[PATCH v2 6/6] tracing/dynevent: Adopt guard() and scoped_guard()

Masami Hiramatsu (Google)
2024-11-29T16:48:45Z

Use guard() or scoped_guard() in dynamic events for critical sections
rather than discrete lock/unlock pairs.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
Changes in v2:
- Use scoped_guard() instead of guard() to avoid goto warnings.
---
kernel/trace/trace_dynevent.c | 35 ++++++++++++++++-------------------
1 file changed, 16 insertions(+), 19 deletions(-)

diff --git a/kernel/trace/trace_dynevent.c b/kernel/trace/trace_dynevent.c
index 4376887e0d8a..eb8f669c15e1 100644
--- a/kernel/trace/trace_dynevent.c
+++ b/kernel/trace/trace_dynevent.c
@@ -63,9 +63,8 @@ int dyn_event_register(struct dyn_event_operations *ops)
return -EINVAL;

INIT_LIST_HEAD(&ops->list);
- mutex_lock(&dyn_event_ops_mutex);
+ guard(mutex)(&dyn_event_ops_mutex);
list_add_tail(&ops->list, &dyn_event_ops_list);
- mutex_unlock(&dyn_event_ops_mutex);
return 0;
}

@@ -106,20 +105,20 @@ int dyn_event_release(const char *raw_command, struct dyn_event_operations *type
goto out;
}

- mutex_lock(&event_mutex);
- for_each_dyn_event_safe(pos, n) {
- if (type && type != pos->ops)
- continue;
- if (!pos->ops->match(system, event,
- argc - 1, (const char **)argv + 1, pos))
- continue;
-
- ret = pos->ops->free(pos);
- if (ret)
- break;
+ scoped_guard(mutex, &event_mutex) {
+ for_each_dyn_event_safe(pos, n) {
+ if (type && type != pos->ops)
+ continue;
+ if (!pos->ops->match(system, event,
+ argc - 1, (const char **)argv + 1, pos))
+ continue;
+
+ ret = pos->ops->free(pos);
+ if (ret)
+ break;
+ }
+ tracing_reset_all_online_cpus();
}
- tracing_reset_all_online_cpus();
- mutex_unlock(&event_mutex);
out:
argv_free(argv);
return ret;
@@ -133,13 +132,12 @@ static int create_dyn_event(const char *raw_command)
if (raw_command[0] == '-' || raw_command[0] == '!')
return dyn_event_release(raw_command, NULL);

- mutex_lock(&dyn_event_ops_mutex);
+ guard(mutex)(&dyn_event_ops_mutex);
list_for_each_entry(ops, &dyn_event_ops_list, list) {
ret = ops->create(raw_command);
if (!ret || ret != -ECANCELED)
break;
}
- mutex_unlock(&dyn_event_ops_mutex);
if (ret == -ECANCELED)
ret = -EINVAL;

@@ -198,7 +196,7 @@ int dyn_events_release_all(struct dyn_event_operations *type)
struct dyn_event *ev, *tmp;
int ret = 0;

- mutex_lock(&event_mutex);
+ guard(mutex)(&event_mutex);
for_each_dyn_event(ev) {
if (type && ev->ops != type)
continue;
@@ -216,7 +214,6 @@ int dyn_events_release_all(struct dyn_event_operations *type)
}
out:
tracing_reset_all_online_cpus();
- mutex_unlock(&event_mutex);

return ret;
}