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

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

[Thorsten Blum]

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@linux.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

Re: [PATCH v2] perf/core: Replace memset(0) + strscpy() with strscpy_pad()

[Thorsten Blum]

On 11. Aug 2025, at 20:18, Thorsten Blum wrote:
> 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/

Actually v1 was just fine because both source and destination buffers
have the same size 'TASK_COMM_LEN' and the string won't be truncated.

Sorry for the noise.