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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Guillaume Nault <gnault@redhat.com>,
        Shuah Khan <skhan@linuxfoundation.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 051/121] selftests: pmtu.sh: Kill nettest processes launched in subshell.
Date:   Mon, 14 Mar 2022 12:53:54 +0100
Message-Id: <20220314112745.550881854@linuxfoundation.org>
In-Reply-To: <20220314112744.120491875@linuxfoundation.org>
References: <20220314112744.120491875@linuxfoundation.org>
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From: Guillaume Nault <gnault@redhat.com>

[ Upstream commit 94a4a4fe4c696413932eed8bdec46574de9576b8 ]

When using "run_cmd <command> &", then "$!" refers to the PID of the
subshell used to run <command>, not the command itself. Therefore
nettest_pids actually doesn't contain the list of the nettest commands
running in the background. So cleanup() can't kill them and the nettest
processes run until completion (fortunately they have a 5s timeout).

Fix this by defining a new command for running processes in the
background, for which "$!" really refers to the PID of the command run.

Also, double quote variables on the modified lines, to avoid shellcheck
warnings.

Fixes: ece1278a9b81 ("selftests: net: add ESP-in-UDP PMTU test")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/testing/selftests/net/pmtu.sh | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh
index 2e8972573d91..694732e4b344 100755
--- a/tools/testing/selftests/net/pmtu.sh
+++ b/tools/testing/selftests/net/pmtu.sh
@@ -374,6 +374,16 @@ run_cmd() {
 	return $rc
 }
 
+run_cmd_bg() {
+	cmd="$*"
+
+	if [ "$VERBOSE" = "1" ]; then
+		printf "    COMMAND: %s &\n" "${cmd}"
+	fi
+
+	$cmd 2>&1 &
+}
+
 # Find the auto-generated name for this namespace
 nsname() {
 	eval echo \$NS_$1
@@ -670,10 +680,10 @@ setup_nettest_xfrm() {
 	[ ${1} -eq 6 ] && proto="-6" || proto=""
 	port=${2}
 
-	run_cmd ${ns_a} nettest ${proto} -q -D -s -x -p ${port} -t 5 &
+	run_cmd_bg "${ns_a}" nettest "${proto}" -q -D -s -x -p "${port}" -t 5
 	nettest_pids="${nettest_pids} $!"
 
-	run_cmd ${ns_b} nettest ${proto} -q -D -s -x -p ${port} -t 5 &
+	run_cmd_bg "${ns_b}" nettest "${proto}" -q -D -s -x -p "${port}" -t 5
 	nettest_pids="${nettest_pids} $!"
 }
 
-- 
2.34.1