[PATCH net-next] net: core: Replace fput with sockfd_put

From: Zheng Yongjun <zhengyongjun3@huawei.com>
To: <john.fastabend@gmail.com>, <daniel@iogearbox.net>,
	<jakub@cloudflare.com>, <lmb@cloudflare.com>,
	<davem@davemloft.net>, <kuba@kernel.org>,
	<netdev@vger.kernel.org>, <bpf@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Cc: Zheng Yongjun <zhengyongjun3@huawei.com>
Subject: [PATCH net-next] net: core: Replace fput with sockfd_put
Date: Tue, 29 Dec 2020 21:48:34 +0800	[thread overview]
Message-ID: <20201229134834.22962-1-zhengyongjun3@huawei.com> (raw)

The function sockfd_lookup uses fget on the value that is stored in
the file field of the returned structure, so fput should ultimately be
applied to this value.  This can be done directly, but it seems better
to use the specific macro sockfd_put, which does the same thing.

The problem was fixed using the following semantic patch.
    (http://www.emn.fr/x-info/coccinelle/)

    // <smpl>
    @@
    expression s;
    @@

       s = sockfd_lookup(...)
       ...
    +  sockfd_put(s);
    ?- fput(s->file);
    // </smpl>

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
---
 net/core/sock_map.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index ddc899e83313..2e59256a06e9 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -611,7 +611,7 @@ int sock_map_update_elem_sys(struct bpf_map *map, void *key, void *value,
 		ret = sock_hash_update_common(map, key, sk, flags);
 	sock_map_sk_release(sk);
 out:
-	fput(sock->file);
+	sockfd_put(sock);
 	return ret;
 }
 
-- 
2.22.0

