Messages in this thread Patch in this message | | | Date | Tue, 21 Jun 2022 15:27:25 +0000 | Subject | [PATCH v2] perf: Adjust perf-inject output data offset for backward compatibility | From | Raul Silvera <> |
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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> --- Changes since v1: - Use the adjusted header->data_offset in do_write_header instead of recomputing it. --- tools/perf/builtin-inject.c | 2 +- tools/perf/util/header.c | 14 ++++++++++++++ tools/perf/util/header.h | 2 ++ 3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c index a75bf11585b5..1dfdcef36607 100644 --- a/tools/perf/builtin-inject.c +++ b/tools/perf/builtin-inject.c @@ -916,7 +916,7 @@ 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; diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 53332da100e8..6ad629db63b7 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -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, diff --git a/tools/perf/util/header.h b/tools/perf/util/header.h index 08563c1f1bff..56916dabce7b 100644 --- a/tools/perf/util/header.h +++ b/tools/perf/util/header.h @@ -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); -- 2.37.0.rc0.104.g0611611a94-goog
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