4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Richter tmricht@linux.ibm.com
[ Upstream commit d121109100bda84bbbb199dab97f9d56432ab235 ]
The "perf test Session topology" entry fails with core dump on s390. The root cause is a NULL pointer dereference 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 Cc: Heiko Carstens heiko.carstens@de.ibm.com Cc: Hendrik Brueckner brueckner@linux.vnet.ibm.com Cc: Martin Schwidefsky schwidefsky@de.ibm.com Link: http://lkml.kernel.org/r/20180528073657.11743-1-tmricht@linux.ibm.com Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/perf/tests/topology.c | 30 ++++++++++++++++++++++++------ 1 file changed, 24 insertions(+), 6 deletions(-)
--- a/tools/perf/tests/topology.c +++ b/tools/perf/tests/topology.c @@ -66,6 +66,27 @@ static int check_cpu_topology(char *path session = perf_session__new(&file, 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; @@ -91,7 +112,7 @@ int test__session_topology(struct test * { 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));
@@ -106,12 +127,9 @@ int test__session_topology(struct test * 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;