perf inject: Adjust output data offset for backward compatibility

When 'perf inject' creates a new file, it reuses the data offset from
the input file. If there has been a change on the size of the header, as
happened in v5.12 -> v5.13, the new offsets will be wrong, resulting in
a corrupted output file.

This change adds the function perf_session__data_offset to compute the
data offset based on the current header size, and uses that instead of
the offset from the original input file.

Signed-off-by: Raul Silvera <rsilvera@google.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Colin Ian King <colin.king@intel.com>
Cc: Dave Marchevsky <davemarchevsky@fb.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220621152725.2668041-1-rsilvera@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
index 063f74f5b8db..54d4e508a092 100644
--- a/tools/perf/builtin-inject.c
+++ b/tools/perf/builtin-inject.c
@@ -918,7 +918,7 @@ static int __cmd_inject(struct perf_inject *inject)
 		inject->tool.tracing_data = perf_event__repipe_tracing_data;
 	}
 
-	output_data_offset = session->header.data_offset;
+	output_data_offset = perf_session__data_offset(session->evlist);
 
 	if (inject->build_id_all) {
 		inject->tool.mmap	  = perf_event__repipe_buildid_mmap;