[PATCH v2 06/18] rtla: Use strncmp_static() in more places

[Wander Lairson Costa <wander@redhat.com>]

The recently introduced strncmp_static() helper provides a safer way
to compare strings with static strings by determining the length at
compile time.

Replace several open-coded strncmp() calls with strncmp_static() to
improve code readability and robustness. This change affects the
parsing of command-line arguments and environment variables.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
---
 tools/tracing/rtla/src/osnoise.c  | 2 +-
 tools/tracing/rtla/src/timerlat.c | 4 ++--
 tools/tracing/rtla/src/trace.c    | 2 +-
 tools/tracing/rtla/src/utils.c    | 8 ++++----
 4 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/tools/tracing/rtla/src/osnoise.c b/tools/tracing/rtla/src/osnoise.c
index c5b41ec26b0a4..f2ec2da7b6d3a 100644
--- a/tools/tracing/rtla/src/osnoise.c
+++ b/tools/tracing/rtla/src/osnoise.c
@@ -1219,7 +1219,7 @@ int osnoise_main(int argc, char *argv[])
 
 	if ((strcmp(argv[1], "-h") == 0) || (strcmp(argv[1], "--help") == 0)) {
 		osnoise_usage(0);
-	} else if (strncmp(argv[1], "-", 1) == 0) {
+	} else if (strncmp_static(argv[1], "-") == 0) {
 		/* the user skipped the tool, call the default one */
 		run_tool(&osnoise_top_ops, argc, argv);
 		exit(0);
diff --git a/tools/tracing/rtla/src/timerlat.c b/tools/tracing/rtla/src/timerlat.c
index df4f9bfe34331..ac2ec89d3b6ba 100644
--- a/tools/tracing/rtla/src/timerlat.c
+++ b/tools/tracing/rtla/src/timerlat.c
@@ -34,7 +34,7 @@ timerlat_apply_config(struct osnoise_tool *tool, struct timerlat_params *params)
 	 * Try to enable BPF, unless disabled explicitly.
 	 * If BPF enablement fails, fall back to tracefs mode.
 	 */
-	if (getenv("RTLA_NO_BPF") && strncmp(getenv("RTLA_NO_BPF"), "1", 2) == 0) {
+	if (getenv("RTLA_NO_BPF") && strncmp_static(getenv("RTLA_NO_BPF"), "1") == 0) {
 		debug_msg("RTLA_NO_BPF set, disabling BPF\n");
 		params->mode = TRACING_MODE_TRACEFS;
 	} else if (!tep_find_event_by_name(tool->trace.tep, "osnoise", "timerlat_sample")) {
@@ -271,7 +271,7 @@ int timerlat_main(int argc, char *argv[])
 
 	if ((strcmp(argv[1], "-h") == 0) || (strcmp(argv[1], "--help") == 0)) {
 		timerlat_usage(0);
-	} else if (strncmp(argv[1], "-", 1) == 0) {
+	} else if (strncmp_static(argv[1], "-") == 0) {
 		/* the user skipped the tool, call the default one */
 		run_tool(&timerlat_top_ops, argc, argv);
 		exit(0);
diff --git a/tools/tracing/rtla/src/trace.c b/tools/tracing/rtla/src/trace.c
index b22bb844b71f3..45328c5121f79 100644
--- a/tools/tracing/rtla/src/trace.c
+++ b/tools/tracing/rtla/src/trace.c
@@ -356,7 +356,7 @@ static void trace_event_save_hist(struct trace_instance *instance,
 		return;
 
 	/* is this a hist: trigger? */
-	retval = strncmp(tevent->trigger, "hist:", strlen("hist:"));
+	retval = strncmp_static(tevent->trigger, "hist:");
 	if (retval)
 		return;
 
diff --git a/tools/tracing/rtla/src/utils.c b/tools/tracing/rtla/src/utils.c
index f3e129d17a82b..e0f31e5cae844 100644
--- a/tools/tracing/rtla/src/utils.c
+++ b/tools/tracing/rtla/src/utils.c
@@ -211,15 +211,15 @@ long parse_ns_duration(char *val)
 	t = strtol(val, &end, 10);
 
 	if (end) {
-		if (!strncmp(end, "ns", 2)) {
+		if (!strncmp_static(end, "ns")) {
 			return t;
-		} else if (!strncmp(end, "us", 2)) {
+		} else if (!strncmp_static(end, "us")) {
 			t *= 1000;
 			return t;
-		} else if (!strncmp(end, "ms", 2)) {
+		} else if (!strncmp_static(end, "ms")) {
 			t *= 1000 * 1000;
 			return t;
-		} else if (!strncmp(end, "s", 1)) {
+		} else if (!strncmp_static(end, "s")) {
 			t *= 1000 * 1000 * 1000;
 			return t;
 		}
-- 
2.52.0