From 8a03222f508bf09e03cf38f6bd77b34b450c1d60 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Mon, 23 Sep 2019 11:41:12 -0700 Subject: selftests/bpf: test_progs: fix client/server race in tcp_rtt This is the same problem I found earlier in test_sockopt_inherit: there is a race between server thread doing accept() and client thread doing connect(). Let's explicitly synchronize them via pthread conditional variable. v2: * don't exit from server_thread without signaling condvar, fixes possible issue where main() would wait forever (Andrii Nakryiko) Fixes: b55873984dab ("selftests/bpf: test BPF_SOCK_OPS_RTT_CB") Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/prog_tests/tcp_rtt.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/prog_tests/tcp_rtt.c b/tools/testing/selftests/bpf/prog_tests/tcp_rtt.c index fdc0b3614a9e..a82da555b1b0 100644 --- a/tools/testing/selftests/bpf/prog_tests/tcp_rtt.c +++ b/tools/testing/selftests/bpf/prog_tests/tcp_rtt.c @@ -203,14 +203,24 @@ static int start_server(void) return fd; } +static pthread_mutex_t server_started_mtx = PTHREAD_MUTEX_INITIALIZER; +static pthread_cond_t server_started = PTHREAD_COND_INITIALIZER; + static void *server_thread(void *arg) { struct sockaddr_storage addr; socklen_t len = sizeof(addr); int fd = *(int *)arg; int client_fd; + int err; + + err = listen(fd, 1); + + pthread_mutex_lock(&server_started_mtx); + pthread_cond_signal(&server_started); + pthread_mutex_unlock(&server_started_mtx); - if (CHECK_FAIL(listen(fd, 1)) < 0) { + if (CHECK_FAIL(err < 0)) { perror("Failed to listed on socket"); return NULL; } @@ -248,7 +258,14 @@ void test_tcp_rtt(void) if (CHECK_FAIL(server_fd < 0)) goto close_cgroup_fd; - pthread_create(&tid, NULL, server_thread, (void *)&server_fd); + if (CHECK_FAIL(pthread_create(&tid, NULL, server_thread, + (void *)&server_fd))) + goto close_cgroup_fd; + + pthread_mutex_lock(&server_started_mtx); + pthread_cond_wait(&server_started, &server_started_mtx); + pthread_mutex_unlock(&server_started_mtx); + CHECK_FAIL(run_test(cgroup_fd, server_fd)); close(server_fd); close_cgroup_fd: -- cgit v1.2.3