diff options
| author | Joonsoo Kim <iamjoonsoo.kim@lge.com> | 2016-03-15 22:55:12 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-16 00:55:16 +0100 |
| commit | d86bd1bece6fc41d59253002db5441fe960a37f6 (patch) | |
| tree | 3881125eb61ec76b5ad87d6a7e9f51061b76e7e6 /include | |
| parent | slub: relax CMPXCHG consistency restrictions (diff) | |
| download | linux-d86bd1bece6fc41d59253002db5441fe960a37f6.tar.xz linux-d86bd1bece6fc41d59253002db5441fe960a37f6.zip | |
mm/slub: support left redzone
SLUB already has a redzone debugging feature. But it is only positioned
at the end of object (aka right redzone) so it cannot catch left oob.
Although current object's right redzone acts as left redzone of next
object, first object in a slab cannot take advantage of this effect.
This patch explicitly adds a left red zone to each object to detect left
oob more precisely.
Background:
Someone complained to me that left OOB doesn't catch even if KASAN is
enabled which does page allocation debugging. That page is out of our
control so it would be allocated when left OOB happens and, in this
case, we can't find OOB. Moreover, SLUB debugging feature can be
enabled without page allocator debugging and, in this case, we will miss
that OOB.
Before trying to implement, I expected that changes would be too
complex, but, it doesn't look that complex to me now. Almost changes
are applied to debug specific functions so I feel okay.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/slub_def.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index b7e57927f521..ac5143f95ee6 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -81,6 +81,7 @@ struct kmem_cache { int reserved; /* Reserved bytes at the end of slabs */ const char *name; /* Name (only for display!) */ struct list_head list; /* List of slab caches */ + int red_left_pad; /* Left redzone padding size */ #ifdef CONFIG_SYSFS struct kobject kobj; /* For sysfs */ #endif |