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| author | Andrey Ryabinin <aryabinin@virtuozzo.com> | 2015-10-19 10:37:18 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-10-20 11:04:19 +0200 |
| commit | f7d27c35ddff7c100d7a98db499ac0040149ac05 (patch) | |
| tree | 0325b7fa7aa4f92950b003944575f5157c3e844b | |
| parent | compiler, atomics, kasan: Provide READ_ONCE_NOCHECK() (diff) | |
| download | linux-f7d27c35ddff7c100d7a98db499ac0040149ac05.tar.xz linux-f7d27c35ddff7c100d7a98db499ac0040149ac05.zip | |
x86/mm, kasan: Silence KASAN warnings in get_wchan()
get_wchan() is racy by design, it may access volatile stack
of running task, thus it may access redzone in a stack frame
and cause KASAN to warn about this.
Use READ_ONCE_NOCHECK() to silence these warnings.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wolfram Gloger <wmglo@dent.med.uni-muenchen.de>
Cc: kasan-dev <kasan-dev@googlegroups.com>
Link: http://lkml.kernel.org/r/1445243838-17763-3-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/kernel/process.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 39e585a554b7..e28db181e4fc 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -550,14 +550,14 @@ unsigned long get_wchan(struct task_struct *p) if (sp < bottom || sp > top) return 0; - fp = READ_ONCE(*(unsigned long *)sp); + fp = READ_ONCE_NOCHECK(*(unsigned long *)sp); do { if (fp < bottom || fp > top) return 0; - ip = READ_ONCE(*(unsigned long *)(fp + sizeof(unsigned long))); + ip = READ_ONCE_NOCHECK(*(unsigned long *)(fp + sizeof(unsigned long))); if (!in_sched_functions(ip)) return ip; - fp = READ_ONCE(*(unsigned long *)fp); + fp = READ_ONCE_NOCHECK(*(unsigned long *)fp); } while (count++ < 16 && p->state != TASK_RUNNING); return 0; } |