[PATCH 1/1] Fixes: cfc8874a485 ("perf script: Process cpu/threads maps")

From: Chris Phlipot
Date: Wed Mar 09 2016 - 00:12:19 EST


fix the perf script python database export crash.
Remove the union in evsel so that the database id and priv pointer can be
used simultainously without conflicting and crashing.

Detailed Description for the fixed bug follows:

perf script crashes with a segmentaiton fault on user space tool version
4.5.rc7.ge2857b when using the python database export API. It works
properly in 4.4 and prior versions.

the crash fist appeared in
cfc8874a485 ("perf script: Process cpu/threads maps")

How to reprodcue the bug:

remove any temporary files left over from a previous crash
(if you have already attemped to reproduce the bug):
$ rm -r test_db-perf-data
$ dropdb test_db

$ ./perf record timeout 1 yes >/dev/null
$ ./perf script -s scripts/python/export-to-postgresql.py test_db

Stack Trace:
Program received signal SIGSEGV, Segmentation fault.
__GI___libc_free (mem=0x1) at malloc.c:2929
2929 malloc.c: No such file or directory.
(gdb) bt
at util/stat.c:122
argv=<optimized out>, prefix=<optimized out>) at builtin-script.c:2231
argc=argc@entry=4, argv=argv@entry=0x7fffffffdf70) at perf.c:390
at perf.c:451

Signed-off-by: Chris Phlipot <cphlipot0@xxxxxxxxx>
---
tools/perf/util/evsel.h | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 8e75434..4d8037a 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -93,10 +93,8 @@ struct perf_evsel {
const char *unit;
struct event_format *tp_format;
off_t id_offset;
- union {
- void *priv;
- u64 db_id;
- };
+ void *priv;
+ u64 db_id;
struct cgroup_sel *cgrp;
void *handler;
struct cpu_map *cpus;
--
1.9.1