[PATCH v2] selftests/powerpc: Avoid remaining process/threads

[Breno Leitao]

There are some powerpc selftests, as tm/tm-unavailable, that run for a long
period (>120 seconds), and if it is interrupted, as pressing CRTL-C
(SIGINT), the foreground process (harness) dies but the child process and
threads continue to execute (with PPID = 1 now) in background.

In this case, you'd think the whole test exited, but there are remaining
threads and processes being executed in background. Sometimes these
zoombies processes are doing annoying things, as consuming the whole CPU or
dumping things to STDOUT.

This patch fixes this problem by creating a SIGINT handler in the harness
process, which will kill the child process group once a SIGINT is caught.

Signed-off-by: Breno Leitao <leitao at debian.org>
Signed-off-by: Gustavo Romero <gromero at linux.vnet.ibm.com>
---
 tools/testing/selftests/powerpc/harness.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/powerpc/harness.c b/tools/testing/selftests/powerpc/harness.c
index 66d31de60b9a..06c51e8d8ccb 100644
--- a/tools/testing/selftests/powerpc/harness.c
+++ b/tools/testing/selftests/powerpc/harness.c
@@ -22,12 +22,12 @@
 #define KILL_TIMEOUT	5
 
 static uint64_t timeout = 120;
+pid_t pid;
 
 int run_test(int (test_function)(void), char *name)
 {
 	bool terminated;
 	int rc, status;
-	pid_t pid;
 
 	/* Make sure output is flushed before forking */
 	fflush(stdout);
@@ -85,13 +85,16 @@ int run_test(int (test_function)(void), char *name)
 	return status;
 }
 
-static void alarm_handler(int signum)
+static void sig_handler(int signum)
 {
-	/* Jut wake us up from waitpid */
+	if (signum == SIGINT)
+		kill(-pid, SIGTERM);
+
+	/* if SIGALRM, just wake us up from waitpid */
 }
 
-static struct sigaction alarm_action = {
-	.sa_handler = alarm_handler,
+static struct sigaction sig_action = {
+	.sa_handler = sig_handler,
 };
 
 void test_harness_set_timeout(uint64_t time)
@@ -106,8 +109,14 @@ int test_harness(int (test_function)(void), char *name)
 	test_start(name);
 	test_set_git_version(GIT_VERSION);
 
-	if (sigaction(SIGALRM, &alarm_action, NULL)) {
-		perror("sigaction");
+	if (sigaction(SIGINT, &sig_action, NULL)) {
+		perror("sigaction (sigint)");
+		test_error(name);
+		return 1;
+	}
+
+	if (sigaction(SIGALRM, &sig_action, NULL)) {
+		perror("sigaction (sigalrm)");
 		test_error(name);
 		return 1;
 	}
-- 
2.16.3