Merge tag 'linux_kselftest-next-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest updates from Shuah Khan:

 - kbuild kselftest-merge target fixes

 - fixes to several tests

 - resctrl test fixes and enhancements

 - ksft_perror() helper and reporting improvements

 - printf attribute to kselftest prints to improve reporting

 - documentation and clang build warning fixes

The bulk of the patches are for resctrl fixes and enhancements.

* tag 'linux_kselftest-next-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (51 commits)
  selftests/resctrl: Fix MBM test failure when MBA unavailable
  selftests/clone3: Report descriptive test names
  selftests:modify the incorrect print format
  selftests/efivarfs: create-read: fix a resource leak
  selftests/ftrace: Add riscv support for kprobe arg tests
  selftests/ftrace: add loongarch support for kprobe args char tests
  selftests/amd-pstate: Added option to provide perf binary path
  selftests/amd-pstate: Fix broken paths to run workloads in amd-pstate-ut
  selftests/resctrl: Move run_benchmark() to a more fitting file
  selftests/resctrl: Fix schemata write error check
  selftests/resctrl: Reduce failures due to outliers in MBA/MBM tests
  selftests/resctrl: Fix feature checks
  selftests/resctrl: Refactor feature check to use resource and feature name
  selftests/resctrl: Move _GNU_SOURCE define into Makefile
  selftests/resctrl: Remove duplicate feature check from CMT test
  selftests/resctrl: Extend signal handler coverage to unmount on receiving signal
  selftests/resctrl: Fix uninitialized .sa_flags
  selftests/resctrl: Cleanup benchmark argument parsing
  selftests/resctrl: Remove ben_count variable
  selftests/resctrl: Make benchmark command const and build it with pointers
  ...

1 files changed, 53 insertions, 109 deletions

diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index bd36ee206602..5ebd43683876 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -8,6 +8,9 @@
  *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
  *    Fenghua Yu <fenghua.yu@intel.com>
  */
+#include <fcntl.h>
+#include <limits.h>
+
 #include "resctrl.h"
 
 static int find_resctrl_mount(char *buffer)
@@ -292,58 +295,6 @@ int taskset_benchmark(pid_t bm_pid, int cpu_no)
 }
 
 /*
- * 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
- *
- * Return: void
- */
-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");
-}
-
-/*
  * create_grp - Create a group only if one doesn't exist
  * @grp_name:	Name of the group
  * @grp:	Full path and name of the group
@@ -488,9 +439,8 @@ out:
  */
 int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
 {
-	char controlgroup[1024], schema[1024], reason[64];
-	int resource_id, ret = 0;
-	FILE *fp;
+	char controlgroup[1024], reason[128], schema[1024] = {};
+	int resource_id, fd, schema_len = -1, ret = 0;
 
 	if (strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR)) &&
 	    strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) &&
@@ -518,28 +468,39 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
 
 	if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR)) ||
 	    !strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)))
-		sprintf(schema, "%s%d%c%s", "L3:", resource_id, '=', schemata);
+		schema_len = snprintf(schema, sizeof(schema), "%s%d%c%s\n",
+				      "L3:", resource_id, '=', schemata);
 	if (!strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR)) ||
 	    !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)))
-		sprintf(schema, "%s%d%c%s", "MB:", resource_id, '=', schemata);
-
-	fp = fopen(controlgroup, "w");
-	if (!fp) {
-		sprintf(reason, "Failed to open control group");
+		schema_len = snprintf(schema, sizeof(schema), "%s%d%c%s\n",
+				      "MB:", resource_id, '=', schemata);
+	if (schema_len < 0 || schema_len >= sizeof(schema)) {
+		snprintf(reason, sizeof(reason),
+			 "snprintf() failed with return value : %d", schema_len);
 		ret = -1;
-
 		goto out;
 	}
 
-	if (fprintf(fp, "%s\n", schema) < 0) {
-		sprintf(reason, "Failed to write schemata in control group");
-		fclose(fp);
+	fd = open(controlgroup, O_WRONLY);
+	if (fd < 0) {
+		snprintf(reason, sizeof(reason),
+			 "open() failed : %s", strerror(errno));
 		ret = -1;
 
-		goto out;
+		goto err_schema_not_empty;
 	}
-	fclose(fp);
+	if (write(fd, schema, schema_len) < 0) {
+		snprintf(reason, sizeof(reason),
+			 "write() failed : %s", strerror(errno));
+		close(fd);
+		ret = -1;
+
+		goto err_schema_not_empty;
+	}
+	close(fd);
 
+err_schema_not_empty:
+	schema[schema_len - 1] = 0;
 out:
 	ksft_print_msg("Write schema \"%s\" to resctrl FS%s%s\n",
 		       schema, ret ? " # " : "",
@@ -604,63 +565,46 @@ char *fgrep(FILE *inf, const char *str)
 
 /*
  * validate_resctrl_feature_request - Check if requested feature is valid.
- * @resctrl_val:	Requested feature
+ * @resource:	Required resource (e.g., MB, L3, L2, L3_MON, etc.)
+ * @feature:	Required monitor feature (in mon_features file). Can only be
+ *		set for L3_MON. Must be NULL for all other resources.
  *
- * Return: True if the feature is supported, else false. False is also
- *         returned if resctrl FS is not mounted.
+ * Return: True if the resource/feature is supported, else false. False is
+ *         also returned if resctrl FS is not mounted.
  */
-bool validate_resctrl_feature_request(const char *resctrl_val)
+bool validate_resctrl_feature_request(const char *resource, const char *feature)
 {
+	char res_path[PATH_MAX];
 	struct stat statbuf;
-	bool found = false;
 	char *res;
 	FILE *inf;
 	int ret;
 
-	if (!resctrl_val)
+	if (!resource)
 		return false;
 
 	ret = find_resctrl_mount(NULL);
 	if (ret)
 		return false;
 
-	if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR))) {
-		if (!stat(L3_PATH, &statbuf))
-			return true;
-	} else if (!strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR))) {
-		if (!stat(MB_PATH, &statbuf))
-			return true;
-	} else if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) ||
-		   !strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) {
-		if (!stat(L3_MON_PATH, &statbuf)) {
-			inf = fopen(L3_MON_FEATURES_PATH, "r");
-			if (!inf)
-				return false;
-
-			if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR))) {
-				res = fgrep(inf, "llc_occupancy");
-				if (res) {
-					found = true;
-					free(res);
-				}
-			}
-
-			if (!strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) {
-				res = fgrep(inf, "mbm_total_bytes");
-				if (res) {
-					free(res);
-					res = fgrep(inf, "mbm_local_bytes");
-					if (res) {
-						found = true;
-						free(res);
-					}
-				}
-			}
-			fclose(inf);
-		}
-	}
+	snprintf(res_path, sizeof(res_path), "%s/%s", INFO_PATH, resource);
+
+	if (stat(res_path, &statbuf))
+		return false;
+
+	if (!feature)
+		return true;
+
+	snprintf(res_path, sizeof(res_path), "%s/%s/mon_features", INFO_PATH, resource);
+	inf = fopen(res_path, "r");
+	if (!inf)
+		return false;
+
+	res = fgrep(inf, feature);
+	free(res);
+	fclose(inf);
 
-	return found;
+	return !!res;
 }
 
 int filter_dmesg(void)