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From:   Chuang Wang <nashuiliang@gmail.com>
Cc:     Chuang Wang <nashuiliang@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>,
        linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: [PATCH] tracing/eprobe: Iterate trace_eprobe directly
Date:   Thu, 10 Aug 2023 16:25:23 +0800
Message-Id: <20230810082523.244397-1-nashuiliang@gmail.com>
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Refer to the description in [1], we can skip "container_of()" following
"list_for_each_entry()" by using "list_for_each_entry()" with
"struct trace_eprobe" and "tp.list".

[1] https://lore.kernel.org/all/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com/

Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
---
 kernel/trace/trace_eprobe.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index a0a704ba27db..d68d660dff7c 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -640,7 +640,7 @@ static int disable_eprobe(struct trace_eprobe *ep,
 static int enable_trace_eprobe(struct trace_event_call *call,
 			       struct trace_event_file *file)
 {
-	struct trace_probe *pos, *tp;
+	struct trace_probe *tp;
 	struct trace_eprobe *ep;
 	bool enabled;
 	int ret = 0;
@@ -662,8 +662,7 @@ static int enable_trace_eprobe(struct trace_event_call *call,
 	if (enabled)
 		return 0;
 
-	list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
-		ep = container_of(pos, struct trace_eprobe, tp);
+	list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
 		ret = enable_eprobe(ep, file);
 		if (ret)
 			break;
@@ -680,8 +679,7 @@ static int enable_trace_eprobe(struct trace_event_call *call,
 			 */
 			WARN_ON_ONCE(ret != -ENOMEM);
 
-			list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
-				ep = container_of(pos, struct trace_eprobe, tp);
+			list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
 				disable_eprobe(ep, file->tr);
 				if (!--cnt)
 					break;
@@ -699,7 +697,7 @@ static int enable_trace_eprobe(struct trace_event_call *call,
 static int disable_trace_eprobe(struct trace_event_call *call,
 				struct trace_event_file *file)
 {
-	struct trace_probe *pos, *tp;
+	struct trace_probe *tp;
 	struct trace_eprobe *ep;
 
 	tp = trace_probe_primary_from_call(call);
@@ -716,8 +714,7 @@ static int disable_trace_eprobe(struct trace_event_call *call,
 		trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
 
 	if (!trace_probe_is_enabled(tp)) {
-		list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
-			ep = container_of(pos, struct trace_eprobe, tp);
+		list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
 			disable_eprobe(ep, file->tr);
 		}
 	}
-- 
2.39.2