From: Eric Dumazet <edumazet@google.com>
Date: Mon, 15 Nov 2021 19:02:47 +0000 (-0800)
Subject: tcp: check local var (timeo) before socket fields in one test
X-Git-Tag: v5.17-rc1~170^2~443^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8bd172b787298124ef75c0e466101107c036d54d;p=thirdparty%2Fkernel%2Flinux.git

tcp: check local var (timeo) before socket fields in one test

Testing timeo before sk_err/sk_state/sk_shutdown makes more sense.

Modern applications use non-blocking IO, while a socket is terminated
only once during its life time.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 33cd9a1c199ce..7b1886103556e 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2399,10 +2399,10 @@ static int tcp_recvmsg_locked(struct sock *sk, struct msghdr *msg, size_t len,
 			break;
 
 		if (copied) {
-			if (sk->sk_err ||
+			if (!timeo ||
+			    sk->sk_err ||
 			    sk->sk_state == TCP_CLOSE ||
 			    (sk->sk_shutdown & RCV_SHUTDOWN) ||
-			    !timeo ||
 			    signal_pending(current))
 				break;
 		} else {