selftests: pmtu.sh: Kill nettest processes launched in subshell.

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: 908296c56720 ("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>

diff --git a/tools/testing/selftests/net/pmtu.sh b/tools/testing/selftests/net/pmtu.sh
index 2e8972573d915ebf869a2bd03795811e949e34fa..694732e4b3448666ffe24f9e58050b2c2bda5a3a 100755 (executable)
--- 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} $!"
 }