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  3. [PATCH net 0/6] selftests: mptcp: join: fix some flaky tests
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[PATCH net 6/6] selftests: mptcp: join: properly kill background tasks

Matthieu Baerts (NGI0) posted 6 patches 2 weeks, 2 days ago
[PATCH net 6/6] selftests: mptcp: join: properly kill background tasks
Posted by Matthieu Baerts (NGI0) 2 weeks, 2 days ago 
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
Posted by Geliang Tang 2 weeks, 2 days ago 
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##*:*}" ]
>

Patchew 2.1-devel-b67e4c2

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