summaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
authorTom Zanussi <tom.zanussi@linux.intel.com>2015-12-10 12:50:49 -0600
committerSteven Rostedt <rostedt@goodmis.org>2016-03-08 11:19:35 -0500
commita88e1cfb1d3081ffb34864d9cf8a5c289630f48e (patch)
treec8b64b61980d5d52ce0d25b3d330cda332c74ec8 /kernel
parenta5863dae84e2da83a1e5de485a7f150d0c28f08e (diff)
downloadop-kernel-dev-a88e1cfb1d3081ffb34864d9cf8a5c289630f48e.zip
op-kernel-dev-a88e1cfb1d3081ffb34864d9cf8a5c289630f48e.tar.gz
tracing: Add an unreg_all() callback to trigger commands
Add a new unreg_all() callback that can be used to remove all command-specific triggers from an event and arrange to have it called whenever a trigger file is opened with O_TRUNC set. Commands that don't want truncate semantics, or existing commands that don't implement this function simply do nothing and their triggers remain intact. Link: http://lkml.kernel.org/r/2b7d62854d01f28c19185e1bbb8f826f385edfba.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/trace.h9
-rw-r--r--kernel/trace/trace_events_trigger.c13
2 files changed, 20 insertions, 2 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8c6aefb..f4dd0ad 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1298,8 +1298,8 @@ struct event_trigger_ops {
* it (filters make a trigger require access to the trace record
* but are not always present).
*
- * All the methods below, except for @set_filter(), must be
- * implemented.
+ * All the methods below, except for @set_filter() and @unreg_all(),
+ * must be implemented.
*
* @func: The callback function responsible for parsing and
* registering the trigger written to the 'trigger' file by the
@@ -1324,6 +1324,10 @@ struct event_trigger_ops {
* This is usually implemented by the generic utility function
* @unregister_trigger() (see trace_event_triggers.c).
*
+ * @unreg_all: An optional function called to remove all the triggers
+ * from the list of triggers associated with the event. Called
+ * when a trigger file is opened in truncate mode.
+ *
* @set_filter: An optional function called to parse and set a filter
* for the trigger. If no @set_filter() method is set for the
* event command, filters set by the user for the command will be
@@ -1350,6 +1354,7 @@ struct event_command {
struct event_trigger_ops *ops,
struct event_trigger_data *data,
struct trace_event_file *file);
+ void (*unreg_all)(struct trace_event_file *file);
int (*set_filter)(char *filter_str,
struct event_trigger_data *data,
struct trace_event_file *file);
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index a11bb47..cbb7ee5 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -193,6 +193,19 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file)
return -ENODEV;
}
+ if ((file->f_mode & FMODE_WRITE) &&
+ (file->f_flags & O_TRUNC)) {
+ struct trace_event_file *event_file;
+ struct event_command *p;
+
+ event_file = event_file_data(file);
+
+ list_for_each_entry(p, &trigger_commands, list) {
+ if (p->unreg_all)
+ p->unreg_all(event_file);
+ }
+ }
+
if (file->f_mode & FMODE_READ) {
ret = seq_open(file, &event_triggers_seq_ops);
if (!ret) {
OpenPOWER on IntegriCloud