Commit-ID: 1e6f85cb6771d54c9346270d7b0667500d9f3eab Gitweb: http://git.kernel.org/tip/1e6f85cb6771d54c9346270d7b0667500d9f3eab Author: Andrey Ryabinin <aryabi...@virtuozzo.com> AuthorDate: Tue, 13 Oct 2015 18:28:08 +0300 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 14 Oct 2015 16:44:06 +0200
x86/mm: 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.le...@oracle.com> Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> Cc: Alexander Potapenko <gli...@google.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Andrey Konovalov <andreyk...@google.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Borislav Petkov <b...@alien8.de> Cc: Denys Vlasenko <dvlas...@redhat.com> Cc: Dmitry Vyukov <dvyu...@google.com> Cc: Kostya Serebryany <k...@google.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Wolfram Gloger <wm...@dent.med.uni-muenchen.de> Cc: kasan-dev <kasan-...@googlegroups.com> Link: http://lkml.kernel.org/r/1444750088-24444-3-git-send-email-aryabi...@virtuozzo.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/process.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 39e585a..e28db18 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
