[PATCH v2 4/6] tracing/uprobe: Adopt guard() and scoped_guard()

[Masami Hiramatsu (Google)]

From: Masami Hiramatsu (Google) <mhira...@kernel.org>

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

Signed-off-by: Masami Hiramatsu (Google) <mhira...@kernel.org>
---
 kernel/trace/trace_uprobe.c |   15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index b30fc8fcd095..4150ab1d835e 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -496,11 +496,11 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
        struct trace_uprobe *old_tu;
        int ret;
 
-       mutex_lock(&event_mutex);
+       guard(mutex)(&event_mutex);
 
        ret = validate_ref_ctr_offset(tu);
        if (ret)
-               goto end;
+               return ret;
 
        /* register as an event */
        old_tu = find_probe_event(trace_probe_name(&tu->tp),
@@ -509,11 +509,9 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
                if (is_ret_probe(tu) != is_ret_probe(old_tu)) {
                        trace_probe_log_set_index(0);
                        trace_probe_log_err(0, DIFF_PROBE_TYPE);
-                       ret = -EEXIST;
-               } else {
-                       ret = append_trace_uprobe(tu, old_tu);
+                       return -EEXIST;
                }
-               goto end;
+               return append_trace_uprobe(tu, old_tu);
        }
 
        ret = register_uprobe_event(tu);
@@ -523,14 +521,11 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
                        trace_probe_log_err(0, EVENT_EXIST);
                } else
                        pr_warn("Failed to register probe event(%d)\n", ret);
-               goto end;
+               return ret;
        }
 
        dyn_event_add(&tu->devent, trace_probe_event_call(&tu->tp));
 
-end:
-       mutex_unlock(&event_mutex);
-
        return ret;
 }