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tracing: Simplify creation and deletion of synthetic events 

Since the event_mutex and synth_event_mutex ordering issue
is gone, we can skip existing event check when adding or
deleting events, and some redundant code in error path.

This changes release_all_synth_events() to abort the process
when it hits any error and returns the error code. It succeeds
only if it has no error.

Link: http://lkml.kernel.org/r/154140847194.17322.17960275728005067803.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu 2018-11-05 18:01:12 +09:00 committed by Steven Rostedt (VMware)
parent fc800a10be
commit faacb361f2
1 changed files with 18 additions and 35 deletions
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53
kernel/trace/trace_events_hist.c
View File

@ -1008,18 +1008,6 @@ struct hist_var_data {
struct hist_trigger_data *hist_data;
};
static void add_or_delete_synth_event(struct synth_event *event, int delete)
{
if (delete)
free_synth_event(event);
else {
if (!find_synth_event(event->name))
list_add(&event->list, &synth_event_list);
else
free_synth_event(event);
}
}
static int create_synth_event(int argc, char **argv)
{
struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
@ -1052,15 +1040,16 @@ static int create_synth_event(int argc, char **argv)
if (event) {
if (delete_event) {
if (event->ref) {
event = NULL;
ret = -EBUSY;
goto out;
}
list_del(&event->list);
goto out;
}
event = NULL;
ret = -EEXIST;
ret = unregister_synth_event(event);
if (!ret) {
list_del(&event->list);
free_synth_event(event);
}
} else
ret = -EEXIST;
goto out;
} else if (delete_event) {
ret = -ENOENT;
@ -1100,29 +1089,21 @@ static int create_synth_event(int argc, char **argv)
event = NULL;
goto err;
}
ret = register_synth_event(event);
if (!ret)
list_add(&event->list, &synth_event_list);
else
free_synth_event(event);
out:
if (event) {
if (delete_event) {
ret = unregister_synth_event(event);
add_or_delete_synth_event(event, !ret);
} else {
ret = register_synth_event(event);
add_or_delete_synth_event(event, ret);
}
}
mutex_unlock(&synth_event_mutex);
mutex_unlock(&event_mutex);
return ret;
err:
mutex_unlock(&synth_event_mutex);
mutex_unlock(&event_mutex);
for (i = 0; i < n_fields; i++)
free_synth_field(fields[i]);
free_synth_event(event);
return ret;
goto out;
}
static int release_all_synth_events(void)
@ -1141,10 +1122,12 @@ static int release_all_synth_events(void)
}
list_for_each_entry_safe(event, e, &synth_event_list, list) {
list_del(&event->list);
ret = unregister_synth_event(event);
add_or_delete_synth_event(event, !ret);
if (!ret) {
list_del(&event->list);
free_synth_event(event);
} else
break;
}
mutex_unlock(&synth_event_mutex);
mutex_unlock(&event_mutex);