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>
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index d67a7e0..f437398 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -133,7 +133,6 @@
void *object, char *unused_reason)
{
struct kasan_alloc_meta *alloc_info = get_alloc_info(cache, object);
- struct kasan_free_meta *free_info;
dump_stack();
pr_err("Object at %p, in cache %s size: %d\n", object, cache->name,
@@ -141,23 +140,11 @@
if (!(cache->flags & SLAB_KASAN))
return;
- switch (alloc_info->state) {
- case KASAN_STATE_INIT:
- pr_err("Object not allocated yet\n");
- break;
- case KASAN_STATE_ALLOC:
- pr_err("Allocation:\n");
- print_track(&alloc_info->track);
- break;
- case KASAN_STATE_FREE:
- case KASAN_STATE_QUARANTINE:
- free_info = get_free_info(cache, object);
- pr_err("Allocation:\n");
- print_track(&alloc_info->track);
- pr_err("Deallocation:\n");
- print_track(&free_info->track);
- break;
- }
+
+ pr_err("Allocated:\n");
+ print_track(&alloc_info->alloc_track);
+ pr_err("Freed:\n");
+ print_track(&alloc_info->free_track);
}
static void print_address_description(struct kasan_access_info *info)