Commit 72786c0a authored by Vlastimil Babka's avatar Vlastimil Babka
Browse files

KASAN: remove code paths guarded by CONFIG_SLAB 



With SLAB removed and SLUB the only remaining allocator, we can clean up
some code that was depending on the choice.

Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarMarco Elver <elver@google.com>
Reviewed-by: default avatarAndrey Konovalov <andreyknvl@gmail.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Tested-by: default avatarDavid Rientjes <rientjes@google.com>
Reviewed-by: default avatarHyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: default avatarHyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
parent 2a19be61

mm/kasan/common.c

+2 −11
Original line number Diff line number Diff line
@@ -153,10 +153,6 @@ void __kasan_poison_object_data(struct kmem_cache *cache, void *object) 
 * 2. A cache might be SLAB_TYPESAFE_BY_RCU, which means objects can be

 *    accessed after being freed. We preassign tags for objects in these

 *    caches as well.

 * 3. For SLAB allocator we can't preassign tags randomly since the freelist

 *    is stored as an array of indexes instead of a linked list. Assign tags

 *    based on objects indexes, so that objects that are next to each other

 *    get different tags.

 */

static inline u8 assign_tag(struct kmem_cache *cache,

					const void *object, bool init)
@@ -171,17 +167,12 @@ static inline u8 assign_tag(struct kmem_cache *cache, 
	if (!cache->ctor && !(cache->flags & SLAB_TYPESAFE_BY_RCU))

		return init ? KASAN_TAG_KERNEL : kasan_random_tag();



	/* For caches that either have a constructor or SLAB_TYPESAFE_BY_RCU: */

#ifdef CONFIG_SLAB

	/* For SLAB assign tags based on the object index in the freelist. */

	return (u8)obj_to_index(cache, virt_to_slab(object), (void *)object);

#else

	/*

	 * For SLUB assign a random tag during slab creation, otherwise reuse

	 * For caches that either have a constructor or SLAB_TYPESAFE_BY_RCU,

	 * assign a random tag during slab creation, otherwise reuse

	 * the already assigned tag.

	 */

	return init ? kasan_random_tag() : get_tag(object);

#endif

}



void * __must_check __kasan_init_slab_obj(struct kmem_cache *cache,

mm/kasan/kasan.h

+1 −2
Original line number Diff line number Diff line
@@ -373,8 +373,7 @@ 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);

void kasan_save_free_info(struct kmem_cache *cache, void *object);



#if defined(CONFIG_KASAN_GENERIC) && \

	(defined(CONFIG_SLAB) || defined(CONFIG_SLUB))

#ifdef CONFIG_KASAN_GENERIC

bool kasan_quarantine_put(struct kmem_cache *cache, void *object);

void kasan_quarantine_reduce(void);

void kasan_quarantine_remove_cache(struct kmem_cache *cache);

mm/kasan/quarantine.c

+0 −7
Original line number Diff line number Diff line
@@ -144,10 +144,6 @@ static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache) 
{

	void *object = qlink_to_object(qlink, cache);

	struct kasan_free_meta *meta = kasan_get_free_meta(cache, object);

	unsigned long flags;



	if (IS_ENABLED(CONFIG_SLAB))

		local_irq_save(flags);



	/*

	 * If init_on_free is enabled and KASAN's free metadata is stored in
@@ -166,9 +162,6 @@ static void qlink_free(struct qlist_node *qlink, struct kmem_cache *cache) 
	*(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREE;



	___cache_free(cache, object, _THIS_IP_);



	if (IS_ENABLED(CONFIG_SLAB))

		local_irq_restore(flags);

}



static void qlist_free_all(struct qlist_head *q, struct kmem_cache *cache)