Messages in this thread Patch in this message | | | From | Thomas Richter <> | Subject | [PATCH] perf test 39 (Session topology) dumps core on s390 | Date | Thu, 24 May 2018 15:56:00 +0200 |
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perf test 39 fails with core dump on s390. The root cause is a NULL pointer reference in function check_cpu_topology() line 76 (or line 82 without -v). The session->header.env.cpu variable is NULL because on s390 function process_cpu_topology() returns with error: socket_id number is too big. You may need to upgrade the perf tool. and releases the env.cpu variable via zfree() and sets it to NULL.
Here is the gdb output: (gdb) n 76 pr_debug("CPU %d, core %d, socket %d\n", i, (gdb) n
Program received signal SIGSEGV, Segmentation fault. 0x00000000010f4d9e in check_cpu_topology (path=0x3ffffffd6c8 "/tmp/perf-test-J6CHMa", map=0x14a1740) at tests/topology.c:76 76 pr_debug("CPU %d, core %d, socket %d\n", i, (gdb)
Make sure the env.cpu variable is not used when its NULL. Test for NULL pointer and return TEST_SKIP if so.
Output before: [root@p23lp27 perf]# ./perf test -F 39 39: Session topology :Segmentation fault (core dumped) [root@p23lp27 perf]#
Output after: [root@p23lp27 perf]# ./perf test -vF 39 39: Session topology : --- start --- templ file: /tmp/perf-test-Ajx59D socket_id number is too big.You may need to upgrade the perf tool. ---- end ---- Session topology: Skip [root@p23lp27 perf]#
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> --- tools/perf/tests/topology.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/tools/perf/tests/topology.c b/tools/perf/tests/topology.c index 17cb1bb3448c..5f366d650d2b 100644 --- a/tools/perf/tests/topology.c +++ b/tools/perf/tests/topology.c @@ -70,6 +70,9 @@ static int check_cpu_topology(char *path, struct cpu_map *map) session = perf_session__new(&data, false, NULL); TEST_ASSERT_VAL("can't get session", session); + if (!session->header.env.cpu) + return TEST_SKIP; + for (i = 0; i < session->header.env.nr_cpus_avail; i++) { if (!cpu_map__has(map, i)) continue; @@ -95,7 +98,7 @@ int test__session_topology(struct test *test __maybe_unused, int subtest __maybe { char path[PATH_MAX]; struct cpu_map *map; - int ret = -1; + int ret; TEST_ASSERT_VAL("can't get templ file", !get_temp(path)); @@ -110,12 +113,9 @@ int test__session_topology(struct test *test __maybe_unused, int subtest __maybe goto free_path; } - if (check_cpu_topology(path, map)) - goto free_map; - ret = 0; - -free_map: + ret = check_cpu_topology(path, map); cpu_map__put(map); + free_path: unlink(path); return ret; -- 2.14.3
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