tools/rtla: Add osnoise_trace_is_off()

All of the users of trace_is_off() passes in &record->trace as the second
parameter, where record is a pointer to a struct osnoise_tool. This record
could be NULL and there is a hidden dependency that the trace field is the
first field to allow &record->trace to work with a NULL record pointer.

In order to make this code a bit more robust, as record shouldn't be
dereferenced if it is NULL, even if the code does work, create a new
function called osnoise_trace_is_off() that takes the pointer to a
struct osnoise_tool as its second parameter. This way it can properly test
if it is NULL before it dereferences it.

The old function trace_is_off() is removed and the function
osnoise_trace_is_off() is added into osnoise.c which is what the
struct osnoise_tool is associated with.

Cc: John Kacur <[email protected]>
Cc: "Luis Claudio R. Goncalves" <[email protected]>
Cc: Eder Zulian <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: Tomas Glozar <[email protected]>
Cc: Gabriele Monaco <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Costa Shulyupin <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>

Author: makelinux

tools/tracing/rtla/src/osnoise.c

@@ -1079,6 +1079,22 @@ struct osnoise_tool *osnoise_init_trace_tool(char *tracer)
 	return NULL;
 }
 
+bool osnoise_trace_is_off(struct osnoise_tool *tool, struct osnoise_tool *record)
+{
+	/*
+	 * The tool instance is always present, it is the one used to collect
+	 * data.
+	 */
+	if (!tracefs_trace_is_on(tool->trace.inst))
+		return true;
+
+	/*
+	 * The trace record instance is only enabled when -t is set. IOW, when the system
+	 * is tracing.
+	 */
+	return record && !tracefs_trace_is_on(record->trace.inst);
+}
+
 static void osnoise_usage(int err)
 {
 	int i;

tools/tracing/rtla/src/osnoise.h

@@ -104,6 +104,7 @@ struct osnoise_tool {
 void osnoise_destroy_tool(struct osnoise_tool *top);
 struct osnoise_tool *osnoise_init_tool(char *tool_name);
 struct osnoise_tool *osnoise_init_trace_tool(char *tracer);
+bool osnoise_trace_is_off(struct osnoise_tool *tool, struct osnoise_tool *record);
 
 int osnoise_hist_main(int argc, char *argv[]);
 int osnoise_top_main(int argc, char **argv);

tools/tracing/rtla/src/osnoise_hist.c

@@ -970,7 +970,7 @@ int osnoise_hist_main(int argc, char *argv[])
 			goto out_hist;
 		}
 
-		if (trace_is_off(&tool->trace, &record->trace))
+		if (osnoise_trace_is_off(tool, record))
 			break;
 	}
 
@@ -980,7 +980,7 @@ int osnoise_hist_main(int argc, char *argv[])
 
 	return_value = 0;
 
-	if (trace_is_off(&tool->trace, &record->trace)) {
+	if (osnoise_trace_is_off(tool, record)) {
 		printf("rtla osnoise hit stop tracing\n");
 		if (params->trace_output) {
 			printf("  Saving trace to %s\n", params->trace_output);

tools/tracing/rtla/src/osnoise_top.c

@@ -801,7 +801,7 @@ int osnoise_top_main(int argc, char **argv)
 		if (!params->quiet)
 			osnoise_print_stats(params, tool);
 
-		if (trace_is_off(&tool->trace, &record->trace))
+		if (osnoise_trace_is_off(tool, record))
 			break;
 
 	}
@@ -810,7 +810,7 @@ int osnoise_top_main(int argc, char **argv)
 
 	return_value = 0;
 
-	if (trace_is_off(&tool->trace, &record->trace)) {
+	if (osnoise_trace_is_off(tool, record)) {
 		printf("osnoise hit stop tracing\n");
 		if (params->trace_output) {
 			printf("  Saving trace to %s\n", params->trace_output);

tools/tracing/rtla/src/timerlat_hist.c

@@ -1347,7 +1347,7 @@ int timerlat_hist_main(int argc, char *argv[])
 			goto out_hist;
 		}
 
-		if (trace_is_off(&tool->trace, &record->trace))
+		if (osnoise_trace_is_off(tool, record))
 			break;
 
 		/* is there still any user-threads ? */
@@ -1368,7 +1368,7 @@ int timerlat_hist_main(int argc, char *argv[])
 
 	return_value = 0;
 
-	if (trace_is_off(&tool->trace, &record->trace) && !stop_tracing) {
+	if (osnoise_trace_is_off(tool, record) && !stop_tracing) {
 		printf("rtla timerlat hit stop tracing\n");
 
 		if (!params->no_aa)

tools/tracing/rtla/src/timerlat_top.c

@@ -1114,7 +1114,7 @@ int timerlat_top_main(int argc, char *argv[])
 	while (!stop_tracing) {
 		sleep(params->sleep_time);
 
-		if (params->aa_only && !trace_is_off(&top->trace, &record->trace))
+		if (params->aa_only && !osnoise_trace_is_off(top, record))
 			continue;
 
 		retval = tracefs_iterate_raw_events(trace->tep,
@@ -1131,7 +1131,7 @@ int timerlat_top_main(int argc, char *argv[])
 		if (!params->quiet)
 			timerlat_print_stats(params, top);
 
-		if (trace_is_off(&top->trace, &record->trace))
+		if (osnoise_trace_is_off(top, record))
 			break;
 
 		/* is there still any user-threads ? */
@@ -1152,7 +1152,7 @@ int timerlat_top_main(int argc, char *argv[])
 
 	return_value = 0;
 
-	if (trace_is_off(&top->trace, &record->trace) && !stop_tracing) {
+	if (osnoise_trace_is_off(top, record) && !stop_tracing) {
 		printf("rtla timerlat hit stop tracing\n");
 
 		if (!params->no_aa)

tools/tracing/rtla/src/trace.c

@@ -530,25 +530,6 @@ void trace_events_destroy(struct trace_instance *instance,
 	trace_events_free(events);
 }
 
-int trace_is_off(struct trace_instance *tool, struct trace_instance *trace)
-{
-	/*
-	 * The tool instance is always present, it is the one used to collect
-	 * data.
-	 */
-	if (!tracefs_trace_is_on(tool->inst))
-		return 1;
-
-	/*
-	 * The trace instance is only enabled when -t is set. IOW, when the system
-	 * is tracing.
-	 */
-	if (trace && !tracefs_trace_is_on(trace->inst))
-		return 1;
-
-	return 0;
-}
-
 /*
  * trace_set_buffer_size - set the per-cpu tracing buffer size.
  */

tools/tracing/rtla/src/trace.h

@@ -48,5 +48,4 @@ int trace_events_enable(struct trace_instance *instance,
 
 int trace_event_add_filter(struct trace_events *event, char *filter);
 int trace_event_add_trigger(struct trace_events *event, char *trigger);
-int trace_is_off(struct trace_instance *tool, struct trace_instance *trace);
 int trace_set_buffer_size(struct trace_instance *trace, int size);