tracing/eprobe: drop unneeded breaks

Started by Julia Lawall on Sep 28, 2023 · 5 messages from 3 authors · Last reply Oct 12, 2023

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STALE1126d LANDED

Status: Landed in mainline as f843249cb6a1 on 2023-10-09.

open the first message on its own page

Julia Lawall Sep 28, 10:43 #

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Drop break after return.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

---
 kernel/trace/trace_eprobe.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 72714cbf475c..03c851f57969 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c

@@ -788,12 +788,9 @@ find_and_get_event(const char *system, const char *event_name)
 		name = trace_event_name(tp_event);
 		if (!name || strcmp(event_name, name))
 			continue;
-		if (!trace_event_try_get_ref(tp_event)) {
+		if (!trace_event_try_get_ref(tp_event))
 			return NULL;
-			break;
-		}
 		return tp_event;
-		break;
 	}
 	return NULL;
 }

Masami Hiramatsu (Google) replied to Julia Lawall Sep 29, 11:33 #

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On Thu, 28 Sep 2023 12:43:34 +0200
Julia Lawall [off-list ref] wrote:

Drop break after return.

Good catch! This looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

And

Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")

quoted hunk

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

---
 kernel/trace/trace_eprobe.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 72714cbf475c..03c851f57969 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c

@@ -788,12 +788,9 @@ find_and_get_event(const char *system, const char *event_name)
 		name = trace_event_name(tp_event);
 		if (!name || strcmp(event_name, name))
 			continue;
-		if (!trace_event_try_get_ref(tp_event)) {
+		if (!trace_event_try_get_ref(tp_event))
 			return NULL;
-			break;
-		}
 		return tp_event;
-		break;
 	}
 	return NULL;
 }


-- 
Masami Hiramatsu (Google) [off-list ref]

Julia Lawall replied to Masami Hiramatsu (Google) Sep 29, 11:37 #

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On Fri, 29 Sep 2023, Masami Hiramatsu  wrote:

On Thu, 28 Sep 2023 12:43:34 +0200
Julia Lawall [off-list ref] wrote:

quoted

Drop break after return.

Good catch! This looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

And

Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")

Thanks.  I didn't include that because it's not a bug.  But it does break
Coccinelle, which is how I noticed it.

julia

quoted

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

---
 kernel/trace/trace_eprobe.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 72714cbf475c..03c851f57969 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c

@@ -788,12 +788,9 @@ find_and_get_event(const char *system, const char *event_name)
 		name = trace_event_name(tp_event);
 		if (!name || strcmp(event_name, name))
 			continue;
-		if (!trace_event_try_get_ref(tp_event)) {
+		if (!trace_event_try_get_ref(tp_event))
 			return NULL;
-			break;
-		}
 		return tp_event;
-		break;
 	}
 	return NULL;
 }


--
Masami Hiramatsu (Google) [off-list ref]

Masami Hiramatsu (Google) replied to Julia Lawall Sep 30, 09:19 #

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On Fri, 29 Sep 2023 13:37:08 +0200 (CEST)
Julia Lawall [off-list ref] wrote:


On Fri, 29 Sep 2023, Masami Hiramatsu  wrote:

quoted

On Thu, 28 Sep 2023 12:43:34 +0200
Julia Lawall [off-list ref] wrote:

quoted

Drop break after return.

Good catch! This looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

And

Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")

Thanks.  I didn't include that because it's not a bug.  But it does break
Coccinelle, which is how I noticed it.

OK, I got it. I thought it may cause a compiler warning because the
'break' never be executed. (maybe it is just a flow-control word,
so it may not need to be warned, but a bit storange.)

julia

quoted

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

---
 kernel/trace/trace_eprobe.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index 72714cbf475c..03c851f57969 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c

@@ -788,12 +788,9 @@ find_and_get_event(const char *system, const char *event_name)
 		name = trace_event_name(tp_event);
 		if (!name || strcmp(event_name, name))
 			continue;
-		if (!trace_event_try_get_ref(tp_event)) {
+		if (!trace_event_try_get_ref(tp_event))
 			return NULL;
-			break;
-		}
 		return tp_event;
-		break;
 	}
 	return NULL;
 }


--
Masami Hiramatsu (Google) [off-list ref]


-- 
Masami Hiramatsu (Google) [off-list ref]

Dan Carpenter replied to Masami Hiramatsu (Google) Oct 12, 10:40 #

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On Sat, Sep 30, 2023 at 06:19:02PM +0900, Masami Hiramatsu wrote:

On Fri, 29 Sep 2023 13:37:08 +0200 (CEST)
Julia Lawall [off-list ref] wrote:

quoted


On Fri, 29 Sep 2023, Masami Hiramatsu  wrote:

quoted

On Thu, 28 Sep 2023 12:43:34 +0200
Julia Lawall [off-list ref] wrote:

quoted

Drop break after return.

Good catch! This looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

And

Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")

Thanks.  I didn't include that because it's not a bug.  But it does break
Coccinelle, which is how I noticed it.

OK, I got it. I thought it may cause a compiler warning because the
'break' never be executed. (maybe it is just a flow-control word,
so it may not need to be warned, but a bit storange.)

I don't think GCC warns about unreachable code, but yeah, in Smatch
unreachable break statements do not trigger a warning.  People like
to add extra break statements to switch statements.

regards,
dan carpenter

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