From: Jakub Kicinski kuba@kernel.org

[ Upstream commit 2d3b8dfd82d76b1295167c6453d683ab99e50794 ]

On slow machines the SND timestamp sometimes doesn't arrive before we quit. The test only waits as long as the packet delay, so it's easy for a race condition to happen.

Double the wait but do a bit of polling, once the SND timestamp arrives there's no point to wait any longer.

This fixes the "TXTIME abs" failures on debug kernels, like:

Case ICMPv4 - TXTIME abs returned '', expected 'OK'

Reviewed-by: Willem de Bruijn willemb@google.com Link: https://lore.kernel.org/r/20240510005705.43069-1-kuba@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/net/cmsg_sender.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/net/cmsg_sender.c b/tools/testing/selftests/net/cmsg_sender.c index c79e65581dc37..161db24e3c409 100644 --- a/tools/testing/selftests/net/cmsg_sender.c +++ b/tools/testing/selftests/net/cmsg_sender.c @@ -333,16 +333,17 @@ static const char *cs_ts_info2str(unsigned int info) return "unknown"; }

-static void +static unsigned long cs_read_cmsg(int fd, struct msghdr *msg, char *cbuf, size_t cbuf_sz) { struct sock_extended_err *see; struct scm_timestamping *ts; + unsigned long ts_seen = 0; struct cmsghdr *cmsg; int i, err;

if (!opt.ts.ena) - return; + return 0; msg->msg_control = cbuf; msg->msg_controllen = cbuf_sz;

@@ -396,8 +397,11 @@ cs_read_cmsg(int fd, struct msghdr *msg, char *cbuf, size_t cbuf_sz) printf(" %5s ts%d %lluus\n", cs_ts_info2str(see->ee_info), i, rel_time); + ts_seen |= 1 << see->ee_info; } } + + return ts_seen; }

static void ca_set_sockopts(int fd) @@ -509,10 +513,16 @@ int main(int argc, char *argv[]) err = ERN_SUCCESS;

if (opt.ts.ena) { - /* Make sure all timestamps have time to loop back */ - usleep(opt.txtime.delay); + unsigned long seen; + int i;

- cs_read_cmsg(fd, &msg, cbuf, sizeof(cbuf)); + /* Make sure all timestamps have time to loop back */ + for (i = 0; i < 40; i++) { + seen = cs_read_cmsg(fd, &msg, cbuf, sizeof(cbuf)); + if (seen & (1 << SCM_TSTAMP_SND)) + break; + usleep(opt.txtime.delay / 20); + } }

err_out: