From a7262ed4b163c411b450d74f2c7b34bde19ac78e Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Wed, 14 May 2025 16:19:25 +0200 Subject: [PATCH 1/3] vsock/test: add timeout_usleep() to allow sleeping in timeout sections The timeout API uses signals, so we have documented not to use sleep(), but we can use nanosleep(2) since POSIX.1 explicitly specifies that it does not interact with signals. Let's provide timeout_usleep() for that. Signed-off-by: Stefano Garzarella Link: https://patch.msgid.link/20250514141927.159456-2-sgarzare@redhat.com Signed-off-by: Jakub Kicinski --- tools/testing/vsock/timeout.c | 18 ++++++++++++++++++ tools/testing/vsock/timeout.h | 1 + 2 files changed, 19 insertions(+) diff --git a/tools/testing/vsock/timeout.c b/tools/testing/vsock/timeout.c index 44aee49b6cee..1453d38e08bb 100644 --- a/tools/testing/vsock/timeout.c +++ b/tools/testing/vsock/timeout.c @@ -21,6 +21,7 @@ #include #include #include +#include #include "timeout.h" static volatile bool timeout; @@ -28,6 +29,8 @@ static volatile bool timeout; /* SIGALRM handler function. Do not use sleep(2), alarm(2), or * setitimer(2) while using this API - they may interfere with each * other. + * + * If you need to sleep, please use timeout_sleep() provided by this API. */ void sigalrm(int signo) { @@ -58,3 +61,18 @@ void timeout_end(void) alarm(0); timeout = false; } + +/* Sleep in a timeout section. + * + * nanosleep(2) can be used with this API since POSIX.1 explicitly + * specifies that it does not interact with signals. + */ +int timeout_usleep(useconds_t usec) +{ + struct timespec ts = { + .tv_sec = usec / 1000000, + .tv_nsec = (usec % 1000000) * 1000, + }; + + return nanosleep(&ts, NULL); +} diff --git a/tools/testing/vsock/timeout.h b/tools/testing/vsock/timeout.h index ecb7c840e65a..1c3fcad87a49 100644 --- a/tools/testing/vsock/timeout.h +++ b/tools/testing/vsock/timeout.h @@ -11,5 +11,6 @@ void sigalrm(int signo); void timeout_begin(unsigned int seconds); void timeout_check(const char *operation); void timeout_end(void); +int timeout_usleep(useconds_t usec); #endif /* TIMEOUT_H */ From 135a8a4d25a2937b2727e3857471f305d78496da Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Wed, 14 May 2025 16:19:26 +0200 Subject: [PATCH 2/3] vsock/test: retry send() to avoid occasional failure in sigpipe test When the other peer calls shutdown(SHUT_RD), there is a chance that the send() call could occur before the message carrying the close information arrives over the transport. In such cases, the send() might still succeed. To avoid this race, let's retry the send() call a few times, ensuring the test is more reliable. Sleep a little before trying again to avoid flooding the other peer and filling its receive buffer, causing false-negative. Signed-off-by: Stefano Garzarella Link: https://patch.msgid.link/20250514141927.159456-3-sgarzare@redhat.com Signed-off-by: Jakub Kicinski --- tools/testing/vsock/vsock_test.c | 38 +++++++++++++++++++++++++------- 1 file changed, 30 insertions(+), 8 deletions(-) diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c index 613551132a96..920867b17965 100644 --- a/tools/testing/vsock/vsock_test.c +++ b/tools/testing/vsock/vsock_test.c @@ -1058,17 +1058,34 @@ static void sigpipe(int signo) have_sigpipe = 1; } +#define SEND_SLEEP_USEC (10 * 1000) + static void test_stream_check_sigpipe(int fd) { ssize_t res; have_sigpipe = 0; - res = send(fd, "A", 1, 0); - if (res != -1) { - fprintf(stderr, "expected send(2) failure, got %zi\n", res); - exit(EXIT_FAILURE); + /* When the other peer calls shutdown(SHUT_RD), there is a chance that + * the send() call could occur before the message carrying the close + * information arrives over the transport. In such cases, the send() + * might still succeed. To avoid this race, let's retry the send() call + * a few times, ensuring the test is more reliable. + */ + timeout_begin(TIMEOUT); + while(1) { + res = send(fd, "A", 1, 0); + if (res == -1) + break; + + /* Sleep a little before trying again to avoid flooding the + * other peer and filling its receive buffer, causing + * false-negative. + */ + timeout_usleep(SEND_SLEEP_USEC); + timeout_check("send"); } + timeout_end(); if (!have_sigpipe) { fprintf(stderr, "SIGPIPE expected\n"); @@ -1077,11 +1094,16 @@ static void test_stream_check_sigpipe(int fd) have_sigpipe = 0; - res = send(fd, "A", 1, MSG_NOSIGNAL); - if (res != -1) { - fprintf(stderr, "expected send(2) failure, got %zi\n", res); - exit(EXIT_FAILURE); + timeout_begin(TIMEOUT); + while(1) { + res = send(fd, "A", 1, MSG_NOSIGNAL); + if (res == -1) + break; + + timeout_usleep(SEND_SLEEP_USEC); + timeout_check("send"); } + timeout_end(); if (have_sigpipe) { fprintf(stderr, "SIGPIPE not expected\n"); From 3c6abbe85bccd8efb5d9147a022b1d4012cb1809 Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Wed, 14 May 2025 16:19:27 +0200 Subject: [PATCH 3/3] vsock/test: check also expected errno on sigpipe test In the sigpipe test, we expect send() to fail, but we do not check if send() fails with the errno we expect (EPIPE). Add this check and repeat the send() in case of EINTR as we do in other tests. Signed-off-by: Stefano Garzarella Link: https://patch.msgid.link/20250514141927.159456-4-sgarzare@redhat.com Signed-off-by: Jakub Kicinski --- tools/testing/vsock/vsock_test.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c index 920867b17965..9ea33b78b9fc 100644 --- a/tools/testing/vsock/vsock_test.c +++ b/tools/testing/vsock/vsock_test.c @@ -1075,7 +1075,7 @@ static void test_stream_check_sigpipe(int fd) timeout_begin(TIMEOUT); while(1) { res = send(fd, "A", 1, 0); - if (res == -1) + if (res == -1 && errno != EINTR) break; /* Sleep a little before trying again to avoid flooding the @@ -1087,6 +1087,10 @@ static void test_stream_check_sigpipe(int fd) } timeout_end(); + if (errno != EPIPE) { + fprintf(stderr, "unexpected send(2) errno %d\n", errno); + exit(EXIT_FAILURE); + } if (!have_sigpipe) { fprintf(stderr, "SIGPIPE expected\n"); exit(EXIT_FAILURE); @@ -1097,7 +1101,7 @@ static void test_stream_check_sigpipe(int fd) timeout_begin(TIMEOUT); while(1) { res = send(fd, "A", 1, MSG_NOSIGNAL); - if (res == -1) + if (res == -1 && errno != EINTR) break; timeout_usleep(SEND_SLEEP_USEC); @@ -1105,6 +1109,10 @@ static void test_stream_check_sigpipe(int fd) } timeout_end(); + if (errno != EPIPE) { + fprintf(stderr, "unexpected send(2) errno %d\n", errno); + exit(EXIT_FAILURE); + } if (have_sigpipe) { fprintf(stderr, "SIGPIPE not expected\n"); exit(EXIT_FAILURE);