FROMGIT: mm/slab: rerform init_on_free earlier

Currently in CONFIG_SLAB init_on_free happens too late, and heap objects
go to the heap quarantine not being erased.

Lets move init_on_free clearing before calling kasan_slab_free().  In that
case heap quarantine will store erased objects, similarly to CONFIG_SLUB=y
behavior.

Link: https://lkml.kernel.org/r/20201210183729.1261524-1-alex.popov@linux.com
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Bug: 177201466
(cherry picked from commit a32d654db5
    https://github.com/hnaz/linux-mm v5.11-rc4-mmots-2021-01-21-20-10)
Test: CONFIG_KFENCE_KUNIT_TEST=y passes on Cuttlefish
Signed-off-by: Alexander Potapenko <glider@google.com>
Change-Id: I2bf5e70c1524619526efd792bbdd959b813af1e4
This commit is contained in:
Alexander Popov 2020-12-14 19:04:33 -08:00 committed by Alistair Delva
parent 1ac855fd1f
commit 1e95fcd132

View File

@ -3416,6 +3416,9 @@ static void cache_flusharray(struct kmem_cache *cachep, struct array_cache *ac)
static __always_inline void __cache_free(struct kmem_cache *cachep, void *objp,
unsigned long caller)
{
if (unlikely(slab_want_init_on_free(cachep)))
memset(objp, 0, cachep->object_size);
/* Put the object into the quarantine, don't touch it for now. */
if (kasan_slab_free(cachep, objp, _RET_IP_))
return;
@ -3434,8 +3437,6 @@ void ___cache_free(struct kmem_cache *cachep, void *objp,
struct array_cache *ac = cpu_cache_get(cachep);
check_irq_off();
if (unlikely(slab_want_init_on_free(cachep)))
memset(objp, 0, cachep->object_size);
kmemleak_free_recursive(objp, cachep->flags);
objp = cache_free_debugcheck(cachep, objp, caller);
memcg_slab_free_hook(cachep, &objp, 1);