[PATCH net 0/6] selftests: mptcp: join: fix some flaky tests

[PATCH net 0/6] selftests: mptcp: join: fix some flaky tests

[Matthieu Baerts (NGI0)]

When looking at the recent CI results on NIPA and MPTCP CIs, a few MPTCP
Join tests are marked as unstable. Here are some fixes for that.

- Patch 1: a small fix for mptcp_connect.sh, printing a note as
  initially intended. For >=v5.13.

- Patch 2: avoid unexpected reset when closing subflows. For >= 5.13.

- Patches 3-4: longer transfer when not waiting for the end. For >=5.18.

- Patch 5: read all received data when expecting a reset. For >= v6.1.

- Patch 6: a fix to properly kill background tasks. For >= v6.5.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Matthieu Baerts (NGI0) (6):
      selftests: mptcp: connect: fix fallback note due to OoO
      selftests: mptcp: join: rm: set backup flag
      selftests: mptcp: join: endpoints: longer transfer
      selftests: mptcp: join: userspace: longer transfer
      selftests: mptcp: connect: trunc: read all recv data
      selftests: mptcp: join: properly kill background tasks

 tools/testing/selftests/net/mptcp/mptcp_connect.c  | 18 +++--
 tools/testing/selftests/net/mptcp/mptcp_connect.sh |  2 +-
 tools/testing/selftests/net/mptcp/mptcp_join.sh    | 90 +++++++++++-----------
 tools/testing/selftests/net/mptcp/mptcp_lib.sh     | 21 +++++
 4 files changed, 80 insertions(+), 51 deletions(-)
---
base-commit: 96a9178a29a6b84bb632ebeb4e84cf61191c73d5
change-id: 20251108-net-mptcp-sft-join-unstable-5a28cdb6ea54

Best regards,
-- 
Matthieu Baerts (NGI0) <matttbe@kernel.org>

[PATCH net 1/6] selftests: mptcp: connect: fix fallback note due to OoO

[Matthieu Baerts (NGI0)]

The "fallback due to TCP OoO" was never printed because the stat_ooo_now
variable was checked twice: once in the parent if-statement, and one in
the child one. The second condition was then always true then, and the
'else' branch was never taken.

The idea is that when there are more ACK + MP_CAPABLE than expected, the
test either fails if there was no out of order packets, or a notice is
printed.

Fixes: 69ca3d29a755 ("mptcp: update selftest for fallback due to OoO")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_connect.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.sh b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
index 47ecb5b3836e..9b7b93f8eb0c 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.sh
@@ -492,7 +492,7 @@ do_transfer()
 				  "than expected (${expect_synrx})"
 		retc=1
 	fi
-	if [ ${stat_ackrx_now_l} -lt ${expect_ackrx} ] && [ ${stat_ooo_now} -eq 0 ]; then
+	if [ ${stat_ackrx_now_l} -lt ${expect_ackrx} ]; then
 		if [ ${stat_ooo_now} -eq 0 ]; then
 			mptcp_lib_pr_fail "lower MPC ACK rx (${stat_ackrx_now_l})" \
 					  "than expected (${expect_ackrx})"

-- 
2.51.0

[PATCH net 2/6] selftests: mptcp: join: rm: set backup flag

[Matthieu Baerts (NGI0)]

Some of these 'remove' tests rarely fail because a subflow has been
reset instead of cleanly removed. This can happen when one extra subflow
which has never carried data is being closed (FIN) on one side, while
the other is sending data for the first time.

To avoid such subflows to be used right at the end, the backup flag has
been added. With that, data will be only carried on the initial subflow.

Fixes: d2c4333a801c ("selftests: mptcp: add testcases for removing addrs")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 54 ++++++++++++-------------
 1 file changed, 27 insertions(+), 27 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 78a1aa4ecff2..9ed9ec7202d6 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -2532,7 +2532,7 @@ remove_tests()
 	if reset "remove single subflow"; then
 		pm_nl_set_limits $ns1 0 1
 		pm_nl_set_limits $ns2 0 1
-		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow,backup
 		addr_nr_ns2=-1 speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 1 1 1
@@ -2545,8 +2545,8 @@ remove_tests()
 	if reset "remove multiple subflows"; then
 		pm_nl_set_limits $ns1 0 2
 		pm_nl_set_limits $ns2 0 2
-		pm_nl_add_endpoint $ns2 10.0.2.2 flags subflow
-		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow
+		pm_nl_add_endpoint $ns2 10.0.2.2 flags subflow,backup
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow,backup
 		addr_nr_ns2=-2 speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 2 2 2
@@ -2557,7 +2557,7 @@ remove_tests()
 	# single address, remove
 	if reset "remove single address"; then
 		pm_nl_set_limits $ns1 0 1
-		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal,backup
 		pm_nl_set_limits $ns2 1 1
 		addr_nr_ns1=-1 speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1
@@ -2570,9 +2570,9 @@ remove_tests()
 	# subflow and signal, remove
 	if reset "remove subflow and signal"; then
 		pm_nl_set_limits $ns1 0 2
-		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal,backup
 		pm_nl_set_limits $ns2 1 2
-		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow,backup
 		addr_nr_ns1=-1 addr_nr_ns2=-1 speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 2 2 2
@@ -2584,10 +2584,10 @@ remove_tests()
 	# subflows and signal, remove
 	if reset "remove subflows and signal"; then
 		pm_nl_set_limits $ns1 0 3
-		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal,backup
 		pm_nl_set_limits $ns2 1 3
-		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow
-		pm_nl_add_endpoint $ns2 10.0.4.2 flags subflow
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow,backup
+		pm_nl_add_endpoint $ns2 10.0.4.2 flags subflow,backup
 		addr_nr_ns1=-1 addr_nr_ns2=-2 speed=10 \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 3 3 3
@@ -2599,9 +2599,9 @@ remove_tests()
 	# addresses remove
 	if reset "remove addresses"; then
 		pm_nl_set_limits $ns1 3 3
-		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal id 250
-		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal
-		pm_nl_add_endpoint $ns1 10.0.4.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal,backup id 250
+		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal,backup
+		pm_nl_add_endpoint $ns1 10.0.4.1 flags signal,backup
 		pm_nl_set_limits $ns2 3 3
 		addr_nr_ns1=-3 speed=10 \
 			run_tests $ns1 $ns2 10.0.1.1
@@ -2614,10 +2614,10 @@ remove_tests()
 	# invalid addresses remove
 	if reset "remove invalid addresses"; then
 		pm_nl_set_limits $ns1 3 3
-		pm_nl_add_endpoint $ns1 10.0.12.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.12.1 flags signal,backup
 		# broadcast IP: no packet for this address will be received on ns1
-		pm_nl_add_endpoint $ns1 224.0.0.1 flags signal
-		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal
+		pm_nl_add_endpoint $ns1 224.0.0.1 flags signal,backup
+		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal,backup
 		pm_nl_set_limits $ns2 2 2
 		addr_nr_ns1=-3 speed=10 \
 			run_tests $ns1 $ns2 10.0.1.1
@@ -2631,10 +2631,10 @@ remove_tests()
 	# subflows and signal, flush
 	if reset "flush subflows and signal"; then
 		pm_nl_set_limits $ns1 0 3
-		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal,backup
 		pm_nl_set_limits $ns2 1 3
-		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow
-		pm_nl_add_endpoint $ns2 10.0.4.2 flags subflow
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow,backup
+		pm_nl_add_endpoint $ns2 10.0.4.2 flags subflow,backup
 		addr_nr_ns1=-8 addr_nr_ns2=-8 speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 3 3 3
@@ -2647,9 +2647,9 @@ remove_tests()
 	if reset "flush subflows"; then
 		pm_nl_set_limits $ns1 3 3
 		pm_nl_set_limits $ns2 3 3
-		pm_nl_add_endpoint $ns2 10.0.2.2 flags subflow id 150
-		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow
-		pm_nl_add_endpoint $ns2 10.0.4.2 flags subflow
+		pm_nl_add_endpoint $ns2 10.0.2.2 flags subflow,backup id 150
+		pm_nl_add_endpoint $ns2 10.0.3.2 flags subflow,backup
+		pm_nl_add_endpoint $ns2 10.0.4.2 flags subflow,backup
 		addr_nr_ns1=-8 addr_nr_ns2=-8 speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1
 		chk_join_nr 3 3 3
@@ -2666,9 +2666,9 @@ remove_tests()
 	# addresses flush
 	if reset "flush addresses"; then
 		pm_nl_set_limits $ns1 3 3
-		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal id 250
-		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal
-		pm_nl_add_endpoint $ns1 10.0.4.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal,backup id 250
+		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal,backup
+		pm_nl_add_endpoint $ns1 10.0.4.1 flags signal,backup
 		pm_nl_set_limits $ns2 3 3
 		addr_nr_ns1=-8 addr_nr_ns2=-8 speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1
@@ -2681,9 +2681,9 @@ remove_tests()
 	# invalid addresses flush
 	if reset "flush invalid addresses"; then
 		pm_nl_set_limits $ns1 3 3
-		pm_nl_add_endpoint $ns1 10.0.12.1 flags signal
-		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal
-		pm_nl_add_endpoint $ns1 10.0.14.1 flags signal
+		pm_nl_add_endpoint $ns1 10.0.12.1 flags signal,backup
+		pm_nl_add_endpoint $ns1 10.0.3.1 flags signal,backup
+		pm_nl_add_endpoint $ns1 10.0.14.1 flags signal,backup
 		pm_nl_set_limits $ns2 3 3
 		addr_nr_ns1=-8 speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1

-- 
2.51.0

[PATCH net 3/6] selftests: mptcp: join: endpoints: longer transfer

[Matthieu Baerts (NGI0)]

In rare cases, when the test environment is very slow, some userspace
tests can fail because some expected events have not been seen.

Because the tests are expecting a long on-going connection, and they are
not waiting for the end of the transfer, it is fine to make the
connection longer. This connection will be killed at the end, after the
verifications, so making it longer doesn't change anything, apart from
avoid it to end before the end of the verifications

To play it safe, all endpoints tests not waiting for the end of the
transfer are now sharing a longer file (128KB) at slow speed.

Fixes: 69c6ce7b6eca ("selftests: mptcp: add implicit endpoint test case")
Cc: stable@vger.kernel.org
Fixes: e274f7154008 ("selftests: mptcp: add subflow limits test-cases")
Fixes: b5e2fb832f48 ("selftests: mptcp: add explicit test case for remove/readd")
Fixes: e06959e9eebd ("selftests: mptcp: join: test for flush/re-add endpoints")
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 9ed9ec7202d6..97af8d89ac5c 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -3943,7 +3943,7 @@ endpoint_tests()
 		pm_nl_set_limits $ns1 2 2
 		pm_nl_set_limits $ns2 2 2
 		pm_nl_add_endpoint $ns1 10.0.2.1 flags signal
-		{ speed=slow \
+		{ test_linkfail=128 speed=slow \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 
@@ -3970,7 +3970,7 @@ endpoint_tests()
 		pm_nl_set_limits $ns2 0 3
 		pm_nl_add_endpoint $ns2 10.0.1.2 id 1 dev ns2eth1 flags subflow
 		pm_nl_add_endpoint $ns2 10.0.2.2 id 2 dev ns2eth2 flags subflow
-		{ test_linkfail=4 speed=5 \
+		{ test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 
@@ -4048,7 +4048,7 @@ endpoint_tests()
 		# broadcast IP: no packet for this address will be received on ns1
 		pm_nl_add_endpoint $ns1 224.0.0.1 id 2 flags signal
 		pm_nl_add_endpoint $ns1 10.0.1.1 id 42 flags signal
-		{ test_linkfail=4 speed=5 \
+		{ test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 
@@ -4121,7 +4121,7 @@ endpoint_tests()
 		# broadcast IP: no packet for this address will be received on ns1
 		pm_nl_add_endpoint $ns1 224.0.0.1 id 2 flags signal
 		pm_nl_add_endpoint $ns2 10.0.3.2 id 3 flags subflow
-		{ test_linkfail=4 speed=20 \
+		{ test_linkfail=128 speed=20 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 

-- 
2.51.0

[PATCH net 4/6] selftests: mptcp: join: userspace: longer transfer

[Matthieu Baerts (NGI0)]

In rare cases, when the test environment is very slow, some userspace
tests can fail because some expected events have not been seen.

Because the tests are expecting a long on-going connection, and they are
not waiting for the end of the transfer, it is fine to make the
connection longer. This connection will be killed at the end, after the
verifications, so making it longer doesn't change anything, apart from
avoid it to end before the end of the verifications

To play it safe, all userspace tests not waiting for the end of the
transfer are now sharing a longer file (128KB) at slow speed.

Fixes: 4369c198e599 ("selftests: mptcp: test userspace pm out of transfer")
Cc: stable@vger.kernel.org
Fixes: b2e2248f365a ("selftests: mptcp: userspace pm create id 0 subflow")
Fixes: e3b47e460b4b ("selftests: mptcp: userspace pm remove initial subflow")
Fixes: b9fb176081fb ("selftests: mptcp: userspace pm send RM_ADDR for ID 0")
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 97af8d89ac5c..01273abfdc89 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -3806,7 +3806,7 @@ userspace_tests()
 	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then
 		set_userspace_pm $ns1
 		pm_nl_set_limits $ns2 2 2
-		{ speed=5 \
+		{ test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 		wait_mpj $ns1
@@ -3839,7 +3839,7 @@ userspace_tests()
 	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then
 		set_userspace_pm $ns2
 		pm_nl_set_limits $ns1 0 1
-		{ speed=5 \
+		{ test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 		wait_mpj $ns2
@@ -3867,7 +3867,7 @@ userspace_tests()
 	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then
 		set_userspace_pm $ns2
 		pm_nl_set_limits $ns1 0 1
-		{ speed=5 \
+		{ test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 		wait_mpj $ns2
@@ -3888,7 +3888,7 @@ userspace_tests()
 	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then
 		set_userspace_pm $ns2
 		pm_nl_set_limits $ns1 0 1
-		{ speed=5 \
+		{ test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 		wait_mpj $ns2
@@ -3912,7 +3912,7 @@ userspace_tests()
 	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then
 		set_userspace_pm $ns1
 		pm_nl_set_limits $ns2 1 1
-		{ speed=5 \
+		{ test_linkfail=128 speed=5 \
 			run_tests $ns1 $ns2 10.0.1.1 & } 2>/dev/null
 		local tests_pid=$!
 		wait_mpj $ns1

-- 
2.51.0

[PATCH net 5/6] selftests: mptcp: connect: trunc: read all recv data

[Matthieu Baerts (NGI0)]

MPTCP Join "fastclose server" selftest is sometimes failing because the
client output file doesn't have the expected size, e.g. 296B instead of
1024B.

When looking at a packet trace when this happens, the server sent the
expected 1024B in two parts -- 100B, then 924B -- then the MP_FASTCLOSE.
It is then strange to see the client only receiving 296B, which would
mean it only got a part of the second packet. The problem is then not on
the networking side, but rather on the data reception side.

When mptcp_connect is launched with '-f -1', it means the connection
might stop before having sent everything, because a reset has been
received. When this happens, the program was directly stopped. But it is
also possible there are still some data to read, simply because the
previous 'read' step was done with a buffer smaller than the pending
data, see do_rnd_read(). In this case, it is important to read what's
left in the kernel buffers before stopping without error like before.

SIGPIPE is now ignored, not to quit the app before having read
everything.

Fixes: 6bf41020b72b ("selftests: mptcp: update and extend fastclose test-cases")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_connect.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/testing/selftests/net/mptcp/mptcp_connect.c
index b148cadb96d0..fc7e22b503d3 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c
@@ -710,8 +710,14 @@ static int copyfd_io_poll(int infd, int peerfd, int outfd,
 
 				bw = do_rnd_write(peerfd, winfo->buf + winfo->off, winfo->len);
 				if (bw < 0) {
-					if (cfg_rcv_trunc)
-						return 0;
+					/* expected reset, continue to read */
+					if (cfg_rcv_trunc &&
+					    (errno == ECONNRESET ||
+					     errno == EPIPE)) {
+						fds.events &= ~POLLOUT;
+						continue;
+					}
+
 					perror("write");
 					return 111;
 				}
@@ -737,8 +743,10 @@ static int copyfd_io_poll(int infd, int peerfd, int outfd,
 		}
 
 		if (fds.revents & (POLLERR | POLLNVAL)) {
-			if (cfg_rcv_trunc)
-				return 0;
+			if (cfg_rcv_trunc) {
+				fds.events &= ~(POLLERR | POLLNVAL);
+				continue;
+			}
 			fprintf(stderr, "Unexpected revents: "
 				"POLLERR/POLLNVAL(%x)\n", fds.revents);
 			return 5;
@@ -1433,7 +1441,7 @@ static void parse_opts(int argc, char **argv)
 			 */
 			if (cfg_truncate < 0) {
 				cfg_rcv_trunc = true;
-				signal(SIGPIPE, handle_signal);
+				signal(SIGPIPE, SIG_IGN);
 			}
 			break;
 		case 'j':

-- 
2.51.0

[PATCH net 6/6] selftests: mptcp: join: properly kill background tasks

[Matthieu Baerts (NGI0)]

The 'run_tests' function is executed in the background, but killing its
associated PID would not kill the children tasks running in the
background.

To properly kill all background tasks, 'kill -- -PID' could be used, but
this requires kill from procps-ng. Instead, all children tasks are
listed using 'ps', and 'kill' is called with all PIDs of this group.

Fixes: 31ee4ad86afd ("selftests: mptcp: join: stop transfer when check is done (part 1)")
Cc: stable@vger.kernel.org
Fixes: 04b57c9e096a ("selftests: mptcp: join: stop transfer when check is done (part 2)")
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
 tools/testing/selftests/net/mptcp/mptcp_join.sh | 18 +++++++++---------
 tools/testing/selftests/net/mptcp/mptcp_lib.sh  | 21 +++++++++++++++++++++
 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 01273abfdc89..41503c241989 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -3831,7 +3831,7 @@ userspace_tests()
 		chk_mptcp_info subflows 0 subflows 0
 		chk_subflows_total 1 1
 		kill_events_pids
-		mptcp_lib_kill_wait $tests_pid
+		mptcp_lib_kill_group_wait $tests_pid
 	fi
 
 	# userspace pm create destroy subflow
@@ -3859,7 +3859,7 @@ userspace_tests()
 		chk_mptcp_info subflows 0 subflows 0
 		chk_subflows_total 1 1
 		kill_events_pids
-		mptcp_lib_kill_wait $tests_pid
+		mptcp_lib_kill_group_wait $tests_pid
 	fi
 
 	# userspace pm create id 0 subflow
@@ -3880,7 +3880,7 @@ userspace_tests()
 		chk_mptcp_info subflows 1 subflows 1
 		chk_subflows_total 2 2
 		kill_events_pids
-		mptcp_lib_kill_wait $tests_pid
+		mptcp_lib_kill_group_wait $tests_pid
 	fi
 
 	# userspace pm remove initial subflow
@@ -3904,7 +3904,7 @@ userspace_tests()
 		chk_mptcp_info subflows 1 subflows 1
 		chk_subflows_total 1 1
 		kill_events_pids
-		mptcp_lib_kill_wait $tests_pid
+		mptcp_lib_kill_group_wait $tests_pid
 	fi
 
 	# userspace pm send RM_ADDR for ID 0
@@ -3930,7 +3930,7 @@ userspace_tests()
 		chk_mptcp_info subflows 1 subflows 1
 		chk_subflows_total 1 1
 		kill_events_pids
-		mptcp_lib_kill_wait $tests_pid
+		mptcp_lib_kill_group_wait $tests_pid
 	fi
 }
 
@@ -3960,7 +3960,7 @@ endpoint_tests()
 		pm_nl_add_endpoint $ns2 10.0.2.2 flags signal
 		pm_nl_check_endpoint "modif is allowed" \
 			$ns2 10.0.2.2 id 1 flags signal
-		mptcp_lib_kill_wait $tests_pid
+		mptcp_lib_kill_group_wait $tests_pid
 	fi
 
 	if reset_with_tcp_filter "delete and re-add" ns2 10.0.3.2 REJECT OUTPUT &&
@@ -4015,7 +4015,7 @@ endpoint_tests()
 			chk_mptcp_info subflows 3 subflows 3
 		done
 
-		mptcp_lib_kill_wait $tests_pid
+		mptcp_lib_kill_group_wait $tests_pid
 
 		kill_events_pids
 		chk_evt_nr ns1 MPTCP_LIB_EVENT_LISTENER_CREATED 1
@@ -4089,7 +4089,7 @@ endpoint_tests()
 		wait_mpj $ns2
 		chk_subflow_nr "after re-re-add ID 0" 3
 		chk_mptcp_info subflows 3 subflows 3
-		mptcp_lib_kill_wait $tests_pid
+		mptcp_lib_kill_group_wait $tests_pid
 
 		kill_events_pids
 		chk_evt_nr ns1 MPTCP_LIB_EVENT_LISTENER_CREATED 1
@@ -4137,7 +4137,7 @@ endpoint_tests()
 		wait_mpj $ns2
 		pm_nl_add_endpoint $ns1 10.0.3.1 id 2 flags signal
 		wait_mpj $ns2
-		mptcp_lib_kill_wait $tests_pid
+		mptcp_lib_kill_group_wait $tests_pid
 
 		join_syn_tx=3 join_connect_err=1 \
 			chk_join_nr 2 2 2
diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index d62e653d48b0..f4388900016a 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -350,6 +350,27 @@ mptcp_lib_kill_wait() {
 	wait "${1}" 2>/dev/null
 }
 
+# $1: PID
+mptcp_lib_pid_list_children() {
+	local curr="${1}"
+	# evoke 'ps' only once
+	local pids="${2:-"$(ps o pid,ppid)"}"
+
+	echo "${curr}"
+
+	local pid
+	for pid in $(echo "${pids}" | awk "\$2 == ${curr} { print \$1 }"); do
+		mptcp_lib_pid_list_children "${pid}" "${pids}"
+	done
+}
+
+# $1: PID
+mptcp_lib_kill_group_wait() {
+	# Some users might not have procps-ng: cannot use "kill -- -PID"
+	mptcp_lib_pid_list_children "${1}" | xargs -r kill &>/dev/null
+	wait "${1}" 2>/dev/null
+}
+
 # $1: IP address
 mptcp_lib_is_v6() {
 	[ -z "${1##*:*}" ]

-- 
2.51.0

Re: [PATCH net 6/6] selftests: mptcp: join: properly kill background tasks

[Geliang Tang]

Hi Matt,

On Mon, 2025-11-10 at 19:23 +0100, Matthieu Baerts (NGI0) wrote:
> The 'run_tests' function is executed in the background, but killing
> its
> associated PID would not kill the children tasks running in the
> background.
> 
> To properly kill all background tasks, 'kill -- -PID' could be used,
> but
> this requires kill from procps-ng. Instead, all children tasks are
> listed using 'ps', and 'kill' is called with all PIDs of this group.
> 
> Fixes: 31ee4ad86afd ("selftests: mptcp: join: stop transfer when
> check is done (part 1)")
> Cc: stable@vger.kernel.org
> Fixes: 04b57c9e096a ("selftests: mptcp: join: stop transfer when
> check is done (part 2)")
> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

This patch looks good to me.

    Reviewed-by: Geliang Tang <geliang@kernel.org>

Thanks,
-Geliang

> ---
>  tools/testing/selftests/net/mptcp/mptcp_join.sh | 18 +++++++++------
> ---
>  tools/testing/selftests/net/mptcp/mptcp_lib.sh  | 21
> +++++++++++++++++++++
>  2 files changed, 30 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh
> b/tools/testing/selftests/net/mptcp/mptcp_join.sh
> index 01273abfdc89..41503c241989 100755
> --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
> +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
> @@ -3831,7 +3831,7 @@ userspace_tests()
>  		chk_mptcp_info subflows 0 subflows 0
>  		chk_subflows_total 1 1
>  		kill_events_pids
> -		mptcp_lib_kill_wait $tests_pid
> +		mptcp_lib_kill_group_wait $tests_pid
>  	fi
>  
>  	# userspace pm create destroy subflow
> @@ -3859,7 +3859,7 @@ userspace_tests()
>  		chk_mptcp_info subflows 0 subflows 0
>  		chk_subflows_total 1 1
>  		kill_events_pids
> -		mptcp_lib_kill_wait $tests_pid
> +		mptcp_lib_kill_group_wait $tests_pid
>  	fi
>  
>  	# userspace pm create id 0 subflow
> @@ -3880,7 +3880,7 @@ userspace_tests()
>  		chk_mptcp_info subflows 1 subflows 1
>  		chk_subflows_total 2 2
>  		kill_events_pids
> -		mptcp_lib_kill_wait $tests_pid
> +		mptcp_lib_kill_group_wait $tests_pid
>  	fi
>  
>  	# userspace pm remove initial subflow
> @@ -3904,7 +3904,7 @@ userspace_tests()
>  		chk_mptcp_info subflows 1 subflows 1
>  		chk_subflows_total 1 1
>  		kill_events_pids
> -		mptcp_lib_kill_wait $tests_pid
> +		mptcp_lib_kill_group_wait $tests_pid
>  	fi
>  
>  	# userspace pm send RM_ADDR for ID 0
> @@ -3930,7 +3930,7 @@ userspace_tests()
>  		chk_mptcp_info subflows 1 subflows 1
>  		chk_subflows_total 1 1
>  		kill_events_pids
> -		mptcp_lib_kill_wait $tests_pid
> +		mptcp_lib_kill_group_wait $tests_pid
>  	fi
>  }
>  
> @@ -3960,7 +3960,7 @@ endpoint_tests()
>  		pm_nl_add_endpoint $ns2 10.0.2.2 flags signal
>  		pm_nl_check_endpoint "modif is allowed" \
>  			$ns2 10.0.2.2 id 1 flags signal
> -		mptcp_lib_kill_wait $tests_pid
> +		mptcp_lib_kill_group_wait $tests_pid
>  	fi
>  
>  	if reset_with_tcp_filter "delete and re-add" ns2 10.0.3.2
> REJECT OUTPUT &&
> @@ -4015,7 +4015,7 @@ endpoint_tests()
>  			chk_mptcp_info subflows 3 subflows 3
>  		done
>  
> -		mptcp_lib_kill_wait $tests_pid
> +		mptcp_lib_kill_group_wait $tests_pid
>  
>  		kill_events_pids
>  		chk_evt_nr ns1 MPTCP_LIB_EVENT_LISTENER_CREATED 1
> @@ -4089,7 +4089,7 @@ endpoint_tests()
>  		wait_mpj $ns2
>  		chk_subflow_nr "after re-re-add ID 0" 3
>  		chk_mptcp_info subflows 3 subflows 3
> -		mptcp_lib_kill_wait $tests_pid
> +		mptcp_lib_kill_group_wait $tests_pid
>  
>  		kill_events_pids
>  		chk_evt_nr ns1 MPTCP_LIB_EVENT_LISTENER_CREATED 1
> @@ -4137,7 +4137,7 @@ endpoint_tests()
>  		wait_mpj $ns2
>  		pm_nl_add_endpoint $ns1 10.0.3.1 id 2 flags signal
>  		wait_mpj $ns2
> -		mptcp_lib_kill_wait $tests_pid
> +		mptcp_lib_kill_group_wait $tests_pid
>  
>  		join_syn_tx=3 join_connect_err=1 \
>  			chk_join_nr 2 2 2
> diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
> b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
> index d62e653d48b0..f4388900016a 100644
> --- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
> +++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
> @@ -350,6 +350,27 @@ mptcp_lib_kill_wait() {
>  	wait "${1}" 2>/dev/null
>  }
>  
> +# $1: PID
> +mptcp_lib_pid_list_children() {
> +	local curr="${1}"
> +	# evoke 'ps' only once
> +	local pids="${2:-"$(ps o pid,ppid)"}"
> +
> +	echo "${curr}"
> +
> +	local pid
> +	for pid in $(echo "${pids}" | awk "\$2 == ${curr} { print
> \$1 }"); do
> +		mptcp_lib_pid_list_children "${pid}" "${pids}"
> +	done
> +}
> +
> +# $1: PID
> +mptcp_lib_kill_group_wait() {
> +	# Some users might not have procps-ng: cannot use "kill -- -
> PID"
> +	mptcp_lib_pid_list_children "${1}" | xargs -r kill
> &>/dev/null
> +	wait "${1}" 2>/dev/null
> +}
> +
>  # $1: IP address
>  mptcp_lib_is_v6() {
>  	[ -z "${1##*:*}" ]
> 

Re: [PATCH net 0/6] selftests: mptcp: join: fix some flaky tests

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 10 Nov 2025 19:23:39 +0100 you wrote:
> When looking at the recent CI results on NIPA and MPTCP CIs, a few MPTCP
> Join tests are marked as unstable. Here are some fixes for that.
> 
> - Patch 1: a small fix for mptcp_connect.sh, printing a note as
>   initially intended. For >=v5.13.
> 
> - Patch 2: avoid unexpected reset when closing subflows. For >= 5.13.
> 
> [...]

Here is the summary with links:
  - [net,1/6] selftests: mptcp: connect: fix fallback note due to OoO
    https://git.kernel.org/netdev/net/c/63c643aa7b72
  - [net,2/6] selftests: mptcp: join: rm: set backup flag
    https://git.kernel.org/netdev/net/c/aea73bae662a
  - [net,3/6] selftests: mptcp: join: endpoints: longer transfer
    https://git.kernel.org/netdev/net/c/6457595db987
  - [net,4/6] selftests: mptcp: join: userspace: longer transfer
    https://git.kernel.org/netdev/net/c/290493078b96
  - [net,5/6] selftests: mptcp: connect: trunc: read all recv data
    https://git.kernel.org/netdev/net/c/ee79980f7a42
  - [net,6/6] selftests: mptcp: join: properly kill background tasks
    https://git.kernel.org/netdev/net/c/852b644acbce

You are awesome, thank you!
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