Pull openat2 support from Al Viro:
"This is the openat2() series from Aleksa Sarai.
I'm afraid that the rest of namei stuff will have to wait - it got
zero review the last time I'd posted #work.namei, and there had been a
leak in the posted series I'd caught only last weekend. I was going to
repost it on Monday, but the window opened and the odds of getting any
review during that... Oh, well.
Anyway, openat2 part should be ready; that _did_ get sane amount of
review and public testing, so here it comes"
From Aleksa's description of the series:
"For a very long time, extending openat(2) with new features has been
incredibly frustrating. This stems from the fact that openat(2) is
possibly the most famous counter-example to the mantra "don't silently
accept garbage from userspace" -- it doesn't check whether unknown
flags are present[1].
This means that (generally) the addition of new flags to openat(2) has
been fraught with backwards-compatibility issues (O_TMPFILE has to be
defined as __O_TMPFILE|O_DIRECTORY|[O_RDWR or O_WRONLY] to ensure old
kernels gave errors, since it's insecure to silently ignore the
flag[2]). All new security-related flags therefore have a tough road
to being added to openat(2).
Furthermore, the need for some sort of control over VFS's path
resolution (to avoid malicious paths resulting in inadvertent
breakouts) has been a very long-standing desire of many userspace
applications.
This patchset is a revival of Al Viro's old AT_NO_JUMPS[3] patchset
(which was a variant of David Drysdale's O_BENEATH patchset[4] which
was a spin-off of the Capsicum project[5]) with a few additions and
changes made based on the previous discussion within [6] as well as
others I felt were useful.
In line with the conclusions of the original discussion of
AT_NO_JUMPS, the flag has been split up into separate flags. However,
instead of being an openat(2) flag it is provided through a new
syscall openat2(2) which provides several other improvements to the
openat(2) interface (see the patch description for more details). The
following new LOOKUP_* flags are added:
LOOKUP_NO_XDEV:
Blocks all mountpoint crossings (upwards, downwards, or through
absolute links). Absolute pathnames alone in openat(2) do not
trigger this. Magic-link traversal which implies a vfsmount jump is
also blocked (though magic-link jumps on the same vfsmount are
permitted).
LOOKUP_NO_MAGICLINKS:
Blocks resolution through /proc/$pid/fd-style links. This is done
by blocking the usage of nd_jump_link() during resolution in a
filesystem. The term "magic-links" is used to match with the only
reference to these links in Documentation/, but I'm happy to change
the name.
It should be noted that this is different to the scope of
~LOOKUP_FOLLOW in that it applies to all path components. However,
you can do openat2(NO_FOLLOW|NO_MAGICLINKS) on a magic-link and it
will *not* fail (assuming that no parent component was a
magic-link), and you will have an fd for the magic-link.
In order to correctly detect magic-links, the introduction of a new
LOOKUP_MAGICLINK_JUMPED state flag was required.
LOOKUP_BENEATH:
Disallows escapes to outside the starting dirfd's
tree, using techniques such as ".." or absolute links. Absolute
paths in openat(2) are also disallowed.
Conceptually this flag is to ensure you "stay below" a certain
point in the filesystem tree -- but this requires some additional
to protect against various races that would allow escape using
"..".
Currently LOOKUP_BENEATH implies LOOKUP_NO_MAGICLINKS, because it
can trivially beam you around the filesystem (breaking the
protection). In future, there might be similar safety checks done
as in LOOKUP_IN_ROOT, but that requires more discussion.
In addition, two new flags are added that expand on the above ideas:
LOOKUP_NO_SYMLINKS:
Does what it says on the tin. No symlink resolution is allowed at
all, including magic-links. Just as with LOOKUP_NO_MAGICLINKS this
can still be used with NOFOLLOW to open an fd for the symlink as
long as no parent path had a symlink component.
LOOKUP_IN_ROOT:
This is an extension of LOOKUP_BENEATH that, rather than blocking
attempts to move past the root, forces all such movements to be
scoped to the starting point. This provides chroot(2)-like
protection but without the cost of a chroot(2) for each filesystem
operation, as well as being safe against race attacks that
chroot(2) is not.
If a race is detected (as with LOOKUP_BENEATH) then an error is
generated, and similar to LOOKUP_BENEATH it is not permitted to
cross magic-links with LOOKUP_IN_ROOT.
The primary need for this is from container runtimes, which
currently need to do symlink scoping in userspace[7] when opening
paths in a potentially malicious container.
There is a long list of CVEs that could have bene mitigated by
having RESOLVE_THIS_ROOT (such as CVE-2017-1002101,
CVE-2017-1002102, CVE-2018-15664, and CVE-2019-5736, just to name a
few).
In order to make all of the above more usable, I'm working on
libpathrs[8] which is a C-friendly library for safe path resolution.
It features a userspace-emulated backend if the kernel doesn't support
openat2(2). Hopefully we can get userspace to switch to using it, and
thus get openat2(2) support for free once it's ready.
Future work would include implementing things like
RESOLVE_NO_AUTOMOUNT and possibly a RESOLVE_NO_REMOTE (to allow
programs to be sure they don't hit DoSes though stale NFS handles)"
* 'work.openat2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
Documentation: path-lookup: include new LOOKUP flags
selftests: add openat2(2) selftests
open: introduce openat2(2) syscall
namei: LOOKUP_{IN_ROOT,BENEATH}: permit limited ".." resolution
namei: LOOKUP_IN_ROOT: chroot-like scoped resolution
namei: LOOKUP_BENEATH: O_BENEATH-like scoped resolution
namei: LOOKUP_NO_XDEV: block mountpoint crossing
namei: LOOKUP_NO_MAGICLINKS: block magic-link resolution
namei: LOOKUP_NO_SYMLINKS: block symlink resolution
namei: allow set_root() to produce errors
namei: allow nd_jump_link() to produce errors
nsfs: clean-up ns_get_path() signature to return int
namei: only return -ECHILD from follow_dotdot_rcu()
Vince reports a worrying issue:
| so I was tracking down some odd behavior in the perf_fuzzer which turns
| out to be because perf_even_open() sometimes returns 0 (indicating a file
| descriptor of 0) even though as far as I can tell stdin is still open.
... and further the cause:
| error is triggered if aux_sample_size has non-zero value.
|
| seems to be this line in kernel/events/core.c:
|
| if (perf_need_aux_event(event) && !perf_get_aux_event(event, group_leader))
| goto err_locked;
|
| (note, err is never set)
This seems to be a thinko in commit:
ab43762ef0 ("perf: Allow normal events to output AUX data")
... and we should probably return -EINVAL here, as this should only
happen when the new event is mis-configured or does not have a
compatible aux_event group leader.
Fixes: ab43762ef0 ("perf: Allow normal events to output AUX data")
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Since commit
28875945ba ("rcu: Add support for consolidated-RCU reader checking")
there is an additional check to ensure that a RCU related lock is held
while the RCU list is iterated.
This section holds the SRCU reader lock instead.
Add annotation to list_for_each_entry_rcu() that pmus_srcu must be
acquired during the list traversal.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Link: https://lkml.kernel.org/r/20191119121429.zhcubzdhm672zasg@linutronix.de
ns_get_path() and ns_get_path_cb() only ever return either NULL or an
ERR_PTR. It is far more idiomatic to simply return an integer, and it
makes all of the callers of ns_get_path() more straightforward to read.
Fixes: e149ed2b80 ("take the targets of /proc/*/ns/* symlinks to separate fs")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
get_unmapped_area() returns an address or -errno on failure. Historically
we have checked for the failure by offset_in_page() which is correct but
quite hard to read. Newer code started using IS_ERR_VALUE which is much
easier to read. Convert remaining users of offset_in_page as well.
[mhocko@suse.com: rewrite changelog]
[mhocko@kernel.org: fix mremap.c and uprobes.c sites also]
Link: http://lkml.kernel.org/r/20191012102512.28051-1-pugaowei@gmail.com
Signed-off-by: Gaowei Pu <pugaowei@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull perf updates from Ingo Molnar:
"The main kernel side changes in this cycle were:
- Various Intel-PT updates and optimizations (Alexander Shishkin)
- Prohibit kprobes on Xen/KVM emulate prefixes (Masami Hiramatsu)
- Add support for LSM and SELinux checks to control access to the
perf syscall (Joel Fernandes)
- Misc other changes, optimizations, fixes and cleanups - see the
shortlog for details.
There were numerous tooling changes as well - 254 non-merge commits.
Here are the main changes - too many to list in detail:
- Enhancements to core tooling infrastructure, perf.data, libperf,
libtraceevent, event parsing, vendor events, Intel PT, callchains,
BPF support and instruction decoding.
- There were updates to the following tools:
perf annotate
perf diff
perf inject
perf kvm
perf list
perf maps
perf parse
perf probe
perf record
perf report
perf script
perf stat
perf test
perf trace
- And a lot of other changes: please see the shortlog and Git log for
more details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (279 commits)
perf parse: Fix potential memory leak when handling tracepoint errors
perf probe: Fix spelling mistake "addrees" -> "address"
libtraceevent: Fix memory leakage in copy_filter_type
libtraceevent: Fix header installation
perf intel-bts: Does not support AUX area sampling
perf intel-pt: Add support for decoding AUX area samples
perf intel-pt: Add support for recording AUX area samples
perf pmu: When using default config, record which bits of config were changed by the user
perf auxtrace: Add support for queuing AUX area samples
perf session: Add facility to peek at all events
perf auxtrace: Add support for dumping AUX area samples
perf inject: Cut AUX area samples
perf record: Add aux-sample-size config term
perf record: Add support for AUX area sampling
perf auxtrace: Add support for AUX area sample recording
perf auxtrace: Move perf_evsel__find_pmu()
perf record: Add a function to test for kernel support for AUX area sampling
perf tools: Add kernel AUX area sampling definitions
perf/core: Make the mlock accounting simple again
perf report: Jump to symbol source view from total cycles view
...
Pull networking updates from David Miller:
"Another merge window, another pull full of stuff:
1) Support alternative names for network devices, from Jiri Pirko.
2) Introduce per-netns netdev notifiers, also from Jiri Pirko.
3) Support MSG_PEEK in vsock/virtio, from Matias Ezequiel Vara
Larsen.
4) Allow compiling out the TLS TOE code, from Jakub Kicinski.
5) Add several new tracepoints to the kTLS code, also from Jakub.
6) Support set channels ethtool callback in ena driver, from Sameeh
Jubran.
7) New SCTP events SCTP_ADDR_ADDED, SCTP_ADDR_REMOVED,
SCTP_ADDR_MADE_PRIM, and SCTP_SEND_FAILED_EVENT. From Xin Long.
8) Add XDP support to mvneta driver, from Lorenzo Bianconi.
9) Lots of netfilter hw offload fixes, cleanups and enhancements,
from Pablo Neira Ayuso.
10) PTP support for aquantia chips, from Egor Pomozov.
11) Add UDP segmentation offload support to igb, ixgbe, and i40e. From
Josh Hunt.
12) Add smart nagle to tipc, from Jon Maloy.
13) Support L2 field rewrite by TC offloads in bnxt_en, from Venkat
Duvvuru.
14) Add a flow mask cache to OVS, from Tonghao Zhang.
15) Add XDP support to ice driver, from Maciej Fijalkowski.
16) Add AF_XDP support to ice driver, from Krzysztof Kazimierczak.
17) Support UDP GSO offload in atlantic driver, from Igor Russkikh.
18) Support it in stmmac driver too, from Jose Abreu.
19) Support TIPC encryption and auth, from Tuong Lien.
20) Introduce BPF trampolines, from Alexei Starovoitov.
21) Make page_pool API more numa friendly, from Saeed Mahameed.
22) Introduce route hints to ipv4 and ipv6, from Paolo Abeni.
23) Add UDP segmentation offload to cxgb4, Rahul Lakkireddy"
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1857 commits)
libbpf: Fix usage of u32 in userspace code
mm: Implement no-MMU variant of vmalloc_user_node_flags
slip: Fix use-after-free Read in slip_open
net: dsa: sja1105: fix sja1105_parse_rgmii_delays()
macvlan: schedule bc_work even if error
enetc: add support Credit Based Shaper(CBS) for hardware offload
net: phy: add helpers phy_(un)lock_mdio_bus
mdio_bus: don't use managed reset-controller
ax88179_178a: add ethtool_op_get_ts_info()
mlxsw: spectrum_router: Fix use of uninitialized adjacency index
mlxsw: spectrum_router: After underlay moves, demote conflicting tunnels
bpf: Simplify __bpf_arch_text_poke poke type handling
bpf: Introduce BPF_TRACE_x helper for the tracing tests
bpf: Add bpf_jit_blinding_enabled for !CONFIG_BPF_JIT
bpf, testing: Add various tail call test cases
bpf, x86: Emit patchable direct jump as tail call
bpf: Constant map key tracking for prog array pokes
bpf: Add poke dependency tracking for prog array maps
bpf: Add initial poke descriptor table for jit images
bpf: Move owner type, jited info into array auxiliary data
...
- Data abort report and injection
- Steal time support
- GICv4 performance improvements
- vgic ITS emulation fixes
- Simplify FWB handling
- Enable halt polling counters
- Make the emulated timer PREEMPT_RT compliant
s390:
- Small fixes and cleanups
- selftest improvements
- yield improvements
PPC:
- Add capability to tell userspace whether we can single-step the guest.
- Improve the allocation of XIVE virtual processor IDs
- Rewrite interrupt synthesis code to deliver interrupts in virtual
mode when appropriate.
- Minor cleanups and improvements.
x86:
- XSAVES support for AMD
- more accurate report of nested guest TSC to the nested hypervisor
- retpoline optimizations
- support for nested 5-level page tables
- PMU virtualization optimizations, and improved support for nested
PMU virtualization
- correct latching of INITs for nested virtualization
- IOAPIC optimization
- TSX_CTRL virtualization for more TAA happiness
- improved allocation and flushing of SEV ASIDs
- many bugfixes and cleanups
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"ARM:
- data abort report and injection
- steal time support
- GICv4 performance improvements
- vgic ITS emulation fixes
- simplify FWB handling
- enable halt polling counters
- make the emulated timer PREEMPT_RT compliant
s390:
- small fixes and cleanups
- selftest improvements
- yield improvements
PPC:
- add capability to tell userspace whether we can single-step the
guest
- improve the allocation of XIVE virtual processor IDs
- rewrite interrupt synthesis code to deliver interrupts in virtual
mode when appropriate.
- minor cleanups and improvements.
x86:
- XSAVES support for AMD
- more accurate report of nested guest TSC to the nested hypervisor
- retpoline optimizations
- support for nested 5-level page tables
- PMU virtualization optimizations, and improved support for nested
PMU virtualization
- correct latching of INITs for nested virtualization
- IOAPIC optimization
- TSX_CTRL virtualization for more TAA happiness
- improved allocation and flushing of SEV ASIDs
- many bugfixes and cleanups"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (127 commits)
kvm: nVMX: Relax guest IA32_FEATURE_CONTROL constraints
KVM: x86: Grab KVM's srcu lock when setting nested state
KVM: x86: Open code shared_msr_update() in its only caller
KVM: Fix jump label out_free_* in kvm_init()
KVM: x86: Remove a spurious export of a static function
KVM: x86: create mmu/ subdirectory
KVM: nVMX: Remove unnecessary TLB flushes on L1<->L2 switches when L1 use apic-access-page
KVM: x86: remove set but not used variable 'called'
KVM: nVMX: Do not mark vmcs02->apic_access_page as dirty when unpinning
KVM: vmx: use MSR_IA32_TSX_CTRL to hard-disable TSX on guest that lack it
KVM: vmx: implement MSR_IA32_TSX_CTRL disable RTM functionality
KVM: x86: implement MSR_IA32_TSX_CTRL effect on CPUID
KVM: x86: do not modify masked bits of shared MSRs
KVM: x86: fix presentation of TSX feature in ARCH_CAPABILITIES
KVM: PPC: Book3S HV: XIVE: Fix potential page leak on error path
KVM: PPC: Book3S HV: XIVE: Free previous EQ page when setting up a new one
KVM: nVMX: Assume TLB entries of L1 and L2 are tagged differently if L0 use EPT
KVM: x86: Unexport kvm_vcpu_reload_apic_access_page()
KVM: nVMX: add CR4_LA57 bit to nested CR4_FIXED1
KVM: nVMX: Use semi-colon instead of comma for exit-handlers initialization
...
Commit:
d44248a413 ("perf/core: Rework memory accounting in perf_mmap()")
does a lot of things to the mlock accounting arithmetics, while the only
thing that actually needed to happen is subtracting the part that is
charged to the mm from the part that is charged to the user, so that the
former isn't charged twice.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Yauheni Kaliuta <yauheni.kaliuta@redhat.com>
Cc: songliubraving@fb.com
Link: https://lkml.kernel.org/r/20191120170640.54123-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Borkmann says:
====================
pull-request: bpf-next 2019-11-20
The following pull-request contains BPF updates for your *net-next* tree.
We've added 81 non-merge commits during the last 17 day(s) which contain
a total of 120 files changed, 4958 insertions(+), 1081 deletions(-).
There are 3 trivial conflicts, resolve it by always taking the chunk from
196e8ca74886c433:
<<<<<<< HEAD
=======
void *bpf_map_area_mmapable_alloc(u64 size, int numa_node);
>>>>>>> 196e8ca748
<<<<<<< HEAD
void *bpf_map_area_alloc(u64 size, int numa_node)
=======
static void *__bpf_map_area_alloc(u64 size, int numa_node, bool mmapable)
>>>>>>> 196e8ca748
<<<<<<< HEAD
if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
=======
/* kmalloc()'ed memory can't be mmap()'ed */
if (!mmapable && size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER)) {
>>>>>>> 196e8ca748
The main changes are:
1) Addition of BPF trampoline which works as a bridge between kernel functions,
BPF programs and other BPF programs along with two new use cases: i) fentry/fexit
BPF programs for tracing with practically zero overhead to call into BPF (as
opposed to k[ret]probes) and ii) attachment of the former to networking related
programs to see input/output of networking programs (covering xdpdump use case),
from Alexei Starovoitov.
2) BPF array map mmap support and use in libbpf for global data maps; also a big
batch of libbpf improvements, among others, support for reading bitfields in a
relocatable manner (via libbpf's CO-RE helper API), from Andrii Nakryiko.
3) Extend s390x JIT with usage of relative long jumps and loads in order to lift
the current 64/512k size limits on JITed BPF programs there, from Ilya Leoshkevich.
4) Add BPF audit support and emit messages upon successful prog load and unload in
order to have a timeline of events, from Daniel Borkmann and Jiri Olsa.
5) Extension to libbpf and xdpsock sample programs to demo the shared umem mode
(XDP_SHARED_UMEM) as well as RX-only and TX-only sockets, from Magnus Karlsson.
6) Several follow-up bug fixes for libbpf's auto-pinning code and a new API
call named bpf_get_link_xdp_info() for retrieving the full set of prog
IDs attached to XDP, from Toke Høiland-Jørgensen.
7) Add BTF support for array of int, array of struct and multidimensional arrays
and enable it for skb->cb[] access in kfree_skb test, from Martin KaFai Lau.
8) Fix AF_XDP by using the correct number of channels from ethtool, from Luigi Rizzo.
9) Two fixes for BPF selftest to get rid of a hang in test_tc_tunnel and to avoid
xdping to be run as standalone, from Jiri Benc.
10) Various BPF selftest fixes when run with latest LLVM trunk, from Yonghong Song.
11) Fix a memory leak in BPF fentry test run data, from Colin Ian King.
12) Various smaller misc cleanups and improvements mostly all over BPF selftests and
samples, from Daniel T. Lee, Andre Guedes, Anders Roxell, Mao Wenan, Yue Haibing.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit:
5e6c3c7b1e ("perf/aux: Fix tracking of auxiliary trace buffer allocation")
tried to guess the correct combination of arithmetic operations that would
undo the AUX buffer's mlock accounting, and failed, leaking the bottom part
when an allocation needs to be charged partially to both user->locked_vm
and mm->pinned_vm, eventually leaving the user with no locked bonus:
$ perf record -e intel_pt//u -m1,128 uname
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.061 MB perf.data ]
$ perf record -e intel_pt//u -m1,128 uname
Permission error mapping pages.
Consider increasing /proc/sys/kernel/perf_event_mlock_kb,
or try again with a smaller value of -m/--mmap_pages.
(current value: 1,128)
Fix this by subtracting both locked and pinned counts when AUX buffer is
unmapped.
Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Similarly to bpf_map's refcnt/usercnt, convert bpf_prog's refcnt to atomic64
and remove artificial 32k limit. This allows to make bpf_prog's refcounting
non-failing, simplifying logic of users of bpf_prog_add/bpf_prog_inc.
Validated compilation by running allyesconfig kernel build.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191117172806.2195367-3-andriin@fb.com
Exporting perf_event_pause() as an external accessor for kernel users (such
as KVM) who may do both disable perf_event and read count with just one
time to hold perf_event_ctx_lock. Also the value could be reset optionally.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, perf_event_period() is used by user tools via ioctl. Based on
naming convention, exporting perf_event_period() for kernel users (such
as KVM) who may recalibrate the event period for their assigned counter
according to their requirements.
The perf_event_period() is an external accessor, just like the
perf_event_{en,dis}able() and should thus use perf_event_ctx_lock().
Suggested-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Like Xu <like.xu@linux.intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
AUX data can be used to annotate perf events such as performance counters
or tracepoints/breakpoints by including it in sample records when
PERF_SAMPLE_AUX flag is set. Such samples would be instrumental in debugging
and profiling by providing, for example, a history of instruction flow
leading up to the event's overflow.
The implementation makes use of grouping an AUX event with all the events
that wish to take samples of the AUX data, such that the former is the
group leader. The samplees should also specify the desired size of the AUX
sample via attr.aux_sample_size.
AUX capable PMUs need to explicitly add support for sampling, because it
relies on a new callback to take a snapshot of the buffer without touching
the event states.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Cc: mathieu.poirier@linaro.org
Link: https://lkml.kernel.org/r/20191025140835.53665-2-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It looks like a "static inline" has been missed in front
of the empty definition of perf_cgroup_switch() under
certain configurations.
Fixes the following sparse warning:
kernel/events/core.c:1035:1: warning: symbol 'perf_cgroup_switch' was not declared. Should it be static?
Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/20191106132527.19977-1-ben.dooks@codethink.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
313ccb9615 ("perf: Allocate context task_ctx_data for child event")
makes the inherit path skip over the current event in case of task_ctx_data
allocation failure. This, however, is inconsistent with allocation failures
in perf_event_alloc(), which would abort the fork.
Correct this by returning an error code on task_ctx_data allocation
failure and failing the fork in that case.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/20191105075702.60319-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit
ab43762ef0 ("perf: Allow normal events to output AUX data")
added 'aux_output' bit to the attribute structure, which relies on AUX
events and grouping, neither of which is supported for the kernel events.
This notwithstanding, attempts have been made to use it in the kernel
code, suggesting the necessity of an explicit hard -EINVAL.
Fix this by rejecting attributes with aux_output set for kernel events.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/20191030134731.5437-3-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A comment is in a wrong place in perf_event_create_kernel_counter().
Fix that.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/20191030134731.5437-2-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While discussing uncore event scheduling, I noticed we do not in fact
seem to dis-allow making uncore-cgroup events. Such events make no
sense what so ever because the cgroup is a CPU local state where
uncore counts across a number of CPUs.
Disallow them.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andi reported that he was hitting the linear search in
perf_init_event() a lot. Now that all !TYPE_SOFTWARE events should hit
the IDR, make sure the TYPE_SOFTWARE events are at the head of the
list such that we'll quickly find the right PMU (provided a valid
event was given).
Signed-off-by: Liang, Kan <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andi reported that he was hitting the linear search in
perf_init_event() a lot. Make more agressive use of the IDR lookup to
avoid hitting the linear search.
With exception of PERF_TYPE_SOFTWARE (which relies on a hideous hack),
we can put everything in the IDR. On top of that, we can alias
TYPE_HARDWARE and TYPE_HW_CACHE to TYPE_RAW on the lookup side.
This greatly reduces the chances of hitting the linear search.
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan <kan.liang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andi reported that when creating a lot of events, a lot of time is
spent in IPIs and asked if it would be possible to elide some of that.
Now when, as for example the perf-tool always does, events are created
disabled, then these events will not need to be scheduled when added
to the context (they're still disable) and therefore the IPI is not
required -- except for the very first event, that will need to set
ctx->is_active.
( It might be possible to set ctx->is_active remotely for cpu_ctx, but
we really need the IPI for task_ctx, so lets not make that
distinction. )
Also use __perf_effective_state() since group events depend on the
state of the leader, if the leader is OFF, the whole group is OFF.
So when sibling events are created enabled (XXX check tool) then we
only need a single IPI to create and enable the whole group (+ that
initial IPI to initialize the context).
Suggested-by: Andi Kleen <andi@firstfloor.org>
Reported-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: kan.liang@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
1a59413124 ("perf: Add wakeup watermark control to the AUX area")
added attr.__reserved_2 padding, but forgot to add an ABI check to reject
attributes with this field set. Fix that.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Cc: mathieu.poirier@linaro.org
Link: https://lkml.kernel.org/r/20191025121636.75182-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf fixes from Thomas Gleixner:
"A set of perf fixes:
kernel:
- Unbreak the tracking of auxiliary buffer allocations which got
imbalanced causing recource limit failures.
- Fix the fallout of splitting of ToPA entries which missed to shift
the base entry PA correctly.
- Use the correct context to lookup the AUX event when unmapping the
associated AUX buffer so the event can be stopped and the buffer
reference dropped.
tools:
- Fix buildiid-cache mode setting in copyfile_mode_ns() when copying
/proc/kcore
- Fix freeing id arrays in the event list so the correct event is
closed.
- Sync sched.h anc kvm.h headers with the kernel sources.
- Link jvmti against tools/lib/ctype.o to have weak strlcpy().
- Fix multiple memory and file descriptor leaks, found by coverity in
perf annotate.
- Fix leaks in error handling paths in 'perf c2c', 'perf kmem', found
by a static analysis tool"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/aux: Fix AUX output stopping
perf/aux: Fix tracking of auxiliary trace buffer allocation
perf/x86/intel/pt: Fix base for single entry topa
perf kmem: Fix memory leak in compact_gfp_flags()
tools headers UAPI: Sync sched.h with the kernel
tools headers kvm: Sync kvm.h headers with the kernel sources
tools headers kvm: Sync kvm headers with the kernel sources
tools headers kvm: Sync kvm headers with the kernel sources
perf c2c: Fix memory leak in build_cl_output()
perf tools: Fix mode setting in copyfile_mode_ns()
perf annotate: Fix multiple memory and file descriptor leaks
perf tools: Fix resource leak of closedir() on the error paths
perf evlist: Fix fix for freed id arrays
perf jvmti: Link against tools/lib/ctype.h to have weak strlcpy()
Commit:
8a58ddae23 ("perf/core: Fix exclusive events' grouping")
allows CAP_EXCLUSIVE events to be grouped with other events. Since all
of those also happen to be AUX events (which is not the case the other
way around, because arch/s390), this changes the rules for stopping the
output: the AUX event may not be on its PMU's context any more, if it's
grouped with a HW event, in which case it will be on that HW event's
context instead. If that's the case, munmap() of the AUX buffer can't
find and stop the AUX event, potentially leaving the last reference with
the atomic context, which will then end up freeing the AUX buffer. This
will then trip warnings:
Fix this by using the context's PMU context when looking for events
to stop, instead of the event's PMU context.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20191022073940.61814-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following commit from the v5.4 merge window:
d44248a413 ("perf/core: Rework memory accounting in perf_mmap()")
... breaks auxiliary trace buffer tracking.
If I run command 'perf record -e rbd000' to record samples and saving
them in the **auxiliary** trace buffer then the value of 'locked_vm' becomes
negative after all trace buffers have been allocated and released:
During allocation the values increase:
[52.250027] perf_mmap user->locked_vm:0x87 pinned_vm:0x0 ret:0
[52.250115] perf_mmap user->locked_vm:0x107 pinned_vm:0x0 ret:0
[52.250251] perf_mmap user->locked_vm:0x188 pinned_vm:0x0 ret:0
[52.250326] perf_mmap user->locked_vm:0x208 pinned_vm:0x0 ret:0
[52.250441] perf_mmap user->locked_vm:0x289 pinned_vm:0x0 ret:0
[52.250498] perf_mmap user->locked_vm:0x309 pinned_vm:0x0 ret:0
[52.250613] perf_mmap user->locked_vm:0x38a pinned_vm:0x0 ret:0
[52.250715] perf_mmap user->locked_vm:0x408 pinned_vm:0x2 ret:0
[52.250834] perf_mmap user->locked_vm:0x408 pinned_vm:0x83 ret:0
[52.250915] perf_mmap user->locked_vm:0x408 pinned_vm:0x103 ret:0
[52.251061] perf_mmap user->locked_vm:0x408 pinned_vm:0x184 ret:0
[52.251146] perf_mmap user->locked_vm:0x408 pinned_vm:0x204 ret:0
[52.251299] perf_mmap user->locked_vm:0x408 pinned_vm:0x285 ret:0
[52.251383] perf_mmap user->locked_vm:0x408 pinned_vm:0x305 ret:0
[52.251544] perf_mmap user->locked_vm:0x408 pinned_vm:0x386 ret:0
[52.251634] perf_mmap user->locked_vm:0x408 pinned_vm:0x406 ret:0
[52.253018] perf_mmap user->locked_vm:0x408 pinned_vm:0x487 ret:0
[52.253197] perf_mmap user->locked_vm:0x408 pinned_vm:0x508 ret:0
[52.253374] perf_mmap user->locked_vm:0x408 pinned_vm:0x589 ret:0
[52.253550] perf_mmap user->locked_vm:0x408 pinned_vm:0x60a ret:0
[52.253726] perf_mmap user->locked_vm:0x408 pinned_vm:0x68b ret:0
[52.253903] perf_mmap user->locked_vm:0x408 pinned_vm:0x70c ret:0
[52.254084] perf_mmap user->locked_vm:0x408 pinned_vm:0x78d ret:0
[52.254263] perf_mmap user->locked_vm:0x408 pinned_vm:0x80e ret:0
The value of user->locked_vm increases to a limit then the memory
is tracked by pinned_vm.
During deallocation the size is subtracted from pinned_vm until
it hits a limit. Then a larger value is subtracted from locked_vm
leading to a large number (because of type unsigned):
[64.267797] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x78d
[64.267826] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x70c
[64.267848] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x68b
[64.267869] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x60a
[64.267891] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x589
[64.267911] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x508
[64.267933] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x487
[64.267952] perf_mmap_close mmap_user->locked_vm:0x408 pinned_vm:0x406
[64.268883] perf_mmap_close mmap_user->locked_vm:0x307 pinned_vm:0x406
[64.269117] perf_mmap_close mmap_user->locked_vm:0x206 pinned_vm:0x406
[64.269433] perf_mmap_close mmap_user->locked_vm:0x105 pinned_vm:0x406
[64.269536] perf_mmap_close mmap_user->locked_vm:0x4 pinned_vm:0x404
[64.269797] perf_mmap_close mmap_user->locked_vm:0xffffffffffffff84 pinned_vm:0x303
[64.270105] perf_mmap_close mmap_user->locked_vm:0xffffffffffffff04 pinned_vm:0x202
[64.270374] perf_mmap_close mmap_user->locked_vm:0xfffffffffffffe84 pinned_vm:0x101
[64.270628] perf_mmap_close mmap_user->locked_vm:0xfffffffffffffe04 pinned_vm:0x0
This value sticks for the user until system is rebooted, causing
follow-on system calls using locked_vm resource limit to fail.
Note: There is no issue using the normal trace buffer.
In fact the issue is in perf_mmap_close(). During allocation auxiliary
trace buffer memory is either traced as 'extra' and added to 'pinned_vm'
or trace as 'user_extra' and added to 'locked_vm'. This applies for
normal trace buffers and auxiliary trace buffer.
However in function perf_mmap_close() all auxiliary trace buffer is
subtraced from 'locked_vm' and never from 'pinned_vm'. This breaks the
ballance.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: gor@linux.ibm.com
Cc: hechaol@fb.com
Cc: heiko.carstens@de.ibm.com
Cc: linux-perf-users@vger.kernel.org
Cc: songliubraving@fb.com
Fixes: d44248a413 ("perf/core: Rework memory accounting in perf_mmap()")
Link: https://lkml.kernel.org/r/20191021083354.67868-1-tmricht@linux.ibm.com
[ Minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Attaching uprobe to text section in THP splits the PMD mapped page table
into PTE mapped entries. On uprobe detach, we would like to regroup PMD
mapped page table entry to regain performance benefit of THP.
However, the regroup is broken For perf_event based trace_uprobe. This
is because perf_event based trace_uprobe calls uprobe_unregister twice
on close: first in TRACE_REG_PERF_CLOSE, then in
TRACE_REG_PERF_UNREGISTER. The second call will split the PMD mapped
page table entry, which is not the desired behavior.
Fix this by only use FOLL_SPLIT_PMD for uprobe register case.
Add a WARN() to confirm uprobe unregister never work on huge pages, and
abort the operation when this WARN() triggers.
Link: http://lkml.kernel.org/r/20191017164223.2762148-6-songliubraving@fb.com
Fixes: 5a52c9df62 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT")
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently perf_mmap_alloc_page() is used to allocate memory in
rb_alloc(), but using free_page() to free memory in the failure path.
It's better to use perf_mmap_free_page() instead.
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <jolsa@redhat.co>
Cc: <acme@kernel.org>
Cc: <mingo@redhat.com>
Cc: <mark.rutland@arm.com>
Cc: <namhyung@kernel.org>
Cc: <alexander.shishkin@linux.intel.com>
Link: https://lkml.kernel.org/r/575c7e8c-90c7-4e3a-b41d-f894d8cdbd7f@huawei.com
In perf_mmap_free_page(), the unsigned long type is converted to the
pointer type, but where the call is made, the pointer type is converted
to the unsigned long type. There is no need to do these operations.
Modify the parameter type of perf_mmap_free_page() to pointer type.
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <jolsa@redhat.co>
Cc: <acme@kernel.org>
Cc: <mingo@redhat.com>
Cc: <mark.rutland@arm.com>
Cc: <namhyung@kernel.org>
Cc: <alexander.shishkin@linux.intel.com>
Link: https://lkml.kernel.org/r/e6ae3f0c-d04c-50f9-544a-aee3b30330cd@huawei.com
In current mainline, the degree of access to perf_event_open(2) system
call depends on the perf_event_paranoid sysctl. This has a number of
limitations:
1. The sysctl is only a single value. Many types of accesses are controlled
based on the single value thus making the control very limited and
coarse grained.
2. The sysctl is global, so if the sysctl is changed, then that means
all processes get access to perf_event_open(2) opening the door to
security issues.
This patch adds LSM and SELinux access checking which will be used in
Android to access perf_event_open(2) for the purposes of attaching BPF
programs to tracepoints, perf profiling and other operations from
userspace. These operations are intended for production systems.
5 new LSM hooks are added:
1. perf_event_open: This controls access during the perf_event_open(2)
syscall itself. The hook is called from all the places that the
perf_event_paranoid sysctl is checked to keep it consistent with the
systctl. The hook gets passed a 'type' argument which controls CPU,
kernel and tracepoint accesses (in this context, CPU, kernel and
tracepoint have the same semantics as the perf_event_paranoid sysctl).
Additionally, I added an 'open' type which is similar to
perf_event_paranoid sysctl == 3 patch carried in Android and several other
distros but was rejected in mainline [1] in 2016.
2. perf_event_alloc: This allocates a new security object for the event
which stores the current SID within the event. It will be useful when
the perf event's FD is passed through IPC to another process which may
try to read the FD. Appropriate security checks will limit access.
3. perf_event_free: Called when the event is closed.
4. perf_event_read: Called from the read(2) and mmap(2) syscalls for the event.
5. perf_event_write: Called from the ioctl(2) syscalls for the event.
[1] https://lwn.net/Articles/696240/
Since Peter had suggest LSM hooks in 2016 [1], I am adding his
Suggested-by tag below.
To use this patch, we set the perf_event_paranoid sysctl to -1 and then
apply selinux checking as appropriate (default deny everything, and then
add policy rules to give access to domains that need it). In the future
we can remove the perf_event_paranoid sysctl altogether.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Co-developed-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: James Morris <jmorris@namei.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: rostedt@goodmis.org
Cc: Yonghong Song <yhs@fb.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: jeffv@google.com
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: primiano@google.com
Cc: Song Liu <songliubraving@fb.com>
Cc: rsavitski@google.com
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Matthew Garrett <matthewgarrett@google.com>
Link: https://lkml.kernel.org/r/20191014170308.70668-1-joel@joelfernandes.org
In perf_rotate_context(), when the first cpu flexible event fail to
schedule, cpu_rotate is 1, while cpu_event is NULL. Since cpu_event is
NULL, perf_rotate_context will _NOT_ call cpu_ctx_sched_out(), thus
cpuctx->ctx.is_active will have EVENT_FLEXIBLE set. Then, the next
perf_event_sched_in() will skip all cpu flexible events because of the
EVENT_FLEXIBLE bit.
In the next call of perf_rotate_context(), cpu_rotate stays 1, and
cpu_event stays NULL, so this process repeats. The end result is, flexible
events on this cpu will not be scheduled (until another event being added
to the cpuctx).
Here is an easy repro of this issue. On Intel CPUs, where ref-cycles
could only use one counter, run one pinned event for ref-cycles, one
flexible event for ref-cycles, and one flexible event for cycles. The
flexible ref-cycles is never scheduled, which is expected. However,
because of this issue, the cycles event is never scheduled either.
$ perf stat -e ref-cycles:D,ref-cycles,cycles -C 5 -I 1000
time counts unit events
1.000152973 15,412,480 ref-cycles:D
1.000152973 <not counted> ref-cycles (0.00%)
1.000152973 <not counted> cycles (0.00%)
2.000486957 18,263,120 ref-cycles:D
2.000486957 <not counted> ref-cycles (0.00%)
2.000486957 <not counted> cycles (0.00%)
To fix this, when the flexible_active list is empty, try rotate the
first event in the flexible_groups. Also, rename ctx_first_active() to
ctx_event_to_rotate(), which is more accurate.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@fb.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 8d5bce0c37 ("perf/core: Optimize perf_rotate_context() event scheduling")
Link: https://lkml.kernel.org/r/20191008165949.920548-1-songliubraving@fb.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
ab43762ef0 ("perf: Allow normal events to output AUX data")
forgets to configure aux_output relation in the inherited groups, which
results in child PEBS events forever failing to schedule.
Fix this by setting up the AUX output link in the inheritance path.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191004125729.32397-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Switch perf_event_open() syscall from it's own copying
struct perf_event_attr from userspace to the new dedicated
copy_struct_from_user() helper.
The change is very straightforward, and helps unify the syscall
interface for struct-from-userspace syscalls.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
[christian.brauner@ubuntu.com: improve commit message]
Link: https://lore.kernel.org/r/20191001011055.19283-5-cyphar@cyphar.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Pull kernel lockdown mode from James Morris:
"This is the latest iteration of the kernel lockdown patchset, from
Matthew Garrett, David Howells and others.
From the original description:
This patchset introduces an optional kernel lockdown feature,
intended to strengthen the boundary between UID 0 and the kernel.
When enabled, various pieces of kernel functionality are restricted.
Applications that rely on low-level access to either hardware or the
kernel may cease working as a result - therefore this should not be
enabled without appropriate evaluation beforehand.
The majority of mainstream distributions have been carrying variants
of this patchset for many years now, so there's value in providing a
doesn't meet every distribution requirement, but gets us much closer
to not requiring external patches.
There are two major changes since this was last proposed for mainline:
- Separating lockdown from EFI secure boot. Background discussion is
covered here: https://lwn.net/Articles/751061/
- Implementation as an LSM, with a default stackable lockdown LSM
module. This allows the lockdown feature to be policy-driven,
rather than encoding an implicit policy within the mechanism.
The new locked_down LSM hook is provided to allow LSMs to make a
policy decision around whether kernel functionality that would allow
tampering with or examining the runtime state of the kernel should be
permitted.
The included lockdown LSM provides an implementation with a simple
policy intended for general purpose use. This policy provides a coarse
level of granularity, controllable via the kernel command line:
lockdown={integrity|confidentiality}
Enable the kernel lockdown feature. If set to integrity, kernel features
that allow userland to modify the running kernel are disabled. If set to
confidentiality, kernel features that allow userland to extract
confidential information from the kernel are also disabled.
This may also be controlled via /sys/kernel/security/lockdown and
overriden by kernel configuration.
New or existing LSMs may implement finer-grained controls of the
lockdown features. Refer to the lockdown_reason documentation in
include/linux/security.h for details.
The lockdown feature has had signficant design feedback and review
across many subsystems. This code has been in linux-next for some
weeks, with a few fixes applied along the way.
Stephen Rothwell noted that commit 9d1f8be5cf ("bpf: Restrict bpf
when kernel lockdown is in confidentiality mode") is missing a
Signed-off-by from its author. Matthew responded that he is providing
this under category (c) of the DCO"
* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
kexec: Fix file verification on S390
security: constify some arrays in lockdown LSM
lockdown: Print current->comm in restriction messages
efi: Restrict efivar_ssdt_load when the kernel is locked down
tracefs: Restrict tracefs when the kernel is locked down
debugfs: Restrict debugfs when the kernel is locked down
kexec: Allow kexec_file() with appropriate IMA policy when locked down
lockdown: Lock down perf when in confidentiality mode
bpf: Restrict bpf when kernel lockdown is in confidentiality mode
lockdown: Lock down tracing and perf kprobes when in confidentiality mode
lockdown: Lock down /proc/kcore
x86/mmiotrace: Lock down the testmmiotrace module
lockdown: Lock down module params that specify hardware parameters (eg. ioport)
lockdown: Lock down TIOCSSERIAL
lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
acpi: Disable ACPI table override if the kernel is locked down
acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
ACPI: Limit access to custom_method when the kernel is locked down
x86/msr: Restrict MSR access when the kernel is locked down
x86: Lock down IO port access when the kernel is locked down
...
Pull more perf updates from Ingo Molnar:
"The only kernel change is comment typo fixes.
The rest is mostly tooling fixes, but also new vendor event additions
and updates, a bigger libperf/libtraceevent library and a header files
reorganization that came in a bit late"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (108 commits)
perf unwind: Fix libunwind build failure on i386 systems
perf parser: Remove needless include directives
perf build: Add detection of java-11-openjdk-devel package
perf jvmti: Include JVMTI support for s390
perf vendor events: Remove P8 HW events which are not supported
perf evlist: Fix access of freed id arrays
perf stat: Fix free memory access / memory leaks in metrics
perf tools: Replace needless mmap.h with what is needed, event.h
perf evsel: Move config terms to a separate header
perf evlist: Remove unused perf_evlist__fprintf() method
perf evsel: Introduce evsel_fprintf.h
perf evsel: Remove need for symbol_conf in evsel_fprintf.c
perf copyfile: Move copyfile routines to separate files
libperf: Add perf_evlist__poll() function
libperf: Add perf_evlist__add_pollfd() function
libperf: Add perf_evlist__alloc_pollfd() function
libperf: Add libperf_init() call to the tests
libperf: Merge libperf_set_print() into libperf_init()
libperf: Add libperf dependency for tests targets
libperf: Use sys/types.h to get ssize_t, not unistd.h
...
After all uprobes are removed from the huge page (with PTE pgtable), it is
possible to collapse the pmd and benefit from THP again. This patch does
the collapse by calling collapse_pte_mapped_thp().
Link: http://lkml.kernel.org/r/20190815164525.1848545-7-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: kbuild test robot <lkp@intel.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the newly added FOLL_SPLIT_PMD in uprobe. This preserves the huge
page when the uprobe is enabled. When the uprobe is disabled, newer
instances of the same application could still benefit from huge page.
For the next step, we will enable khugepaged to regroup the pmd, so that
existing instances of the application could also benefit from huge page
after the uprobe is disabled.
Link: http://lkml.kernel.org/r/20190815164525.1848545-5-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, uprobe swaps the target page with a anonymous page in both
install_breakpoint() and remove_breakpoint(). When all uprobes on a page
are removed, the given mm is still using an anonymous page (not the
original page).
This patch allows uprobe to use original page when possible (all uprobes
on the page are already removed, and the original page is in page cache
and uptodate).
As suggested by Oleg, we unmap the old_page and let the original page
fault in.
Link: http://lkml.kernel.org/r/20190815164525.1848545-3-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix typos in a few functions' documentation comments.
Signed-off-by: Roy Ben Shlomo <royb@sentinelone.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: royb@sentinelone.com
Link: http://lore.kernel.org/lkml/20190920171254.31373-1-royb@sentinelone.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull core timer updates from Thomas Gleixner:
"Timers and timekeeping updates:
- A large overhaul of the posix CPU timer code which is a preparation
for moving the CPU timer expiry out into task work so it can be
properly accounted on the task/process.
An update to the bogus permission checks will come later during the
merge window as feedback was not complete before heading of for
travel.
- Switch the timerqueue code to use cached rbtrees and get rid of the
homebrewn caching of the leftmost node.
- Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a
single function
- Implement the separation of hrtimers to be forced to expire in hard
interrupt context even when PREEMPT_RT is enabled and mark the
affected timers accordingly.
- Implement a mechanism for hrtimers and the timer wheel to protect
RT against priority inversion and live lock issues when a (hr)timer
which should be canceled is currently executing the callback.
Instead of infinitely spinning, the task which tries to cancel the
timer blocks on a per cpu base expiry lock which is held and
released by the (hr)timer expiry code.
- Enable the Hyper-V TSC page based sched_clock for Hyper-V guests
resulting in faster access to timekeeping functions.
- Updates to various clocksource/clockevent drivers and their device
tree bindings.
- The usual small improvements all over the place"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
posix-cpu-timers: Fix permission check regression
posix-cpu-timers: Always clear head pointer on dequeue
hrtimer: Add a missing bracket and hide `migration_base' on !SMP
posix-cpu-timers: Make expiry_active check actually work correctly
posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build
tick: Mark sched_timer to expire in hard interrupt context
hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD
x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n
posix-cpu-timers: Utilize timerqueue for storage
posix-cpu-timers: Move state tracking to struct posix_cputimers
posix-cpu-timers: Deduplicate rlimit handling
posix-cpu-timers: Remove pointless comparisons
posix-cpu-timers: Get rid of 64bit divisions
posix-cpu-timers: Consolidate timer expiry further
posix-cpu-timers: Get rid of zero checks
rlimit: Rewrite non-sensical RLIMIT_CPU comment
posix-cpu-timers: Respect INFINITY for hard RTTIME limit
posix-cpu-timers: Switch thread group sampling to array
posix-cpu-timers: Restructure expiry array
posix-cpu-timers: Remove cputime_expires
...
Linus Torvalds
Mark Rutland
Sebastian Andrzej Siewior
Aleksa Sarai
Gaowei Pu
Ingo Molnar
Paolo Bonzini
Alexander Shishkin
David S. Miller
Andrii Nakryiko
Like Xu
Qian Cai
Ben Dooks (Codethink)
Peter Zijlstra
Liang, Kan
Alexey Budankov
Thomas Richter
Song Liu
Yunfeng Ye
Joel Fernandes (Google)
Roy Ben Shlomo