diff options
Diffstat (limited to 'mm/kasan')
| -rw-r--r-- | mm/kasan/Makefile | 2 | ||||
| -rw-r--r-- | mm/kasan/common.c | 29 | ||||
| -rw-r--r-- | mm/kasan/tags.c | 2 |
3 files changed, 20 insertions, 13 deletions
diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile index e2bb06c1b45e..5d1065efbd47 100644 --- a/mm/kasan/Makefile +++ b/mm/kasan/Makefile @@ -7,6 +7,8 @@ KCOV_INSTRUMENT := n CFLAGS_REMOVE_common.o = -pg CFLAGS_REMOVE_generic.o = -pg +CFLAGS_REMOVE_tags.o = -pg + # Function splitter causes unnecessary splits in __asan_load1/__asan_store1 # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533 diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 73c9cbfdedf4..09b534fbba17 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -361,10 +361,15 @@ void kasan_poison_object_data(struct kmem_cache *cache, void *object) * get different tags. */ static u8 assign_tag(struct kmem_cache *cache, const void *object, - bool init, bool krealloc) + bool init, bool keep_tag) { - /* Reuse the same tag for krealloc'ed objects. */ - if (krealloc) + /* + * 1. When an object is kmalloc()'ed, two hooks are called: + * kasan_slab_alloc() and kasan_kmalloc(). We assign the + * tag only in the first one. + * 2. We reuse the same tag for krealloc'ed objects. + */ + if (keep_tag) return get_tag(object); /* @@ -405,12 +410,6 @@ void * __must_check kasan_init_slab_obj(struct kmem_cache *cache, return (void *)object; } -void * __must_check kasan_slab_alloc(struct kmem_cache *cache, void *object, - gfp_t flags) -{ - return kasan_kmalloc(cache, object, cache->object_size, flags); -} - static inline bool shadow_invalid(u8 tag, s8 shadow_byte) { if (IS_ENABLED(CONFIG_KASAN_GENERIC)) @@ -467,7 +466,7 @@ bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip) } static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, - size_t size, gfp_t flags, bool krealloc) + size_t size, gfp_t flags, bool keep_tag) { unsigned long redzone_start; unsigned long redzone_end; @@ -485,7 +484,7 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, KASAN_SHADOW_SCALE_SIZE); if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) - tag = assign_tag(cache, object, false, krealloc); + tag = assign_tag(cache, object, false, keep_tag); /* Tag is ignored in set_tag without CONFIG_KASAN_SW_TAGS */ kasan_unpoison_shadow(set_tag(object, tag), size); @@ -498,10 +497,16 @@ static void *__kasan_kmalloc(struct kmem_cache *cache, const void *object, return set_tag(object, tag); } +void * __must_check kasan_slab_alloc(struct kmem_cache *cache, void *object, + gfp_t flags) +{ + return __kasan_kmalloc(cache, object, cache->object_size, flags, false); +} + void * __must_check kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size, gfp_t flags) { - return __kasan_kmalloc(cache, object, size, flags, false); + return __kasan_kmalloc(cache, object, size, flags, true); } EXPORT_SYMBOL(kasan_kmalloc); diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index 0777649e07c4..63fca3172659 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -46,7 +46,7 @@ void kasan_init_tags(void) int cpu; for_each_possible_cpu(cpu) - per_cpu(prng_state, cpu) = get_random_u32(); + per_cpu(prng_state, cpu) = (u32)get_cycles(); } /* |
