1 files changed, 70 insertions, 16 deletions

diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index f0f6c5f6e98b..88789678917b 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -468,7 +468,9 @@ pid_t bm_pid, ppid;
 
 void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
 {
-	kill(bm_pid, SIGKILL);
+	/* Only kill child after bm_pid is set after fork() */
+	if (bm_pid)
+		kill(bm_pid, SIGKILL);
 	umount_resctrlfs();
 	tests_cleanup();
 	ksft_print_msg("Ending\n\n");
@@ -482,9 +484,11 @@ void ctrlc_handler(int signum, siginfo_t *info, void *ptr)
  */
 int signal_handler_register(void)
 {
-	struct sigaction sigact;
+	struct sigaction sigact = {};
 	int ret = 0;
 
+	bm_pid = 0;
+
 	sigact.sa_sigaction = ctrlc_handler;
 	sigemptyset(&sigact.sa_mask);
 	sigact.sa_flags = SA_SIGINFO;
@@ -504,7 +508,7 @@ int signal_handler_register(void)
  */
 void signal_handler_unregister(void)
 {
-	struct sigaction sigact;
+	struct sigaction sigact = {};
 
 	sigact.sa_handler = SIG_DFL;
 	sigemptyset(&sigact.sa_mask);
@@ -622,6 +626,56 @@ measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start)
 }
 
 /*
+ * run_benchmark - Run a specified benchmark or fill_buf (default benchmark)
+ *		   in specified signal. Direct benchmark stdio to /dev/null.
+ * @signum:	signal number
+ * @info:	signal info
+ * @ucontext:	user context in signal handling
+ */
+static void run_benchmark(int signum, siginfo_t *info, void *ucontext)
+{
+	int operation, ret, memflush;
+	char **benchmark_cmd;
+	size_t span;
+	bool once;
+	FILE *fp;
+
+	benchmark_cmd = info->si_ptr;
+
+	/*
+	 * Direct stdio of child to /dev/null, so that only parent writes to
+	 * stdio (console)
+	 */
+	fp = freopen("/dev/null", "w", stdout);
+	if (!fp)
+		PARENT_EXIT("Unable to direct benchmark status to /dev/null");
+
+	if (strcmp(benchmark_cmd[0], "fill_buf") == 0) {
+		/* Execute default fill_buf benchmark */
+		span = strtoul(benchmark_cmd[1], NULL, 10);
+		memflush =  atoi(benchmark_cmd[2]);
+		operation = atoi(benchmark_cmd[3]);
+		if (!strcmp(benchmark_cmd[4], "true"))
+			once = true;
+		else if (!strcmp(benchmark_cmd[4], "false"))
+			once = false;
+		else
+			PARENT_EXIT("Invalid once parameter");
+
+		if (run_fill_buf(span, memflush, operation, once))
+			fprintf(stderr, "Error in running fill buffer\n");
+	} else {
+		/* Execute specified benchmark */
+		ret = execvp(benchmark_cmd[0], benchmark_cmd);
+		if (ret)
+			perror("wrong\n");
+	}
+
+	fclose(stdout);
+	PARENT_EXIT("Unable to run specified benchmark");
+}
+
+/*
  * resctrl_val:	execute benchmark and measure memory bandwidth on
  *			the benchmark
  * @benchmark_cmd:	benchmark command and its arguments
@@ -629,7 +683,7 @@ measure_vals(struct resctrl_val_param *param, unsigned long *bw_resc_start)
  *
  * Return:		0 on success. non-zero on failure.
  */
-int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
+int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *param)
 {
 	char *resctrl_val = param->resctrl_val;
 	unsigned long bw_resc_start = 0;
@@ -706,28 +760,30 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
 
 	ksft_print_msg("Benchmark PID: %d\n", bm_pid);
 
-	ret = signal_handler_register();
-	if (ret)
-		goto out;
-
-	value.sival_ptr = benchmark_cmd;
+	/*
+	 * The cast removes constness but nothing mutates benchmark_cmd within
+	 * the context of this process. At the receiving process, it becomes
+	 * argv, which is mutable, on exec() but that's after fork() so it
+	 * doesn't matter for the process running the tests.
+	 */
+	value.sival_ptr = (void *)benchmark_cmd;
 
 	/* Taskset benchmark to specified cpu */
 	ret = taskset_benchmark(bm_pid, param->cpu_no);
 	if (ret)
-		goto unregister;
+		goto out;
 
 	/* Write benchmark to specified control&monitoring grp in resctrl FS */
 	ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp,
 				      resctrl_val);
 	if (ret)
-		goto unregister;
+		goto out;
 
 	if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) ||
 	    !strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) {
 		ret = initialize_mem_bw_imc();
 		if (ret)
-			goto unregister;
+			goto out;
 
 		initialize_mem_bw_resctrl(param->ctrlgrp, param->mongrp,
 					  param->cpu_no, resctrl_val);
@@ -742,7 +798,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
 		    sizeof(pipe_message)) {
 			perror("# failed reading message from child process");
 			close(pipefd[0]);
-			goto unregister;
+			goto out;
 		}
 	}
 	close(pipefd[0]);
@@ -751,7 +807,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
 	if (sigqueue(bm_pid, SIGUSR1, value) == -1) {
 		perror("# sigqueue SIGUSR1 to child");
 		ret = errno;
-		goto unregister;
+		goto out;
 	}
 
 	/* Give benchmark enough time to fully run */
@@ -780,8 +836,6 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param)
 		}
 	}
 
-unregister:
-	signal_handler_unregister();
 out:
 	kill(bm_pid, SIGKILL);