From ce3ba2af9695e4bd64d797e0026321e5dca29dd3 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Fri, 18 Nov 2022 18:23:05 +0100 Subject: x86: Suppress KMSAN reports in arch_within_stack_frames() arch_within_stack_frames() performs stack walking and may confuse KMSAN by stepping on stale shadow values. To prevent false positive reports, disable KMSAN checks in this function. This fixes KMSAN's interoperability with CONFIG_HARDENED_USERCOPY. Signed-off-by: Alexander Potapenko Signed-off-by: Dave Hansen Tested-by: Eric Biggers Link: https://github.com/google/kmsan/issues/89 Link: https://lore.kernel.org/lkml/Y3b9AAEKp2Vr3e6O@sol.localdomain/ Link: https://lore.kernel.org/all/20221118172305.3321253-1-glider%40google.com --- arch/x86/include/asm/thread_info.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/x86/include/asm') diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index f0cb881c1d69..f1cccba52eb9 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -163,7 +163,12 @@ struct thread_info { * GOOD_FRAME if within a frame * BAD_STACK if placed across a frame boundary (or outside stack) * NOT_STACK unable to determine (no frame pointers, etc) + * + * This function reads pointers from the stack and dereferences them. The + * pointers may not have their KMSAN shadow set up properly, which may result + * in false positive reports. Disable instrumentation to avoid those. */ +__no_kmsan_checks static inline int arch_within_stack_frames(const void * const stack, const void * const stackend, const void *obj, unsigned long len) -- cgit v1.2.3