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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-20 11:13:58 +08:00
linux-next/arch
Josh Poimboeuf 84936118bd x86/unwind: Disable KASAN checks for non-current tasks
There are a handful of callers to save_stack_trace_tsk() and
show_stack() which try to unwind the stack of a task other than current.
In such cases, it's remotely possible that the task is running on one
CPU while the unwinder is reading its stack from another CPU, causing
the unwinder to see stack corruption.

These cases seem to be mostly harmless.  The unwinder has checks which
prevent it from following bad pointers beyond the bounds of the stack.
So it's not really a bug as long as the caller understands that
unwinding another task will not always succeed.

In such cases, it's possible that the unwinder may read a KASAN-poisoned
region of the stack.  Account for that by using READ_ONCE_NOCHECK() when
reading the stack of another task.

Use READ_ONCE() when reading the stack of the current task, since KASAN
warnings can still be useful for finding bugs in that case.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/4c575eb288ba9f73d498dfe0acde2f58674598f1.1483978430.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-12 09:28:27 +01:00
..
alpha clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
arc 2nd round of ARC udpates for 4.10rc1 2016-12-23 10:22:47 -08:00
arm Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
arm64 arm64: don't pull uaccess.h into *.S 2016-12-26 13:05:17 -05:00
avr32 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
blackfin Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
c6x clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
cris Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
frv Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
h8300 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
hexagon clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
ia64 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
m32r Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
m68k clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
metag Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:05:56 -08:00
microblaze clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
mips Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
mn10300 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
nios2 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
openrisc openrisc: Add _text symbol to fix ksym build error 2017-01-02 10:35:11 +09:00
parisc parisc: Add line-break when printing segfault info 2017-01-02 18:07:25 +01:00
powerpc powerpc: Fix build warning on 32-bit PPC 2016-12-25 16:12:20 -08:00
s390 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2017-01-02 09:08:45 -08:00
score Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sh Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
sparc clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
tile Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
um clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
unicore32 clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
x86 x86/unwind: Disable KASAN checks for non-current tasks 2017-01-12 09:28:27 +01:00
xtensa Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
.gitignore
Kconfig powerpc: ima: get the kexec buffer passed by the previous kernel 2016-12-20 09:48:40 -08:00