Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm...

[deliverable/linux.git] / kernel / bpf / syscall.c

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 2a2efe1bc76c7a2ef2e0a4af3ebec7f988a4b4a6..cf5e9f7ad13ad13ebb5b6bc5a775beca834c7c86 100644 (file)
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -137,11 +137,13 @@ static void bpf_map_show_fdinfo(struct seq_file *m, struct file *filp)
                   "map_type:\t%u\n"
                   "key_size:\t%u\n"
                   "value_size:\t%u\n"
-                  "max_entries:\t%u\n",
+                  "max_entries:\t%u\n"
+                  "map_flags:\t%#x\n",
                   map->map_type,
                   map->key_size,
                   map->value_size,
-                  map->max_entries);
+                  map->max_entries,
+                  map->map_flags);
 }
 #endif
 
@@ -216,11 +218,18 @@ struct bpf_map *__bpf_map_get(struct fd f)
        return f.file->private_data;
 }
 
-void bpf_map_inc(struct bpf_map *map, bool uref)
+/* prog's and map's refcnt limit */
+#define BPF_MAX_REFCNT 32768
+
+struct bpf_map *bpf_map_inc(struct bpf_map *map, bool uref)
 {
-       atomic_inc(&map->refcnt);
+       if (atomic_inc_return(&map->refcnt) > BPF_MAX_REFCNT) {
+               atomic_dec(&map->refcnt);
+               return ERR_PTR(-EBUSY);
+       }
        if (uref)
                atomic_inc(&map->usercnt);
+       return map;
 }
 
 struct bpf_map *bpf_map_get_with_uref(u32 ufd)
@@ -232,7 +241,7 @@ struct bpf_map *bpf_map_get_with_uref(u32 ufd)
        if (IS_ERR(map))
                return map;
 
-       bpf_map_inc(map, true);
+       map = bpf_map_inc(map, true);
        fdput(f);
 
        return map;
@@ -656,6 +665,15 @@ static struct bpf_prog *__bpf_prog_get(struct fd f)
        return f.file->private_data;
 }
 
+struct bpf_prog *bpf_prog_inc(struct bpf_prog *prog)
+{
+       if (atomic_inc_return(&prog->aux->refcnt) > BPF_MAX_REFCNT) {
+               atomic_dec(&prog->aux->refcnt);
+               return ERR_PTR(-EBUSY);
+       }
+       return prog;
+}
+
 /* called by sockets/tracing/seccomp before attaching program to an event
  * pairs with bpf_prog_put()
  */
@@ -668,7 +686,7 @@ struct bpf_prog *bpf_prog_get(u32 ufd)
        if (IS_ERR(prog))
                return prog;
 
-       atomic_inc(&prog->aux->refcnt);
+       prog = bpf_prog_inc(prog);
        fdput(f);
 
        return prog;