[PATCH v4 2/3] selftests/resctrl: Simplify cleanup in ctrl-c handler

[Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx>]

Ctrl-c handler isn't aware of what test is currently running. Because of
that it executes all cleanups even if they aren't necessary. Since the
ctrl-c handler uses the sa_sigaction system no parameters can be passed
to it as function arguments.

Add a global variable to make ctrl-c handler aware of the currently run
test and only execute the correct cleanup callback.

Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx>
---
Changelog v4:
- Reset current_test pointer and check if it's not NULL before calling.
  (Reinette)

Changelog v3:
- Make current_test static. (Ilpo)
- Add callback NULL pointer guard in ctrl-c handler. (Ilpo)

Changelog v2:
- Remove tests_cleanup() from resctrl.h.
- Make current_test a const pointer only inside resctrl_val.c. (Ilpo)

 tools/testing/selftests/resctrl/resctrl.h       |  3 +--
 tools/testing/selftests/resctrl/resctrl_tests.c | 14 +++-----------
 tools/testing/selftests/resctrl/resctrl_val.c   |  8 ++++++--
 3 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 0f49df4961ea..826783b29c9d 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -153,7 +153,6 @@ int resctrl_val(const struct resctrl_test *test,
 		const struct user_params *uparams,
 		const char * const *benchmark_cmd,
 		struct resctrl_val_param *param);
-void tests_cleanup(void);
 void mbm_test_cleanup(void);
 void mba_test_cleanup(void);
 unsigned long create_bit_mask(unsigned int start, unsigned int len);
@@ -162,7 +161,7 @@ int get_full_cbm(const char *cache_type, unsigned long *mask);
 int get_mask_no_shareable(const char *cache_type, unsigned long *mask);
 int get_cache_size(int cpu_no, const char *cache_type, unsigned long *cache_size);
 void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
-int signal_handler_register(void);
+int signal_handler_register(const struct resctrl_test *test);
 void signal_handler_unregister(void);
 void cat_test_cleanup(void);
 unsigned int count_bits(unsigned long n);
diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
index 75fc49ba3efb..161f5365b4f0 100644
--- a/tools/testing/selftests/resctrl/resctrl_tests.c
+++ b/tools/testing/selftests/resctrl/resctrl_tests.c
@@ -75,19 +75,11 @@ static void cmd_help(void)
 	printf("\t-h: help\n");
 }
 
-void tests_cleanup(void)
-{
-	mbm_test_cleanup();
-	mba_test_cleanup();
-	cmt_test_cleanup();
-	cat_test_cleanup();
-}
-
-static int test_prepare(void)
+static int test_prepare(const struct resctrl_test *test)
 {
 	int res;
 
-	res = signal_handler_register();
+	res = signal_handler_register(test);
 	if (res) {
 		ksft_print_msg("Failed to register signal handler\n");
 		return res;
@@ -130,7 +122,7 @@ static void run_single_test(const struct resctrl_test *test, const struct user_p
 
 	ksft_print_msg("Starting %s test ...\n", test->name);
 
-	if (test_prepare()) {
+	if (test_prepare(test)) {
 		ksft_exit_fail_msg("Abnormal failure when preparing for the test\n");
 		return;
 	}
diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 5a49f07a6c85..445f306d4c2f 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -62,6 +62,7 @@ struct imc_counter_config {
 static char mbm_total_path[1024];
 static int imcs;
 static struct imc_counter_config imc_counters_config[MAX_IMCS][2];
+static const struct resctrl_test *current_test;
 
 void membw_initialize_perf_event_attr(int i, int j)
 {
@@ -472,7 +473,8 @@ void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
 	if (bm_pid)
 		kill(bm_pid, SIGKILL);
 	umount_resctrlfs();
-	tests_cleanup();
+	if (current_test && current_test->cleanup)
+		current_test->cleanup();
 	ksft_print_msg("Ending\n\n");
 
 	exit(EXIT_SUCCESS);
@@ -482,13 +484,14 @@ void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
  * Register CTRL-C handler for parent, as it has to kill
  * child process before exiting.
  */
-int signal_handler_register(void)
+int signal_handler_register(const struct resctrl_test *test)
 {
 	struct sigaction sigact = {};
 	int ret = 0;
 
 	bm_pid = 0;
 
+	current_test = test;
 	sigact.sa_sigaction = ctrlc_handler;
 	sigemptyset(&sigact.sa_mask);
 	sigact.sa_flags = SA_SIGINFO;
@@ -510,6 +513,7 @@ void signal_handler_unregister(void)
 {
 	struct sigaction sigact = {};
 
+	current_test = NULL;
 	sigact.sa_handler = SIG_DFL;
 	sigemptyset(&sigact.sa_mask);
 	if (sigaction(SIGINT, &sigact, NULL) ||
-- 
2.43.2