Messages in this thread Patch in this message | | | From | David Ahern <> | Subject | [PATCH v2] perf: detect when perf.data file not closed out properly | Date | Thu, 9 May 2013 13:27:23 -0600 |
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perf-record updates the header in the perf.data file at termination. Without this update perf-report (and other processing builtins) cannot properly read events from the file -- the algorithm in __perf_session__process_events depends on the data_size which is read from the file header and that function loops if data_size is 0.
Catch this condition when the file is opened and warn the user.
v2: put error message on one line
Signed-off-by: David Ahern <dsahern@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> --- tools/perf/util/header.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 326068a..95baef4 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2802,6 +2802,17 @@ int perf_session__read_header(struct perf_session *session, int fd) if (perf_file_header__read(&f_header, header, fd) < 0) return -EINVAL; + /* + * sanity check that perf.data was written cleanly: data size + * is initialized to 0 and updated only if the on_exit function + * is run. If data size is still 0 then the file cannot be + * processed. + */ + if (f_header.data.size == 0) { + pr_err("Data size is 0. Was the record command properly terminated?\n"); + return -1; + } + nr_attrs = f_header.attrs.size / f_header.attr_size; lseek(fd, f_header.attrs.offset, SEEK_SET); -- 1.7.10.1
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