We should not call lseek(2) for pipes as it won't work. And we already
in the proper place to read the data for AUXTRACE. Add the comment like
in the PERF_RECORD_HEADER_TRACING_DATA.
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/session.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 7c021c6cedb9..fdfe772f2699 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1699,8 +1699,13 @@ static s64 perf_session__process_user_event(struct perf_session *session,
case PERF_RECORD_AUXTRACE_INFO:
return tool->auxtrace_info(session, event);
case PERF_RECORD_AUXTRACE:
- /* setup for reading amidst mmap */
- lseek(fd, file_offset + event->header.size, SEEK_SET);
+ /*
+ * Setup for reading amidst mmap, but only when we
+ * are in 'file' mode. The 'pipe' fd is in proper
+ * place already.
+ */
+ if (!perf_data__is_pipe(session->data))
+ lseek(fd, file_offset + event->header.size, SEEK_SET);
return tool->auxtrace(session, event);
case PERF_RECORD_AUXTRACE_ERROR:
perf_session__auxtrace_error_inc(session, event);
--
2.39.1.456.gfc5497dd1b-goog