On Wed, Oct 22, 2025 at 06:00:06PM -0700, Bobby Eshleman wrote:
> From: Bobby Eshleman <[email protected]>
>
> Save/restore pipefail to not mistakenly trip the if-condition
> in wait_for_listener().
>
> awk doesn't gracefully handle SIGPIPE with a non-zero exit code, so grep
> exiting upon finding a match causes false-positives when the pipefail
> option is used. This will enable pipefail usage, so that we can losing
> failures when piping test output into log() functions.
>
> Fixes: a4a65c6fe08b ("selftests/vsock: add initial vmtest.sh for vsock")
> Signed-off-by: Bobby Eshleman <[email protected]>
> ---
> tools/testing/selftests/vsock/vmtest.sh | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/tools/testing/selftests/vsock/vmtest.sh
> b/tools/testing/selftests/vsock/vmtest.sh
> index 561600814bef..ec3ff443f49a 100755
> --- a/tools/testing/selftests/vsock/vmtest.sh
> +++ b/tools/testing/selftests/vsock/vmtest.sh
> @@ -243,6 +243,7 @@ wait_for_listener()
> local port=$1
> local interval=$2
> local max_intervals=$3
> + local old_pipefail
> local protocol=tcp
> local pattern
> local i
> @@ -251,6 +252,13 @@ wait_for_listener()
>
> # for tcp protocol additionally check the socket state
> [ "${protocol}" = "tcp" ] && pattern="${pattern}0A"
> +
> + # 'grep -q' exits on match, sending SIGPIPE to 'awk', which exits with
> + # an error, causing the if-condition to fail when pipefail is set.
> + # Instead, temporarily disable pipefail and restore it later.
> + old_pipefail=$(set -o | awk '/^pipefail[[:space:]]+(on|off)$/{print
> $2}')
> + set +o pipefail
> +
> for i in $(seq "${max_intervals}"); do
> if awk '{print $2" "$4}' /proc/net/"${protocol}"* | \
> grep -q "${pattern}"; then
Hi Bobby,
I agree this is a problem. But I'm wondering if you considered
moving the pattern matching into the awk script. I'm no awk expert.
But suspect that would lead to a more elegant solution.
> @@ -258,6 +266,10 @@ wait_for_listener()
> fi
> sleep "${interval}"
> done
> +
> + if [[ "${old_pipefail}" == on ]]; then
> + set -o pipefail
> + fi
> }
>
> vm_wait_for_listener() {
>
> --
> 2.47.3
>
>
