summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--mm/slab.c7
-rw-r--r--mm/slab.h18
-rw-r--r--mm/slub.c10
3 files changed, 27 insertions, 8 deletions
diff --git a/mm/slab.c b/mm/slab.c
index 59c8e28f7b6a..26f41d47f5f1 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3254,7 +3254,8 @@ slab_alloc_node(struct kmem_cache *cachep, struct list_lru *lru, gfp_t flags,
init = slab_want_init_on_alloc(flags, cachep);
out:
- slab_post_alloc_hook(cachep, objcg, flags, 1, &objp, init);
+ slab_post_alloc_hook(cachep, objcg, flags, 1, &objp, init,
+ cachep->object_size);
return objp;
}
@@ -3507,13 +3508,13 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
* Done outside of the IRQ disabled section.
*/
slab_post_alloc_hook(s, objcg, flags, size, p,
- slab_want_init_on_alloc(flags, s));
+ slab_want_init_on_alloc(flags, s), s->object_size);
/* FIXME: Trace call missing. Christoph would like a bulk variant */
return size;
error:
local_irq_enable();
cache_alloc_debugcheck_after_bulk(s, flags, i, p, _RET_IP_);
- slab_post_alloc_hook(s, objcg, flags, i, p, false);
+ slab_post_alloc_hook(s, objcg, flags, i, p, false, s->object_size);
kmem_cache_free_bulk(s, i, p);
return 0;
}
diff --git a/mm/slab.h b/mm/slab.h
index 0202a8c2f0d2..2642102f6699 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -720,13 +720,27 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
static inline void slab_post_alloc_hook(struct kmem_cache *s,
struct obj_cgroup *objcg, gfp_t flags,
- size_t size, void **p, bool init)
+ size_t size, void **p, bool init,
+ unsigned int orig_size)
{
+ unsigned int zero_size = s->object_size;
size_t i;
flags &= gfp_allowed_mask;
/*
+ * For kmalloc object, the allocated memory size(object_size) is likely
+ * larger than the requested size(orig_size). If redzone check is
+ * enabled for the extra space, don't zero it, as it will be redzoned
+ * soon. The redzone operation for this extra space could be seen as a
+ * replacement of current poisoning under certain debug option, and
+ * won't break other sanity checks.
+ */
+ if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) &&
+ (s->flags & SLAB_KMALLOC))
+ zero_size = orig_size;
+
+ /*
* As memory initialization might be integrated into KASAN,
* kasan_slab_alloc and initialization memset must be
* kept together to avoid discrepancies in behavior.
@@ -736,7 +750,7 @@ static inline void slab_post_alloc_hook(struct kmem_cache *s,
for (i = 0; i < size; i++) {
p[i] = kasan_slab_alloc(s, p[i], flags, init);
if (p[i] && init && !kasan_has_integrated_init())
- memset(p[i], 0, s->object_size);
+ memset(p[i], 0, zero_size);
kmemleak_alloc_recursive(p[i], s->object_size, 1,
s->flags, flags);
kmsan_slab_alloc(s, p[i], flags);
diff --git a/mm/slub.c b/mm/slub.c
index 157527d7101b..ecc44067625c 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3395,7 +3395,11 @@ redo:
init = slab_want_init_on_alloc(gfpflags, s);
out:
- slab_post_alloc_hook(s, objcg, gfpflags, 1, &object, init);
+ /*
+ * When init equals 'true', like for kzalloc() family, only
+ * @orig_size bytes might be zeroed instead of s->object_size
+ */
+ slab_post_alloc_hook(s, objcg, gfpflags, 1, &object, init, orig_size);
return object;
}
@@ -3852,11 +3856,11 @@ int kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t size,
* Done outside of the IRQ disabled fastpath loop.
*/
slab_post_alloc_hook(s, objcg, flags, size, p,
- slab_want_init_on_alloc(flags, s));
+ slab_want_init_on_alloc(flags, s), s->object_size);
return i;
error:
slub_put_cpu_ptr(s->cpu_slab);
- slab_post_alloc_hook(s, objcg, flags, i, p, false);
+ slab_post_alloc_hook(s, objcg, flags, i, p, false, s->object_size);
kmem_cache_free_bulk(s, i, p);
return 0;
}