android_kernel_motorola_sm6225/tools/perf/tests/topology.c
Thomas Richter d121109100 perf test: "Session topology" dumps core on s390
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>
2018-05-30 11:43:58 -03:00

140 lines
3.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "tests.h"
#include "util.h"
#include "session.h"
#include "evlist.h"
#include "debug.h"
#define TEMPL "/tmp/perf-test-XXXXXX"
#define DATA_SIZE 10
static int get_temp(char *path)
{
int fd;
strcpy(path, TEMPL);
fd = mkstemp(path);
if (fd < 0) {
perror("mkstemp failed");
return -1;
}
close(fd);
return 0;
}
static int session_write_header(char *path)
{
struct perf_session *session;
struct perf_data data = {
.file = {
.path = path,
},
.mode = PERF_DATA_MODE_WRITE,
};
session = perf_session__new(&data, false, NULL);
TEST_ASSERT_VAL("can't get session", session);
session->evlist = perf_evlist__new_default();
TEST_ASSERT_VAL("can't get evlist", session->evlist);
perf_header__set_feat(&session->header, HEADER_CPU_TOPOLOGY);
perf_header__set_feat(&session->header, HEADER_NRCPUS);
session->header.data_size += DATA_SIZE;
TEST_ASSERT_VAL("failed to write header",
!perf_session__write_header(session, session->evlist, data.file.fd, true));
perf_session__delete(session);
return 0;
}
static int check_cpu_topology(char *path, struct cpu_map *map)
{
struct perf_session *session;
struct perf_data data = {
.file = {
.path = path,
},
.mode = PERF_DATA_MODE_READ,
};
int i;
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;
pr_debug("CPU %d, core %d, socket %d\n", i,
session->header.env.cpu[i].core_id,
session->header.env.cpu[i].socket_id);
}
for (i = 0; i < map->nr; i++) {
TEST_ASSERT_VAL("Core ID doesn't match",
(session->header.env.cpu[map->map[i]].core_id == (cpu_map__get_core(map, i, NULL) & 0xffff)));
TEST_ASSERT_VAL("Socket ID doesn't match",
(session->header.env.cpu[map->map[i]].socket_id == cpu_map__get_socket(map, i, NULL)));
}
perf_session__delete(session);
return 0;
}
int test__session_topology(struct test *test __maybe_unused, int subtest __maybe_unused)
{
char path[PATH_MAX];
struct cpu_map *map;
int ret = TEST_FAIL;
TEST_ASSERT_VAL("can't get templ file", !get_temp(path));
pr_debug("templ file: %s\n", path);
if (session_write_header(path))
goto free_path;
map = cpu_map__new(NULL);
if (map == NULL) {
pr_debug("failed to get system cpumap\n");
goto free_path;
}
ret = check_cpu_topology(path, map);
cpu_map__put(map);
free_path:
unlink(path);
return ret;
}