Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [PATCH] perf session: Fix infinite loop on invalid perf.data file | Date | Mon, 30 Sep 2013 17:19:48 +0900 |
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From: Namhyung Kim <namhyung.kim@lge.com>
perf-record updates the header in the perf.data file at termination. Without this update perf-report (and other processing built-ins) it caused an infinite loop when perf report (or something like) called.
This is because the algorithm in __perf_session__process_events() depends on the data_size which is read from file header. Use file size directly instead in this case to do the best-effort processing.
Cc: David Ahern <dsahern@gmail.com> Cc: Sonny Rao <sonnyrao@chromium.org> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> --- tools/perf/util/header.c | 9 +++++++++ tools/perf/util/session.c | 2 +- 2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 26441d0e571b..cedccde6a6b2 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2753,6 +2753,15 @@ int perf_session__read_header(struct perf_session *session) 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 contains only partial + * information. Just warn user and process it as much as it can. + */ + if (f_header.data.size == 0) + pr_warning("Data size is 0. Was the record command properly terminated?\n"); + nr_attrs = f_header.attrs.size / f_header.attr_size; lseek(fd, f_header.attrs.offset, SEEK_SET); diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 6c1d4447c5b4..7bbd60c0a0ed 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1323,7 +1323,7 @@ int __perf_session__process_events(struct perf_session *session, file_offset = page_offset; head = data_offset - page_offset; - if (data_offset + data_size < file_size) + if (data_size && (data_offset + data_size < file_size)) file_size = data_offset + data_size; progress_next = file_size / 16; -- 1.7.11.7
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