From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753859AbeE1HhK (ORCPT ); Mon, 28 May 2018 03:37:10 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:53238 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753612AbeE1HhI (ORCPT ); Mon, 28 May 2018 03:37:08 -0400 From: Thomas Richter To: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, acme@kernel.org Cc: brueckner@linux.vnet.ibm.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, Thomas Richter Subject: [PATCH v2] perf test 39 (Session topology) dumps core on s390 Date: Mon, 28 May 2018 09:36:57 +0200 X-Mailer: git-send-email 2.16.3 X-TM-AS-GCONF: 00 x-cbid: 18052807-0040-0000-0000-0000043E773F X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18052807-0041-0000-0000-00002643C056 Message-Id: <20180528073657.11743-1-tmricht@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-05-28_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805280093 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- --- tools/perf/tests/topology.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-) diff --git a/tools/perf/tests/topology.c b/tools/perf/tests/topology.c index 17cb1bb3448c..40e30a26b23c 100644 --- a/tools/perf/tests/topology.c +++ b/tools/perf/tests/topology.c @@ -70,6 +70,27 @@ 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); + /* On platforms with large numbers of CPUs process_cpu_topology() + * might issue an error while reading the perf.data file section + * HEADER_CPU_TOPOLOGY and the cpu_topology_map pointed to by member + * cpu is a NULL pointer. + * Example: On s390 + * CPU 0 is on core_id 0 and physical_package_id 6 + * CPU 1 is on core_id 1 and physical_package_id 3 + * + * Core_id and physical_package_id are platform and architecture + * dependend and might have higher numbers than the CPU id. + * This actually depends on the configuration. + * + * In this case process_cpu_topology() prints error message: + * "socket_id number is too big. You may need to upgrade the + * perf tool." + * + * This is the reason why this test might be skipped. + */ + 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 +116,7 @@ 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_FAIL; TEST_ASSERT_VAL("can't get templ file", !get_temp(path)); @@ -110,12 +131,9 @@ 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