[PATCHv3 1/2] perf tools: Fix raw sample reading

Jiri Olsa
2011-09-29T15:05:38Z

Wrong pointer is being passed for raw data sanity checking,
when parsing sample event.

This ends up with invalid event and perf record being stuck in
__perf_session__process_events function during processing
build IDs (process_buildids function).

Following command hangs up in my setup:
./perf record -e raw_syscalls:sys_enter ls

The fix is to use proper pointer to the raw data instead
of the 'u' union.

CC: David Ahern <dsahern@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
---
tools/perf/util/evsel.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index c5748c5..e389815 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -449,6 +449,8 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
}

if (type & PERF_SAMPLE_RAW) {
+ const u64 *pdata;
+
u.val64 = *array;
if (WARN_ONCE(swapped,
"Endianness of raw data not corrected!\n")) {
@@ -462,11 +464,12 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
return -EFAULT;

data->raw_size = u.val32[0];
+ pdata = (void *) array + sizeof(u32);

- if (sample_overlap(event, &u.val32[1], data->raw_size))
+ if (sample_overlap(event, pdata, data->raw_size))
return -EFAULT;

- data->raw_data = &u.val32[1];
+ data->raw_data = (void *) pdata;
}

return 0;
--
1.7.4