Merge remote-tracking branches 'spi/topic/dw', 'spi/topic/dw-mid', 'spi/topic/fsl...

[mirror_ubuntu-hirsute-kernel.git] / kernel / bpf / syscall.c

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0d3313d02a7e512e1ca7f58fb52aa3e39bae60a3..3b39550d84856494d43aefe926457add41d2a435 100644 (file)
--- 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)
  */
@@ -93,17 +101,15 @@ void bpf_map_put(struct bpf_map *map)
        }
 }
 
-static int bpf_map_release(struct inode *inode, struct file *filp)
+void bpf_map_put_with_uref(struct bpf_map *map)
 {
-       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_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;
 }
 
@@ -142,6 +148,7 @@ 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 +181,14 @@ 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 +197,7 @@ 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 +240,7 @@ 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 +299,7 @@ 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;