diff options
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/mm/slub.c b/mm/slub.c index 5fdec3b83706..71e09c675047 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -5004,15 +5004,17 @@ bool slab_post_alloc_hook(struct kmem_cache *s, struct list_lru *lru, gfp_t init_flags = 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. + * For kmalloc object, the allocated size (object_size) can be larger + * than the requested size (orig_size). We however need to zero the + * whole object_size to handle possible later krealloc() with + *__GFP_ZERO properly. + * + * But if we keep track of the requested size, krealloc() uses that + * information. Additionally if red zoning is enabled, the extra space + * is also red zone, so we should not overwrite it. So limit zeroing to + * orig_size if we track it. */ - if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) && - (s->flags & SLAB_KMALLOC)) + if (slub_debug_orig_size(s)) zero_size = orig_size; /* |