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Diffstat (limited to 'mm/kasan/kasan.c')
-rw-r--r--mm/kasan/kasan.c63
1 files changed, 32 insertions, 31 deletions
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c
index 6845f9294696..b6f99e81bfeb 100644
--- a/mm/kasan/kasan.c
+++ b/mm/kasan/kasan.c
@@ -351,7 +351,6 @@ 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.
@@ -373,16 +372,8 @@ 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;
+ int orig_size = *size;
+
/* Add alloc meta. */
cache->kasan_info.alloc_meta_offset = *size;
*size += sizeof(struct kasan_alloc_meta);
@@ -395,14 +386,26 @@ void kasan_cache_create(struct kmem_cache *cache, size_t *size,
}
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)));
+
+ *size = min(KMALLOC_MAX_SIZE, max(*size, cache->object_size +
+ optimal_redzone(cache->object_size)));
+
+ /*
+ * If the metadata doesn't fit, don't enable KASAN at all.
+ */
+ if (*size <= cache->kasan_info.alloc_meta_offset ||
+ *size <= cache->kasan_info.free_meta_offset) {
+ cache->kasan_info.alloc_meta_offset = 0;
+ cache->kasan_info.free_meta_offset = 0;
+ *size = orig_size;
+ return;
+ }
+
+ *flags |= SLAB_KASAN;
}
-#endif
void kasan_cache_shrink(struct kmem_cache *cache)
{
@@ -414,6 +417,14 @@ void kasan_cache_destroy(struct kmem_cache *cache)
quarantine_remove_cache(cache);
}
+size_t kasan_metadata_size(struct kmem_cache *cache)
+{
+ return (cache->kasan_info.alloc_meta_offset ?
+ sizeof(struct kasan_alloc_meta) : 0) +
+ (cache->kasan_info.free_meta_offset ?
+ sizeof(struct kasan_free_meta) : 0);
+}
+
void kasan_poison_slab(struct page *page)
{
kasan_poison_shadow(page_address(page),
@@ -431,16 +442,13 @@ 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
}
-#ifdef CONFIG_SLAB
static inline int in_irqentry_text(unsigned long ptr)
{
return (ptr >= (unsigned long)&__irqentry_text_start &&
@@ -501,7 +509,6 @@ struct kasan_free_meta *get_free_info(struct kmem_cache *cache,
BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32);
return (void *)object + cache->kasan_info.free_meta_offset;
}
-#endif
void kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags)
{
@@ -522,16 +529,16 @@ static void kasan_poison_slab_free(struct kmem_cache *cache, void *object)
bool kasan_slab_free(struct kmem_cache *cache, void *object)
{
-#ifdef CONFIG_SLAB
/* RCU slabs could be legally used after free within the RCU period */
if (unlikely(cache->flags & SLAB_DESTROY_BY_RCU))
return false;
if (likely(cache->flags & SLAB_KASAN)) {
- struct kasan_alloc_meta *alloc_info =
- get_alloc_info(cache, object);
- struct kasan_free_meta *free_info =
- get_free_info(cache, object);
+ struct kasan_alloc_meta *alloc_info;
+ struct kasan_free_meta *free_info;
+
+ alloc_info = get_alloc_info(cache, object);
+ free_info = get_free_info(cache, object);
switch (alloc_info->state) {
case KASAN_STATE_ALLOC:
@@ -550,10 +557,6 @@ bool kasan_slab_free(struct kmem_cache *cache, void *object)
}
}
return false;
-#else
- kasan_poison_slab_free(cache, object);
- return false;
-#endif
}
void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size,
@@ -576,7 +579,6 @@ 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);
@@ -585,7 +587,6 @@ void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size,
alloc_info->alloc_size = size;
set_track(&alloc_info->track, flags);
}
-#endif
}
EXPORT_SYMBOL(kasan_kmalloc);