[PATCH 03/25] perf/core: Export output copy helpers for CoreSight

Leo Yan leo.yan at arm.com
Tue Sep 15 08:48:49 PDT 2026


CoreSight AUX sampling needs perf_output_copy_aux() to copy trace data
into samples and perf_output_copy() to prepend zero bytes when the
available trace is shorter than the requested snapshot.

Export both helpers so the CoreSight snapshot_aux() callback can use
them when CONFIG_CORESIGHT=m.

Assisted-by: Codex:gpt-6
Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 kernel/events/ring_buffer.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index 1b1ffe0533e58a9d976d0eb0fc23e09d5936da2b..e69ea5b077a5e94b5b6bb1f4c6f0ca5b8a94a6cc 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -298,6 +298,7 @@ unsigned int perf_output_copy(struct perf_output_handle *handle,
 {
 	return __output_copy(handle, buf, len);
 }
+EXPORT_SYMBOL_GPL(perf_output_copy);
 
 unsigned int perf_output_skip(struct perf_output_handle *handle,
 			      unsigned int len)
@@ -617,6 +618,7 @@ long perf_output_copy_aux(struct perf_output_handle *aux_handle,
 
 	return len;
 }
+EXPORT_SYMBOL_GPL(perf_output_copy_aux);
 
 #define PERF_AUX_GFP	(GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY)
 

-- 
2.34.1




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