From: Dmitry V. Levin <ldv@altlinux.org>
Date: Tue, 4 Jul 2017 22:31:08 +0000 (+0000)
Subject: tests: robustify create_nl_socket based tests against the race condition
X-Git-Tag: v4.18~1
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=bcc7daac6cac9fcabd8197073ba9bcf843a851a4;p=strace

tests: robustify create_nl_socket based tests against the race condition

There is a race condition between the moment a netlink socket is created
and the moment it is reported via SOCK_DIAG_BY_FAMILY interface.
Add one more operation on the socket created by create_nl_socket
to increase chances of winning the race.

* tests/create_nl_socket.c (create_nl_socket_ext): Add a getsockopt call
with the created socket.
---

diff --git a/tests/create_nl_socket.c b/tests/create_nl_socket.c
index 064960fa..c2708d8f 100644
--- a/tests/create_nl_socket.c
+++ b/tests/create_nl_socket.c
@@ -37,10 +37,16 @@ create_nl_socket_ext(const int proto, const char *const name)
 		perror_msg_and_skip("socket AF_NETLINK %s", name);
 
 	const struct sockaddr_nl addr = { .nl_family = AF_NETLINK };
-	const socklen_t len = sizeof(addr);
+	socklen_t len = sizeof(addr);
 
 	if (bind(fd, (const struct sockaddr *) &addr, len))
 		perror_msg_and_skip("bind AF_NETLINK %s", name);
 
+	/* one more operation on this socket to win the race */
+	int listening;
+	len = sizeof(listening);
+	if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &listening, &len))
+		perror_msg_and_fail("getsockopt");
+
 	return fd;
 }