[PATCH] perf buildid: Avoid copy of uninitialized memory

[Ian Rogers]

build_id__init only copies the buildid data up to size leaving the
rest of the data array uninitialized. Copying the full array during
synthesis means the written event contains uninitialized memory.  This
was detected by the Clang/LLVM memory sanitizer.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/util/synthetic-events.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index 3ab6a92b1a6d..348d05e4ec03 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -2219,7 +2219,7 @@ int perf_event__synthesize_build_id(struct perf_tool *tool, struct dso *pos, u16
 
 	len = pos->long_name_len + 1;
 	len = PERF_ALIGN(len, NAME_ALIGN);
-	memcpy(&ev.build_id.build_id, pos->bid.data, sizeof(pos->bid.data));
+	memcpy(&ev.build_id.build_id, pos->bid.data, pos->bid.size);
 	ev.build_id.size = pos->bid.size;
 	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;
 	ev.build_id.header.misc = misc | PERF_RECORD_MISC_BUILD_ID_SIZE;
-- 
2.39.0.314.g84b9a713c41-goog