[PATCH 4/5] selftests/resctrl: Kill the child process before exiting the parent process if an exception occurs

[Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>]

After creating a child process with fork() in CAT test, if there is
an exception occurs, the parent process will be terminated immediately,
but the child process will not be killed and umount_resctrlfs() will not
be called.

When fork() is used in CMT/MBA/MBM tests.
If an exception occurs, before parent process exiting,
the child process is killed and umount_resctrlfs() is called.

Kill the child process before exiting the parent process
if an exception occurs in CAT test, like in CMT/MBA/MBM tests.

Signed-off-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
---
 tools/testing/selftests/resctrl/cat_test.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index d1134f66469f..f62da445acbb 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -186,11 +186,11 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
 
 	ret = cat_val(&param);
 	if (ret)
-		return ret;
+		goto out;
 
 	ret = check_results(&param);
 	if (ret)
-		return ret;
+		goto out;
 
 	if (bm_pid == 0) {
 		/* Tell parent that child is ready */
@@ -200,7 +200,8 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
 		    sizeof(pipe_message)) {
 			close(pipefd[1]);
 			perror("# failed signaling parent process");
-			return errno;
+			ret = errno;
+			goto out;
 		}
 
 		close(pipefd[1]);
@@ -218,11 +219,11 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
 			}
 		}
 		close(pipefd[0]);
-		kill(bm_pid, SIGKILL);
 	}
 
-	if (bm_pid)
-		umount_resctrlfs();
+out:
+	kill(bm_pid, SIGKILL);
+	umount_resctrlfs();
 
-	return 0;
+	return ret;
 }
-- 
2.27.0