From e8a4efd041734c248674f585d44b770ef8ea79aa Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Fri, 31 Mar 2017 15:12:04 -0700 Subject: BACKPORT: kasan: report only the first error by default Disable kasan after the first report. There are several reasons for this: - Single bug quite often has multiple invalid memory accesses causing storm in the dmesg. - Write OOB access might corrupt metadata so the next report will print bogus alloc/free stacktraces. - Reports after the first easily could be not bugs by itself but just side effects of the first one. Given that multiple reports usually only do harm, it makes sense to disable kasan after the first one. If user wants to see all the reports, the boot-time parameter kasan_multi_shot must be used. [aryabinin@virtuozzo.com: wrote changelog and doc, added missing include] Link: http://lkml.kernel.org/r/20170323154416.30257-1-aryabinin@virtuozzo.com Signed-off-by: Mark Rutland Signed-off-by: Andrey Ryabinin Cc: Andrey Konovalov Cc: Alexander Potapenko Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Bug: 64145065 (cherry-picked from b0845ce58379d11dcad4cdb6824a6410de260216) Change-Id: Ia8c6d40dd0d4f5b944bf3501c08d7a825070b116 Signed-off-by: Paul Lawrence --- include/linux/kasan.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 7793036eac80..b37afd197eed 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -75,6 +75,9 @@ size_t ksize(const void *); static inline void kasan_unpoison_slab(const void *ptr) { ksize(ptr); } size_t kasan_metadata_size(struct kmem_cache *cache); +bool kasan_save_enable_multi_shot(void); +void kasan_restore_multi_shot(bool enabled); + #else /* CONFIG_KASAN */ static inline void kasan_unpoison_shadow(const void *address, size_t size) {} -- cgit v1.2.3