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authorStanislav Fomichev <sdf@google.com>2019-08-14 10:37:48 -0700
committerDaniel Borkmann <daniel@iogearbox.net>2019-08-17 23:18:54 +0200
commitb0e4701ce15d0381cdea0643c7f0a35dc529cec2 (patch)
tree35f71eca49d4baa3ce31be4c830db41f60f2cb32 /kernel/bpf
parentfae55527ac1164b66bee983a4d82ade2bfedb332 (diff)
bpf: export bpf_map_inc_not_zero
Rename existing bpf_map_inc_not_zero to __bpf_map_inc_not_zero to indicate that it's caller's responsibility to do proper locking. Create and export bpf_map_inc_not_zero wrapper that properly locks map_idr_lock. Will be used in the next commit to hold a map while cloning a socket. Cc: Martin KaFai Lau <kafai@fb.com> Cc: Yonghong Song <yhs@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Yonghong Song <yhs@fb.com> Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'kernel/bpf')
-rw-r--r--kernel/bpf/syscall.c16
1 files changed, 13 insertions, 3 deletions
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 5d141f16f6fa..cf8052b016e7 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -683,8 +683,8 @@ struct bpf_map *bpf_map_get_with_uref(u32 ufd)
}
/* map_idr_lock should have been held */
-static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map,
- bool uref)
+static struct bpf_map *__bpf_map_inc_not_zero(struct bpf_map *map,
+ bool uref)
{
int refold;
@@ -704,6 +704,16 @@ static struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map,
return map;
}
+struct bpf_map *bpf_map_inc_not_zero(struct bpf_map *map, bool uref)
+{
+ spin_lock_bh(&map_idr_lock);
+ map = __bpf_map_inc_not_zero(map, uref);
+ spin_unlock_bh(&map_idr_lock);
+
+ return map;
+}
+EXPORT_SYMBOL_GPL(bpf_map_inc_not_zero);
+
int __weak bpf_stackmap_copy(struct bpf_map *map, void *key, void *value)
{
return -ENOTSUPP;
@@ -2177,7 +2187,7 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr)
spin_lock_bh(&map_idr_lock);
map = idr_find(&map_idr, id);
if (map)
- map = bpf_map_inc_not_zero(map, true);
+ map = __bpf_map_inc_not_zero(map, true);
else
map = ERR_PTR(-ENOENT);
spin_unlock_bh(&map_idr_lock);