diff options
| -rw-r--r-- | mm/slub.c | 57 |
1 files changed, 34 insertions, 23 deletions
diff --git a/mm/slub.c b/mm/slub.c index 4fb037c98782..44aa7847324a 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1363,10 +1363,8 @@ static __always_inline void kfree_hook(void *x) kasan_kfree_large(x, _RET_IP_); } -static __always_inline void *slab_free_hook(struct kmem_cache *s, void *x) +static __always_inline bool slab_free_hook(struct kmem_cache *s, void *x) { - void *freeptr; - kmemleak_free_recursive(x, s->flags); /* @@ -1386,17 +1384,12 @@ static __always_inline void *slab_free_hook(struct kmem_cache *s, void *x) if (!(s->flags & SLAB_DEBUG_OBJECTS)) debug_check_no_obj_freed(x, s->object_size); - freeptr = get_freepointer(s, x); - /* - * kasan_slab_free() may put x into memory quarantine, delaying its - * reuse. In this case the object's freelist pointer is changed. - */ - kasan_slab_free(s, x, _RET_IP_); - return freeptr; + /* KASAN might put x into memory quarantine, delaying its reuse */ + return kasan_slab_free(s, x, _RET_IP_); } -static inline void slab_free_freelist_hook(struct kmem_cache *s, - void *head, void *tail) +static inline bool slab_free_freelist_hook(struct kmem_cache *s, + void **head, void **tail) { /* * Compiler cannot detect this function can be removed if slab_free_hook() @@ -1407,13 +1400,33 @@ static inline void slab_free_freelist_hook(struct kmem_cache *s, defined(CONFIG_DEBUG_OBJECTS_FREE) || \ defined(CONFIG_KASAN) - void *object = head; - void *tail_obj = tail ? : head; - void *freeptr; + void *object; + void *next = *head; + void *old_tail = *tail ? *tail : *head; + + /* Head and tail of the reconstructed freelist */ + *head = NULL; + *tail = NULL; do { - freeptr = slab_free_hook(s, object); - } while ((object != tail_obj) && (object = freeptr)); + object = next; + next = get_freepointer(s, object); + /* If object's reuse doesn't have to be delayed */ + if (!slab_free_hook(s, object)) { + /* Move object to the new freelist */ + set_freepointer(s, object, *head); + *head = object; + if (!*tail) + *tail = object; + } + } while (object != old_tail); + + if (*head == *tail) + *tail = NULL; + + return *head != NULL; +#else + return true; #endif } @@ -2968,14 +2981,12 @@ static __always_inline void slab_free(struct kmem_cache *s, struct page *page, void *head, void *tail, int cnt, unsigned long addr) { - slab_free_freelist_hook(s, head, tail); /* - * slab_free_freelist_hook() could have put the items into quarantine. - * If so, no need to free them. + * With KASAN enabled slab_free_freelist_hook modifies the freelist + * to remove objects, whose reuse must be delayed. */ - if (s->flags & SLAB_KASAN && !(s->flags & SLAB_TYPESAFE_BY_RCU)) - return; - do_slab_free(s, page, head, tail, cnt, addr); + if (slab_free_freelist_hook(s, &head, &tail)) + do_slab_free(s, page, head, tail, cnt, addr); } #ifdef CONFIG_KASAN |