perf inject: correct event attribute sizes
diff mbox series

Message ID 20201124195818.30603-1-al.grant@arm.com
State New, archived
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Series
  • perf inject: correct event attribute sizes
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Commit Message

Al Grant Nov. 24, 2020, 7:58 p.m. UTC
When perf inject reads a perf.data file from an older version of perf,
it writes event attributes into the output with the original size field,
but lays them out as if they had the size currently used. Readers see
a corrupt file. Update the size field to match the layout.

Signed-off-by: Al Grant <al.grant@foss.arm.com>
---
 tools/perf/util/header.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Patch
diff mbox series

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index be850e9f8852..0d95981df8dd 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -3331,6 +3331,14 @@  int perf_session__write_header(struct perf_session *session,
 	attr_offset = lseek(ff.fd, 0, SEEK_CUR);
 
 	evlist__for_each_entry(evlist, evsel) {
+		if (evsel->core.attr.size < sizeof(evsel->core.attr)) {
+			/*
+			 * We are likely in "perf inject" and have read
+			 * from an older file. Update attr size so that
+			 * reader gets the right offset to the ids.
+			 */
+			evsel->core.attr.size = sizeof(evsel->core.attr);
+		}
 		f_attr = (struct perf_file_attr){
 			.attr = evsel->core.attr,
 			.ids  = {