diff options
author | Alexander Potapenko <glider@google.com> | 2016-03-25 22:21:59 +0100 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-26 00:37:42 +0100 |
commit | 7ed2f9e663854db313f177a511145630e398b402 (patch) | |
tree | f9dfba81a688864a4d78689470f624b0a482f545 /mm/kasan/kasan.c | |
parent | kasan: modify kmalloc_large_oob_right(), add kmalloc_pagealloc_oob_right() (diff) | |
download | linux-7ed2f9e663854db313f177a511145630e398b402.tar.xz linux-7ed2f9e663854db313f177a511145630e398b402.zip |
mm, kasan: SLAB support
Add KASAN hooks to SLAB allocator.
This patch is based on the "mm: kasan: unified support for SLUB and SLAB
allocators" patch originally prepared by Dmitry Chernenkov.
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan/kasan.c')
-rw-r--r-- | mm/kasan/kasan.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 1ad20ade8c91..7c82509ef169 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -334,6 +334,59 @@ void kasan_free_pages(struct page *page, unsigned int order) KASAN_FREE_PAGE); } +#ifdef CONFIG_SLAB +/* + * Adaptive redzone policy taken from the userspace AddressSanitizer runtime. + * For larger allocations larger redzones are used. + */ +static size_t optimal_redzone(size_t object_size) +{ + int rz = + object_size <= 64 - 16 ? 16 : + object_size <= 128 - 32 ? 32 : + object_size <= 512 - 64 ? 64 : + object_size <= 4096 - 128 ? 128 : + object_size <= (1 << 14) - 256 ? 256 : + object_size <= (1 << 15) - 512 ? 512 : + object_size <= (1 << 16) - 1024 ? 1024 : 2048; + return rz; +} + +void kasan_cache_create(struct kmem_cache *cache, size_t *size, + unsigned long *flags) +{ + int redzone_adjust; + /* Make sure the adjusted size is still less than + * KMALLOC_MAX_CACHE_SIZE. + * TODO: this check is only useful for SLAB, but not SLUB. We'll need + * to skip it for SLUB when it starts using kasan_cache_create(). + */ + if (*size > KMALLOC_MAX_CACHE_SIZE - + sizeof(struct kasan_alloc_meta) - + sizeof(struct kasan_free_meta)) + return; + *flags |= SLAB_KASAN; + /* Add alloc meta. */ + cache->kasan_info.alloc_meta_offset = *size; + *size += sizeof(struct kasan_alloc_meta); + + /* Add free meta. */ + if (cache->flags & SLAB_DESTROY_BY_RCU || cache->ctor || + cache->object_size < sizeof(struct kasan_free_meta)) { + cache->kasan_info.free_meta_offset = *size; + *size += sizeof(struct kasan_free_meta); + } + redzone_adjust = optimal_redzone(cache->object_size) - + (*size - cache->object_size); + if (redzone_adjust > 0) + *size += redzone_adjust; + *size = min(KMALLOC_MAX_CACHE_SIZE, + max(*size, + cache->object_size + + optimal_redzone(cache->object_size))); +} +#endif + void kasan_poison_slab(struct page *page) { kasan_poison_shadow(page_address(page), @@ -351,8 +404,36 @@ void kasan_poison_object_data(struct kmem_cache *cache, void *object) kasan_poison_shadow(object, round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE), KASAN_KMALLOC_REDZONE); +#ifdef CONFIG_SLAB + if (cache->flags & SLAB_KASAN) { + struct kasan_alloc_meta *alloc_info = + get_alloc_info(cache, object); + alloc_info->state = KASAN_STATE_INIT; + } +#endif +} + +static inline void set_track(struct kasan_track *track) +{ + track->cpu = raw_smp_processor_id(); + track->pid = current->pid; + track->when = jiffies; } +#ifdef CONFIG_SLAB +struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache, + const void *object) +{ + return (void *)object + cache->kasan_info.alloc_meta_offset; +} + +struct kasan_free_meta *get_free_info(struct kmem_cache *cache, + const void *object) +{ + return (void *)object + cache->kasan_info.free_meta_offset; +} +#endif + void kasan_slab_alloc(struct kmem_cache *cache, void *object) { kasan_kmalloc(cache, object, cache->object_size); @@ -367,6 +448,17 @@ void kasan_slab_free(struct kmem_cache *cache, void *object) if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU)) return; +#ifdef CONFIG_SLAB + if (cache->flags & SLAB_KASAN) { + struct kasan_free_meta *free_info = + get_free_info(cache, object); + struct kasan_alloc_meta *alloc_info = + get_alloc_info(cache, object); + alloc_info->state = KASAN_STATE_FREE; + set_track(&free_info->track); + } +#endif + kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE); } @@ -386,6 +478,16 @@ void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size) kasan_unpoison_shadow(object, size); kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start, KASAN_KMALLOC_REDZONE); +#ifdef CONFIG_SLAB + if (cache->flags & SLAB_KASAN) { + struct kasan_alloc_meta *alloc_info = + get_alloc_info(cache, object); + + alloc_info->state = KASAN_STATE_ALLOC; + alloc_info->alloc_size = size; + set_track(&alloc_info->track); + } +#endif } EXPORT_SYMBOL(kasan_kmalloc); |