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authorAndrey Ryabinin <aryabinin@virtuozzo.com>2016-08-03 00:02:52 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-08-03 00:31:41 +0300
commitb3cbd9bf77cd1888114dbee1653e79aa23fd4068 (patch)
treef9a10e2c14b336f276805f8a4714d0bd437d1646 /mm/kasan/kasan.h
parent47b5c2a0f021e90a79845d1a1353780e5edd0bce (diff)
downloadlinux-b3cbd9bf77cd1888114dbee1653e79aa23fd4068.tar.xz
mm/kasan: get rid of ->state in struct kasan_alloc_meta
The state of object currently tracked in two places - shadow memory, and the ->state field in struct kasan_alloc_meta. We can get rid of the latter. The will save us a little bit of memory. Also, this allow us to move free stack into struct kasan_alloc_meta, without increasing memory consumption. So now we should always know when the last time the object was freed. This may be useful for long delayed use-after-free bugs. As a side effect this fixes following UBSAN warning: UBSAN: Undefined behaviour in mm/kasan/quarantine.c:102:13 member access within misaligned address ffff88000d1efebc for type 'struct qlist_node' which requires 8 byte alignment Link: http://lkml.kernel.org/r/1470062715-14077-5-git-send-email-aryabinin@virtuozzo.com Reported-by: kernel test robot <xiaolong.ye@intel.com> Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan/kasan.h')
-rw-r--r--mm/kasan/kasan.h12
1 files changed, 2 insertions, 10 deletions
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index aa175460c8f9..9b7b31e25fd2 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -59,13 +59,6 @@ struct kasan_global {
* Structures to keep alloc and free tracks *
*/
-enum kasan_state {
- KASAN_STATE_INIT,
- KASAN_STATE_ALLOC,
- KASAN_STATE_QUARANTINE,
- KASAN_STATE_FREE
-};
-
#define KASAN_STACK_DEPTH 64
struct kasan_track {
@@ -74,8 +67,8 @@ struct kasan_track {
};
struct kasan_alloc_meta {
- struct kasan_track track;
- u32 state;
+ struct kasan_track alloc_track;
+ struct kasan_track free_track;
};
struct qlist_node {
@@ -86,7 +79,6 @@ struct kasan_free_meta {
* Otherwise it might be used for the allocator freelist.
*/
struct qlist_node quarantine_link;
- struct kasan_track track;
};
struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache,