selftest: net: Fix weird setsockopt() in bind_bhash.c.

[ Upstream commit fd2004d ]

bind_bhash.c passes (SO_REUSEADDR | SO_REUSEPORT) to setsockopt().

In the asm-generic definition, the value happens to match with the
bare SO_REUSEPORT, (2 | 15) == 15, but not on some arch.

arch/alpha/include/uapi/asm/socket.h:18:#define SO_REUSEADDR	0x0004
arch/alpha/include/uapi/asm/socket.h:24:#define SO_REUSEPORT	0x0200
arch/mips/include/uapi/asm/socket.h:24:#define SO_REUSEADDR	0x0004	/* Allow reuse of local addresses.  */
arch/mips/include/uapi/asm/socket.h:33:#define SO_REUSEPORT 0x0200	/* Allow local address and port reuse.  */
arch/parisc/include/uapi/asm/socket.h:12:#define SO_REUSEADDR	0x0004
arch/parisc/include/uapi/asm/socket.h:18:#define SO_REUSEPORT	0x0200
arch/sparc/include/uapi/asm/socket.h:13:#define SO_REUSEADDR	0x0004
arch/sparc/include/uapi/asm/socket.h:20:#define SO_REUSEPORT	0x0200
include/uapi/asm-generic/socket.h:12:#define SO_REUSEADDR	2
include/uapi/asm-generic/socket.h:27:#define SO_REUSEPORT	15

Let's pass SO_REUSEPORT only.

Fixes: c35ecb9 ("selftests/net: Add test for timing a bind request to a port with a populated bhash entry")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250903222938.2601522-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: q2ven

tools/testing/selftests/net/bind_bhash.c

@@ -75,7 +75,7 @@ static void *setup(void *arg)
 	int *array = (int *)arg;
 
 	for (i = 0; i < MAX_CONNECTIONS; i++) {
-		sock_fd = bind_socket(SO_REUSEADDR | SO_REUSEPORT, setup_addr);
+		sock_fd = bind_socket(SO_REUSEPORT, setup_addr);
 		if (sock_fd < 0) {
 			ret = sock_fd;
 			pthread_exit(&ret);
@@ -103,7 +103,7 @@ int main(int argc, const char *argv[])
 
 	setup_addr = use_v6 ? setup_addr_v6 : setup_addr_v4;
 
-	listener_fd = bind_socket(SO_REUSEADDR | SO_REUSEPORT, setup_addr);
+	listener_fd = bind_socket(SO_REUSEPORT, setup_addr);
 	if (listen(listener_fd, 100) < 0) {
 		perror("listen failed");
 		return -1;