commit 9349b5cd09 upstream
check_bugs() is about to be phased out. Switch over to the new
arch_cpu_finalize_init() implementation.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Richard Weinberger <richard@nod.at>
Link: https://lore.kernel.org/r/20230613224545.493148694@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b99ddbe833 upstream.
With CONFIG_VIRTIO_UML=y, GNU ld < 2.36 fails to link UML vmlinux
(w/wo CONFIG_LD_SCRIPT_STATIC).
`.exit.text' referenced in section `.uml.exitcall.exit' of arch/um/drivers/virtio_uml.o: defined in discarded section `.exit.text' of arch/um/drivers/virtio_uml.o
collect2: error: ld returned 1 exit status
This fix is similar to the following commits:
- 4b9880dbf3 ("powerpc/vmlinux.lds: Define RUNTIME_DISCARD_EXIT")
- a494398bde ("s390: define RUNTIME_DISCARD_EXIT to fix link error
with GNU ld < 2.36")
- c1c551bebf ("sh: define RUNTIME_DISCARD_EXIT")
Fixes: 99cb0d917f ("arch: fix broken BuildID for arm64 and riscv")
Reported-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 782b1f70f8 ]
OpenWrt's UML with 5.15 was producing odd errors/warnings during preinit
part of the early userspace portion:
|[ 0.000000] Kernel command line: ubd0=root.img root=98:0 console=tty
|[...]
|[ 0.440000] random: jshn: uninitialized urandom read (4 bytes read)
|[ 0.460000] random: jshn: uninitialized urandom read (4 bytes read)
|/etc/preinit: line 47: can't create /dev/tty: No such device or address
|/etc/preinit: line 48: can't create /dev/tty: No such device or address
|/etc/preinit: line 58: can't open /dev/tty: No such device or address
|[...] repeated many times
That "/dev/tty" came from the command line (which is automatically
added if no console= parameter was specified for the uml binary).
The TLDP project tells the following about the /dev/tty:
<https://tldp.org/HOWTO/Text-Terminal-HOWTO-7.html#ss7.3>
| /dev/tty stands for the controlling terminal (if any) for the current
| process.[...]
| /dev/tty is something like a link to the actually terminal device[..]
The "(if any)" is important here, since it's possible for processes to
not have a controlling terminal.
I think this was a simple typo and the author wanted tty0 there.
CC: Thomas Meyer <thomas@m3y3r.de>
Fixes: d7ffac3363 ("um: stdio_console: Make preferred console")
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 0b9ba6135d upstream.
UML generally does not provide access to special CPU instructions like
RDRAND, and execution tends to be rather deterministic, with no real
hardware interrupts, making good randomness really very hard, if not
all together impossible. Not only is this a security eyebrow raiser, but
it's also quite annoying when trying to do various pieces of UML-based
automation that takes a long time to boot, if ever.
Fix this by trivially calling getrandom() in the host and using that
seed as "bootloader randomness", which initializes the rng immediately
at UML boot.
The old behavior can be restored the same way as on any other arch, by
way of CONFIG_TRUST_BOOTLOADER_RANDOMNESS=n or
random.trust_bootloader=0. So seen from that perspective, this just
makes UML act like other archs, which is positive in its own right.
Additionally, wire up arch_get_random_{int,long}() in the same way, so
that reseeds can also make use of the host RNG, controllable by
CONFIG_TRUST_CPU_RANDOMNESS and random.trust_cpu, per usual.
Cc: stable@vger.kernel.org
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 564d998106 upstream.
Implement apply_returns() stub for UM, just like all the other patching
routines.
Fixes: 15e67227c4 ("x86: Undo return-thunk damage")
Reported-by: Randy Dunlap <rdunlap@infradead.org)
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/Ys%2Ft45l%2FgarIrD0u@worktop.programming.kicks-ass.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7508500900 upstream.
Rewrite retpoline thunk call sites to be indirect calls for
spectre_v2=off. This ensures spectre_v2=off is as near to a
RETPOLINE=n build as possible.
This is the replacement for objtool writing alternative entries to
ensure the same and achieves feature-parity with the previous
approach.
One noteworthy feature is that it relies on the thunks to be in
machine order to compute the register index.
Specifically, this does not yet address the Jcc __x86_indirect_thunk_*
calls generated by clang, a future patch will add this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20211026120310.232495794@infradead.org
[cascardo: small conflict fixup at arch/x86/kernel/module.c]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c200e4bb44 upstream.
User mode linux is the last user of the PT_DTRACE flag. Using the flag to indicate
single stepping is a little confusing and worse changing tsk->ptrace without locking
could potentionally cause problems.
So use a thread info flag with a better name instead of flag in tsk->ptrace.
Remove the definition PT_DTRACE as uml is the last user.
Cc: stable@vger.kernel.org
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20220505182645.497868-3-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit bbe33504d4 ]
Rename set_signals() as there's at least one driver that
uses the same name and can now be built on UM due to PCI
support, and thus we can get symbol conflicts.
Also rename set_signals_trace() to be consistent.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 68f5d3f3b6 ("um: add PCI over virtio emulation driver")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit e21294a7aa upstream.
Now that force_fatal_sig exists it is unnecessary and a bit confusing
to use force_sigsegv in cases where the simpler force_fatal_sig is
wanted. So change every instance we can to make the code clearer.
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Link: https://lkml.kernel.org/r/877de7jrev.fsf@disp2133
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Thomas Backlund <tmb@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Support for VMAP_STACK
- Support for splice_write in hostfs
- Fixes for virt-pci
- Fixes for virtio_uml
- Various fixes
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Merge tag 'for-linus-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML updates from Richard Weinberger:
- Support for VMAP_STACK
- Support for splice_write in hostfs
- Fixes for virt-pci
- Fixes for virtio_uml
- Various fixes
* tag 'for-linus-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: fix stub location calculation
um: virt-pci: fix uapi documentation
um: enable VMAP_STACK
um: virt-pci: don't do DMA from stack
hostfs: support splice_write
um: virtio_uml: fix memory leak on init failures
um: virtio_uml: include linux/virtio-uml.h
lib/logic_iomem: fix sparse warnings
um: make PCI emulation driver init/exit static
Merge more updates from Andrew Morton:
"147 patches, based on 7d2a07b769.
Subsystems affected by this patch series: mm (memory-hotplug, rmap,
ioremap, highmem, cleanups, secretmem, kfence, damon, and vmscan),
alpha, percpu, procfs, misc, core-kernel, MAINTAINERS, lib,
checkpatch, epoll, init, nilfs2, coredump, fork, pids, criu, kconfig,
selftests, ipc, and scripts"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (94 commits)
scripts: check_extable: fix typo in user error message
mm/workingset: correct kernel-doc notations
ipc: replace costly bailout check in sysvipc_find_ipc()
selftests/memfd: remove unused variable
Kconfig.debug: drop selecting non-existing HARDLOCKUP_DETECTOR_ARCH
configs: remove the obsolete CONFIG_INPUT_POLLDEV
prctl: allow to setup brk for et_dyn executables
pid: cleanup the stale comment mentioning pidmap_init().
kernel/fork.c: unexport get_{mm,task}_exe_file
coredump: fix memleak in dump_vma_snapshot()
fs/coredump.c: log if a core dump is aborted due to changed file permissions
nilfs2: use refcount_dec_and_lock() to fix potential UAF
nilfs2: fix memory leak in nilfs_sysfs_delete_snapshot_group
nilfs2: fix memory leak in nilfs_sysfs_create_snapshot_group
nilfs2: fix memory leak in nilfs_sysfs_delete_##name##_group
nilfs2: fix memory leak in nilfs_sysfs_create_##name##_group
nilfs2: fix NULL pointer in nilfs_##name##_attr_release
nilfs2: fix memory leak in nilfs_sysfs_create_device_group
trap: cleanup trap_init()
init: move usermodehelper_enable() to populate_rootfs()
...
There are some empty trap_init() definitions in different ARCHs, Introduce
a new weak trap_init() function to clean them up.
Link: https://lkml.kernel.org/r/20210812123602.76356-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> [arm32]
Acked-by: Vineet Gupta [arc]
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <palmerdabbelt@google.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit 9f0b4807a4 ("um: rework userspace stubs to not hard-code
stub location") I changed stub_segv_handler() to do a calculation with
a pointer to a stack variable to find the data page that we're using
for the stack and the rest of the data. This same commit was meant to
do it as well for stub_clone_handler(), but the change inadvertently
went into commit 84b2789d61 ("um: separate child and parent errors
in clone stub") instead.
This was reported to not be compiled correctly by gcc 5, causing the
code to crash here. I'm not sure why, perhaps it's UB because the var
isn't initialized? In any case, this trick always seemed bad, so just
create a new inline function that does the calculation in assembly.
Reported-by: subashab@codeaurora.org
Fixes: 9f0b4807a4 ("um: rework userspace stubs to not hard-code stub location")
Fixes: 84b2789d61 ("um: separate child and parent errors in clone stub")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This is a preparation for changing over architectures to the
generic implementation one at a time. As there are no callers
of either __strncpy_from_user() or __strnlen_user(), fold these
into the strncpy_from_user() and strnlen_user() functions to make
each implementation independent of the others.
Many of these implementations have known bugs, but the intention
here is to not change behavior at all and stay compatible with
those bugs for the moment.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
- Support for optimized routines based on the host CPU
- Support for PCI via virtio
- Various fixes
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Merge tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML updates from Richard Weinberger:
- Support for optimized routines based on the host CPU
- Support for PCI via virtio
- Various fixes
* tag 'for-linus-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: remove unneeded semicolon in um_arch.c
um: Remove the repeated declaration
um: fix error return code in winch_tramp()
um: fix error return code in slip_open()
um: Fix stack pointer alignment
um: implement flush_cache_vmap/flush_cache_vunmap
um: add a UML specific futex implementation
um: enable the use of optimized xor routines in UML
um: Add support for host CPU flags and alignment
um: allow not setting extra rpaths in the linux binary
um: virtio/pci: enable suspend/resume
um: add PCI over virtio emulation driver
um: irqs: allow invoking time-travel handler multiple times
um: time-travel/signals: fix ndelay() in interrupt
um: expose time-travel mode to userspace side
um: export signals_enabled directly
um: remove unused smp_sigio_handler() declaration
lib: add iomem emulation (logic_iomem)
um: allow disabling NO_IOMEM
Merge more updates from Andrew Morton:
"190 patches.
Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
signals, exec, kcov, selftests, compress/decompress, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
ipc/util.c: use binary search for max_idx
ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
ipc: use kmalloc for msg_queue and shmid_kernel
ipc sem: use kvmalloc for sem_undo allocation
lib/decompressors: remove set but not used variabled 'level'
selftests/vm/pkeys: exercise x86 XSAVE init state
selftests/vm/pkeys: refill shadow register after implicit kernel write
selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
kcov: add __no_sanitize_coverage to fix noinstr for all architectures
exec: remove checks in __register_bimfmt()
x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
hfsplus: report create_date to kstat.btime
hfsplus: remove unnecessary oom message
nilfs2: remove redundant continue statement in a while-loop
kprobes: remove duplicated strong free_insn_page in x86 and s390
init: print out unknown kernel parameters
checkpatch: do not complain about positive return values starting with EPOLL
checkpatch: improve the indented label test
checkpatch: scripts/spdxcheck.py now requires python3
...
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out panic and
oops helpers.
There are several purposes of doing this:
- dropping dependency in bug.h
- dropping a loop by moving out panic_notifier.h
- unload kernel.h from something which has its own domain
At the same time convert users tree-wide to use new headers, although for
the time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.
[akpm@linux-foundation.org: thread_info.h needs limits.h]
[andriy.shevchenko@linux.intel.com: ia64 fix]
Link: https://lkml.kernel.org/r/20210520130557.55277-1-andriy.shevchenko@linux.intel.com
Link: https://lkml.kernel.org/r/20210511074137.33666-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Sebastian Reichel <sre@kernel.org>
Acked-by: Luis Chamberlain <mcgrof@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Consolidate the macros for .byte ... opcode sequences
- Deduplicate register offset defines in include files
- Simplify the ia32,x32 compat handling of the related syscall tables to
get rid of #ifdeffery.
- Clear all EFLAGS which are not required for syscall handling
- Consolidate the syscall tables and switch the generation over to the
generic shell script and remove the CFLAGS tweaks which are not longer
required.
- Use 'int' type for system call numbers to match the generic code.
- Add more selftests for syscalls
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Merge tag 'x86-entry-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 entry code related updates from Thomas Gleixner:
- Consolidate the macros for .byte ... opcode sequences
- Deduplicate register offset defines in include files
- Simplify the ia32,x32 compat handling of the related syscall tables
to get rid of #ifdeffery.
- Clear all EFLAGS which are not required for syscall handling
- Consolidate the syscall tables and switch the generation over to the
generic shell script and remove the CFLAGS tweaks which are not
longer required.
- Use 'int' type for system call numbers to match the generic code.
- Add more selftests for syscalls
* tag 'x86-entry-2021-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/syscalls: Don't adjust CFLAGS for syscall tables
x86/syscalls: Remove -Wno-override-init for syscall tables
x86/uml/syscalls: Remove array index from syscall initializers
x86/syscalls: Clear 'offset' and 'prefix' in case they are set in env
x86/entry: Use int everywhere for system call numbers
x86/entry: Treat out of range and gap system calls the same
x86/entry/64: Sign-extend system calls on entry to int
selftests/x86/syscall: Add tests under ptrace to syscall_numbering_64
selftests/x86/syscall: Simplify message reporting in syscall_numbering
selftests/x86/syscall: Update and extend syscall_numbering_64
x86/syscalls: Switch to generic syscallhdr.sh
x86/syscalls: Use __NR_syscalls instead of __NR_syscall_max
x86/unistd: Define X32_NR_syscalls only for 64-bit kernel
x86/syscalls: Stop filling syscall arrays with *_sys_ni_syscall
x86/syscalls: Switch to generic syscalltbl.sh
x86/entry/x32: Rename __x32_compat_sys_* to __x64_compat_sys_*
Fix following coccicheck warning:
./arch/um/kernel/um_arch.c:284:34-35: Unneeded semicolon
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Replace a bunch of 'p->state == TASK_RUNNING' with a new helper:
task_is_running(p).
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210611082838.222401495@infradead.org
GCC assumes that stack is aligned to 16-byte on call sites [1].
Since GCC 8, GCC began using 16-byte aligned SSE instructions to
implement assignments to structs on stack. When
CC_OPTIMIZE_FOR_PERFORMANCE is enabled, this affects
os-Linux/sigio.c, write_sigio_thread:
struct pollfds *fds, tmp;
tmp = current_poll;
Note that struct pollfds is exactly 16 bytes in size.
GCC 8+ generates assembly similar to:
movdqa (%rdi),%xmm0
movaps %xmm0,-0x50(%rbp)
This is an issue, because movaps will #GP if -0x50(%rbp) is not
aligned to 16 bytes [2], and how rbp gets assigned to is via glibc
clone thread_start, then function prologue, going though execution
trace similar to (showing only relevant instructions):
sub $0x10,%rsi
mov %rcx,0x8(%rsi)
mov %rdi,(%rsi)
syscall
pop %rax
pop %rdi
callq *%rax
push %rbp
mov %rsp,%rbp
The stack pointer always points to the topmost element on stack,
rather then the space right above the topmost. On push, the
pointer decrements first before writing to the memory pointed to
by it. Therefore, there is no need to have the stack pointer
pointer always point to valid memory unless the stack is poped;
so the `- sizeof(void *)` in the code is unnecessary.
On the other hand, glibc reserves the 16 bytes it needs on stack
and pops itself, so by the call instruction the stack pointer
is exactly the caller-supplied sp. It then push the 16 bytes of
the return address and the saved stack pointer, so the base
pointer will be 16-byte aligned if and only if the caller
supplied sp is 16-byte aligned. Therefore, the caller must supply
a 16-byte aligned pointer, which `stack + UM_KERN_PAGE_SIZE`
already satisfies.
On a side note, musl is unaffected by this issue because it forces
16 byte alignment via `and $-16,%rsi` in its clone wrapper.
Similarly, glibc i386 is also unaffected because it has
`andl $0xfffffff0, %ecx`.
To reproduce this bug, enable CONFIG_UML_RTC and
CC_OPTIMIZE_FOR_PERFORMANCE. uml_rtc will call
add_sigio_fd which will then cause write_sigio_thread to either go
into segfault loop or panic with "Segfault with no mm".
Similarly, signal stacks will be aligned by the host kernel upon
signal delivery. `- sizeof(void *)` to sigaltstack is
unconventional and extraneous.
On a related note, initialization of longjmp buffers do require
`- sizeof(void *)`. This is to account for the return address
that would have been pushed to the stack at the call site.
The reason for uml to respect 16-byte alignment, rather than
telling GCC to assume 8-byte alignment like the host kernel since
commit d9b0cde91c ("x86-64, gcc: Use
-mpreferred-stack-boundary=3 if supported"), is because uml links
against libc. There is no reason to assume libc is also compiled
with that flag and assumes 8-byte alignment rather than 16-byte.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40838
[2] https://c9x.me/x86/html/file_module_x86_id_180.html
Signed-off-by: YiFei Zhu <zhuyifei1999@gmail.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Richard Weinberger <richard@nod.at>
The generic asm futex implementation emulates atomic access to
memory by doing a get_user followed by put_user. These translate
to two mapping operations on UML with paging enabled in the
meantime. This, in turn may end up changing interrupts,
invoking the signal loop, etc.
This replaces the generic implementation by a mapping followed
by an operation on the mapped segment.
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
1. Reflect host cpu flags into the UML instance so they can
be used to select the correct implementations for xor, crypto, etc.
2. Reflect host cache alignment into UML instance. This is
important when running 32 bit on a 64 bit host as 32 bit by
default aligns to 32 while the actual alignment should be 64.
Ditto for some Xeons which align at 128.
Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
To support testing of PCI/PCIe drivers in UML, add a PCI bus
support driver. This driver uses virtio, which in UML is really
just vhost-user, to talk to devices, and adds the devices to
the virtual PCI bus in the system.
Since virtio already allows DMA/bus mastering this really isn't
all that hard, of course we need the logic_iomem infrastructure
that was added by a previous patch.
The protocol to talk to the device is has a few fairly simple
messages for reading to/writing from config and IO spaces, and
messages for the device to send the various interrupts (INT#,
MSI/MSI-X and while suspended PME#).
Note that currently no offical virtio device ID is assigned for
this protocol, as a consequence this patch requires defining it
in the Kconfig, with a default that makes the driver refuse to
work at all.
Finally, in order to add support for MSI/MSI-X interrupts, some
small changes are needed in the UML IRQ code, it needs to have
more interrupts, changing NR_IRQS from 64 to 128 if this driver
is enabled, but not actually use them for anything so that the
generic IRQ domain/MSI infrastructure can allocate IRQ numbers.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
If we happen to get multiple messages while IRQS are already
suspended, we still need to handle them, since otherwise the
simulation blocks.
Remove the "prevent nesting" part, time_travel_add_irq_event()
will deal with being called multiple times just fine.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
We should be able to ndelay() from any context, even from an
interrupt context! However, this is broken (not functionally,
but locking-wise) in time-travel because we'll get into the
time-travel code and enable interrupts to handle messages on
other time-travel aware subsystems (only virtio for now).
Luckily, I've already reworked the time-travel aware signal
(interrupt) delivery for suspend/resume to have a time travel
handler, which runs directly in the context of the signal and
not from the Linux interrupt.
In order to fix this time-travel issue then, we need to do a
few things:
1) rework the signal handling code to call time-travel handlers
(only) if interrupts are disabled but signals aren't blocked,
instead of marking it only pending there. This is needed to
not deadlock other communication.
2) rework time-travel to not enable interrupts while it's
waiting for a message;
3) rework time-travel to not (just) disable interrupts but
rather block signals at a lower level while it needs them
disabled for communicating with the controller.
Finally, since now we can actually spend even virtual time
in interrupts-disabled sections, the delay warning when we
deliver a time-travel delayed interrupt is no longer valid,
things can (and should) now get delayed.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Use signals_enabled instead of always jumping through
a function call to read it, there's not much point in
that.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
__NR_syscall_max is only used by x86 and UML. In contrast, __NR_syscalls is
widely used by all the architectures.
Convert __NR_syscall_max to __NR_syscalls and adjust the usage sites.
This prepares x86 to switch to the generic syscallhdr.sh script.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210517073815.97426-6-masahiroy@kernel.org
- Disable CONFIG_GCOV when built with modules
- Many fixes for W=1 related warnings
- Code cleanup
Due to lack of time I was unable to prepare a bigger pull request.
PR for the next merge window will contain more interesting material, I promise. :-)
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Merge tag 'for-linus-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML updates from Richard Weinberger:
- Disable CONFIG_GCOV when built with modules
- Many fixes for W=1 related warnings
- Code cleanup
* tag 'for-linus-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Fix W=1 missing-include-dirs warnings
um: elf.h: Fix W=1 warning for empty body in 'do' statement
um: pgtable.h: Fix W=1 warning for empty body in 'do' statement
um: Remove unused including <linux/version.h>
um: Add 2 missing libs to fix various build errors
um: Replace if (cond) BUG() with BUG_ON()
um: Disable CONFIG_GCOV with MODULES
um: Remove unneeded variable 'ret'
um: Mark all kernel symbols as local
um: Fix tag order in stub_32.h
mem_init_print_info() is called in mem_init() on each architecture, and
pass NULL argument, so using void argument and move it into mm_init().
Link: https://lkml.kernel.org/r/20210317015210.33641-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86]
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr> [powerpc]
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Anatoly Pugachev <matorola@gmail.com> [sparc64]
Acked-by: Russell King <rmk+kernel@armlinux.org.uk> [arm]
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Guo Ren <guoren@kernel.org>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek:
- Stop synchronizing kernel log buffer readers by logbuf_lock. As a
result, the access to the buffer is fully lockless now.
Note that printk() itself still uses locks because it tries to flush
the messages to the console immediately. Also the per-CPU temporary
buffers are still there because they prevent infinite recursion and
serialize backtraces from NMI. All this is going to change in the
future.
- kmsg_dump API rework and cleanup as a side effect of the logbuf_lock
removal.
- Make bstr_printf() aware that %pf and %pF formats could deference the
given pointer.
- Show also page flags by %pGp format.
- Clarify the documentation for plain pointer printing.
- Do not show no_hash_pointers warning multiple times.
- Update Senozhatsky email address.
- Some clean up.
* tag 'printk-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (24 commits)
lib/vsprintf.c: remove leftover 'f' and 'F' cases from bstr_printf()
printk: clarify the documentation for plain pointer printing
kernel/printk.c: Fixed mundane typos
printk: rename vprintk_func to vprintk
vsprintf: dump full information of page flags in pGp
mm, slub: don't combine pr_err with INFO
mm, slub: use pGp to print page flags
MAINTAINERS: update Senozhatsky email address
lib/vsprintf: do not show no_hash_pointers message multiple times
printk: console: remove unnecessary safe buffer usage
printk: kmsg_dump: remove _nolock() variants
printk: remove logbuf_lock
printk: introduce a kmsg_dump iterator
printk: kmsg_dumper: remove @active field
printk: add syslog_lock
printk: use atomic64_t for devkmsg_user.seq
printk: use seqcount_latch for clear_seq
printk: introduce CONSOLE_LOG_MAX
printk: consolidate kmsg_dump_get_buffer/syslog_print_all code
printk: refactor kmsg_dump_get_buffer()
...
Fix the following coccinelle reports:
./arch/um/kernel/mem.c:77:3-6: WARNING: Use BUG_ON instead of if
condition followed by BUG.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
CONFIG_GCOV doesn't work with modules, and for various reasons
it cannot work, see also
https://lore.kernel.org/r/d36ea54d8c0a8dd706826ba844a6f27691f45d55.camel@sipsolutions.net
Make CONFIG_GCOV depend on !MODULES to avoid anyone
running into issues there. This also means we need
not export the gcov symbols.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Ritesh reported a bug [1] against UML, noting that it crashed on
startup. The backtrace shows the following (heavily redacted):
(gdb) bt
...
#26 0x0000000060015b5d in sem_init () at ipc/sem.c:268
#27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2
#28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72
...
#40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359
...
#44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486
#45 0x00007f8990968b85 in __getgrnam_r [...]
#46 0x00007f89909d6b77 in grantpt [...]
#47 0x00007f8990a9394e in __GI_openpty [...]
#48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407
#49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598
#50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45
#51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334
#52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144
indicating that the UML function openpty_cb() calls openpty(),
which internally calls __getgrnam_r(), which causes the nsswitch
machinery to get started.
This loads, through lots of indirection that I snipped, the
libcom_err.so.2 library, which (in an unknown function, "??")
calls sem_init().
Now, of course it wants to get libpthread's sem_init(), since
it's linked against libpthread. However, the dynamic linker
looks up that symbol against the binary first, and gets the
kernel's sem_init().
Hajime Tazaki noted that "objcopy -L" can localize a symbol,
so the dynamic linker wouldn't do the lookup this way. I tried,
but for some reason that didn't seem to work.
Doing the same thing in the linker script instead does seem to
work, though I cannot entirely explain - it *also* works if I
just add "VERSION { { global: *; }; }" instead, indicating that
something else is happening that I don't really understand. It
may be that explicitly doing that marks them with some kind of
empty version, and that's different from the default.
Explicitly marking them with a version breaks kallsyms, so that
doesn't seem to be possible.
Marking all the symbols as local seems correct, and does seem
to address the issue, so do that. Also do it for static link,
nsswitch libraries could still be loaded there.
[1] https://bugs.debian.org/983379
Reported-by: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Tested-By: Ritesh Raj Sarraf <rrs@debian.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Rather than storing the iterator information in the registered
kmsg_dumper structure, create a separate iterator structure. The
kmsg_dump_iter structure can reside on the stack of the caller, thus
allowing lockless use of the kmsg_dump functions.
Update code that accesses the kernel logs using the kmsg_dumper
structure to use the new kmsg_dump_iter structure. For kmsg_dumpers,
this also means adding a call to kmsg_dump_rewind() to initialize
the iterator.
All this is in preparation for removal of @logbuf_lock.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org> # pstore
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210303101528.29901-13-john.ogness@linutronix.de
The kmsg_dumper can be called from any context and CPU, possibly
from multiple CPUs simultaneously. Since a static buffer is used
to retrieve the kernel logs, this buffer must be protected against
simultaneous dumping. Skip dumping if another context is already
dumping.
Signed-off-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/20210303101528.29901-2-john.ogness@linutronix.de
PF_IO_WORKER are kernel threads too, but they aren't PF_KTHREAD in the
sense that we don't assign ->set_child_tid with our own structure. Just
ensure that every arch sets up the PF_IO_WORKER threads like kthreads
in the arch implementation of copy_thread().
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a pseudo RTC that simply is able to send an alarm signal
waking up the system at a given time in the future.
Since apparently timerfd_create() FDs don't support SIGIO, we
use the sigio-creating helper thread, which just learned to do
suspend/resume properly in the previous patch.
For time-travel mode, OTOH, just add an event at the specified
time in the future, and that's already sufficient to wake up
the system at that point in time since suspend will just be in
an "endless wait".
For s2idle support also call pm_system_wakeup().
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This mostly reverts the old commit 3963333fe6 ("uml: cover stubs
with a VMA") which had added a VMA to the existing PTEs. However,
there's no real reason to have the PTEs in the first place and the
VMA cannot be 'fixed' in place, which leads to bugs that userspace
could try to unmap them and be forcefully killed, or such. Also,
there's a bit of an ugly hole in userspace's address space.
Simplify all this: just install the stub code/page at the top of
the (inner) address space, i.e. put it just above TASK_SIZE. The
pages are simply hard-coded to be mapped in the userspace process
we use to implement an mm context, and they're out of reach of the
inner mmap/munmap/mprotect etc. since they're above TASK_SIZE.
Getting rid of the VMA also makes vma_merge() no longer hit one of
the VM_WARN_ON()s there because we installed a VMA while the code
assumes the stack VMA is the first one.
It also removes a lockdep warning about mmap_sem usage since we no
longer have uml_setup_stubs() and thus no longer need to do any
manipulation that would require mmap_sem in activate_mm().
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
The userspace stacks mostly have a stack (and in the case of the
syscall stub we can just set their stack pointer) that points to
the location of the stub data page already.
Rework the stubs to use the stack pointer to derive the start of
the data page, rather than requiring it to be hard-coded.
In the clone stub, also integrate the int3 into the stack remap,
since we really must not use the stack while we remap it.
This prepares for putting the stub at a variable location that's
not part of the normal address space of the userspace processes
running inside the UML machine.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
If the two are mixed up, then it looks as though the parent
returned an error if the child failed (before) the mmap(),
and then the resulting process never gets killed. Fix this
by splitting the child and parent errors, reporting and
using them appropriately.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
In some cases we can get to fix_range_common() with mmap_sem held,
and in others we get there without it being held. For example, we
get there with it held from sys_mprotect(), and without it held
from fork_handler().
Avoid any issues in this and simply defer killing the task until
it runs the next time. Do it on the mm so that another task that
shares the same mm can't continue running afterwards.
Cc: stable@vger.kernel.org
Fixes: 468f65976a ("um: Fix hung task in fix_range_common()")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
If userspace tries to change the stub, we need to kill it,
because otherwise it can escape the virtual machine. In a
few cases the stub checks weren't good, e.g. if userspace
just tries to
mmap(0x100000 - 0x1000, 0x3000, ...)
it could succeed to get a new private/anonymous mapping
replacing the stubs. Fix this by checking everywhere, and
checking for _overlap_, not just direct changes.
Cc: stable@vger.kernel.org
Fixes: 3963333fe6 ("uml: cover stubs with a VMA")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
In external time-travel mode, where time is controlled via the
controller application socket, interrupt handling is a little
tricky. For example on virtio, the following happens:
* we receive a message (that requires an ACK) on the vhost-user socket
* we add a time-travel event to handle the interrupt
(this causes communication on the time socket)
* we ACK the original vhost-user message
* we then handle the interrupt once the event is triggered
This protocol ensures that the sender of the interrupt only continues
to run in the simulation when the time-travel event has been added.
So far, this was only done in the virtio driver, but it was actually
wrong, because only virtqueue interrupts were handled this way, and
config change interrupts were handled immediately. Additionally, the
messages were actually handled in the real Linux interrupt handler,
but Linux interrupt handlers are part of the simulation and shouldn't
run while there's no time event.
To really do this properly and only handle all kinds of interrupts in
the time-travel event when we are scheduled to run in the simulation,
rework this to plug in to the lower interrupt layers in UML directly:
Add a um_request_irq_tt() function that let's a time-travel aware
driver request an interrupt with an additional timetravel_handler()
that is called outside of the context of the simulation, to handle
the message only. It then adds an event to the time-travel calendar
if necessary, and no "real" Linux code runs outside of the time
simulation.
This also hooks in with suspend/resume properly now, since this new
timetravel_handler() can run while Linux is suspended and interrupts
are disabled, and decide to wake up (or not) the system based on the
message it received. Importantly in this case, it ACKs the message
before the system even resumes and interrupts are re-enabled, thus
allowing the simulation to progress properly.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
In time-travel mode, since my previous patch, the start time was
initialized too late, so that the system would read it before we
set it, thus always starting system time at 0 (1970-01-01). This
happens because timekeeping_init() reads the time and is called
before time_init().
Unfortunately, I didn't see this before because I was testing it
only with the RTC patch applied (and enabled), and then the time
is read again by the RTC a little - after time_init() this time.
Fix this by just doing the initialization whenever necessary.
Fixes: 2701c1bd91 ("um: time: Fix read_persistent_clock64() in time-travel")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This reverts commit 963285b0b4 ("um: support some of
ARCH_HAS_SET_MEMORY"), as it turns out that it's not only not
working (due to um never using the protection bits in the
page tables) but also corrupts the page tables if used on a
non-vmalloc page, since um never allocates proper page tables
for the 'physmem' in the first place.
Fixing all this will take more effort, so for now revert it.
Reported-by: Benjamin Berg <benjamin@sipsolutions.net>
Fixes: 963285b0b4 ("um: support some of ARCH_HAS_SET_MEMORY")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
This reverts commit ef4459a6da ("um: allocate a guard page to
helper threads"), it's broken in multiple ways:
1) the free no longer matches the alloc; and
2) more importantly, the set_memory_ro() causes allocation of
page tables for the normal memory that doesn't have any,
and that later causes corruption and crashes (usually but
not always in vfree()).
We could fix the first bug and use vmalloc() to work around the
second, but set_memory_ro() actually doesn't do anything either
so I'll just revert that as well.
Reported-by: Benjamin Berg <benjamin@sipsolutions.net>
Fixes: ef4459a6da ("um: allocate a guard page to helper threads")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
With the addition of the ttynull console driver, the chance that a
console driver was already registerd did increase. Refine the logic when
to dump the kernel message buffer: always dump the buffer, when the UML
stdio console driver is not active and the preferred console.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
The addition of the "ttynull" console driver did break the ordering of the
UML stdio console driver.
The UML stdio console driver is added in late_initcall (7), whereby the
ttynull driver is added in device_initcall (6), which always does make the
ttynull driver the default console.
Fix it by explicitly adding the UML stdio console as the preferred console,
in case no 'console=' command line option was specified.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
Thomas Gleixner
Masahiro Yamada
Huacai Chen
Christian Lamparter
Jason A. Donenfeld
Peter Zijlstra
Eric W. Biederman
Johannes Berg
Linus Torvalds
Kefeng Wang
Arnd Bergmann
Andy Shevchenko
Wan Jiabing
YiFei Zhu
Anton Ivanov
Yang Li
John Ogness
Jens Axboe
Thomas Meyer