From 836daba099472baaa8b6a57772e8bb2d55f1f9d7 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Mon, 5 Sep 2022 23:05:23 +0200 Subject: [PATCH] kasan: introduce kasan_init_object_meta Add a kasan_init_object_meta() helper that initializes metadata for a slab object and use it in the common code. For now, the implementations of this helper are the same for the Generic and tag-based modes, but they will diverge later in the series. This change hides references to alloc_meta from the common code. This is desired as only the Generic mode will be using per-object metadata after this series. Link: https://lkml.kernel.org/r/47c12938fc7f8105e7aaa592527c0e9d3c81fc37.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Marco Elver Cc: Alexander Potapenko Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Peter Collingbourne Signed-off-by: Andrew Morton --- mm/kasan/common.c | 10 +++------- mm/kasan/generic.c | 9 +++++++++ mm/kasan/kasan.h | 2 ++ mm/kasan/tags.c | 9 +++++++++ 4 files changed, 23 insertions(+), 7 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 93e64e1..1810767 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -313,13 +313,9 @@ static inline u8 assign_tag(struct kmem_cache *cache, void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache, const void *object) { - struct kasan_alloc_meta *alloc_meta; - - if (kasan_stack_collection_enabled()) { - alloc_meta = kasan_get_alloc_meta(cache, object); - if (alloc_meta) - __memset(alloc_meta, 0, sizeof(*alloc_meta)); - } + /* Initialize per-object metadata if it is present. */ + if (kasan_stack_collection_enabled()) + kasan_init_object_meta(cache, object); /* Tag is ignored in set_tag() without CONFIG_KASAN_SW/HW_TAGS */ object = set_tag(object, assign_tag(cache, object, true)); diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index f212b9a..5462ddb 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -328,6 +328,15 @@ DEFINE_ASAN_SET_SHADOW(f3); DEFINE_ASAN_SET_SHADOW(f5); DEFINE_ASAN_SET_SHADOW(f8); +void kasan_init_object_meta(struct kmem_cache *cache, const void *object) +{ + struct kasan_alloc_meta *alloc_meta; + + alloc_meta = kasan_get_alloc_meta(cache, object); + if (alloc_meta) + __memset(alloc_meta, 0, sizeof(*alloc_meta)); +} + static void __kasan_record_aux_stack(void *addr, bool can_alloc) { struct slab *slab = kasan_addr_to_slab(addr); diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index b65a513..2c8c3cc 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -279,6 +279,8 @@ void kasan_report_invalid_free(void *object, unsigned long ip, enum kasan_report struct page *kasan_addr_to_page(const void *addr); struct slab *kasan_addr_to_slab(const void *addr); +void kasan_init_object_meta(struct kmem_cache *cache, const void *object); + depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc); void kasan_set_track(struct kasan_track *track, gfp_t flags); void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags); diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index 7b1fc8e..2e20096 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -17,6 +17,15 @@ #include "kasan.h" +void kasan_init_object_meta(struct kmem_cache *cache, const void *object) +{ + struct kasan_alloc_meta *alloc_meta; + + alloc_meta = kasan_get_alloc_meta(cache, object); + if (alloc_meta) + __memset(alloc_meta, 0, sizeof(*alloc_meta)); +} + void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags) { struct kasan_alloc_meta *alloc_meta; -- 2.7.4