trace-cmd stat: Add -o option to show options

Add "-o" to trace-cmd stat to list the options that are enabled or disable
(like it does with trace-cmd list). The difference with stat is that it
allows you to see the available options for an instance, where as
trace-cmd list does not.

 trace-cmd stat -B foo -o

Will list the options that are set for instance foo.

Link: https://lore.kernel.org/linux-trace-devel/20210416172331.3870833-4-rostedt@goodmis.org

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

5 files changed, 29 insertions, 11 deletions

diff --git a/Documentation/trace-cmd/trace-cmd-stat.1.txt b/Documentation/trace-cmd/trace-cmd-stat.1.txt
index 1be9e609..fb800f91 100644
--- a/Documentation/trace-cmd/trace-cmd-stat.1.txt
+++ b/Documentation/trace-cmd/trace-cmd-stat.1.txt
@@ -55,6 +55,10 @@ OPTIONS
     If *-B* is also specified, show the status of the top level tracing directory
     as well as the instance(s).
 
+*-o*::
+    Display the all the options along with their values. If they start with "no", then
+    the option is disabled.
+
 SEE ALSO
 --------
 trace-cmd(1), trace-cmd-record(1), trace-cmd-report(1), trace-cmd-start(1),
diff --git a/tracecmd/include/trace-local.h b/tracecmd/include/trace-local.h
index 13dab44c..bb33de06 100644
--- a/tracecmd/include/trace-local.h
+++ b/tracecmd/include/trace-local.h
@@ -300,6 +300,7 @@ void add_instance(struct buffer_instance *instance, int cpu_count);
 void update_first_instance(struct buffer_instance *instance, int topt);
 
 void show_instance_file(struct buffer_instance *instance, const char *name);
+void show_options(const char *prefix, struct buffer_instance *buffer);
 
 struct trace_guest {
 	struct tracefs_instance *instance;
diff --git a/tracecmd/trace-list.c b/tracecmd/trace-list.c
index 0574e563..fbf2882e 100644
--- a/tracecmd/trace-list.c
+++ b/tracecmd/trace-list.c
@@ -399,14 +399,18 @@ static void show_tracers(void)
 	show_file("available_tracers");
 }
 
-static void show_options(void)
+void show_options(const char *prefix, struct buffer_instance *buffer)
 {
+	struct tracefs_instance *instance = buffer ? buffer->tracefs : NULL;
 	struct dirent *dent;
 	struct stat st;
 	char *path;
 	DIR *dir;
 
-	path = tracefs_get_tracing_file("options");
+	if (!prefix)
+		prefix = "";
+
+	path = tracefs_instance_get_file(instance, "options");
 	if (!path)
 		goto show_file;
 	if (stat(path, &st) < 0)
@@ -432,12 +436,12 @@ static void show_options(void)
 		ret = asprintf(&file, "options/%s", name);
 		if (ret < 0)
 			die("Failed to allocate file name");
-		ret = tracefs_instance_file_read_number(NULL, file, &val);
+		ret = tracefs_instance_file_read_number(instance, file, &val);
 		if (!ret) {
 			if (val)
-				printf("%s\n", name);
+				printf("%s%s\n", prefix, name);
 			else
-				printf("no%s\n", name);
+				printf("%sno%s\n", prefix, name);
 		}
 		free(file);
 	}
@@ -719,7 +723,7 @@ void trace_list(int argc, char **argv)
 		show_tracers();
 
 	if (options)
-		show_options();
+		show_options(NULL, NULL);
 
 	if (plug)
 		show_plugins();
@@ -747,7 +751,7 @@ void trace_list(int argc, char **argv)
 		printf("\ntracers:\n");
 		show_tracers();
 		printf("\noptions:\n");
-		show_options();
+		show_options(NULL, NULL);
 		show_compression();
 	}
 
diff --git a/tracecmd/trace-stat.c b/tracecmd/trace-stat.c
index b4428e49..a5fb777b 100644
--- a/tracecmd/trace-stat.c
+++ b/tracecmd/trace-stat.c
@@ -835,7 +835,7 @@ static void report_traceon(struct buffer_instance *instance)
 	free(str);
 }
 
-static void stat_instance(struct buffer_instance *instance)
+static void stat_instance(struct buffer_instance *instance, bool opt)
 {
 	if (instance != &top_instance) {
 		if (instance != first_instance)
@@ -859,6 +859,10 @@ static void stat_instance(struct buffer_instance *instance)
 	report_file(instance, "set_event_pid", "", "Filtered event PIDs:\n");
 	report_file(instance, "set_ftrace_pid", "no pid",
 		    "Filtered function tracer PIDs:\n");
+	if (opt) {
+		printf("\nOptions:\n");
+		show_options("   ", instance);
+	}
 	report_traceon(instance);
 	report_file(instance, "error_log", "", "Error log:\n");
 	if (instance == &top_instance)
@@ -868,6 +872,7 @@ static void stat_instance(struct buffer_instance *instance)
 void trace_stat (int argc, char **argv)
 {
 	struct buffer_instance *instance = &top_instance;
+	bool opt = false;
 	int topt = 0;
 	int status;
 	int c;
@@ -875,7 +880,7 @@ void trace_stat (int argc, char **argv)
 	init_top_instance();
 
 	for (;;) {
-		c = getopt(argc-1, argv+1, "htB:");
+		c = getopt(argc-1, argv+1, "htoB:");
 		if (c == -1)
 			break;
 		switch (c) {
@@ -896,6 +901,9 @@ void trace_stat (int argc, char **argv)
 			topt = 1;
 			instance = &top_instance;
 			break;
+		case 'o':
+			opt = 1;
+			break;
 		default:
 			usage(argv);
 		}
@@ -904,7 +912,7 @@ void trace_stat (int argc, char **argv)
 	update_first_instance(instance, topt);
 
 	for_all_instances(instance) {
-		stat_instance(instance);
+		stat_instance(instance, opt);
 	}
 
 	if (tracecmd_stack_tracer_status(&status) >= 0) {
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index b5ef7733..20995fab 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -283,9 +283,10 @@ static struct usage_help usage_help[] = {
 	{
 		"stat",
 		"show the status of the running tracing (ftrace) system",
-		" %s stat [-B buf][-t]"
+		" %s stat [-B buf][-t][-o]"
 		"          -B show the status of a instance buffer\n"
 		"          -t show the top level status along with buffer specified by -B\n"
+		"          -o list tracing options\n"
 	},
 	{
 		"split",