| Message ID | 20241025154124.732008-1-kshk@linux.ibm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [v3] vsock/test: fix failures due to wrong SO_RCVLOWAT parameter | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On Fri, Oct 25, 2024 at 10:41:24AM -0500, Konstantin Shkolnyy wrote: >This happens on 64-bit big-endian machines. >SO_RCVLOWAT requires an int parameter. However, instead of int, the test >uses unsigned long in one place and size_t in another. Both are 8 bytes >long on 64-bit machines. The kernel, having received the 8 bytes, doesn't >test for the exact size of the parameter, it only cares that it's >= >sizeof(int), and casts the 4 lower-addressed bytes to an int, which, on >a big-endian machine, contains 0. 0 doesn't trigger an error, SO_RCVLOWAT >returns with success and the socket stays with the default SO_RCVLOWAT = 1, >which results in vsock_test failures, while vsock_perf doesn't even notice >that it's failed to change it. > >Fixes: b1346338fbae ("vsock_test: POLLIN + SO_RCVLOWAT test") >Fixes: 542e893fbadc ("vsock/test: two tests to check credit update logic") >Fixes: 8abbffd27ced ("test/vsock: vsock_perf utility") >Signed-off-by: Konstantin Shkolnyy <kshk@linux.ibm.com> >--- > >Notes: > The problem was found on s390 (big endian), while x86-64 didn't show it. After this fix, all tests pass on s390. >Changes for v3: >- fix the same problem in vsock_perf and update commit message >Changes for v2: >- add "Fixes:" lines to the commit message Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> > > tools/testing/vsock/vsock_perf.c | 6 +++--- > tools/testing/vsock/vsock_test.c | 4 ++-- > 2 files changed, 5 insertions(+), 5 deletions(-) > >diff --git a/tools/testing/vsock/vsock_perf.c b/tools/testing/vsock/vsock_perf.c >index 4e8578f815e0..22633c2848cc 100644 >--- a/tools/testing/vsock/vsock_perf.c >+++ b/tools/testing/vsock/vsock_perf.c >@@ -133,7 +133,7 @@ static float get_gbps(unsigned long bits, time_t ns_delta) > ((float)ns_delta / NSEC_PER_SEC); > } > >-static void run_receiver(unsigned long rcvlowat_bytes) >+static void run_receiver(int rcvlowat_bytes) > { > unsigned int read_cnt; > time_t rx_begin_ns; >@@ -163,7 +163,7 @@ static void run_receiver(unsigned long rcvlowat_bytes) > printf("Listen port %u\n", port); > printf("RX buffer %lu bytes\n", buf_size_bytes); > printf("vsock buffer %lu bytes\n", vsock_buf_bytes); >- printf("SO_RCVLOWAT %lu bytes\n", rcvlowat_bytes); >+ printf("SO_RCVLOWAT %d bytes\n", rcvlowat_bytes); > > fd = socket(AF_VSOCK, SOCK_STREAM, 0); > >@@ -439,7 +439,7 @@ static long strtolx(const char *arg) > int main(int argc, char **argv) > { > unsigned long to_send_bytes = DEFAULT_TO_SEND_BYTES; >- unsigned long rcvlowat_bytes = DEFAULT_RCVLOWAT_BYTES; >+ int rcvlowat_bytes = DEFAULT_RCVLOWAT_BYTES; > int peer_cid = -1; > bool sender = false; > >diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c >index f851f8961247..30857dd4ca97 100644 >--- a/tools/testing/vsock/vsock_test.c >+++ b/tools/testing/vsock/vsock_test.c >@@ -833,7 +833,7 @@ static void test_stream_poll_rcvlowat_server(const struct test_opts *opts) > > static void test_stream_poll_rcvlowat_client(const struct test_opts *opts) > { >- unsigned long lowat_val = RCVLOWAT_BUF_SIZE; >+ int lowat_val = RCVLOWAT_BUF_SIZE; > char buf[RCVLOWAT_BUF_SIZE]; > struct pollfd fds; > short poll_flags; >@@ -1282,7 +1282,7 @@ static void test_stream_rcvlowat_def_cred_upd_client(const struct test_opts *opt > static void test_stream_credit_update_test(const struct test_opts *opts, > bool low_rx_bytes_test) > { >- size_t recv_buf_size; >+ int recv_buf_size; > struct pollfd fds; > size_t buf_size; > void *buf; >-- >2.34.1 >
diff --git a/tools/testing/vsock/vsock_perf.c b/tools/testing/vsock/vsock_perf.c index 4e8578f815e0..22633c2848cc 100644 --- a/tools/testing/vsock/vsock_perf.c +++ b/tools/testing/vsock/vsock_perf.c @@ -133,7 +133,7 @@ static float get_gbps(unsigned long bits, time_t ns_delta) ((float)ns_delta / NSEC_PER_SEC); } -static void run_receiver(unsigned long rcvlowat_bytes) +static void run_receiver(int rcvlowat_bytes) { unsigned int read_cnt; time_t rx_begin_ns; @@ -163,7 +163,7 @@ static void run_receiver(unsigned long rcvlowat_bytes) printf("Listen port %u\n", port); printf("RX buffer %lu bytes\n", buf_size_bytes); printf("vsock buffer %lu bytes\n", vsock_buf_bytes); - printf("SO_RCVLOWAT %lu bytes\n", rcvlowat_bytes); + printf("SO_RCVLOWAT %d bytes\n", rcvlowat_bytes); fd = socket(AF_VSOCK, SOCK_STREAM, 0); @@ -439,7 +439,7 @@ static long strtolx(const char *arg) int main(int argc, char **argv) { unsigned long to_send_bytes = DEFAULT_TO_SEND_BYTES; - unsigned long rcvlowat_bytes = DEFAULT_RCVLOWAT_BYTES; + int rcvlowat_bytes = DEFAULT_RCVLOWAT_BYTES; int peer_cid = -1; bool sender = false; diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c index f851f8961247..30857dd4ca97 100644 --- a/tools/testing/vsock/vsock_test.c +++ b/tools/testing/vsock/vsock_test.c @@ -833,7 +833,7 @@ static void test_stream_poll_rcvlowat_server(const struct test_opts *opts) static void test_stream_poll_rcvlowat_client(const struct test_opts *opts) { - unsigned long lowat_val = RCVLOWAT_BUF_SIZE; + int lowat_val = RCVLOWAT_BUF_SIZE; char buf[RCVLOWAT_BUF_SIZE]; struct pollfd fds; short poll_flags; @@ -1282,7 +1282,7 @@ static void test_stream_rcvlowat_def_cred_upd_client(const struct test_opts *opt static void test_stream_credit_update_test(const struct test_opts *opts, bool low_rx_bytes_test) { - size_t recv_buf_size; + int recv_buf_size; struct pollfd fds; size_t buf_size; void *buf;
This happens on 64-bit big-endian machines. SO_RCVLOWAT requires an int parameter. However, instead of int, the test uses unsigned long in one place and size_t in another. Both are 8 bytes long on 64-bit machines. The kernel, having received the 8 bytes, doesn't test for the exact size of the parameter, it only cares that it's >= sizeof(int), and casts the 4 lower-addressed bytes to an int, which, on a big-endian machine, contains 0. 0 doesn't trigger an error, SO_RCVLOWAT returns with success and the socket stays with the default SO_RCVLOWAT = 1, which results in vsock_test failures, while vsock_perf doesn't even notice that it's failed to change it. Fixes: b1346338fbae ("vsock_test: POLLIN + SO_RCVLOWAT test") Fixes: 542e893fbadc ("vsock/test: two tests to check credit update logic") Fixes: 8abbffd27ced ("test/vsock: vsock_perf utility") Signed-off-by: Konstantin Shkolnyy <kshk@linux.ibm.com> --- Notes: The problem was found on s390 (big endian), while x86-64 didn't show it. After this fix, all tests pass on s390. Changes for v3: - fix the same problem in vsock_perf and update commit message Changes for v2: - add "Fixes:" lines to the commit message tools/testing/vsock/vsock_perf.c | 6 +++--- tools/testing/vsock/vsock_test.c | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-)