[PATCH net 10/11] selftests: mptcp: check output: catch cmd errors
From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Date: 2026-05-05 15:01:51
Also in:
linux-kselftest, lkml, mptcp, stable
Subsystem:
kernel selftest framework, networking [general], networking [mptcp], the rest · Maintainers:
Shuah Khan, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Matthieu Baerts, Mat Martineau, Linus Torvalds
Using '${?}' inside the if-statement to check the returned value from
the command that was evaluated as part of the if-statement is not
correct: here, '${?}' will be linked to the previous instruction, not
the one that is expected here (${cmd}).
Instead, simply mark the error, except if an error is expected. If
that's the case, 1 can be passed as the 4th argument of this helper.
Three checks from pm_netlink.sh expect an error.
While at it, improve the error message when the command unexpectedly
fails or succeeds.
Note that we could expect a specific returned value, but the checks
currently expecting an error can be used with 'ip mptcp' or 'pm_nl_ctl',
and these two tools don't return the same error code.
Fixes: 2d0c1d27ea4e ("selftests: mptcp: add mptcp_lib_check_output helper")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
---
tools/testing/selftests/net/mptcp/mptcp_lib.sh | 16 ++++++++++------
tools/testing/selftests/net/mptcp/pm_netlink.sh | 10 ++++++----
2 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index 5fea7e7df628..989a5975dcea 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh@@ -474,20 +474,24 @@ mptcp_lib_wait_local_port_listen() { wait_local_port_listen "${@}" "tcp" } +# $1: error file, $2: cmd, $3: expected msg, [$4: expected error] mptcp_lib_check_output() { local err="${1}" local cmd="${2}" local expected="${3}" + local exp_error="${4:-0}" local cmd_ret=0 local out - if ! out=$(${cmd} 2>"${err}"); then - cmd_ret=${?} - fi + out=$(${cmd} 2>"${err}") || cmd_ret=1 - if [ ${cmd_ret} -ne 0 ]; then - mptcp_lib_pr_fail "command execution '${cmd}' stderr" - cat "${err}" + if [ "${cmd_ret}" != "${exp_error}" ]; then + mptcp_lib_pr_fail "unexpected returned code for '${cmd}', info:" + if [ "${exp_error}" = 0 ]; then + cat "${err}" + else + echo "${out}" + fi return 2 elif [ "${out}" = "${expected}" ]; then return 0
diff --git a/tools/testing/selftests/net/mptcp/pm_netlink.sh b/tools/testing/selftests/net/mptcp/pm_netlink.sh
index 123d9d7a0278..b69f30fcb91e 100755
--- a/tools/testing/selftests/net/mptcp/pm_netlink.sh
+++ b/tools/testing/selftests/net/mptcp/pm_netlink.sh@@ -122,10 +122,12 @@ check() local cmd="$1" local expected="$2" local msg="$3" + local exp_error="$4" local rc=0 mptcp_lib_print_title "$msg" - mptcp_lib_check_output "${err}" "${cmd}" "${expected}" || rc=${?} + mptcp_lib_check_output "${err}" "${cmd}" "${expected}" "${exp_error}" || + rc=${?} if [ ${rc} -eq 2 ]; then mptcp_lib_result_fail "${msg} # error ${rc}" ret=${KSFT_FAIL}
@@ -158,13 +160,13 @@ check "show_endpoints" \ "3,10.0.1.3,signal backup")" "dump addrs" del_endpoint 2 -check "get_endpoint 2" "" "simple del addr" +check "get_endpoint 2" "" "simple del addr" 1 check "show_endpoints" \ "$(format_endpoints "1,10.0.1.1" \ "3,10.0.1.3,signal backup")" "dump addrs after del" add_endpoint 10.0.1.3 2>/dev/null -check "get_endpoint 4" "" "duplicate addr" +check "get_endpoint 4" "" "duplicate addr" 1 add_endpoint 10.0.1.4 flags signal check "get_endpoint 4" "$(format_endpoints "4,10.0.1.4,signal")" "id addr increment"
@@ -173,7 +175,7 @@ for i in $(seq 5 9); do add_endpoint "10.0.1.${i}" flags signal >/dev/null 2>&1 done check "get_endpoint 9" "$(format_endpoints "9,10.0.1.9,signal")" "hard addr limit" -check "get_endpoint 10" "" "above hard addr limit" +check "get_endpoint 10" "" "above hard addr limit" 1 del_endpoint 9 for i in $(seq 10 255); do
--
2.53.0