[PATCH] coresight: trbe: Use scope-based resource management in arm_trbe_alloc_buffer()

[Markus Elfring]

From: Markus Elfring <elfring at users.sourceforge.net>
Date: Tue, 9 Sep 2025 14:20:06 +0200

Scope-based resource management became supported for some
programming interfaces by contributions of Peter Zijlstra on 2023-05-26.
See also the commit 54da6a0924311c7cf5015533991e44fb8eb12773 ("locking:
Introduce __cleanup() based infrastructure").

* Thus use the attribute “__free(kfree)”.

* Reduce the scopes for the local variables “buf” and “pglist”.

* Omit four kfree() calls accordingly.

Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 21 ++++++++------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 8f9bbef71f23..1b0d58bf8613 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -733,8 +733,6 @@ static void *arm_trbe_alloc_buffer(struct coresight_device *csdev,
 				   struct perf_event *event, void **pages,
 				   int nr_pages, bool snapshot)
 {
-	struct trbe_buf *buf;
-	struct page **pglist;
 	int i;
 
 	/*
@@ -746,32 +744,29 @@ static void *arm_trbe_alloc_buffer(struct coresight_device *csdev,
 	if (nr_pages < 2)
 		return NULL;
 
-	buf = kzalloc_node(sizeof(*buf), GFP_KERNEL, trbe_alloc_node(event));
+	struct trbe_buf *buf __free(kfree) = kzalloc_node(sizeof(*buf),
+							  GFP_KERNEL,
+							  trbe_alloc_node(event));
 	if (!buf)
 		return NULL;
 
-	pglist = kcalloc(nr_pages, sizeof(*pglist), GFP_KERNEL);
-	if (!pglist) {
-		kfree(buf);
+	struct page **pglist __free(kfree) = kcalloc(nr_pages, sizeof(*pglist), GFP_KERNEL);
+	if (!pglist)
 		return NULL;
-	}
 
 	for (i = 0; i < nr_pages; i++)
 		pglist[i] = virt_to_page(pages[i]);
 
 	buf->trbe_base = (unsigned long)vmap(pglist, nr_pages, VM_MAP, PAGE_KERNEL);
-	if (!buf->trbe_base) {
-		kfree(pglist);
-		kfree(buf);
+	if (!buf->trbe_base)
 		return NULL;
-	}
+
 	buf->trbe_limit = buf->trbe_base + nr_pages * PAGE_SIZE;
 	buf->trbe_write = buf->trbe_base;
 	buf->snapshot = snapshot;
 	buf->nr_pages = nr_pages;
 	buf->pages = pages;
-	kfree(pglist);
-	return buf;
+	return_ptr(buf);
 }
 
 static void arm_trbe_free_buffer(void *config)
-- 
2.51.0