From ac605bee0bfab40fd5d11964705e907d2d5a32de Mon Sep 17 00:00:00 2001 From: Dmitry Vyukov Date: Mon, 29 Jan 2018 18:26:07 +0100 Subject: locking/atomic, asm-generic, x86: Add comments for atomic instrumentation The comments are factored out from the code changes to make them easier to read. Add them separately to explain some non-obvious aspects. Signed-off-by: Dmitry Vyukov Cc: Andrew Morton Cc: Andrey Ryabinin Cc: Linus Torvalds Cc: Mark Rutland Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Cc: kasan-dev@googlegroups.com Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/cc595efc644bb905407012d82d3eb8bac3368e7a.1517246437.git.dvyukov@google.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/atomic.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/x86/include/asm/atomic.h') diff --git a/arch/x86/include/asm/atomic.h b/arch/x86/include/asm/atomic.h index 33afc966d6a9..0db6bec95489 100644 --- a/arch/x86/include/asm/atomic.h +++ b/arch/x86/include/asm/atomic.h @@ -24,6 +24,10 @@ */ static __always_inline int arch_atomic_read(const atomic_t *v) { + /* + * Note for KASAN: we deliberately don't use READ_ONCE_NOCHECK() here, + * it's non-inlined function that increases binary size and stack usage. + */ return READ_ONCE((v)->counter); } -- cgit v1.2.3