UPSTREAM: mm/kasan: get rid of ->alloc_size in struct kasan_alloc_meta

Size of slab object already stored in cache->object_size.

Note, that kmalloc() internally rounds up size of allocation, so
object_size may be not equal to alloc_size, but, usually we don't need
to know the exact size of allocated object.  In case if we need that
information, we still can figure it out from the report.  The dump of
shadow memory allows to identify the end of allocated memory, and
thereby the exact allocation size.

Link: http://lkml.kernel.org/r/1470062715-14077-4-git-send-email-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Bug: 64145065
(cherry-picked from 47b5c2a0f021e90a79845d1a1353780e5edd0bce)
Change-Id: I76b555f9a8469f685607ca50f6c51b2e0ad1b4ab
Signed-off-by: Paul Lawrence <paullawrence@google.com>
This commit is contained in:
Andrey Ryabinin 2016-08-02 14:02:49 -07:00 committed by Paul Lawrence
parent 30d8b5b402
commit 1f93a556df
3 changed files with 4 additions and 8 deletions

View file

@ -584,7 +584,6 @@ void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size,
get_alloc_info(cache, object);
alloc_info->state = KASAN_STATE_ALLOC;
alloc_info->alloc_size = size;
set_track(&alloc_info->track, flags);
}
}

View file

@ -78,8 +78,7 @@ struct kasan_track {
struct kasan_alloc_meta {
struct kasan_track track;
u32 state : 2; /* enum kasan_state */
u32 alloc_size : 30;
u32 state;
};
struct qlist_node {

View file

@ -137,7 +137,9 @@ static void kasan_object_err(struct kmem_cache *cache, struct page *page,
struct kasan_free_meta *free_info;
dump_stack();
pr_err("Object at %p, in cache %s\n", object, cache->name);
pr_err("Object at %p, in cache %s size: %d\n", object, cache->name,
cache->object_size);
if (!(cache->flags & SLAB_KASAN))
return;
switch (alloc_info->state) {
@ -145,15 +147,11 @@ static void kasan_object_err(struct kmem_cache *cache, struct page *page,
pr_err("Object not allocated yet\n");
break;
case KASAN_STATE_ALLOC:
pr_err("Object allocated with size %u bytes.\n",
alloc_info->alloc_size);
pr_err("Allocation:\n");
print_track(&alloc_info->track);
break;
case KASAN_STATE_FREE:
case KASAN_STATE_QUARANTINE:
pr_err("Object freed, allocated with size %u bytes\n",
alloc_info->alloc_size);
free_info = get_free_info(cache, object);
pr_err("Allocation:\n");
print_track(&alloc_info->track);