1 files changed, 29 insertions, 15 deletions

diff --git a/mm/slub.c b/mm/slub.c
index f6063ec97a55..fb603fdf58cb 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -454,6 +454,18 @@ static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page,
 static unsigned long object_map[BITS_TO_LONGS(MAX_OBJS_PER_PAGE)];
 static DEFINE_SPINLOCK(object_map_lock);
 
+static void __fill_map(unsigned long *obj_map, struct kmem_cache *s,
+		       struct page *page)
+{
+	void *addr = page_address(page);
+	void *p;
+
+	bitmap_zero(obj_map, page->objects);
+
+	for (p = page->freelist; p; p = get_freepointer(s, p))
+		set_bit(__obj_to_index(s, addr, p), obj_map);
+}
+
 #if IS_ENABLED(CONFIG_KUNIT)
 static bool slab_add_kunit_errors(void)
 {
@@ -483,17 +495,11 @@ static inline bool slab_add_kunit_errors(void) { return false; }
 static unsigned long *get_map(struct kmem_cache *s, struct page *page)
 	__acquires(&object_map_lock)
 {
-	void *p;
-	void *addr = page_address(page);
-
 	VM_BUG_ON(!irqs_disabled());
 
 	spin_lock(&object_map_lock);
 
-	bitmap_zero(object_map, page->objects);
-
-	for (p = page->freelist; p; p = get_freepointer(s, p))
-		set_bit(__obj_to_index(s, addr, p), object_map);
+	__fill_map(object_map, s, page);
 
 	return object_map;
 }
@@ -4879,17 +4885,17 @@ static int add_location(struct loc_track *t, struct kmem_cache *s,
 }
 
 static void process_slab(struct loc_track *t, struct kmem_cache *s,
-		struct page *page, enum track_item alloc)
+		struct page *page, enum track_item alloc,
+		unsigned long *obj_map)
 {
 	void *addr = page_address(page);
 	void *p;
-	unsigned long *map;
 
-	map = get_map(s, page);
+	__fill_map(obj_map, s, page);
+
 	for_each_object(p, s, addr, page->objects)
-		if (!test_bit(__obj_to_index(s, addr, p), map))
+		if (!test_bit(__obj_to_index(s, addr, p), obj_map))
 			add_location(t, s, get_track(s, p, alloc));
-	put_map(map);
 }
 #endif  /* CONFIG_DEBUG_FS   */
 #endif	/* CONFIG_SLUB_DEBUG */
@@ -5816,14 +5822,21 @@ static int slab_debug_trace_open(struct inode *inode, struct file *filep)
 	struct loc_track *t = __seq_open_private(filep, &slab_debugfs_sops,
 						sizeof(struct loc_track));
 	struct kmem_cache *s = file_inode(filep)->i_private;
+	unsigned long *obj_map;
+
+	obj_map = bitmap_alloc(oo_objects(s->oo), GFP_KERNEL);
+	if (!obj_map)
+		return -ENOMEM;
 
 	if (strcmp(filep->f_path.dentry->d_name.name, "alloc_traces") == 0)
 		alloc = TRACK_ALLOC;
 	else
 		alloc = TRACK_FREE;
 
-	if (!alloc_loc_track(t, PAGE_SIZE / sizeof(struct location), GFP_KERNEL))
+	if (!alloc_loc_track(t, PAGE_SIZE / sizeof(struct location), GFP_KERNEL)) {
+		bitmap_free(obj_map);
 		return -ENOMEM;
+	}
 
 	for_each_kmem_cache_node(s, node, n) {
 		unsigned long flags;
@@ -5834,12 +5847,13 @@ static int slab_debug_trace_open(struct inode *inode, struct file *filep)
 
 		spin_lock_irqsave(&n->list_lock, flags);
 		list_for_each_entry(page, &n->partial, slab_list)
-			process_slab(t, s, page, alloc);
+			process_slab(t, s, page, alloc, obj_map);
 		list_for_each_entry(page, &n->full, slab_list)
-			process_slab(t, s, page, alloc);
+			process_slab(t, s, page, alloc, obj_map);
 		spin_unlock_irqrestore(&n->list_lock, flags);
 	}
 
+	bitmap_free(obj_map);
 	return 0;
 }