[PATCH RFC v2 2/6] mm/slab: Perform init_on_free earlier

[Alexander Popov]

Currently in CONFIG_SLAB init_on_free happens too late, and heap
objects go to the heap quarantine being dirty. Lets move memory
clearing before calling kasan_slab_free() to fix that.

Signed-off-by: Alexander Popov <alex.popov@xxxxxxxxx>
---
 mm/slab.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index 3160dff6fd76..5140203c5b76 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3414,6 +3414,9 @@ 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;
@@ -3432,8 +3435,6 @@ 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, virt_to_head_page(objp), objp);
-- 
2.26.2