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authorThomas Richter <tmricht@linux.ibm.com>2018-05-28 09:36:57 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-08 15:30:52 +0200
commitbe5af6bec31a5c22f61de1be848c3fd0e6e3a2f8 (patch)
treeec9a6984f6ff4a4e52c90da3badfa0e02d7f133c /tools/perf
parentd689ad5c91af0843aceef7975d7ca9356c84a335 (diff)
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perf test: "Session topology" dumps core on s390
[ 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>
Diffstat (limited to 'tools/perf')
-rw-r--r--tools/perf/tests/topology.c30
1 files changed, 24 insertions, 6 deletions
diff --git a/tools/perf/tests/topology.c b/tools/perf/tests/topology.c
index a59db7c45a65..81ede20f49d7 100644
--- a/tools/perf/tests/topology.c
+++ b/tools/perf/tests/topology.c
@@ -66,6 +66,27 @@ static int check_cpu_topology(char *path, struct cpu_map *map)
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 *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));
@@ -106,12 +127,9 @@ 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;