[PATCH 13/14] tracing: Switch trace_stack.c code over to use guard()

[Steven Rostedt]

From: Steven Rostedt <rost...@goodmis.org>

The function stack_trace_sysctl() uses a goto on the error path to jump to
the mutex_unlock() code. Replace the logic to use guard() and let the
compiler worry about it.

Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org>
---
 kernel/trace/trace_osnoise.c | 2 +-
 kernel/trace/trace_stack.c   | 6 ++----
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index b8626892c66d..b25c30b05dd0 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -2086,7 +2086,7 @@ static void osnoise_hotplug_workfn(struct work_struct 
*dummy)
        guard(mutex)(&trace_types_lock);
 
        if (!osnoise_has_registered_instances())
-               goto out_unlock_trace;
+               return;
 
        guard(mutex)(&interface_lock);
        guard(cpus_read_lock)();
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 7f9572a37333..14c6f272c4d8 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -520,20 +520,18 @@ stack_trace_sysctl(const struct ctl_table *table, int 
write, void *buffer,
        int was_enabled;
        int ret;
 
-       mutex_lock(&stack_sysctl_mutex);
+       guard(mutex)(&stack_sysctl_mutex);
        was_enabled = !!stack_tracer_enabled;
 
        ret = proc_dointvec(table, write, buffer, lenp, ppos);
 
        if (ret || !write || (was_enabled == !!stack_tracer_enabled))
-               goto out;
+               return ret;
 
        if (stack_tracer_enabled)
                register_ftrace_function(&trace_ops);
        else
                unregister_ftrace_function(&trace_ops);
- out:
-       mutex_unlock(&stack_sysctl_mutex);
        return ret;
 }
 
-- 
2.45.2