syscall_64+0x3a/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Kernel panic - not syncing: Fatal exception
So call INIT_LIST_HEAD() to initialize the list member to fix this issue.
Link: https://lkml.kernel.org/r/20221116015207.30858-1-xiujianfeng@huawei.com
Cc: stable@vger.kernel.org
Fixes: 673feb9d76 ("ftrace: Add :mod: caching infrastructure to trace_array")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bcea02b096 upstream.
If we can't allocate this size, try something smaller with half of the
size. Its order should be decreased by one instead of divided by two.
Link: https://lkml.kernel.org/r/20221109094434.84046-3-wangwensheng4@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Fixes: a790087554 ("ftrace: Allocate the mcount record pages as groups")
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 08948caebe upstream.
If the number of mcount entries is an integer multiple of
ENTRIES_PER_PAGE, the page count showing on the console would be wrong.
Link: https://lkml.kernel.org/r/20221109094434.84046-2-wangwensheng4@huawei.com
Cc: <mhiramat@kernel.org>
Cc: <mark.rutland@arm.com>
Cc: stable@vger.kernel.org
Fixes: 5821e1b74f ("function tracing: fix wrong pos computing when read buffer has been fulfilled")
Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 4b45cd81f7 ]
pcpu_freelist_populate() initializes nr_elems / num_possible_cpus() + 1
free nodes for some CPUs, and then possibly one CPU with fewer nodes,
followed by remaining cpus with 0 nodes. For example, when nr_elems == 256
and num_possible_cpus() == 32, CPU 0~27 each gets 9 free nodes, CPU 28 gets
4 free nodes, CPU 29~31 get 0 free nodes, while in fact each CPU should get
8 nodes equally.
This patch initializes nr_elems / num_possible_cpus() free nodes for each
CPU firstly, then allocates the remaining free nodes by one for each CPU
until no free nodes left.
Fixes: e19494edab ("bpf: introduce percpu_freelist")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221110122128.105214-1-xukuohai@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit eb86559a69 ]
kmemleak reports this issue:
unreferenced object 0xffff88817139d000 (size 2048):
comm "test_progs", pid 33246, jiffies 4307381979 (age 45851.820s)
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000045f075f0>] kmalloc_trace+0x27/0xa0
[<0000000098b7c90a>] __check_func_call+0x316/0x1230
[<00000000b4c3c403>] check_helper_call+0x172e/0x4700
[<00000000aa3875b7>] do_check+0x21d8/0x45e0
[<000000001147357b>] do_check_common+0x767/0xaf0
[<00000000b5a595b4>] bpf_check+0x43e3/0x5bc0
[<0000000011e391b1>] bpf_prog_load+0xf26/0x1940
[<0000000007f765c0>] __sys_bpf+0xd2c/0x3650
[<00000000839815d6>] __x64_sys_bpf+0x75/0xc0
[<00000000946ee250>] do_syscall_64+0x3b/0x90
[<0000000000506b7f>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
The root case here is: In function prepare_func_exit(), the callee is
not released in the abnormal scenario after "state->curframe--;". To
fix, move "state->curframe--;" to the very bottom of the function,
right when we free callee and reset frame[] pointer to NULL, as Andrii
suggested.
In addition, function __check_func_call() has a similar problem. In
the abnormal scenario before "state->curframe++;", the callee also
should be released by free_func_state().
Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Fixes: fd978bf7fd ("bpf: Add reference tracking to verifier")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Link: https://lore.kernel.org/r/1667884291-15666-1-git-send-email-wangyufen@huawei.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f1db20814a ]
Some helper functions will allocate memory. To avoid memory leaks, the
verifier requires the eBPF program to release these memories by calling
the corresponding helper functions.
When a resource is released, all pointer registers corresponding to the
resource should be invalidated. The verifier use release_references() to
do this job, by apply __mark_reg_unknown() to each relevant register.
It will give these registers the type of SCALAR_VALUE. A register that
will contain a pointer value at runtime, but of type SCALAR_VALUE, which
may allow the unprivileged user to get a kernel pointer by storing this
register into a map.
Using __mark_reg_not_init() while NOT allow_ptr_leaks can mitigate this
problem.
Fixes: fd978bf7fd ("bpf: Add reference tracking to verifier")
Signed-off-by: Youlin Li <liulin063@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20221103093440.3161-1-liulin063@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b239da3420 ]
For a lot of use cases in future patches, we will want to modify the
state of registers part of some same 'group' (e.g. same ref_obj_id). It
won't just be limited to releasing reference state, but setting a type
flag dynamically based on certain actions, etc.
Hence, we need a way to easily pass a callback to the function that
iterates over all registers in current bpf_verifier_state in all frames
upto (and including) the curframe.
While in C++ we would be able to easily use a lambda to pass state and
the callback together, sadly we aren't using C++ in the kernel. The next
best thing to avoid defining a function for each case seems like
statement expressions in GNU C. The kernel already uses them heavily,
hence they can passed to the macro in the style of a lambda. The
statement expression will then be substituted in the for loop bodies.
Variables __state and __reg are set to current bpf_func_state and reg
for each invocation of the expression inside the passed in verifier
state.
Then, convert mark_ptr_or_null_regs, clear_all_pkt_pointers,
release_reference, find_good_pkt_pointers, find_equal_scalars to
use bpf_for_each_reg_in_vstate.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220904204145.3089-16-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: f1db20814a ("bpf: Fix wrong reg type conversion in release_reference()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 42378a9ca5 ]
If an error (NULL) is returned by krealloc(), callers of realloc_array()
were setting their allocation pointers to NULL, but on error krealloc()
does not touch the original allocation. This would result in a memory
resource leak. Instead, free the old allocation on the error handling
path.
The memory leak information is as follows as also reported by Zhengchao:
unreferenced object 0xffff888019801800 (size 256):
comm "bpf_repo", pid 6490, jiffies 4294959200 (age 17.170s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<00000000b211474b>] __kmalloc_node_track_caller+0x45/0xc0
[<0000000086712a0b>] krealloc+0x83/0xd0
[<00000000139aab02>] realloc_array+0x82/0xe2
[<00000000b1ca41d1>] grow_stack_state+0xfb/0x186
[<00000000cd6f36d2>] check_mem_access.cold+0x141/0x1341
[<0000000081780455>] do_check_common+0x5358/0xb350
[<0000000015f6b091>] bpf_check.cold+0xc3/0x29d
[<000000002973c690>] bpf_prog_load+0x13db/0x2240
[<00000000028d1644>] __sys_bpf+0x1605/0x4ce0
[<00000000053f29bd>] __x64_sys_bpf+0x75/0xb0
[<0000000056fedaf5>] do_syscall_64+0x35/0x80
[<000000002bd58261>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: c69431aab6 ("bpf: verifier: Improve function state reallocation")
Reported-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Bill Wendling <morbo@google.com>
Cc: Lorenz Bauer <oss@lmb.io>
Link: https://lore.kernel.org/bpf/20221029025433.2533810-1-keescook@chromium.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7433632c9f upstream.
On some machines the number of listed CPUs may be bigger than the actual
CPUs that exist. The tracing subsystem allocates a per_cpu directory with
access to the per CPU ring buffer via a cpuX file. But to save space, the
ring buffer will only allocate buffers for online CPUs, even though the
CPU array will be as big as the nr_cpu_ids.
With the addition of waking waiters on the ring buffer when closing the
file, the ring_buffer_wake_waiters() now needs to make sure that the
buffer is allocated (with the irq_work allocated with it) before trying to
wake waiters, as it will cause a NULL pointer dereference.
While debugging this, I added a NULL check for the buffer itself (which is
OK to do), and also NULL pointer checks against buffer->buffers (which is
not fine, and will WARN) as well as making sure the CPU number passed in
is within the nr_cpu_ids (which is also not fine if it isn't).
Link: https://lore.kernel.org/all/87h6zklb6n.wl-tiwai@suse.de/
Link: https://lore.kernel.org/all/CAM6Wdxc0KRJMXVAA0Y=u6Jh2V=uWB-_Fn6M4xRuNppfXzL1mUg@mail.gmail.com/
Link: https://lkml.kernel.org/linux-trace-kernel/20221101191009.1e7378c8@rorschach.local.home
Cc: stable@vger.kernel.org
Cc: Steven Noonan <steven.noonan@gmail.com>
Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=1204705
Reported-by: Takashi Iwai <tiwai@suse.de>
Reported-by: Roland Ruckerbauer <roland.rucky@gmail.com>
Fixes: f3ddb74ad0 ("tracing: Wake up ring buffer waiters on closing of the file")
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4a6f316d68 upstream.
In aggregate kprobe case, when arm_kprobe failed,
we need set the kp->flags with KPROBE_FLAG_DISABLED again.
If not, the 'kp' kprobe will been considered as enabled
but it actually not enabled.
Link: https://lore.kernel.org/all/20220902155820.34755-1-liq3ea@163.com/
Fixes: 12310e3437 ("kprobes: Propagate error from arm_kprobe_ftrace()")
Cc: stable@vger.kernel.org
Signed-off-by: Li Qiang <liq3ea@163.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0e792b89e6 upstream.
KASAN reported a use-after-free with ftrace ops [1]. It was found from
vmcore that perf had registered two ops with the same content
successively, both dynamic. After unregistering the second ops, a
use-after-free occurred.
In ftrace_shutdown(), when the second ops is unregistered, the
FTRACE_UPDATE_CALLS command is not set because there is another enabled
ops with the same content. Also, both ops are dynamic and the ftrace
callback function is ftrace_ops_list_func, so the
FTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value
of 'command' will be 0 and ftrace_shutdown() will skip the rcu
synchronization.
However, ftrace may be activated. When the ops is released, another CPU
may be accessing the ops. Add the missing synchronization to fix this
problem.
[1]
BUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline]
BUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049
Read of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468
CPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132
show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b4/0x248 lib/dump_stack.c:118
print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387
__kasan_report mm/kasan/report.c:547 [inline]
kasan_report+0x118/0x210 mm/kasan/report.c:564
check_memory_region_inline mm/kasan/generic.c:187 [inline]
__asan_load8+0x98/0xc0 mm/kasan/generic.c:253
__ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline]
ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049
ftrace_graph_call+0x0/0x4
__might_sleep+0x8/0x100 include/linux/perf_event.h:1170
__might_fault mm/memory.c:5183 [inline]
__might_fault+0x58/0x70 mm/memory.c:5171
do_strncpy_from_user lib/strncpy_from_user.c:41 [inline]
strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139
getname_flags+0xb0/0x31c fs/namei.c:149
getname+0x2c/0x40 fs/namei.c:209
[...]
Allocated by task 14445:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:48
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc mm/kasan/common.c:479 [inline]
__kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449
kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493
kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950
kmalloc include/linux/slab.h:563 [inline]
kzalloc include/linux/slab.h:675 [inline]
perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230
perf_event_alloc kernel/events/core.c:11733 [inline]
__do_sys_perf_event_open kernel/events/core.c:11831 [inline]
__se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723
__arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723
[...]
Freed by task 14445:
kasan_save_stack+0x24/0x50 mm/kasan/common.c:48
kasan_set_track+0x24/0x34 mm/kasan/common.c:56
kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358
__kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437
__kasan_slab_free mm/kasan/common.c:445 [inline]
kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446
slab_free_hook mm/slub.c:1569 [inline]
slab_free_freelist_hook mm/slub.c:1608 [inline]
slab_free mm/slub.c:3179 [inline]
kfree+0x12c/0xc10 mm/slub.c:4176
perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434
perf_event_alloc kernel/events/core.c:11733 [inline]
__do_sys_perf_event_open kernel/events/core.c:11831 [inline]
__se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723
[...]
Link: https://lore.kernel.org/linux-trace-kernel/20221103031010.166498-1-lihuafei1@huawei.com
Fixes: edb096e007 ("ftrace: Fix memleak when unregistering dynamic ops when tracing disabled")
Cc: stable@vger.kernel.org
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Li Huafei <lihuafei1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 85850af4fc ]
Hybrid sleep is currently hardcoded to only operate with S3 even
on systems that might not support it.
Instead of assuming this mode is what the user wants to use, for
hybrid sleep follow the setting of `mem_sleep_current` which
will respect mem_sleep_default kernel command line and policy
decisions made by the presence of the FADT low power idle bit.
Fixes: 81d45bdf89 ("PM / hibernate: Untangle power_down()")
Reported-and-tested-by: kolAflash <kolAflash@kolahilft.de>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216574
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e705968dd6 ]
In commit 97886d9dcd ("sched: Migration changes for core scheduling"),
sched_group_cookie_match() was added to help determine if a cookie
matches the core state.
However, while it iterates the SMT group, it fails to actually use the
RQ for each of the CPUs iterated, use cpu_rq(cpu) instead of rq to fix
things.
Fixes: 97886d9dcd ("sched: Migration changes for core scheduling")
Signed-off-by: Lin Shengwang <linshengwang1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221008022709.642-1-linshengwang1@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ca6c21327c ]
Marco reported:
Due to the implementation of how SIGTRAP are delivered if
perf_event_attr::sigtrap is set, we've noticed 3 issues:
1. Missing SIGTRAP due to a race with event_sched_out() (more
details below).
2. Hardware PMU events being disabled due to returning 1 from
perf_event_overflow(). The only way to re-enable the event is
for user space to first "properly" disable the event and then
re-enable it.
3. The inability to automatically disable an event after a
specified number of overflows via PERF_EVENT_IOC_REFRESH.
The worst of the 3 issues is problem (1), which occurs when a
pending_disable is "consumed" by a racing event_sched_out(), observed
as follows:
CPU0 | CPU1
--------------------------------+---------------------------
__perf_event_overflow() |
perf_event_disable_inatomic() |
pending_disable = CPU0 | ...
| _perf_event_enable()
| event_function_call()
| task_function_call()
| /* sends IPI to CPU0 */
<IPI> | ...
__perf_event_enable() +---------------------------
ctx_resched()
task_ctx_sched_out()
ctx_sched_out()
group_sched_out()
event_sched_out()
pending_disable = -1
</IPI>
<IRQ-work>
perf_pending_event()
perf_pending_event_disable()
/* Fails to send SIGTRAP because no pending_disable! */
</IRQ-work>
In the above case, not only is that particular SIGTRAP missed, but also
all future SIGTRAPs because 'event_limit' is not reset back to 1.
To fix, rework pending delivery of SIGTRAP via IRQ-work by introduction
of a separate 'pending_sigtrap', no longer using 'event_limit' and
'pending_disable' for its delivery.
Additionally; and different to Marco's proposed patch:
- recognise that pending_disable effectively duplicates oncpu for
the case where it is set. As such, change the irq_work handler to
use ->oncpu to target the event and use pending_* as boolean toggles.
- observe that SIGTRAP targets the ctx->task, so the context switch
optimization that carries contexts between tasks is invalid. If
the irq_work were delayed enough to hit after a context switch the
SIGTRAP would be delivered to the wrong task.
- observe that if the event gets scheduled out
(rotation/migration/context-switch/...) the irq-work would be
insufficient to deliver the SIGTRAP when the event gets scheduled
back in (the irq-work might still be pending on the old CPU).
Therefore have event_sched_out() convert the pending sigtrap into a
task_work which will deliver the signal at return_to_user.
Fixes: 97ba62b278 ("perf: Add support for SIGTRAP on perf events")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Debugged-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Marco Elver <elver@google.com>
Debugged-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Marco Elver <elver@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a541a9559b ]
The ftrace_boot_snapshot and alloc_snapshot cmdline options allocate the
snapshot buffer at boot up for use later. The ftrace_boot_snapshot in
particular requires the snapshot to be allocated because it will take a
snapshot at the end of boot up allowing to see the traces that happened
during boot so that it's not lost when user space takes over.
When a tracer is registered (started) there's a path that checks if it
requires the snapshot buffer or not, and if it does not and it was
allocated it will do a synchronization and free the snapshot buffer.
This is only required if the previous tracer was using it for "max
latency" snapshots, as it needs to make sure all max snapshots are
complete before freeing. But this is only needed if the previous tracer
was using the snapshot buffer for latency (like irqoff tracer and
friends). But it does not make sense to free it, if the previous tracer
was not using it, and the snapshot was allocated by the cmdline
parameters. This basically takes away the point of allocating it in the
first place!
Note, the allocated snapshot worked fine for just trace events, but fails
when a tracer is enabled on the cmdline.
Further investigation, this goes back even further and it does not require
a tracer on the cmdline to fail. Simply enable snapshots and then enable a
tracer, and it will remove the snapshot.
Link: https://lkml.kernel.org/r/20221005113757.041df7fe@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: 45ad21ca55 ("tracing: Have trace_array keep track if snapshot buffer is allocated")
Reported-by: Ross Zwisler <zwisler@kernel.org>
Tested-by: Ross Zwisler <zwisler@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f4b0d31809 ]
Two conditional compilation directives "#ifdef CONFIG_TRACER_MAX_TRACE"
are used consecutively, and no other code in between. Simplify conditional
the compilation code and only use one "#ifdef CONFIG_TRACER_MAX_TRACE".
Link: https://lkml.kernel.org/r/20220602140613.545069-1-sunliming@kylinos.cn
Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Stable-dep-of: a541a9559b ("tracing: Do not free snapshot if tracer is on cmdline")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 977ef30a7d upstream.
Starting with GCC 12.1, the created .gcda format can't be read by gcov
tool. There are 2 significant changes to the .gcda file format that
need to be supported:
a) [gcov: Use system IO buffering]
(23eb66d1d46a34cb28c4acbdf8a1deb80a7c5a05) changed that all sizes in
the format are in bytes and not in words (4B)
b) [gcov: make profile merging smarter]
(72e0c742bd01f8e7e6dcca64042b9ad7e75979de) add a new checksum to the
file header.
Tested with GCC 7.5, 10.4, 12.2 and the current master.
Link: https://lkml.kernel.org/r/624bda92-f307-30e9-9aaa-8cc678b2dfb2@suse.cz
Signed-off-by: Martin Liska <mliska@suse.cz>
Tested-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit fcd53c8a4d ]
Kernels built with CONFIG_PROVE_RCU=y and CONFIG_DEBUG_LOCK_ALLOC=y
attempt to emit a warning when the synchronize_rcu_tasks_generic()
function is called during early boot while the rcu_scheduler_active
variable is RCU_SCHEDULER_INACTIVE. However the warnings is not
actually be printed because the debug_lockdep_rcu_enabled() returns
false, exactly because the rcu_scheduler_active variable is still equal
to RCU_SCHEDULER_INACTIVE.
This commit therefore replaces RCU_LOCKDEP_WARN() with WARN_ONCE()
to force these warnings to actually be printed.
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 093590c16b ]
The fill_page_cache_func() function allocates couple of pages to store
kvfree_rcu_bulk_data structures. This is a lightweight (GFP_NORETRY)
allocation which can fail under memory pressure. The function will,
however keep retrying even when the previous attempt has failed.
This retrying is in theory correct, but in practice the allocation is
invoked from workqueue context, which means that if the memory reclaim
gets stuck, these retries can hog the worker for quite some time.
Although the workqueues subsystem automatically adjusts concurrency, such
adjustment is not guaranteed to happen until the worker context sleeps.
And the fill_page_cache_func() function's retry loop is not guaranteed
to sleep (see the should_reclaim_retry() function).
And we have seen this function cause workqueue lockups:
kernel: BUG: workqueue lockup - pool cpus=93 node=1 flags=0x1 nice=0 stuck for 32s!
[...]
kernel: pool 74: cpus=37 node=0 flags=0x1 nice=0 hung=32s workers=2 manager: 2146
kernel: pwq 498: cpus=249 node=1 flags=0x1 nice=0 active=4/256 refcnt=5
kernel: in-flight: 1917:fill_page_cache_func
kernel: pending: dbs_work_handler, free_work, kfree_rcu_monitor
Originally, we thought that the root cause of this lockup was several
retries with direct reclaim, but this is not yet confirmed. Furthermore,
we have seen similar lockups without any heavy memory pressure. This
suggests that there are other factors contributing to these lockups.
However, it is not really clear that endless retries are desireable.
So let's make the fill_page_cache_func() function back off after
allocation failure.
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 621189a1fe ]
Kernels built with PREEMPT_RCU=y and RCU_STRICT_GRACE_PERIOD=y trigger
irq-work from rcu_read_unlock(), and the resulting irq-work handler
invokes rcu_preempt_deferred_qs_handle(). The point of this triggering
is to force grace periods to end quickly in order to give tools like KASAN
a better chance of detecting RCU usage bugs such as leaking RCU-protected
pointers out of an RCU read-side critical section.
However, this irq-work triggering is unconditional. This works, but
there is no point in doing this irq-work unless the current grace period
is waiting on the running CPU or task, which is not the common case.
After all, in the common case there are many rcu_read_unlock() calls
per CPU per grace period.
This commit therefore triggers the irq-work only when the current grace
period is waiting on the running CPU or task.
This change was tested as follows on a four-CPU system:
echo rcu_preempt_deferred_qs_handler > /sys/kernel/debug/tracing/set_ftrace_filter
echo 1 > /sys/kernel/debug/tracing/function_profile_enabled
insmod rcutorture.ko
sleep 20
rmmod rcutorture.ko
echo 0 > /sys/kernel/debug/tracing/function_profile_enabled
echo > /sys/kernel/debug/tracing/set_ftrace_filter
This procedure produces results in this per-CPU set of files:
/sys/kernel/debug/tracing/trace_stat/function*
Sample output from one of these files is as follows:
Function Hit Time Avg s^2
-------- --- ---- --- ---
rcu_preempt_deferred_qs_handle 838746 182650.3 us 0.217 us 0.004 us
The baseline sum of the "Hit" values (the number of calls to this
function) was 3,319,015. With this commit, that sum was 1,140,359,
for a 2.9x reduction. The worst-case variance across the CPUs was less
than 25%, so this large effect size is statistically significant.
The raw data is available in the Link: URL.
Link: https://lore.kernel.org/all/20220808022626.12825-1-qiang1.zhang@intel.com/
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 99ee9317a1 ]
There is a recursive lock on the cpu_hotplug_lock.
In kernel/trace/trace_osnoise.c:<start/stop>_per_cpu_kthreads:
- start_per_cpu_kthreads calls cpus_read_lock() and if
start_kthreads returns a error it will call stop_per_cpu_kthreads.
- stop_per_cpu_kthreads then calls cpus_read_lock() again causing
deadlock.
Fix this by calling cpus_read_unlock() before calling
stop_per_cpu_kthreads. This behavior can also be seen in commit
f46b16520a ("trace/hwlat: Implement the per-cpu mode").
This error was noticed during the LTP ftrace-stress-test:
WARNING: possible recursive locking detected
--------------------------------------------
sh/275006 is trying to acquire lock:
ffffffffb02f5400 (cpu_hotplug_lock){++++}-{0:0}, at: stop_per_cpu_kthreads
but task is already holding lock:
ffffffffb02f5400 (cpu_hotplug_lock){++++}-{0:0}, at: start_per_cpu_kthreads
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(cpu_hotplug_lock);
lock(cpu_hotplug_lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by sh/275006:
#0: ffff8881023f0470 (sb_writers#24){.+.+}-{0:0}, at: ksys_write
#1: ffffffffb084f430 (trace_types_lock){+.+.}-{3:3}, at: rb_simple_write
#2: ffffffffb02f5400 (cpu_hotplug_lock){++++}-{0:0}, at: start_per_cpu_kthreads
Link: https://lkml.kernel.org/r/20220919144932.3064014-1-npache@redhat.com
Fixes: c8895e271f ("trace/osnoise: Support hotplug operations")
Signed-off-by: Nico Pache <npache@redhat.com>
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d8ef45d66c ]
For now, this selftest module can only work in x86 because of the
kprobe cmd was fixed use of x86 registers.
This patch adapted to register names under arm and riscv, So that
this module can be worked on those platform.
Link: https://lkml.kernel.org/r/20220919125629.238242-3-zouyipeng@huawei.com
Cc: <linux-riscv@lists.infradead.org>
Cc: <mingo@redhat.com>
Cc: <paul.walmsley@sifive.com>
Cc: <palmer@dabbelt.com>
Cc: <aou@eecs.berkeley.edu>
Cc: <zanussi@kernel.org>
Cc: <liaochang1@huawei.com>
Cc: <chris.zjh@huawei.com>
Fixes: 64836248dd ("tracing: Add kprobe event command generation test module")
Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ec5fbdfb99 ]
Previously, update_tasks_cpumask() is not supposed to be called with
top cpuset. With cpuset partition that takes CPUs away from the top
cpuset, adjusting the cpus_mask of the tasks in the top cpuset is
necessary. Percpu kthreads, however, are ignored.
Fixes: ee8dde0cd2 ("cpuset: Add new v2 cpuset.sched.partition flag")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 74e4b956eb ]
cgroup_get_from_path() is not widely used function. Its callers presume
the path is resolved under cgroup namespace. (There is one caller
currently and resolving in init NS won't make harm (netfilter). However,
future users may be subject to different effects when resolving
globally.)
Since, there's currently no use for the global resolution, modify the
existing function to take cgroup NS into account.
Fixes: a79a908fd2 ("cgroup: introduce cgroup namespaces")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 83c10cc362 ]
The documentation for find_vpid() clearly states:
"Must be called with the tasklist_lock or rcu_read_lock() held."
Presently we do neither for find_vpid() instance in bpf_task_fd_query().
Add proper rcu_read_lock/unlock() to fix the issue.
Fixes: 41bdc4b40e ("bpf: introduce bpf subcommand BPF_TASK_FD_QUERY")
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220912133855.1218900-1-lee@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a37a32583e ]
When trying to finish resolving a struct member, btf_struct_resolve
saves the member type id in a u16 temporary variable. This truncates
the 32 bit type id value if it exceeds UINT16_MAX.
As a result, structs that have members with type ids > UINT16_MAX and
which need resolution will fail with a message like this:
[67414] STRUCT ff_device size=120 vlen=12
effect_owners type_id=67434 bits_offset=960 Member exceeds struct_size
Fix this by changing the type of last_member_type_id to u32.
Fixes: a0791f0df7 ("bpf: fix BTF limits")
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Lorenz Bauer <oss@lmb.io>
Link: https://lore.kernel.org/r/20220910110120.339242-1-oss@lmb.io
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 197827a05e ]
Now migrate_disable() does not disable preemption and under some
architectures (e.g. arm64) __this_cpu_{inc|dec|inc_return} are neither
preemption-safe nor IRQ-safe, so for fully preemptible kernel concurrent
lookups or updates on the same task local storage and on the same CPU
may make bpf_task_storage_busy be imbalanced, and
bpf_task_storage_trylock() on the specific cpu will always fail.
Fixing it by using this_cpu_{inc|dec|inc_return} when manipulating
bpf_task_storage_busy.
Fixes: bc235cdb42 ("bpf: Prevent deadlock from recursive bpf_task_storage_[get|delete]")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20220901061938.3789460-2-houtao@huaweicloud.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 66a7a92e4d ]
In __htab_map_lookup_and_delete_batch() if htab_lock_bucket() returns
-EBUSY, it will go to next bucket. Going to next bucket may not only
skip the elements in current bucket silently, but also incur
out-of-bound memory access or expose kernel memory to userspace if
current bucket_cnt is greater than bucket_size or zero.
Fixing it by stopping batch operation and returning -EBUSY when
htab_lock_bucket() fails, and the application can retry or skip the busy
batch as needed.
Fixes: 20b6cc34ea ("bpf: Avoid hashtab deadlock with map_locked")
Reported-by: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20220831042629.130006-3-houtao@huaweicloud.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2775da2162 ]
Per-cpu htab->map_locked is used to prohibit the concurrent accesses
from both NMI and non-NMI contexts. But since commit 74d862b682
("sched: Make migrate_disable/enable() independent of RT"),
migrate_disable() is also preemptible under CONFIG_PREEMPT case, so now
map_locked also disallows concurrent updates from normal contexts
(e.g. userspace processes) unexpectedly as shown below:
process A process B
htab_map_update_elem()
htab_lock_bucket()
migrate_disable()
/* return 1 */
__this_cpu_inc_return()
/* preempted by B */
htab_map_update_elem()
/* the same bucket as A */
htab_lock_bucket()
migrate_disable()
/* return 2, so lock fails */
__this_cpu_inc_return()
return -EBUSY
A fix that seems feasible is using in_nmi() in htab_lock_bucket() and
only checking the value of map_locked for nmi context. But it will
re-introduce dead-lock on bucket lock if htab_lock_bucket() is re-entered
through non-tracing program (e.g. fentry program).
One cannot use preempt_disable() to fix this issue as htab_use_raw_lock
being false causes the bucket lock to be a spin lock which can sleep and
does not work with preempt_disable().
Therefore, use migrate_disable() when using the spinlock instead of
preempt_disable() and defer fixing concurrent updates to when the kernel
has its own BPF memory allocator.
Fixes: 74d862b682 ("sched: Make migrate_disable/enable() independent of RT")
Reviewed-by: Hao Luo <haoluo@google.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20220831042629.130006-2-houtao@huaweicloud.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9d9d00ac29 ]
Currently, verifier verifies callback functions (sync and async) as if
they will be executed once, (i.e. it explores execution state as if the
function was being called once). The next insn to explore is set to
start of subprog and the exit from nested frame is handled using
curframe > 0 and prepare_func_exit. In case of async callback it uses a
customized variant of push_stack simulating a kind of branch to set up
custom state and execution context for the async callback.
While this approach is simple and works when callback really will be
executed only once, it is unsafe for all of our current helpers which
are for_each style, i.e. they execute the callback multiple times.
A callback releasing acquired references of the caller may do so
multiple times, but currently verifier sees it as one call inside the
frame, which then returns to caller. Hence, it thinks it released some
reference that the cb e.g. got access through callback_ctx (register
filled inside cb from spilled typed register on stack).
Similarly, it may see that an acquire call is unpaired inside the
callback, so the caller will copy the reference state of callback and
then will have to release the register with new ref_obj_ids. But again,
the callback may execute multiple times, but the verifier will only
account for acquired references for a single symbolic execution of the
callback, which will cause leaks.
Note that for async callback case, things are different. While currently
we have bpf_timer_set_callback which only executes it once, even for
multiple executions it would be safe, as reference state is NULL and
check_reference_leak would force program to release state before
BPF_EXIT. The state is also unaffected by analysis for the caller frame.
Hence async callback is safe.
Since we want the reference state to be accessible, e.g. for pointers
loaded from stack through callback_ctx's PTR_TO_STACK, we still have to
copy caller's reference_state to callback's bpf_func_state, but we
enforce that whatever references it adds to that reference_state has
been released before it hits BPF_EXIT. This requires introducing a new
callback_ref member in the reference state to distinguish between caller
vs callee references. Hence, check_reference_leak now errors out if it
sees we are in callback_fn and we have not released callback_ref refs.
Since there can be multiple nested callbacks, like frame 0 -> cb1 -> cb2
etc. we need to also distinguish between whether this particular ref
belongs to this callback frame or parent, and only error for our own, so
we store state->frameno (which is always non-zero for callbacks).
In short, callbacks can read parent reference_state, but cannot mutate
it, to be able to use pointers acquired by the caller. They must only
undo their changes (by releasing their own acquired_refs before
BPF_EXIT) on top of caller reference_state before returning (at which
point the caller and callback state will match anyway, so no need to
copy it back to caller).
Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220823013125.24938-1-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0934ae9977 upstream.
The follow commands caused a crash:
# cd /sys/kernel/tracing
# echo 's:open char file[]' > dynamic_events
# echo 'hist:keys=common_pid:file=filename:onchange($file).trace(open,$file)' > events/syscalls/sys_enter_openat/trigger'
# echo 1 > events/synthetic/open/enable
BOOM!
The problem is that the synthetic event field "char file[]" will read
the value given to it as a string without any memory checks to make sure
the address is valid. The above example will pass in the user space
address and the sythetic event code will happily call strlen() on it
and then strscpy() where either one will cause an oops when accessing
user space addresses.
Use the helper functions from trace_kprobe and trace_eprobe that can
read strings safely (and actually succeed when the address is from user
space and the memory is mapped in).
Now the above can show:
packagekitd-1721 [000] ...2. 104.597170: open: file=/usr/lib/rpm/fileattrs/cmake.attr
in:imjournal-978 [006] ...2. 104.599642: open: file=/var/lib/rsyslog/imjournal.state.tmp
packagekitd-1721 [000] ...2. 104.626308: open: file=/usr/lib/rpm/fileattrs/debuginfo.attr
Link: https://lkml.kernel.org/r/20221012104534.826549315@goodmis.org
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Fixes: bd82631d7c ("tracing: Add support for dynamic strings to synthetic events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2e9906f84f upstream.
Have the specific functions for kernel probes that read strings to inject
the "(fault)" name directly. trace_probes.c does this too (for uprobes)
but as the code to read strings are going to be used by synthetic events
(and perhaps other utilities), it simplifies the code by making sure those
other uses do not need to implement the "(fault)" name injection as well.
Link: https://lkml.kernel.org/r/20221012104534.644803645@goodmis.org
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Fixes: bd82631d7c ("tracing: Add support for dynamic strings to synthetic events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f1d3cbfaaf upstream.
The functions:
fetch_store_strlen_user()
fetch_store_strlen()
fetch_store_string_user()
fetch_store_string()
are identical in both trace_kprobe.c and trace_eprobe.c. Move them into
a new header file trace_probe_kernel.h to share it. This code will later
be used by the synthetic events as well.
Marked for stable as a fix for a crash in synthetic events requires it.
Link: https://lkml.kernel.org/r/20221012104534.467668078@goodmis.org
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Fixes: bd82631d7c ("tracing: Add support for dynamic strings to synthetic events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 01b2a52171 upstream.
If a process is waiting on the ring buffer for data, there currently isn't
a clean way to force it to wake up. Add an ioctl call that will force any
tasks that are waiting on the trace_pipe_raw file to wake up.
Link: https://lkml.kernel.org/r/20220929095029.117f913f@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: e30f53aad2 ("tracing: Do not busy wait in buffer splice")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2b0fd9a59b upstream.
When tracing is disabled, there's no reason that waiters should stay
waiting, wake them up, otherwise tasks get stuck when they should be
flushing the buffers.
Cc: stable@vger.kernel.org
Fixes: e30f53aad2 ("tracing: Do not busy wait in buffer splice")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f3ddb74ad0 upstream.
When the file that represents the ring buffer is closed, there may be
waiters waiting on more input from the ring buffer. Call
ring_buffer_wake_waiters() to wake up any waiters when the file is
closed.
Link: https://lkml.kernel.org/r/20220927231825.182416969@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: e30f53aad2 ("tracing: Do not busy wait in buffer splice")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c0a581d712 upstream.
It was found that some tracing functions in kernel/trace/trace.c acquire
an arch_spinlock_t with preemption and irqs enabled. An example is the
tracing_saved_cmdlines_size_read() function which intermittently causes
a "BUG: using smp_processor_id() in preemptible" warning when the LTP
read_all_proc test is run.
That can be problematic in case preemption happens after acquiring the
lock. Add the necessary preemption or interrupt disabling code in the
appropriate places before acquiring an arch_spinlock_t.
The convention here is to disable preemption for trace_cmdline_lock and
interupt for max_lock.
Link: https://lkml.kernel.org/r/20220922145622.1744826-1-longman@redhat.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: stable@vger.kernel.org
Fixes: a35873a099 ("tracing: Add conditional snapshot")
Fixes: 939c7a4f04 ("tracing: Introduce saved_cmdlines_size file")
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a0fcaaed0c upstream.
The ring buffer is broken up into sub buffers (currently of page size).
Each sub buffer has a pointer to its "tail" (the last event written to the
sub buffer). When a new event is requested, the tail is locally
incremented to cover the size of the new event. This is done in a way that
there is no need for locking.
If the tail goes past the end of the sub buffer, the process of moving to
the next sub buffer takes place. After setting the current sub buffer to
the next one, the previous one that had the tail go passed the end of the
sub buffer needs to be reset back to the original tail location (before
the new event was requested) and the rest of the sub buffer needs to be
"padded".
The race happens when a reader takes control of the sub buffer. As readers
do a "swap" of sub buffers from the ring buffer to get exclusive access to
the sub buffer, it replaces the "head" sub buffer with an empty sub buffer
that goes back into the writable portion of the ring buffer. This swap can
happen as soon as the writer moves to the next sub buffer and before it
updates the last sub buffer with padding.
Because the sub buffer can be released to the reader while the writer is
still updating the padding, it is possible for the reader to see the event
that goes past the end of the sub buffer. This can cause obvious issues.
To fix this, add a few memory barriers so that the reader definitely sees
the updates to the sub buffer, and also waits until the writer has put
back the "tail" of the sub buffer back to the last event that was written
on it.
To be paranoid, it will only spin for 1 second, otherwise it will
warn and shutdown the ring buffer code. 1 second should be enough as
the writer does have preemption disabled. If the writer doesn't move
within 1 second (with preemption disabled) something is horribly
wrong. No interrupt should last 1 second!
Link: https://lore.kernel.org/all/20220830120854.7545-1-jiazi.li@transsion.com/
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216369
Link: https://lkml.kernel.org/r/20220929104909.0650a36c@gandalf.local.home
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Fixes: c7b0930857 ("ring-buffer: prevent adding write in discarded area")
Reported-by: Jiazi.Li <jiazi.li@transsion.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7e9fbbb1b7 upstream.
On closing of a file that represents a ring buffer or flushing the file,
there may be waiters on the ring buffer that needs to be woken up and exit
the ring_buffer_wait() function.
Add ring_buffer_wake_waiters() to wake up the waiters on the ring buffer
and allow them to exit the wait loop.
Link: https://lkml.kernel.org/r/20220928133938.28dc2c27@gandalf.local.home
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 15693458c4 ("tracing/ring-buffer: Move poll wake ups into ring buffer code")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ec0bbc5ec5 upstream.
The wake up waiters only checks the "wakeup_full" variable and not the
"full_waiters_pending". The full_waiters_pending is set when a waiter is
added to the wait queue. The wakeup_full is only set when an event is
triggered, and it clears the full_waiters_pending to avoid multiple calls
to irq_work_queue().
The irq_work callback really needs to check both wakeup_full as well as
full_waiters_pending such that this code can be used to wake up waiters
when a file is closed that represents the ring buffer and the waiters need
to be woken up.
Link: https://lkml.kernel.org/r/20220927231824.209460321@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 15693458c4 ("tracing/ring-buffer: Move poll wake ups into ring buffer code")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3b19d614b6 upstream.
The logic to know when the shortest waiters on the ring buffer should be
woken up or not has uses a less than instead of a greater than compare,
which causes the shortest_full to actually be the longest.
Link: https://lkml.kernel.org/r/20220927231823.718039222@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 2c2b0a78b3 ("ring-buffer: Add percentage of ring buffer full to wake up reader")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fa8f4a8973 upstream.
If a page is partially read, and then the splice system call is run
against the ring buffer, it will always fail to read, no matter how much
is in the ring buffer. That's because the code path for a partial read of
the page does will fail if the "full" flag is set.
The splice system call wants full pages, so if the read of the ring buffer
is not yet full, it should return zero, and the splice will block. But if
a previous read was done, where the beginning has been consumed, it should
still be given to the splice caller if the rest of the page has been
written to.
This caused the splice command to never consume data in this scenario, and
let the ring buffer just fill up and lose events.
Link: https://lkml.kernel.org/r/20220927144317.46be6b80@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 8789a9e7df ("ring-buffer: read page interface")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0ce0638edf upstream.
When executing following commands like what document said, but the log
"#### all functions enabled ####" was not shown as expect:
1. Set a 'mod' filter:
$ echo 'write*:mod:ext3' > /sys/kernel/tracing/set_ftrace_filter
2. Invert above filter:
$ echo '!write*:mod:ext3' >> /sys/kernel/tracing/set_ftrace_filter
3. Read the file:
$ cat /sys/kernel/tracing/set_ftrace_filter
By some debugging, I found that flag FTRACE_HASH_FL_MOD was not unset
after inversion like above step 2 and then result of ftrace_hash_empty()
is incorrect.
Link: https://lkml.kernel.org/r/20220926152008.2239274-1-zhengyejian1@huawei.com
Cc: <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 8c08f0d5c6 ("ftrace: Have cached module filters be an active filter")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 747f7a2901 upstream.
The KLP transition code depends on the TIF_PATCH_PENDING and
the task->patch_state to stay in sync. On a normal (forward)
transition, TIF_PATCH_PENDING will be set on every task in
the system, while on a reverse transition (after a failed
forward one) first TIF_PATCH_PENDING will be cleared from
every task, followed by it being set on tasks that need to
be transitioned back to the original code.
However, the fork code copies over the TIF_PATCH_PENDING flag
from the parent to the child early on, in dup_task_struct and
setup_thread_stack. Much later, klp_copy_process will set
child->patch_state to match that of the parent.
However, the parent's patch_state may have been changed by KLP loading
or unloading since it was initially copied over into the child.
This results in the KLP code occasionally hitting this warning in
klp_complete_transition:
for_each_process_thread(g, task) {
WARN_ON_ONCE(test_tsk_thread_flag(task, TIF_PATCH_PENDING));
task->patch_state = KLP_UNDEFINED;
}
Set, or clear, the TIF_PATCH_PENDING flag in the child task
depending on whether or not it is needed at the time
klp_copy_process is called, at a point in copy_process where the
tasklist_lock is held exclusively, preventing races with the KLP
code.
The KLP code does have a few places where the state is changed
without the tasklist_lock held, but those should not cause
problems because klp_update_patch_state(current) cannot be
called while the current task is in the middle of fork,
klp_check_and_switch_task() which is called under the pi_lock,
which prevents rescheduling, and manipulation of the patch
state of idle tasks, which do not fork.
This should prevent this warning from triggering again in the
future, and close the race for both normal and reverse transitions.
Signed-off-by: Rik van Riel <riel@surriel.com>
Reported-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Fixes: d83a7cb375 ("livepatch: change to a per-task consistency model")
Cc: stable@kernel.org
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220808150019.03d6a67b@imladris.surriel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 82806744fd upstream.
swiotlb_find_slots() skips slots according to io tlb aligned mask
calculated from min aligned mask and original physical address
offset. This affects max mapping size. The mapping size can't
achieve the IO_TLB_SEGSIZE * IO_TLB_SIZE when original offset is
non-zero. This will cause system boot up failure in Hyper-V
Isolation VM where swiotlb force is enabled. Scsi layer use return
value of dma_max_mapping_size() to set max segment size and it
finally calls swiotlb_max_mapping_size(). Hyper-V storage driver
sets min align mask to 4k - 1. Scsi layer may pass 256k length of
request buffer with 0~4k offset and Hyper-V storage driver can't
get swiotlb bounce buffer via DMA API. Swiotlb_find_slots() can't
find 256k length bounce buffer with offset. Make swiotlb_max_mapping
_size() take min align mask into account.
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Rishabh Bhatnagar <risbhat@amazon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit df02452f3d ]
cgroup has to be one kernfs dir, otherwise kernel panic is caused,
especially cgroup id is provide from userspace.
Reported-by: Marco Patalano <mpatalan@redhat.com>
Fixes: 6b658c4863 ("scsi: cgroup: Add cgroup_get_from_id()")
Cc: Muneendra <muneendra.kumar@broadcom.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit be28816971 ]
Currently cgroup_get_from_path() and cgroup_get_from_id() grab
cgroup_mutex before traversing the default hierarchy to find the
kernfs_node corresponding to the path/id and then extract the linked
cgroup. Since cgroup_mutex is still held, it is guaranteed that the
cgroup will be alive and the reference can be taken on it.
However similar guarantee can be provided without depending on the
cgroup_mutex and potentially reducing avenues of cgroup_mutex contentions.
The kernfs_node's priv pointer is RCU protected pointer and with just
rcu read lock we can grab the reference on the cgroup without
cgroup_mutex. So, remove cgroup_mutex from them.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Stable-dep-of: df02452f3d ("cgroup: cgroup_get_from_id() must check the looked-up kn is a directory")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c0feea594e ]
Like Hillf Danton mentioned
syzbot should have been able to catch cancel_work_sync() in work context
by checking lockdep_map in __flush_work() for both flush and cancel.
in [1], being unable to report an obvious deadlock scenario shown below is
broken. From locking dependency perspective, sync version of cancel request
should behave as if flush request, for it waits for completion of work if
that work has already started execution.
----------
#include <linux/module.h>
#include <linux/sched.h>
static DEFINE_MUTEX(mutex);
static void work_fn(struct work_struct *work)
{
schedule_timeout_uninterruptible(HZ / 5);
mutex_lock(&mutex);
mutex_unlock(&mutex);
}
static DECLARE_WORK(work, work_fn);
static int __init test_init(void)
{
schedule_work(&work);
schedule_timeout_uninterruptible(HZ / 10);
mutex_lock(&mutex);
cancel_work_sync(&work);
mutex_unlock(&mutex);
return -EINVAL;
}
module_init(test_init);
MODULE_LICENSE("GPL");
----------
The check this patch restores was added by commit 0976dfc1d0
("workqueue: Catch more locking problems with flush_work()").
Then, lockdep's crossrelease feature was added by commit b09be676e0
("locking/lockdep: Implement the 'crossrelease' feature"). As a result,
this check was once removed by commit fd1a5b04df ("workqueue: Remove
now redundant lock acquisitions wrt. workqueue flushes").
But lockdep's crossrelease feature was removed by commit e966eaeeb6
("locking/lockdep: Remove the cross-release locking checks"). At this
point, this check should have been restored.
Then, commit d6e89786be ("workqueue: skip lockdep wq dependency in
cancel_work_sync()") introduced a boolean flag in order to distinguish
flush_work() and cancel_work_sync(), for checking "struct workqueue_struct"
dependency when called from cancel_work_sync() was causing false positives.
Then, commit 87915adc3f ("workqueue: re-add lockdep dependencies for
flushing") tried to restore "struct work_struct" dependency check, but by
error checked this boolean flag. Like an example shown above indicates,
"struct work_struct" dependency needs to be checked for both flush_work()
and cancel_work_sync().
Link: https://lkml.kernel.org/r/20220504044800.4966-1-hdanton@sina.com [1]
Reported-by: Hillf Danton <hdanton@sina.com>
Suggested-by: Lai Jiangshan <jiangshanlai@gmail.com>
Fixes: 87915adc3f ("workqueue: re-add lockdep dependencies for flushing")
Cc: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 54c3931957 ]
Currently, The arguments passing to lockdep_hardirqs_{on,off} was fixed
in CALLER_ADDR0.
The function trace_hardirqs_on_caller should have been intended to use
caller_addr to represent the address that caller wants to be traced.
For example, lockdep log in riscv showing the last {enabled,disabled} at
__trace_hardirqs_{on,off} all the time(if called by):
[ 57.853175] hardirqs last enabled at (2519): __trace_hardirqs_on+0xc/0x14
[ 57.853848] hardirqs last disabled at (2520): __trace_hardirqs_off+0xc/0x14
After use trace_hardirqs_xx_caller, we can get more effective information:
[ 53.781428] hardirqs last enabled at (2595): restore_all+0xe/0x66
[ 53.782185] hardirqs last disabled at (2596): ret_from_exception+0xa/0x10
Link: https://lkml.kernel.org/r/20220901104515.135162-2-zouyipeng@huawei.com
Cc: stable@vger.kernel.org
Fixes: c3bc8fd637 ("tracing: Centralize preemptirq tracepoints and unify their usage")
Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8b023accc8 ]
While looking into a bug related to the compiler's handling of addresses
of labels, I noticed some uses of _THIS_IP_ seemed unused in lockdep.
Drive by cleanup.
-Wunused-parameter:
kernel/locking/lockdep.c:1383:22: warning: unused parameter 'ip'
kernel/locking/lockdep.c:4246:48: warning: unused parameter 'ip'
kernel/locking/lockdep.c:4844:19: warning: unused parameter 'ip'
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20220314221909.2027027-1-ndesaulniers@google.com
Stable-dep-of: 54c3931957 ("tracing: hold caller_addr to hardirq_{enable,disable}_ip")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3f0461613e ]
The second operand passed to slot_addr() is declared as int or unsigned int
in all call sites. The left-shift to get the offset of a slot can overflow
if swiotlb size is larger than 4G.
Convert the macro to an inline function and declare the second argument as
phys_addr_t to avoid the potential overflow.
Fixes: 26a7e09478 ("swiotlb: refactor swiotlb_tbl_map_single")
Signed-off-by: Chao Gao <chao.gao@intel.com>
Reviewed-by: Dongli Zhang <dongli.zhang@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 85eaeb5058 ]
Fix a nested dead lock as part of ODP flow by using mmput_async().
From the below call trace [1] can see that calling mmput() once we have
the umem_odp->umem_mutex locked as required by
ib_umem_odp_map_dma_and_lock() might trigger in the same task the
exit_mmap()->__mmu_notifier_release()->mlx5_ib_invalidate_range() which
may dead lock when trying to lock the same mutex.
Moving to use mmput_async() will solve the problem as the above
exit_mmap() flow will be called in other task and will be executed once
the lock will be available.
[1]
[64843.077665] task:kworker/u133:2 state:D stack: 0 pid:80906 ppid:
2 flags:0x00004000
[64843.077672] Workqueue: mlx5_ib_page_fault mlx5_ib_eqe_pf_action [mlx5_ib]
[64843.077719] Call Trace:
[64843.077722] <TASK>
[64843.077724] __schedule+0x23d/0x590
[64843.077729] schedule+0x4e/0xb0
[64843.077735] schedule_preempt_disabled+0xe/0x10
[64843.077740] __mutex_lock.constprop.0+0x263/0x490
[64843.077747] __mutex_lock_slowpath+0x13/0x20
[64843.077752] mutex_lock+0x34/0x40
[64843.077758] mlx5_ib_invalidate_range+0x48/0x270 [mlx5_ib]
[64843.077808] __mmu_notifier_release+0x1a4/0x200
[64843.077816] exit_mmap+0x1bc/0x200
[64843.077822] ? walk_page_range+0x9c/0x120
[64843.077828] ? __cond_resched+0x1a/0x50
[64843.077833] ? mutex_lock+0x13/0x40
[64843.077839] ? uprobe_clear_state+0xac/0x120
[64843.077860] mmput+0x5f/0x140
[64843.077867] ib_umem_odp_map_dma_and_lock+0x21b/0x580 [ib_core]
[64843.077931] pagefault_real_mr+0x9a/0x140 [mlx5_ib]
[64843.077962] pagefault_mr+0xb4/0x550 [mlx5_ib]
[64843.077992] pagefault_single_data_segment.constprop.0+0x2ac/0x560
[mlx5_ib]
[64843.078022] mlx5_ib_eqe_pf_action+0x528/0x780 [mlx5_ib]
[64843.078051] process_one_work+0x22b/0x3d0
[64843.078059] worker_thread+0x53/0x410
[64843.078065] ? process_one_work+0x3d0/0x3d0
[64843.078073] kthread+0x12a/0x150
[64843.078079] ? set_kthread_struct+0x50/0x50
[64843.078085] ret_from_fork+0x22/0x30
[64843.078093] </TASK>
Fixes: 36f30e486d ("IB/core: Improve ODP to use hmm_range_fault()")
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/74d93541ea533ef7daec6f126deb1072500aeb16.1661251841.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4f7e723643 ]
Bringing up a CPU may involve creating and destroying tasks which requires
read-locking threadgroup_rwsem, so threadgroup_rwsem nests inside
cpus_read_lock(). However, cpuset's ->attach(), which may be called with
thredagroup_rwsem write-locked, also wants to disable CPU hotplug and
acquires cpus_read_lock(), leading to a deadlock.
Fix it by guaranteeing that ->attach() is always called with CPU hotplug
disabled and removing cpus_read_lock() call from cpuset_attach().
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-and-tested-by: Imran Khan <imran.f.khan@oracle.com>
Reported-and-tested-by: Xuewen Yan <xuewen.yan@unisoc.com>
Fixes: 05c7b7a92c ("cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug")
Cc: stable@vger.kernel.org # v5.17+
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 671c11f061 ]
cgroup_update_dfl_csses() write-lock the threadgroup_rwsem as updating the
csses can trigger process migrations. However, if the subtree doesn't
contain any tasks, there aren't gonna be any cgroup migrations. This
condition can be trivially detected by testing whether
mgctx.preloaded_src_csets is empty. Elide write-locking threadgroup_rwsem if
the subtree is empty.
After this optimization, the usage pattern of creating a cgroup, enabling
the necessary controllers, and then seeding it with CLONE_INTO_CGROUP and
then removing the cgroup after it becomes empty doesn't need to write-lock
threadgroup_rwsem at all.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c2e4065965 upstream.
Kuyo reports that the pattern of using debugfs_remove(debugfs_lookup())
leaks a dentry and with a hotplug stress test, the machine eventually
runs out of memory.
Fix this up by using the newly created debugfs_lookup_and_remove() call
instead which properly handles the dentry reference counting logic.
Cc: Major Chen <major.chen@samsung.com>
Cc: stable <stable@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Reported-by: Kuyo Chang <kuyo.chang@mediatek.com>
Tested-by: Kuyo Chang <kuyo.chang@mediatek.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220902123107.109274-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cecf8e128e upstream.
Since the check_user_trigger() is called outside of RCU
read lock, this list_for_each_entry_rcu() caused a suspicious
RCU usage warning.
# echo hist:keys=pid > events/sched/sched_stat_runtime/trigger
# cat events/sched/sched_stat_runtime/trigger
[ 43.167032]
[ 43.167418] =============================
[ 43.167992] WARNING: suspicious RCU usage
[ 43.168567] 5.19.0-rc5-00029-g19ebe4651abf #59 Not tainted
[ 43.169283] -----------------------------
[ 43.169863] kernel/trace/trace_events_trigger.c:145 RCU-list traversed in non-reader section!!
...
However, this file->triggers list is safe when it is accessed
under event_mutex is held.
To fix this warning, adds a lockdep_is_held check to the
list_for_each_entry_rcu().
Link: https://lkml.kernel.org/r/166226474977.223837.1992182913048377113.stgit@devnote2
Cc: stable@vger.kernel.org
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 14b20b784f ]
The verifier cannot perform sufficient validation of any pointers passed
into bpf_attr and treats them as integers rather than pointers. The helper
will then read from arbitrary pointers passed into it. Restrict the helper
to CAP_PERFMON since the security model in BPF of arbitrary kernel read is
CAP_BPF + CAP_PERFMON.
Fixes: af2ac3e13e ("bpf: Prepare bpf syscall to be used from kernel and user space.")
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220816205517.682470-1-zhuyifei@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a657182a5c upstream.
Hsin-Wei reported a KASAN splat triggered by their BPF runtime fuzzer which
is based on a customized syzkaller:
BUG: KASAN: slab-out-of-bounds in bpf_int_jit_compile+0x1257/0x13f0
Read of size 8 at addr ffff888004e90b58 by task syz-executor.0/1489
CPU: 1 PID: 1489 Comm: syz-executor.0 Not tainted 5.19.0 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x9c/0xc9
print_address_description.constprop.0+0x1f/0x1f0
? bpf_int_jit_compile+0x1257/0x13f0
kasan_report.cold+0xeb/0x197
? kvmalloc_node+0x170/0x200
? bpf_int_jit_compile+0x1257/0x13f0
bpf_int_jit_compile+0x1257/0x13f0
? arch_prepare_bpf_dispatcher+0xd0/0xd0
? rcu_read_lock_sched_held+0x43/0x70
bpf_prog_select_runtime+0x3e8/0x640
? bpf_obj_name_cpy+0x149/0x1b0
bpf_prog_load+0x102f/0x2220
? __bpf_prog_put.constprop.0+0x220/0x220
? find_held_lock+0x2c/0x110
? __might_fault+0xd6/0x180
? lock_downgrade+0x6e0/0x6e0
? lock_is_held_type+0xa6/0x120
? __might_fault+0x147/0x180
__sys_bpf+0x137b/0x6070
? bpf_perf_link_attach+0x530/0x530
? new_sync_read+0x600/0x600
? __fget_files+0x255/0x450
? lock_downgrade+0x6e0/0x6e0
? fput+0x30/0x1a0
? ksys_write+0x1a8/0x260
__x64_sys_bpf+0x7a/0xc0
? syscall_enter_from_user_mode+0x21/0x70
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f917c4e2c2d
The problem here is that a range of tnum_range(0, map->max_entries - 1) has
limited ability to represent the concrete tight range with the tnum as the
set of resulting states from value + mask can result in a superset of the
actual intended range, and as such a tnum_in(range, reg->var_off) check may
yield true when it shouldn't, for example tnum_range(0, 2) would result in
00XX -> v = 0000, m = 0011 such that the intended set of {0, 1, 2} is here
represented by a less precise superset of {0, 1, 2, 3}. As the register is
known const scalar, really just use the concrete reg->var_off.value for the
upper index check.
Fixes: d2e4c1e6c2 ("bpf: Constant map key tracking for prog array pokes")
Reported-by: Hsin-Wei Hung <hsinweih@uci.edu>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/984b37f9fdf7ac36831d2137415a4a915744c1b6.1661462653.git.daniel@iogearbox.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a8faed3a02 upstream.
When CONFIG_ADVISE_SYSCALLS is not set/enabled and CONFIG_COMPAT is
set/enabled, the riscv compat_syscall_table references
'compat_sys_fadvise64_64', which is not defined:
riscv64-linux-ld: arch/riscv/kernel/compat_syscall_table.o:(.rodata+0x6f8):
undefined reference to `compat_sys_fadvise64_64'
Add 'fadvise64_64' to kernel/sys_ni.c as a conditional COMPAT function so
that when CONFIG_ADVISE_SYSCALLS is not set, there is a fallback function
available.
Link: https://lkml.kernel.org/r/20220807220934.5689-1-rdunlap@infradead.org
Fixes: d3ac21cacc ("mm: Support compiling out madvise and fadvise")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 763f4fb76e upstream.
Root cause:
The rebind_subsystems() is no lock held when move css object from A
list to B list,then let B's head be treated as css node at
list_for_each_entry_rcu().
Solution:
Add grace period before invalidating the removed rstat_css_node.
Reported-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Suggested-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Tested-by: Jing-Ting Wu <jing-ting.wu@mediatek.com>
Link: https://lore.kernel.org/linux-arm-kernel/d8f0bc5e2fb6ed259f9334c83279b4c011283c41.camel@mediatek.com/T/
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
Fixes: a7df69b81a ("cgroup: rstat: support cgroup1")
Cc: stable@vger.kernel.org # v5.13+
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ad982c3be4 upstream.
Audit_alloc_mark() assign pathname to audit_mark->path, on error path
from fsnotify_add_inode_mark(), fsnotify_put_mark will free memory
of audit_mark->path, but the caller of audit_alloc_mark will free
the pathname again, so there will be double free problem.
Fix this by resetting audit_mark->path to NULL pointer on error path
from fsnotify_add_inode_mark().
Cc: stable@vger.kernel.org
Fixes: 7b12932340 ("fsnotify: Add group pointer in fsnotify_init_mark()")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 7c56a8733d ]
In some circumstances it may be interesting to reconfigure the watchdog
from inside the kernel.
On PowerPC, this may helpful before and after a LPAR migration (LPM) is
initiated, because it implies some latencies, watchdog, and especially NMI
watchdog is expected to be triggered during this operation. Reconfiguring
the watchdog with a factor, would prevent it to happen too frequently
during LPM.
Rename lockup_detector_reconfigure() as __lockup_detector_reconfigure() and
create a new function lockup_detector_reconfigure() calling
__lockup_detector_reconfigure() under the protection of watchdog_mutex.
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
[mpe: Squash in build fix from Laurent, reported by Sachin]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220713154729.80789-3-ldufour@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f04dec9346 upstream.
Currently when an event probe (eprobe) hooks to a string field, it does
not display it as a string, but instead as a number. This makes the field
rather useless. Handle the different kinds of strings, dynamic, static,
relational/dynamic etc.
Now when a string field is used, the ":string" type can be used to display
it:
echo "e:sw sched/sched_switch comm=$next_comm:string" > dynamic_events
Link: https://lkml.kernel.org/r/20220820134400.959640191@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ef1e93d2ee upstream.
bpf_iter_attach_map() acquires a map uref, and the uref may be released
before or in the middle of iterating map elements. For example, the uref
could be released in bpf_iter_detach_map() as part of
bpf_link_release(), or could be released in bpf_map_put_with_uref() as
part of bpf_map_release().
So acquiring an extra map uref in bpf_iter_init_hash_map() and
releasing it in bpf_iter_fini_hash_map().
Fixes: d6c4503cc2 ("bpf: Implement bpf iterator for hash maps")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220810080538.1845898-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f76fa6b338 upstream.
bpf_iter_attach_map() acquires a map uref, and the uref may be released
before or in the middle of iterating map elements. For example, the uref
could be released in bpf_iter_detach_map() as part of
bpf_link_release(), or could be released in bpf_map_put_with_uref() as
part of bpf_map_release().
Alternative fix is acquiring an extra bpf_link reference just like
a pinned map iterator does, but it introduces unnecessary dependency
on bpf_link instead of bpf_map.
So choose another fix: acquiring an extra map uref in .init_seq_private
for array map iterator.
Fixes: d3cc2ab546 ("bpf: Implement bpf iterator for array maps")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20220810080538.1845898-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 275c30bcee upstream.
The LRU map that is preallocated may have its elements reused while
another program holds a pointer to it from bpf_map_lookup_elem. Hence,
only check_and_free_fields is appropriate when the element is being
deleted, as it ensures proper synchronization against concurrent access
of the map value. After that, we cannot call check_and_init_map_value
again as it may rewrite bpf_spin_lock, bpf_timer, and kptr fields while
they can be concurrently accessed from a BPF program.
This is safe to do as when the map entry is deleted, concurrent access
is protected against by check_and_free_fields, i.e. an existing timer
would be freed, and any existing kptr will be released by it. The
program can create further timers and kptrs after check_and_free_fields,
but they will eventually be released once the preallocated items are
freed on map destruction, even if the item is never reused again. Hence,
the deleted item sitting in the free list can still have resources
attached to it, and they would never leak.
With spin_lock, we never touch the field at all on delete or update, as
we may end up modifying the state of the lock. Since the verifier
ensures that a bpf_spin_lock call is always paired with bpf_spin_unlock
call, the program will eventually release the lock so that on reuse the
new user of the value can take the lock.
Essentially, for the preallocated case, we must assume that the map
value may always be in use by the program, even when it is sitting in
the freelist, and handle things accordingly, i.e. use proper
synchronization inside check_and_free_fields, and never reinitialize the
special fields when it is reused on update.
Fixes: 68134668c1 ("bpf: Add map side support for bpf timers.")
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220809213033.24147-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b2380577d4 upstream.
Make filtering consistent with histograms. As "cpu" can be a field of an
event, allow for "common_cpu" to keep it from being confused with the
"cpu" field of the event.
Link: https://lkml.kernel.org/r/20220820134401.513062765@goodmis.org
Link: https://lore.kernel.org/all/20220820220920.e42fa32b70505b1904f0a0ad@kernel.org/
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 1e3bac71c5 ("tracing/histogram: Rename "cpu" to "common_cpu"")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ab8384442e upstream.
Both $comm and $COMM can be used to get current->comm in eprobes and the
filtering and histogram logic. Make kprobes and uprobes consistent in this
regard and allow both $comm and $COMM as well. Currently kprobes and
uprobes only handle $comm, which is inconsistent with the other utilities,
and can be confusing to users.
Link: https://lkml.kernel.org/r/20220820134401.317014913@goodmis.org
Link: https://lore.kernel.org/all/20220820220442.776e1ddaf8836e82edb34d01@kernel.org/
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 533059281e ("tracing: probeevent: Introduce new argument fetching code")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6a832ec3d6 upstream.
Currently, if a symbol "@" is attempted to be used with an event probe
(eprobes), it will cause a NULL pointer dereference crash.
Both kprobes and uprobes can reference data other than the main registers.
Such as immediate address, symbols and the current task name. Have eprobes
do the same thing.
For "comm", if "comm" is used and the event being attached to does not
have the "comm" field, then make it the "$comm" that kprobes has. This is
consistent to the way histograms and filters work.
Link: https://lkml.kernel.org/r/20220820134401.136924220@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 02333de90e upstream.
The variable $comm is hard coded as a string, which is true for both
kprobes and uprobes, but for event probes (eprobes) it is a field name. In
most cases the "comm" field would be a string, but there's no guarantee of
that fact.
Do not assume that comm is a string. Not to mention, it currently forces
comm fields to fault, as string processing for event probes is currently
broken.
Link: https://lkml.kernel.org/r/20220820134400.756152112@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Fixes: 7491e2c442 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7249921d94 upstream.
If in perf_trace_event_init(), the perf_trace_event_open() fails, then it
will call perf_trace_event_unreg() which will not only unregister the perf
trace event, but will also call the put() function of the tp_event.
The problem here is that the trace_event_try_get_ref() is called by the
caller of perf_trace_event_init() and if perf_trace_event_init() returns a
failure, it will then call trace_event_put(). But since the
perf_trace_event_unreg() already called the trace_event_put() function, it
triggers a WARN_ON().
WARNING: CPU: 1 PID: 30309 at kernel/trace/trace_dynevent.c:46 trace_event_dyn_put_ref+0x15/0x20
If perf_trace_event_reg() does not call the trace_event_try_get_ref() then
the perf_trace_event_unreg() should not be calling trace_event_put(). This
breaks symmetry and causes bugs like these.
Pull out the trace_event_put() from perf_trace_event_unreg() and call it
in the locations that perf_trace_event_unreg() is called. This not only
fixes this bug, but also brings back the proper symmetry of the reg/unreg
vs get/put logic.
Link: https://lore.kernel.org/all/cover.1660347763.git.kjlx@templeofstupid.com/
Link: https://lkml.kernel.org/r/20220816192817.43d5e17f@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 1d18538e6a ("tracing: Have dynamic events have a ref counter")
Reported-by: Krister Johansen <kjlx@templeofstupid.com>
Reviewed-by: Krister Johansen <kjlx@templeofstupid.com>
Tested-by: Krister Johansen <kjlx@templeofstupid.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 55de2c0b56 ]
Add '__rel_loc' using trace event macros. These macros are usually
not used in the kernel, except for testing purpose.
This also add "rel_" variant of macros for dynamic_array string,
and bitmask.
Link: https://lkml.kernel.org/r/163757342119.510314.816029622439099016.stgit@devnote2
Cc: Beau Belgrave <beaub@linux.microsoft.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9c9b26b0df ]
The csdlock_debug kernel-boot parameter is parsed by the
early_param() function csdlock_debug(). If set, csdlock_debug()
invokes static_branch_enable() to enable csd_lock_wait feature, which
triggers a panic on arm64 for kernels built with CONFIG_SPARSEMEM=y and
CONFIG_SPARSEMEM_VMEMMAP=n.
With CONFIG_SPARSEMEM_VMEMMAP=n, __nr_to_section is called in
static_key_enable() and returns NULL, resulting in a NULL dereference
because mem_section is initialized only later in sparse_init().
This is also a problem for powerpc because early_param() functions
are invoked earlier than jump_label_init(), also resulting in
static_key_enable() failures. These failures cause the warning "static
key 'xxx' used before call to jump_label_init()".
Thus, early_param is too early for csd_lock_wait to run
static_branch_enable(), so changes it to __setup to fix these.
Fixes: 8d0968cc6b ("locking/csd_lock: Add boot parameter for controlling CSD lock debugging")
Cc: stable@vger.kernel.org
Reported-by: Chen jingwen <chenjingwen6@huawei.com>
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b8ac29b401 ]
The rng's random_init() function contributes the real time to the rng at
boot time, so that events can at least start in relation to something
particular in the real world. But this clock might not yet be set that
point in boot, so nothing is contributed. In addition, the relation
between minor clock changes from, say, NTP, and the cycle counter is
potentially useful entropic data.
This commit addresses this by mixing in a time stamp on calls to
settimeofday and adjtimex. No entropy is credited in doing so, so it
doesn't make initialization faster, but it is still useful input to
have.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 751d4cbc43 ]
The following warning was triggered on a large machine early in boot on
a distribution kernel but the same problem should also affect mainline.
WARNING: CPU: 439 PID: 10 at ../kernel/workqueue.c:2231 process_one_work+0x4d/0x440
Call Trace:
<TASK>
rescuer_thread+0x1f6/0x360
kthread+0x156/0x180
ret_from_fork+0x22/0x30
</TASK>
Commit c6e7bd7afa ("sched/core: Optimize ttwu() spinning on p->on_cpu")
optimises ttwu by queueing a task that is descheduling on the wakelist,
but does not check if the task descheduling is still allowed to run on that CPU.
In this warning, the problematic task is a workqueue rescue thread which
checks if the rescue is for a per-cpu workqueue and running on the wrong CPU.
While this is early in boot and it should be possible to create workers,
the rescue thread may still used if the MAYDAY_INITIAL_TIMEOUT is reached
or MAYDAY_INTERVAL and on a sufficiently large machine, the rescue
thread is being used frequently.
Tracing confirmed that the task should have migrated properly using the
stopper thread to handle the migration. However, a parallel wakeup from udev
running on another CPU that does not share CPU cache observes p->on_cpu and
uses task_cpu(p), queues the task on the old CPU and triggers the warning.
Check that the wakee task that is descheduling is still allowed to run
on its current CPU and if not, wait for the descheduling to complete
and select an allowed CPU.
Fixes: c6e7bd7afa ("sched/core: Optimize ttwu() spinning on p->on_cpu")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20220804092119.20137-1-mgorman@techsingularity.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f3dd3f6745 ]
Wakelist can help avoid cache bouncing and offload the overhead of waker
cpu. So far, using wakelist within the same llc only happens on
WF_ON_CPU, and this limitation could be removed to further improve
wakeup performance.
The commit 518cd62341 ("sched: Only queue remote wakeups when
crossing cache boundaries") disabled queuing tasks on wakelist when
the cpus share llc. This is because, at that time, the scheduler must
send IPIs to do ttwu_queue_wakelist. Nowadays, ttwu_queue_wakelist also
supports TIF_POLLING, so this is not a problem now when the wakee cpu is
in idle polling.
Benefits:
Queuing the task on idle cpu can help improving performance on waker cpu
and utilization on wakee cpu, and further improve locality because
the wakee cpu can handle its own rq. This patch helps improving rt on
our real java workloads where wakeup happens frequently.
Consider the normal condition (CPU0 and CPU1 share same llc)
Before this patch:
CPU0 CPU1
select_task_rq() idle
rq_lock(CPU1->rq)
enqueue_task(CPU1->rq)
notify CPU1 (by sending IPI or CPU1 polling)
resched()
After this patch:
CPU0 CPU1
select_task_rq() idle
add to wakelist of CPU1
notify CPU1 (by sending IPI or CPU1 polling)
rq_lock(CPU1->rq)
enqueue_task(CPU1->rq)
resched()
We see CPU0 can finish its work earlier. It only needs to put task to
wakelist and return.
While CPU1 is idle, so let itself handle its own runqueue data.
This patch brings no difference about IPI.
This patch only takes effect when the wakee cpu is:
1) idle polling
2) idle not polling
For 1), there will be no IPI with or without this patch.
For 2), there will always be an IPI before or after this patch.
Before this patch: waker cpu will enqueue task and check preempt. Since
"idle" will be sure to be preempted, waker cpu must send a resched IPI.
After this patch: waker cpu will put the task to the wakelist of wakee
cpu, and send an IPI.
Benchmark:
We've tested schbench, unixbench, and hachbench on both x86 and arm64.
On x86 (Intel Xeon Platinum 8269CY):
schbench -m 2 -t 8
Latency percentiles (usec) before after
50.0000th: 8 6
75.0000th: 10 7
90.0000th: 11 8
95.0000th: 12 8
*99.0000th: 13 10
99.5000th: 15 11
99.9000th: 18 14
Unixbench with full threads (104)
before after
Dhrystone 2 using register variables 3011862938 3009935994 -0.06%
Double-Precision Whetstone 617119.3 617298.5 0.03%
Execl Throughput 27667.3 27627.3 -0.14%
File Copy 1024 bufsize 2000 maxblocks 785871.4 784906.2 -0.12%
File Copy 256 bufsize 500 maxblocks 210113.6 212635.4 1.20%
File Copy 4096 bufsize 8000 maxblocks 2328862.2 2320529.1 -0.36%
Pipe Throughput 145535622.8 145323033.2 -0.15%
Pipe-based Context Switching 3221686.4 3583975.4 11.25%
Process Creation 101347.1 103345.4 1.97%
Shell Scripts (1 concurrent) 120193.5 123977.8 3.15%
Shell Scripts (8 concurrent) 17233.4 17138.4 -0.55%
System Call Overhead 5300604.8 5312213.6 0.22%
hackbench -g 1 -l 100000
before after
Time 3.246 2.251
On arm64 (Ampere Altra):
schbench -m 2 -t 8
Latency percentiles (usec) before after
50.0000th: 14 10
75.0000th: 19 14
90.0000th: 22 16
95.0000th: 23 16
*99.0000th: 24 17
99.5000th: 24 17
99.9000th: 28 25
Unixbench with full threads (80)
before after
Dhrystone 2 using register variables 3536194249 3537019613 0.02%
Double-Precision Whetstone 629383.6 629431.6 0.01%
Execl Throughput 65920.5 65846.2 -0.11%
File Copy 1024 bufsize 2000 maxblocks 1063722.8 1064026.8 0.03%
File Copy 256 bufsize 500 maxblocks 322684.5 318724.5 -1.23%
File Copy 4096 bufsize 8000 maxblocks 2348285.3 2328804.8 -0.83%
Pipe Throughput 133542875.3 131619389.8 -1.44%
Pipe-based Context Switching 3215356.1 3576945.1 11.25%
Process Creation 108520.5 120184.6 10.75%
Shell Scripts (1 concurrent) 122636.3 121888 -0.61%
Shell Scripts (8 concurrent) 17462.1 17381.4 -0.46%
System Call Overhead 4429998.9 4435006.7 0.11%
hackbench -g 1 -l 100000
before after
Time 4.217 2.916
Our patch has improvement on schbench, hackbench
and Pipe-based Context Switching of unixbench
when there exists idle cpus,
and no obvious regression on other tests of unixbench.
This can help improve rt in scenes where wakeup happens frequently.
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20220608233412.327341-3-dtcccc@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 28156108fe ]
The commit 2ebb177175 ("sched/core: Offload wakee task activation if it
the wakee is descheduling") checked rq->nr_running <= 1 to avoid task
stacking when WF_ON_CPU.
Per the ordering of writes to p->on_rq and p->on_cpu, observing p->on_cpu
(WF_ON_CPU) in ttwu_queue_cond() implies !p->on_rq, IOW p has gone through
the deactivate_task() in __schedule(), thus p has been accounted out of
rq->nr_running. As such, the task being the only runnable task on the rq
implies reading rq->nr_running == 0 at that point.
The benchmark result is in [1].
[1] https://lore.kernel.org/all/e34de686-4e85-bde1-9f3c-9bbc86b38627@linux.alibaba.com/
Suggested-by: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Link: https://lore.kernel.org/r/20220608233412.327341-2-dtcccc@linux.alibaba.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b6e8d40d43 ]
With cgroup v2, the cpuset's cpus_allowed mask can be empty indicating
that the cpuset will just use the effective CPUs of its parent. So
cpuset_can_attach() can call task_can_attach() with an empty mask.
This can lead to cpumask_any_and() returns nr_cpu_ids causing the call
to dl_bw_of() to crash due to percpu value access of an out of bound
CPU value. For example:
[80468.182258] BUG: unable to handle page fault for address: ffffffff8b6648b0
:
[80468.191019] RIP: 0010:dl_cpu_busy+0x30/0x2b0
:
[80468.207946] Call Trace:
[80468.208947] cpuset_can_attach+0xa0/0x140
[80468.209953] cgroup_migrate_execute+0x8c/0x490
[80468.210931] cgroup_update_dfl_csses+0x254/0x270
[80468.211898] cgroup_subtree_control_write+0x322/0x400
[80468.212854] kernfs_fop_write_iter+0x11c/0x1b0
[80468.213777] new_sync_write+0x11f/0x1b0
[80468.214689] vfs_write+0x1eb/0x280
[80468.215592] ksys_write+0x5f/0xe0
[80468.216463] do_syscall_64+0x5c/0x80
[80468.224287] entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix that by using effective_cpus instead. For cgroup v1, effective_cpus
is the same as cpus_allowed. For v2, effective_cpus is the real cpumask
to be used by tasks within the cpuset anyway.
Also update task_can_attach()'s 2nd argument name to cs_effective_cpus to
reflect the change. In addition, a check is added to task_can_attach()
to guard against the possibility that cpumask_any_and() may return a
value >= nr_cpu_ids.
Fixes: 7f51412a41 ("sched/deadline: Fix bandwidth check/update when migrating tasks between exclusive cpusets")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20220803015451.2219567-1-longman@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 772b6539fd ]
Both functions are doing almost the same, that is checking if admission
control is still respected.
With exclusive cpusets, dl_task_can_attach() checks if the destination
cpuset (i.e. its root domain) has enough CPU capacity to accommodate the
task.
dl_cpu_busy() checks if there is enough CPU capacity in the cpuset in
case the CPU is hot-plugged out.
dl_task_can_attach() is used to check if a task can be admitted while
dl_cpu_busy() is used to check if a CPU can be hotplugged out.
Make dl_cpu_busy() able to deal with a task and use it instead of
dl_task_can_attach() in task_can_attach().
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://lore.kernel.org/r/20220302183433.333029-4-dietmar.eggemann@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 28f6c37a29 ]
kernel_text_address() treats ftrace_trampoline, kprobe_insn_slot
and bpf_text_address as valid kprobe addresses - which is not ideal.
These text areas are removable and changeable without any notification
to kprobes, and probing on them can trigger unexpected behavior:
https://lkml.org/lkml/2022/7/26/1148
Considering that jump_label and static_call text are already
forbiden to probe, kernel_text_address() should be replaced with
core_kernel_text() and is_module_text_address() to check other text
areas which are unsafe to kprobe.
[ mingo: Rewrote the changelog. ]
Fixes: 5b485629ba ("kprobes, extable: Identify kprobes trampolines as kernel text area")
Fixes: 74451e66d5 ("bpf: make jited programs visible in traces")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20220801033719.228248-1-chenzhongjin@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c51ba246cb ]
In the failure case of trying to use a buffer which we'd previously
failed to allocate, the "!mem" condition is no longer sufficient since
io_tlb_default_mem became static and assigned by default. Update the
condition to work as intended per the rest of that conversion.
Fixes: 463e862ac6 ("swiotlb: Convert io_default_tlb_mem to static allocation")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 151c8e499f ]
Using msleep() is problematic because it's compared against
ratelimiter.c's ktime_get_coarse_boottime_ns(), which means on systems
with slow jiffies (such as UML's forced HZ=100), the result is
inaccurate. So switch to using schedule_hrtimeout().
However, hrtimer gives us access only to the traditional posix timers,
and none of the _COARSE variants. So now, rather than being too
imprecise like jiffies, it's too precise.
One solution would be to give it a large "range" value, but this will
still fire early on a loaded system. A better solution is to align the
timeout to the actual coarse timer, and then round up to the nearest
tick, plus change.
So add the timeout to the current coarse time, and then
schedule_hrtimer() until the absolute computed time.
This should hopefully reduce flakes in CI as well. Note that we keep the
retry loop in case the entire function is running behind, because the
test could still be scheduled out, by either the kernel or by the
hypervisor's kernel, in which case restarting the test and hoping to not
be scheduled out still helps.
Fixes: e7096c131e ("net: WireGuard secure network tunnel")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9c7c48d6a1 ]
The commit 7337224fc1 ("bpf: Improve the info.func_info and info.func_info_rec_size behavior")
accidently made bpf_prog_ksym_set_name() conservative for bpf subprograms.
Fixed it so instead of "bpf_prog_tag_F" the stack traces print "bpf_prog_tag_full_subprog_name".
Fixes: 7337224fc1 ("bpf: Improve the info.func_info and info.func_info_rec_size behavior")
Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220714211637.17150-1-alexei.starovoitov@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3002153a91 ]
The RCU priority boosting can fail in two situations:
1) If (nr_cpus= > maxcpus=), which means if the total number of CPUs
is higher than those brought online at boot, then torture_onoff() may
later bring up CPUs that weren't online on boot. Now since rcutorture
initialization only boosts the ksoftirqds of the CPUs that have been
set online on boot, the CPUs later set online by torture_onoff won't
benefit from the boost, making RCU priority boosting fail.
2) The ksoftirqd kthreads are boosted after the creation of
rcu_torture_boost() kthreads, which opens a window large enough for these
rcu_torture_boost() kthreads to wait (despite running at FIFO priority)
for ksoftirqds that are still running at SCHED_NORMAL priority.
The issues can trigger for example with:
./kvm.sh --configs TREE01 --kconfig "CONFIG_RCU_BOOST=y"
[ 34.968561] rcu-torture: !!!
[ 34.968627] ------------[ cut here ]------------
[ 35.014054] WARNING: CPU: 4 PID: 114 at kernel/rcu/rcutorture.c:1979 rcu_torture_stats_print+0x5ad/0x610
[ 35.052043] Modules linked in:
[ 35.069138] CPU: 4 PID: 114 Comm: rcu_torture_sta Not tainted 5.18.0-rc1 #1
[ 35.096424] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014
[ 35.154570] RIP: 0010:rcu_torture_stats_print+0x5ad/0x610
[ 35.198527] Code: 63 1b 02 00 74 02 0f 0b 48 83 3d 35 63 1b 02 00 74 02 0f 0b 48 83 3d 21 63 1b 02 00 74 02 0f 0b 48 83 3d 0d 63 1b 02 00 74 02 <0f> 0b 83 eb 01 0f 8e ba fc ff ff 0f 0b e9 b3 fc ff f82
[ 37.251049] RSP: 0000:ffffa92a0050bdf8 EFLAGS: 00010202
[ 37.277320] rcu: De-offloading 8
[ 37.290367] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000001
[ 37.290387] RDX: 0000000000000000 RSI: 00000000ffffbfff RDI: 00000000ffffffff
[ 37.290398] RBP: 000000000000007b R08: 0000000000000000 R09: c0000000ffffbfff
[ 37.290407] R10: 000000000000002a R11: ffffa92a0050bc18 R12: ffffa92a0050be20
[ 37.290417] R13: ffffa92a0050be78 R14: 0000000000000000 R15: 000000000001bea0
[ 37.290427] FS: 0000000000000000(0000) GS:ffff96045eb00000(0000) knlGS:0000000000000000
[ 37.290448] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 37.290460] CR2: 0000000000000000 CR3: 000000001dc0c000 CR4: 00000000000006e0
[ 37.290470] Call Trace:
[ 37.295049] <TASK>
[ 37.295065] ? preempt_count_add+0x63/0x90
[ 37.295095] ? _raw_spin_lock_irqsave+0x12/0x40
[ 37.295125] ? rcu_torture_stats_print+0x610/0x610
[ 37.295143] rcu_torture_stats+0x29/0x70
[ 37.295160] kthread+0xe3/0x110
[ 37.295176] ? kthread_complete_and_exit+0x20/0x20
[ 37.295193] ret_from_fork+0x22/0x30
[ 37.295218] </TASK>
Fix this with boosting the ksoftirqds kthreads from the boosting
hotplug callback itself and before the boosting kthreads are created.
Fixes: ea6d962e80 ("rcutorture: Judge RCU priority boosting on grace periods, not callbacks")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fd13fe16db ]
Currently, in CONFIG_RCU_BOOST kernels, if the rcu_torture_init()
function's call to cpuhp_setup_state() fails, rcu_torture_cleanup()
gamely passes nonsense to cpuhp_remove_state(). This results in
strange and misleading splats. This commit therefore ensures that if
the rcu_torture_init() function's call to cpuhp_setup_state() fails,
rcu_torture_cleanup() avoids invoking cpuhp_remove_state().
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit efeff6b39b ]
When running rcutorture as a module, any rcu_torture_init() issues will be
reflected in the error code from modprobe or insmod, as the case may be.
However, these error codes are not available when running rcutorture
built-in, for example, when using the kvm.sh script. This commit
therefore adds WARN_ON_ONCE() to allow distinguishing rcu_torture_init()
errors when running rcutorture built-in.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5c66d1b9b3 ]
dequeue_task_rt() only decrements 'rt_rq->rt_nr_running' after having
called sched_update_tick_dependency() preventing it from re-enabling the
tick on systems that no longer have pending SCHED_RT tasks but have
multiple runnable SCHED_OTHER tasks:
dequeue_task_rt()
dequeue_rt_entity()
dequeue_rt_stack()
dequeue_top_rt_rq()
sub_nr_running() // decrements rq->nr_running
sched_update_tick_dependency()
sched_can_stop_tick() // checks rq->rt.rt_nr_running,
...
__dequeue_rt_entity()
dec_rt_tasks() // decrements rq->rt.rt_nr_running
...
Every other scheduler class performs the operation in the opposite
order, and sched_update_tick_dependency() expects the values to be
updated as such. So avoid the misbehaviour by inverting the order in
which the above operations are performed in the RT scheduler.
Fixes: 76d92ac305 ("sched: Migrate sched to use new tick dependency mask model")
Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://lore.kernel.org/r/20220628092259.330171-1-nsaenzju@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6f194c99f4 ]
When using a NOMAP domain, __irq_resolve_mapping() doesn't store
the Linux IRQ number at the address optionally provided by the caller.
While this isn't a huge deal (the returned value is guaranteed
to the hwirq that was passed as a parameter), let's honour the letter
of the API by writing the expected value.
Fixes: d22558dd0a (“irqdomain: Introduce irq_resolve_mapping()”)
Signed-off-by: Xu Qiang <xuqiang36@huawei.com>
[maz: commit message]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220719063641.56541-2-xuqiang36@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 22c80aac88 ]
Trace the remapped operation and its flags instead of only the data
direction of remapped operations. This issue was detected by analyzing
the warnings reported by sparse related to the new blk_opf_t type.
Reviewed-by: Jun'ichi Nomura <junichi.nomura@nec.com>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Fixes: 1b9a9ab78b ("blktrace: use op accessors")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-11-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit eae6d58d67 ]
Commit dfd5e3f5fe ("locking/lockdep: Mark local_lock_t") added yet
another lockdep_init_map_*() variant, but forgot to update all the
existing users of the most complicated version.
This could lead to a loss of lock_type and hence an incorrect report.
Given the relative rarity of both local_lock and these annotations,
this is unlikely to happen in practise, still, best fix things.
Fixes: dfd5e3f5fe ("locking/lockdep: Mark local_lock_t")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YqyEDtoan20K0CVD@worktop.programming.kicks-ass.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8386c414e2 ]
syzbot is reporting hung task at misc_open() [1], for there is a race
window of AB-BA deadlock which involves probe_count variable. Currently
wait_for_device_probe() from snapshot_open() from misc_open() can sleep
forever with misc_mtx held if probe_count cannot become 0.
When a device is probed by hub_event() work function, probe_count is
incremented before the probe function starts, and probe_count is
decremented after the probe function completed.
There are three cases that can prevent probe_count from dropping to 0.
(a) A device being probed stopped responding (i.e. broken/malicious
hardware).
(b) A process emulating a USB device using /dev/raw-gadget interface
stopped responding for some reason.
(c) New device probe requests keeps coming in before existing device
probe requests complete.
The phenomenon syzbot is reporting is (b). A process which is holding
system_transition_mutex and misc_mtx is waiting for probe_count to become
0 inside wait_for_device_probe(), but the probe function which is called
from hub_event() work function is waiting for the processes which are
blocked at mutex_lock(&misc_mtx) to respond via /dev/raw-gadget interface.
This patch mitigates (b) by deferring wait_for_device_probe() from
snapshot_open() to snapshot_write() and snapshot_ioctl(). Please note that
the possibility of (b) remains as long as any thread which is emulating a
USB device via /dev/raw-gadget interface can be blocked by uninterruptible
blocking operations (e.g. mutex_lock()).
Please also note that (a) and (c) are not addressed. Regarding (c), we
should change the code to wait for only one device which contains the
image for resuming from hibernation. I don't know how to address (a), for
use of timeout for wait_for_device_probe() might result in loss of user
data in the image. Maybe we should require the userland to wait for the
image device before opening /dev/snapshot interface.
Link: https://syzkaller.appspot.com/bug?extid=358c9ab4c93da7b7238c [1]
Reported-by: syzbot <syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 401e4963bf ]
With CONFIG_PREEMPT_RT, it is possible to hit a deadlock between two
normal priority tasks (SCHED_OTHER, nice level zero):
INFO: task kworker/u8:0:8 blocked for more than 491 seconds.
Not tainted 5.15.49-rt46 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:0 state:D stack: 0 pid: 8 ppid: 2 flags:0x00000000
Workqueue: writeback wb_workfn (flush-7:0)
[<c08a3a10>] (__schedule) from [<c08a3d84>] (schedule+0xdc/0x134)
[<c08a3d84>] (schedule) from [<c08a65a0>] (rt_mutex_slowlock_block.constprop.0+0xb8/0x174)
[<c08a65a0>] (rt_mutex_slowlock_block.constprop.0) from [<c08a6708>]
+(rt_mutex_slowlock.constprop.0+0xac/0x174)
[<c08a6708>] (rt_mutex_slowlock.constprop.0) from [<c0374d60>] (fat_write_inode+0x34/0x54)
[<c0374d60>] (fat_write_inode) from [<c0297304>] (__writeback_single_inode+0x354/0x3ec)
[<c0297304>] (__writeback_single_inode) from [<c0297998>] (writeback_sb_inodes+0x250/0x45c)
[<c0297998>] (writeback_sb_inodes) from [<c0297c20>] (__writeback_inodes_wb+0x7c/0xb8)
[<c0297c20>] (__writeback_inodes_wb) from [<c0297f24>] (wb_writeback+0x2c8/0x2e4)
[<c0297f24>] (wb_writeback) from [<c0298c40>] (wb_workfn+0x1a4/0x3e4)
[<c0298c40>] (wb_workfn) from [<c0138ab8>] (process_one_work+0x1fc/0x32c)
[<c0138ab8>] (process_one_work) from [<c0139120>] (worker_thread+0x22c/0x2d8)
[<c0139120>] (worker_thread) from [<c013e6e0>] (kthread+0x16c/0x178)
[<c013e6e0>] (kthread) from [<c01000fc>] (ret_from_fork+0x14/0x38)
Exception stack(0xc10e3fb0 to 0xc10e3ff8)
3fa0: 00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
INFO: task tar:2083 blocked for more than 491 seconds.
Not tainted 5.15.49-rt46 #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:tar state:D stack: 0 pid: 2083 ppid: 2082 flags:0x00000000
[<c08a3a10>] (__schedule) from [<c08a3d84>] (schedule+0xdc/0x134)
[<c08a3d84>] (schedule) from [<c08a41b0>] (io_schedule+0x14/0x24)
[<c08a41b0>] (io_schedule) from [<c08a455c>] (bit_wait_io+0xc/0x30)
[<c08a455c>] (bit_wait_io) from [<c08a441c>] (__wait_on_bit_lock+0x54/0xa8)
[<c08a441c>] (__wait_on_bit_lock) from [<c08a44f4>] (out_of_line_wait_on_bit_lock+0x84/0xb0)
[<c08a44f4>] (out_of_line_wait_on_bit_lock) from [<c0371fb0>] (fat_mirror_bhs+0xa0/0x144)
[<c0371fb0>] (fat_mirror_bhs) from [<c0372a68>] (fat_alloc_clusters+0x138/0x2a4)
[<c0372a68>] (fat_alloc_clusters) from [<c0370b14>] (fat_alloc_new_dir+0x34/0x250)
[<c0370b14>] (fat_alloc_new_dir) from [<c03787c0>] (vfat_mkdir+0x58/0x148)
[<c03787c0>] (vfat_mkdir) from [<c0277b60>] (vfs_mkdir+0x68/0x98)
[<c0277b60>] (vfs_mkdir) from [<c027b484>] (do_mkdirat+0xb0/0xec)
[<c027b484>] (do_mkdirat) from [<c0100060>] (ret_fast_syscall+0x0/0x1c)
Exception stack(0xc2e1bfa8 to 0xc2e1bff0)
bfa0: 01ee42f0 01ee4208 01ee42f0 000041ed 00000000 00004000
bfc0: 01ee42f0 01ee4208 00000000 00000027 01ee4302 00000004 000dcb00 01ee4190
bfe0: 000dc368 bed11924 0006d4b0 b6ebddfc
Here the kworker is waiting on msdos_sb_info::s_lock which is held by
tar which is in turn waiting for a buffer which is locked waiting to be
flushed, but this operation is plugged in the kworker.
The lock is a normal struct mutex, so tsk_is_pi_blocked() will always
return false on !RT and thus the behaviour changes for RT.
It seems that the intent here is to skip blk_flush_plug() in the case
where a non-preemptible lock (such as a spinlock) has been converted to
a rtmutex on RT, which is the case covered by the SM_RTLOCK_WAIT
schedule flag. But sched_submit_work() is only called from schedule()
which is never called in this scenario, so the check can simply be
deleted.
Looking at the history of the -rt patchset, in fact this change was
present from v5.9.1-rt20 until being dropped in v5.13-rt1 as it was part
of a larger patch [1] most of which was replaced by commit b4bfa3fcfe
("sched/core: Rework the __schedule() preempt argument").
As described in [1]:
The schedule process must distinguish between blocking on a regular
sleeping lock (rwsem and mutex) and a RT-only sleeping lock (spinlock
and rwlock):
- rwsem and mutex must flush block requests (blk_schedule_flush_plug())
even if blocked on a lock. This can not deadlock because this also
happens for non-RT.
There should be a warning if the scheduling point is within a RCU read
section.
- spinlock and rwlock must not flush block requests. This will deadlock
if the callback attempts to acquire a lock which is already acquired.
Similarly to being preempted, there should be no warning if the
scheduling point is within a RCU read section.
and with the tsk_is_pi_blocked() in the scheduler path, we hit the first
issue.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/tree/patches/0022-locking-rtmutex-Use-custom-scheduling-function-for-s.patch?h=linux-5.10.y-rt-patches
Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20220708162702.1758865-1-john@metanate.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0f5209fee9 ]
The generic IPI code depends on the IRQ affinity mask being allocated
and initialized. This will not be the case if SMP is disabled. Fix up
the remaining driver that selected GENERIC_IRQ_IPI in a non-SMP config.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220701200056.46555-3-samuel@sholland.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 95001b7564 ]
Function irq_chip::irq_request_resources() is reported as optional
in the declaration of struct irq_chip.
If the parent irq_chip does not implement it, we should ignore it
and return.
Don't return error if the functions is missing.
Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220512160544.13561-1-antonio.borneo@foss.st.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Vincent Guittot
Zhang Qiao
Frederic Weisbecker
Mark Rutland
Daniel Borkmann
Tero Kristo
Cai Huoqing
Costa Shulyupin
Song Liu
Yang Jihong
Budimir Markovic
Chen Zhongjin
Steven Rostedt (Google)
Sung-hun Kim
David Disseldorp
Johan Hovold
Lorenz Bauer
Tobias Klauser
Greg Kroah-Hartman
Jia-Ju Bai
Mukesh Ojha
Dan Williams
Marc Zyngier
Waiman Long
Feng Tang
Jann Horn
Zqiang
Paul E. McKenney
Andrii Nakryiko
Pietro Borrello
Dietmar Eggemann
Muchun Song
Linus Torvalds
Dave Hansen
Thomas Gleixner
Munehisa Kamata
Masami Hiramatsu
Wander Lairson Costa
Shiju Jose
Hao Sun
Martin KaFai Lau
Paul Chaignon
Eduard Zingerman
Yonghong Song
Natalia Petrova
Petr Pavlu
Kees Cook
Eric W. Biederman
Tiezhu Yang
tangmeng
Max Filippov
Luis Gerhorst
Paul Moore
Zheng Yejian
Namhyung Kim
Marco Elver
Rickard x Andersson
Stanislav Fomichev
Daniel Jordan
Björn Töpel
Kumar Kartikeya Dwivedi
Gavrilov Ilia
Vincent Donnefort
Phil Auld
Alexey Izbyshev
Peter Zijlstra
Yang Yingliang
xiongxin
Qais Yousef
Vincent Donnefort
Kuniyuki Iwashima
Jens Axboe
Tejun Heo
Daniel Bristot de Oliveira
Xu Kuohai
Hou Tao
Luiz Capitulino
Li Huafei
Shang XiaoJing
Wang Yufen
Daniil Tatianin
Xiu Jianfeng
Wang Wensheng
Youlin Li
Li Qiang
Mario Limonciello
Lin Shengwang
sunliming
Martin Liska
Michal Hocko
Nico Pache
Yipeng Zou
Michal Koutný
Lee Jones
Lorenz Bauer
Rik van Riel
Tianyu Lan
Ming Lei
Shakeel Butt
Tetsuo Handa
Nick Desaulniers
Chao Gao
Yishai Hadas
Christian A. Ehrhardt
Pu Lehui
YiFei Zhu
Randy Dunlap
Jing-Ting Wu
Gaosheng Cui
Laurent Dufour
Jason A. Donenfeld
Mel Gorman
Tianchen Ding
Robin Murphy
Alexei Starovoitov
Nicolas Saenz Julienne
Xu Qiang
Bart Van Assche
John Keeping
Samuel Holland
Antonio Borneo