[PATCH 1/1] trace-cmd: Add --no-filter option to not filter out recording processes

[Slavomir Kaslev <kaslevs@vmware.com>]

Add trace-cmd --no-filter option that disables filtering out of trace-cmd
recording processes from the trace.

Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
---
 Documentation/trace-cmd-record.1.txt |  5 +++++
 tracecmd/trace-record.c              | 14 +++++++++++---
 tracecmd/trace-usage.c               |  1 +
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/Documentation/trace-cmd-record.1.txt b/Documentation/trace-cmd-record.1.txt
index 68afa16..26a8299 100644
--- a/Documentation/trace-cmd-record.1.txt
+++ b/Documentation/trace-cmd-record.1.txt
@@ -83,6 +83,11 @@ OPTIONS
 
     The above are usually safe to use to compare fields.
 
+*--no-filter*::
+    Do not filter out the trace-cmd threads. By default, the threads are
+    filtered out to not be traced by events. This option will have the trace-cmd
+    threads also be traced.
+
 *-R* 'trigger'::
     Specify a trigger for the previous event. This must come after a *-e*. 
     This will add a given trigger to the given event. To only enable the trigger
diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
index d5c66ab..4523128 100644
--- a/tracecmd/trace-record.c
+++ b/tracecmd/trace-record.c
@@ -86,6 +86,7 @@ static int do_ptrace;
 
 static int filter_task;
 static int filter_pid = -1;
+static bool no_filter = false;
 
 static int local_cpu_count;
 
@@ -1065,6 +1066,9 @@ static void update_task_filter(void)
 	struct buffer_instance *instance;
 	int pid = getpid();
 
+	if (no_filter)
+		return;
+
 	if (filter_task)
 		add_filter_pid(pid, 0);
 
@@ -4379,9 +4383,9 @@ void update_first_instance(struct buffer_instance *instance, int topt)
 }
 
 enum {
-
-	OPT_quiet		= 246,
-	OPT_debug		= 247,
+	OPT_quiet		= 245,
+	OPT_debug		= 246,
+	OPT_no_filter		= 247,
 	OPT_max_graph_depth	= 248,
 	OPT_tsoffset		= 249,
 	OPT_bycomm		= 250,
@@ -4605,6 +4609,7 @@ static void parse_record_options(int argc,
 			{"by-comm", no_argument, NULL, OPT_bycomm},
 			{"ts-offset", required_argument, NULL, OPT_tsoffset},
 			{"max-graph-depth", required_argument, NULL, OPT_max_graph_depth},
+			{"no-filter", no_argument, NULL, OPT_no_filter},
 			{"debug", no_argument, NULL, OPT_debug},
 			{"quiet", no_argument, NULL, OPT_quiet},
 			{"help", no_argument, NULL, '?'},
@@ -4879,6 +4884,9 @@ static void parse_record_options(int argc,
 			if (!ctx->max_graph_depth)
 				die("Could not allocate option");
 			break;
+		case OPT_no_filter:
+			no_filter = true;
+			break;
 		case OPT_debug:
 			debug = 1;
 			break;
diff --git a/tracecmd/trace-usage.c b/tracecmd/trace-usage.c
index 9ea1906..d2a1089 100644
--- a/tracecmd/trace-usage.c
+++ b/tracecmd/trace-usage.c
@@ -56,6 +56,7 @@ static struct usage_help usage_help[] = {
 		"          --func-stack perform a stack trace for function tracer\n"
 		"             (use with caution)\n"
 		"          --max-graph-depth limit function_graph depth\n"
+		"          --no-filter include trace-cmd threads in the trace\n"
 	},
 	{
 		"start",
-- 
2.19.1