1 files changed, 32 insertions, 18 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 6d1407bc1531..637397059f76 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -82,6 +82,14 @@ static void bpf_map_free_deferred(struct work_struct *work)
 	map->ops->map_free(map);
 }
 
+static void bpf_map_put_uref(struct bpf_map *map)
+{
+	if (atomic_dec_and_test(&map->usercnt)) {
+		if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
+			bpf_fd_array_map_clear(map);
+	}
+}
+
 /* decrement map refcnt and schedule it for freeing via workqueue
  * (unrelying map implementation ops->map_free() might sleep)
  */
@@ -93,6 +101,18 @@ void bpf_map_put(struct bpf_map *map)
 	}
 }
 
+void bpf_map_put_with_uref(struct bpf_map *map)
+{
+	bpf_map_put_uref(map);
+	bpf_map_put(map);
+}
+
+static int bpf_map_release(struct inode *inode, struct file *filp)
+{
+	bpf_map_put_with_uref(filp->private_data);
+	return 0;
+}
+
 #ifdef CONFIG_PROC_FS
 static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 {
@@ -110,20 +130,6 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
 }
 #endif
 
-static int bpf_map_release(struct inode *inode, struct file *filp)
-{
-	struct bpf_map *map = filp->private_data;
-
-	if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
-		/* prog_array stores refcnt-ed bpf_prog pointers
-		 * release them all when user space closes prog_array_fd
-		 */
-		bpf_fd_array_map_clear(map);
-
-	bpf_map_put(map);
-	return 0;
-}
-
 static const struct file_operations bpf_map_fops = {
 #ifdef CONFIG_PROC_FS
 	.show_fdinfo	= bpf_map_show_fdinfo,
@@ -162,6 +168,7 @@ static int map_create(union bpf_attr *attr)
 		return PTR_ERR(map);
 
 	atomic_set(&map->refcnt, 1);
+	atomic_set(&map->usercnt, 1);
 
 	err = bpf_map_charge_memlock(map);
 	if (err)
@@ -194,7 +201,14 @@ struct bpf_map *__bpf_map_get(struct fd f)
 	return f.file->private_data;
 }
 
-struct bpf_map *bpf_map_get(u32 ufd)
+void bpf_map_inc(struct bpf_map *map, bool uref)
+{
+	atomic_inc(&map->refcnt);
+	if (uref)
+		atomic_inc(&map->usercnt);
+}
+
+struct bpf_map *bpf_map_get_with_uref(u32 ufd)
 {
 	struct fd f = fdget(ufd);
 	struct bpf_map *map;
@@ -203,7 +217,7 @@ struct bpf_map *bpf_map_get(u32 ufd)
 	if (IS_ERR(map))
 		return map;
 
-	atomic_inc(&map->refcnt);
+	bpf_map_inc(map, true);
 	fdput(f);
 
 	return map;
@@ -246,7 +260,7 @@ static int map_lookup_elem(union bpf_attr *attr)
 		goto free_key;
 
 	err = -ENOMEM;
-	value = kmalloc(map->value_size, GFP_USER);
+	value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;
 
@@ -305,7 +319,7 @@ static int map_update_elem(union bpf_attr *attr)
 		goto free_key;
 
 	err = -ENOMEM;
-	value = kmalloc(map->value_size, GFP_USER);
+	value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
 	if (!value)
 		goto free_key;