[PATCH 2/2] trace-cmd list: Add ftrace events to listing of events

[Steven Rostedt <rostedt@goodmis.org>]

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

If a search of events is done with trace-cmd list -e, check if any matches
the ftrace events. This is useful to get the fields and print fmt of the
events under the ftrace system.

Note, just "trace-cmd list -e" will still not list ftrace events by
default.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 tracecmd/trace-list.c | 52 +++++++++++++++++++++++++++----------------
 1 file changed, 33 insertions(+), 19 deletions(-)

diff --git a/tracecmd/trace-list.c b/tracecmd/trace-list.c
index 84ee573b..81f157ac 100644
--- a/tracecmd/trace-list.c
+++ b/tracecmd/trace-list.c
@@ -139,18 +139,34 @@ static void show_event_systems(process_file_func func, char **systems)
 }
 
 
+static void match_system_events(process_file_func func, const char *system,
+				regex_t *reg)
+{
+	char **events;
+	int e;
+
+	events = tracefs_system_events(NULL, system);
+	if (!events) /* die? */
+		return;
+	for (e = 0; events[e]; e++) {
+		if (regexec(reg, events[e], 0, NULL, 0) == 0)
+			show_event(func, system, events[e]);
+	}
+	tracefs_list_free(events);
+}
+
 static void process_events(process_file_func func, const char *re)
 {
 	regex_t system_reg;
 	regex_t event_reg;
+	const char *ftrace = "ftrace";
 	char *str;
 	size_t l = strlen(re);
 	bool just_systems = true;
 	char **systems;
-	char **events;
 	char *system;
 	char *event;
-	int s, e;
+	int s;
 
 	systems = tracefs_event_systems(NULL);
 	if (!systems)
@@ -184,6 +200,19 @@ static void process_events(process_file_func func, const char *re)
 	}
 	free(str);
 
+	/*
+	 * See if this matches the special ftrace system, as ftrace is not included
+	 * in the systems list, but can get events from tracefs_system_events().
+	 */
+	if (regexec(&system_reg, ftrace, 0, NULL, 0) == 0) {
+		if (!event)
+			show_system(func, ftrace);
+		else
+			match_system_events(func, ftrace, &event_reg);
+	} else if (!just_systems) {
+		match_system_events(func, ftrace, &system_reg);
+	}
+
 	for (s = 0; systems[s]; s++) {
 
 		if (regexec(&system_reg, systems[s], 0, NULL, 0) == 0) {
@@ -191,28 +220,13 @@ static void process_events(process_file_func func, const char *re)
 				show_system(func, systems[s]);
 				continue;
 			}
-			events = tracefs_system_events(NULL, systems[s]);
-			if (!events) /* die? */
-				continue;
-			for (e = 0; events[e]; e++) {
-				if (regexec(&event_reg, events[e], 0, NULL, 0) == 0)
-					show_event(func, systems[s], events[e]);
-			}
-			tracefs_list_free(events);
+			match_system_events(func, systems[s], &event_reg);
 			continue;
 		}
 		if (just_systems)
 			continue;
 
-		events = tracefs_system_events(NULL, systems[s]);
-		if (!events) /* die? */
-			continue;
-
-		for (e = 0; events[e]; e++) {
-			if (regexec(&system_reg, events[e], 0, NULL, 0) == 0)
-				show_event(func, systems[s], events[e]);
-		}
-		tracefs_list_free(events);
+		match_system_events(func, systems[s], &system_reg);
 	}
 	tracefs_list_free(systems);
 
-- 
2.29.2