linux-kernel - [PATCH v2] perf/core: Replace memset(0) + strscpy() with strscpy

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Message-ID: <20250811181802.72970-2-thorsten.blum@linux.dev>
Date: Mon, 11 Aug 2025 20:18:03 +0200
From: Thorsten Blum <thorsten.blum@...ux.dev>
To: Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Ian Rogers <irogers@...gle.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	"Liang, Kan" <kan.liang@...ux.intel.com>
Cc: Thorsten Blum <thorsten.blum@...ux.dev>,
	linux-perf-users@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH v2] perf/core: Replace memset(0) + strscpy() with strscpy_pad()

Replace memset(0) followed by strscpy() with strscpy_pad() to improve
perf_event_comm_event(). This avoids zeroing the memory before copying
the string and ensures the destination buffer is only written to once,
simplifying the code and improving efficiency.

Signed-off-by: Thorsten Blum <thorsten.blum@...ux.dev>
---
Changes in v2:
- Keep strlen() as we're not checking the return value of strscpy_pad()
  for string truncation
- Link to v1: https://lore.kernel.org/lkml/20250811091637.4492-2-thorsten.blum@linux.dev/
---
 kernel/events/core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 8060c2857bb2..414212b02d54 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8981,8 +8981,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event)
 	char comm[TASK_COMM_LEN];
 	unsigned int size;
 
-	memset(comm, 0, sizeof(comm));
-	strscpy(comm, comm_event->task->comm);
+	strscpy_pad(comm, comm_event->task->comm);
 	size = ALIGN(strlen(comm)+1, sizeof(u64));
 
 	comm_event->comm = comm;
-- 
2.50.1