Commit 37ed2cdd authored by Raul Silvera's avatar Raul Silvera Committed by Arnaldo Carvalho de Melo
Browse files

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: default avatarRaul Silvera <rsilvera@google.com>
Acked-by: default avatarAdrian 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 3713e249

tools/perf/builtin-inject.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

tools/perf/util/header.c

+14 −0
Original line number Diff line number Diff line
@@ -3686,6 +3686,20 @@ int perf_session__write_header(struct perf_session *session, 
	return perf_session__do_write_header(session, evlist, fd, at_exit, NULL);

}



size_t perf_session__data_offset(const struct evlist *evlist)

{

	struct evsel *evsel;

	size_t data_offset;



	data_offset = sizeof(struct perf_file_header);

	evlist__for_each_entry(evlist, evsel) {

		data_offset += evsel->core.ids * sizeof(u64);

	}

	data_offset += evlist->core.nr_entries * sizeof(struct perf_file_attr);



	return data_offset;

}



int perf_session__inject_header(struct perf_session *session,

				struct evlist *evlist,

				int fd,

tools/perf/util/header.h

+2 −0
Original line number Diff line number Diff line
@@ -136,6 +136,8 @@ int perf_session__inject_header(struct perf_session *session, 
				int fd,

				struct feat_copier *fc);



size_t perf_session__data_offset(const struct evlist *evlist);



void perf_header__set_feat(struct perf_header *header, int feat);

void perf_header__clear_feat(struct perf_header *header, int feat);

bool perf_header__has_feat(const struct perf_header *header, int feat);