diff options
| author | Kuniyuki Iwashima <kuniyu@google.com> | 2025-07-02 22:35:13 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-07-08 18:05:25 -0700 |
| commit | b429a5ad19cb4efe63d18388a2a4deebcba742c6 (patch) | |
| tree | 5c76eaca5eec9fd983cb9f842db9efa82142dfbc /net/unix/af_unix.c | |
| parent | d18e43dddf2e7f4d16764cca14032631ab8ef012 (diff) | |
af_unix: Don't hold unix_state_lock() in __unix_dgram_recvmsg().
When __skb_try_recv_datagram() returns NULL in __unix_dgram_recvmsg(),
we hold unix_state_lock() unconditionally.
This is because SOCK_SEQPACKET sk needs to return EOF in case its peer
has been close()d concurrently.
This behaviour totally depends on the timing of the peer's close() and
reading sk->sk_shutdown, and taking the lock does not play a role.
Let's drop the lock from __unix_dgram_recvmsg() and use READ_ONCE().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250702223606.1054680-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/unix/af_unix.c')
| -rw-r--r-- | net/unix/af_unix.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index cd0d582bc7d48..becd84737635c 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2527,12 +2527,10 @@ int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size, &err, &timeo, last)); if (!skb) { /* implies iolock unlocked */ - unix_state_lock(sk); /* Signal EOF on disconnected non-blocking SEQPACKET socket. */ if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN && - (sk->sk_shutdown & RCV_SHUTDOWN)) + (READ_ONCE(sk->sk_shutdown) & RCV_SHUTDOWN)) err = 0; - unix_state_unlock(sk); goto out; } |