From 682ed08924407b719fa0b1123a26971748d76ace Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Mon, 5 Sep 2022 23:05:33 +0200 Subject: kasan: only define kasan_cache_create for Generic mode Right now, kasan_cache_create() assigns SLAB_KASAN for all KASAN modes and then sets up metadata-related cache parameters for the Generic mode. SLAB_KASAN is used in two places: 1. In slab_ksize() to account for per-object metadata when calculating the size of the accessible memory within the object. 2. In slab_common.c via kasan_never_merge() to prevent merging of caches with per-object metadata. Both cases are only relevant when per-object metadata is present, which is only the case with the Generic mode. Thus, assign SLAB_KASAN and define kasan_cache_create() only for the Generic mode. Also update the SLAB_KASAN-related comment. Link: https://lkml.kernel.org/r/61faa2aa1906e2d02c97d00ddf99ce8911dda095.1662411799.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 | 16 ---------------- mm/kasan/generic.c | 17 ++++++++++++++++- 2 files changed, 16 insertions(+), 17 deletions(-) (limited to 'mm') diff --git a/mm/kasan/common.c b/mm/kasan/common.c index c2690e938030..8efa63190951 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -110,22 +110,6 @@ void __kasan_poison_pages(struct page *page, unsigned int order, bool init) KASAN_PAGE_FREE, init); } -void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size, - slab_flags_t *flags) -{ - /* - * SLAB_KASAN is used to mark caches as ones that are sanitized by - * KASAN. Currently this flag is used in two places: - * 1. In slab_ksize() when calculating the size of the accessible - * memory within the object. - * 2. In slab_common.c to prevent merging of sanitized caches. - */ - *flags |= SLAB_KASAN; - - if (kasan_requires_meta()) - kasan_init_cache_meta(cache, size); -} - void __kasan_cache_create_kmalloc(struct kmem_cache *cache) { cache->kasan_info.is_kmalloc = true; diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 25333bf3c99f..f6bef347de87 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -352,11 +352,26 @@ static inline unsigned int optimal_redzone(unsigned int object_size) object_size <= (1 << 16) - 1024 ? 1024 : 2048; } -void kasan_init_cache_meta(struct kmem_cache *cache, unsigned int *size) +void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, + slab_flags_t *flags) { unsigned int ok_size; unsigned int optimal_size; + if (!kasan_requires_meta()) + return; + + /* + * SLAB_KASAN is used to mark caches that are sanitized by KASAN + * and that thus have per-object metadata. + * Currently this flag is used in two places: + * 1. In slab_ksize() to account for per-object metadata when + * calculating the size of the accessible memory within the object. + * 2. In slab_common.c via kasan_never_merge() to prevent merging of + * caches with per-object metadata. + */ + *flags |= SLAB_KASAN; + ok_size = *size; /* Add alloc meta into redzone. */ -- cgit v1.2.3-58-ga151