1 files changed, 47 insertions, 13 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0d3313d02a7e..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)
  */
@@ -93,22 +101,40 @@ 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)
 {
-	struct bpf_map *map = filp->private_data;
+	bpf_map_put_with_uref(filp->private_data);
+	return 0;
+}
 
-	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);
+#ifdef CONFIG_PROC_FS
+static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
+{
+	const struct bpf_map *map = filp->private_data;
 
-	bpf_map_put(map);
-	return 0;
+	seq_printf(m,
+		   "map_type:\t%u\n"
+		   "key_size:\t%u\n"
+		   "value_size:\t%u\n"
+		   "max_entries:\t%u\n",
+		   map->map_type,
+		   map->key_size,
+		   map->value_size,
+		   map->max_entries);
 }
+#endif
 
 static const struct file_operations bpf_map_fops = {
-	.release = bpf_map_release,
+#ifdef CONFIG_PROC_FS
+	.show_fdinfo	= bpf_map_show_fdinfo,
+#endif
+	.release	= bpf_map_release,
 };
 
 int bpf_map_new_fd(struct bpf_map *map)
@@ -142,6 +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)
@@ -174,7 +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;
@@ -183,7 +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;
@@ -226,7 +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;
 
@@ -285,7 +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;