[PATCH 5.14 258/849] kselftests/sched: cleanup the child processes

Greg Kroah-Hartman
2021-11-15T22:23:52Z

From: Li Zhijian <lizhijian@cn.fujitsu.com>

[ Upstream commit 1c36432b278cecf1499f21fae19836e614954309 ]

Previously, 'make -C sched run_tests' will block forever when it occurs
something wrong where the *selftests framework* is waiting for its child
processes to exit.

[root@iaas-rpma sched]# ./cs_prctl_test

## Create a thread/process/process group hiearchy
Not a core sched system
tid=74985, / tgid=74985 / pgid=74985: ffffffffffffffff
Not a core sched system
tid=74986, / tgid=74986 / pgid=74985: ffffffffffffffff
Not a core sched system
tid=74988, / tgid=74986 / pgid=74985: ffffffffffffffff
Not a core sched system
tid=74989, / tgid=74986 / pgid=74985: ffffffffffffffff
Not a core sched system
tid=74990, / tgid=74986 / pgid=74985: ffffffffffffffff
Not a core sched system
tid=74987, / tgid=74987 / pgid=74985: ffffffffffffffff
Not a core sched system
tid=74991, / tgid=74987 / pgid=74985: ffffffffffffffff
Not a core sched system
tid=74992, / tgid=74987 / pgid=74985: ffffffffffffffff
Not a core sched system
tid=74993, / tgid=74987 / pgid=74985: ffffffffffffffff

Not a core sched system
(268) FAILED: get_cs_cookie(0) == 0

## Set a cookie on entire process group
-1 = prctl(62, 1, 0, 2, 0)
core_sched create failed -- PGID: Invalid argument
(cs_prctl_test.c:272) -
[root@iaas-rpma sched]# ps
PID TTY TIME CMD
4605 pts/2 00:00:00 bash
74986 pts/2 00:00:00 cs_prctl_test
74987 pts/2 00:00:00 cs_prctl_test
74999 pts/2 00:00:00 ps

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chris Hyser <chris.hyser@oracle.com>
Link: https://lore.kernel.org/r/20210902024333.75983-1-lizhijian@cn.fujitsu.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/testing/selftests/sched/cs_prctl_test.c | 28 ++++++++++++-------
1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/sched/cs_prctl_test.c b/tools/testing/selftests/sched/cs_prctl_test.c
index 63fe6521c56d9..1829383715c66 100644
--- a/tools/testing/selftests/sched/cs_prctl_test.c
+++ b/tools/testing/selftests/sched/cs_prctl_test.c
@@ -64,6 +64,17 @@ enum pid_type {PIDTYPE_PID = 0, PIDTYPE_TGID, PIDTYPE_PGID};

const int THREAD_CLONE_FLAGS = CLONE_THREAD | CLONE_SIGHAND | CLONE_FS | CLONE_VM | CLONE_FILES;

+struct child_args {
+ int num_threads;
+ int pfd[2];
+ int cpid;
+ int thr_tids[MAX_THREADS];
+};
+
+static struct child_args procs[MAX_PROCESSES];
+static int num_processes = 2;
+static int need_cleanup = 0;
+
static int _prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4,
unsigned long arg5)
{
@@ -80,8 +91,14 @@ static int _prctl(int option, unsigned long arg2, unsigned long arg3, unsigned l
#define handle_error(msg) __handle_error(__FILE__, __LINE__, msg)
static void __handle_error(char *fn, int ln, char *msg)
{
+ int pidx;
printf("(%s:%d) - ", fn, ln);
perror(msg);
+ if (need_cleanup) {
+ for (pidx = 0; pidx < num_processes; ++pidx)
+ kill(procs[pidx].cpid, 15);
+ need_cleanup = 0;
+ }
exit(EXIT_FAILURE);
}

@@ -108,13 +125,6 @@ static unsigned long get_cs_cookie(int pid)
return cookie;
}

-struct child_args {
- int num_threads;
- int pfd[2];
- int cpid;
- int thr_tids[MAX_THREADS];
-};
-
static int child_func_thread(void __attribute__((unused))*arg)
{
while (1)
@@ -214,10 +224,7 @@ void _validate(int line, int val, char *msg)

int main(int argc, char *argv[])
{
- struct child_args procs[MAX_PROCESSES];
-
int keypress = 0;
- int num_processes = 2;
int num_threads = 3;
int delay = 0;
int res = 0;
@@ -264,6 +271,7 @@ int main(int argc, char *argv[])

printf("\n## Create a thread/process/process group hiearchy\n");
create_processes(num_processes, num_threads, procs);
+ need_cleanup = 1;
disp_processes(num_processes, procs);
validate(get_cs_cookie(0) == 0);

--
2.33.0