On Wed, 27 May 2026 10:10:15 +0900
Masami Hiramatsu (Google) [off-list ref] wrote:

On Tue, 26 May 2026 17:51:05 +0800
Yu Peng [off-list ref] wrote:

quoted

The HIST_FIELD_FL_CONST path duplicates the literal "u64" type with
kstrdup(), then releases it through kfree_const().

Use kstrdup_const() instead, avoiding the allocation for a .rodata string
while keeping the matching free helper.
  

Since we are using kfree_const() to free hist_field->type,
we can just point it as same as HIST_FIELD_FL_HITCOUNT case.

Agreed.

Thanks,

quoted

Signed-off-by: Yu Peng <redacted>
---
 kernel/trace/trace_events_hist.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index eb2c2bc8bc3d..6ffe9f4720a0 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c

@@ -1992,7 +1992,7 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
 	if (flags & HIST_FIELD_FL_CONST) {
 		hist_field->fn_num = HIST_FIELD_FN_CONST;
 		hist_field->size = sizeof(u64);
-		hist_field->type = kstrdup("u64", GFP_KERNEL);
+		hist_field->type = kstrdup_const("u64", GFP_KERNEL);

This can simply be made to point to "u64".

Thanks,

-- Steve

quoted

 		if (!hist_field->type)
 			goto free;
 		goto out;
-- 
2.43.0