From: Andrii Nakryiko <andriin@fb.com>
Date: Wed, 11 Mar 2020 15:27:49 -0700
Subject: selftests/bpf: Make tcp_rtt test more robust to failures
Patch-mainline: v5.7-rc1
Git-commit: 4cd729fa022cb5142e5b65f25589af61c8148cf6
References: bsc#1177028
Switch to non-blocking accept and wait for server thread to exit before
proceeding. I noticed that sometimes tcp_rtt server thread failure would
"spill over" into other tests (that would run after tcp_rtt), probably just
because server thread exits much later and tcp_rtt doesn't wait for it.
v1->v2:
- add usleep() while waiting on initial non-blocking accept() (Stanislav);
Fixes: 8a03222f508b ("selftests/bpf: test_progs: fix client/server race in tcp_rtt")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20200311222749.458015-1-andriin@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Gary Lin <glin@suse.com>
---
tools/testing/selftests/bpf/prog_tests/tcp_rtt.c | 32 ++++++++++++++---------
1 file changed, 20 insertions(+), 12 deletions(-)
--- a/tools/testing/selftests/bpf/prog_tests/tcp_rtt.c
+++ b/tools/testing/selftests/bpf/prog_tests/tcp_rtt.c
@@ -188,7 +188,7 @@ static int start_server(void)
};
int fd;
- fd = socket(AF_INET, SOCK_STREAM, 0);
+ fd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
if (fd < 0) {
log_err("Failed to create server socket");
return -1;
@@ -205,6 +205,7 @@ static int start_server(void)
static pthread_mutex_t server_started_mtx = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t server_started = PTHREAD_COND_INITIALIZER;
+static volatile bool server_done = false;
static void *server_thread(void *arg)
{
@@ -222,23 +223,24 @@ static void *server_thread(void *arg)
if (CHECK_FAIL(err < 0)) {
perror("Failed to listed on socket");
- return NULL;
+ return ERR_PTR(err);
}
- client_fd = accept(fd, (struct sockaddr *)&addr, &len);
+ while (!server_done) {
+ client_fd = accept(fd, (struct sockaddr *)&addr, &len);
+ if (client_fd == -1 && errno == EAGAIN) {
+ usleep(50);
+ continue;
+ }
+ break;
+ }
if (CHECK_FAIL(client_fd < 0)) {
perror("Failed to accept client");
- return NULL;
+ return ERR_PTR(err);
}
- /* Wait for the next connection (that never arrives)
- * to keep this thread alive to prevent calling
- * close() on client_fd.
- */
- if (CHECK_FAIL(accept(fd, (struct sockaddr *)&addr, &len) >= 0)) {
- perror("Unexpected success in second accept");
- return NULL;
- }
+ while (!server_done)
+ usleep(50);
close(client_fd);
@@ -249,6 +251,7 @@ void test_tcp_rtt(void)
{
int server_fd, cgroup_fd;
pthread_t tid;
+ void *server_res;
cgroup_fd = test__join_cgroup("/tcp_rtt");
if (CHECK_FAIL(cgroup_fd < 0))
@@ -267,6 +270,11 @@ void test_tcp_rtt(void)
pthread_mutex_unlock(&server_started_mtx);
CHECK_FAIL(run_test(cgroup_fd, server_fd));
+
+ server_done = true;
+ pthread_join(tid, &server_res);
+ CHECK_FAIL(IS_ERR(server_res));
+
close_server_fd:
close(server_fd);
close_cgroup_fd: