[PATCH v1 1/3] perf synthetic-events: Ensure features are aligned

[Ian Rogers]

Features like hostname have arbitrary size and break the assumed
8-byte alignment of perf events. Pad all feature events until 8-byte
alignment is restored.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/util/synthetic-events.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index f8ac2ac2da45..5b14244253b5 100644
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -2401,6 +2401,11 @@ int perf_event__synthesize_features(const struct perf_tool *tool, struct perf_se
 			pr_debug("Error writing feature\n");
 			continue;
 		}
+		while (PERF_ALIGN(ff.offset, sizeof(u64)) != ff.offset) {
+			char c = 0;
+
+			do_write(&ff, &c, 1);
+		}
 		/* ff.buf may have changed due to realloc in do_write() */
 		fe = ff.buf;
 		memset(fe, 0, sizeof(*fe));
-- 
2.47.1.613.gc27f4b7a9f-goog