Commit-ID: b314e5cfd11fd78545ce6c2be42646254390c1aa
Gitweb: http://git.kernel.org/tip/b314e5cfd11fd78545ce6c2be42646254390c1aa
Author: Namhyung Kim <namhyung.kim@xxxxxxx>
AuthorDate: Mon, 30 Sep 2013 17:19:48 +0900
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Fri, 4 Oct 2013 15:17:46 -0300
perf session: Fix infinite loop on invalid perf.data file
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.
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Tested-by: David Ahern <dsahern@xxxxxxxxx>
Tested-by: Sonny Rao <sonnyrao@xxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Sonny Rao <sonnyrao@xxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1380529188-27193-1-git-send-email-namhyung@xxxxxxxxxx
Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
[ Reworded warning as per Ingo Molnar suggestion, replaces 'perf.data'
with session->filename, to precisely identify the data file involved ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/header.c | 12 ++++++++++++
tools/perf/util/session.c | 2 +-
2 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index ce69901..c3e5a3b 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2768,6 +2768,18 @@ 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("WARNING: The %s file's data size field is 0 which is unexpected.\n"
+ "Was the 'perf record' command properly terminated?\n",
+ session->filename);
+ }
+
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 37c4718..568b750 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1312,7 +1312,7 @@ 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;
--
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