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