linux/tools/perf/tests/cpumap.c
Thomas Richter 0dd1979f7f perf test: Fix test case Merge cpu map
Commit a2408a7036 ("perf evlist: Maintain evlist->all_cpus")
introduces a test case for cpumap merge operation, see functions
perf_cpu_map__merge() and test__cpu_map_merge().

The test case fails on s390 with this error message:

 [root@m35lp76 perf]# ./perf test -Fvvvvv 52
 52: Merge cpu map                                         :
 --- start ---
 cpumask list: 1-2,4-5,7
 perf: /root/linux/tools/include/linux/refcount.h:131:\
          refcount_sub_and_test: Assertion `!(new > val)' failed.
 Aborted (core dumped)
 [root@m35lp76 perf]#

The root cause is in the function test__cpu_map_merge():
It creates two cpu_maps named 'a' and 'b':

  struct perf_cpu_map *a = perf_cpu_map__new("4,2,1");
  struct perf_cpu_map *b = perf_cpu_map__new("4,5,7");

and creates a third map named 'c' which is the result of
the merge of maps a and b:

  struct perf_cpu_map *c = perf_cpu_map__merge(a, b);

After some verifaction of the merged cpu_map all three
of them are have their reference count reduced and are
freed:

   perf_cpu_map__put(a); (1)
   perf_cpu_map__put(b);
   perf_cpu_map__put(c);

The release of perf_cpu_map__put(a) is wrong. The map
is already released and free'ed as part of the function

  perf_cpu_map__merge(struct perf_cpu_map *orig,
  |	              struct perf_cpu_map *other)
  +--> perf_cpu_map__put(orig);
       |
       +--> cpu_map__delete(orig)

At the end perf_cpu_map_put() is called for map 'orig'
alias 'a' and since the reference count is 1, the map
is deleted, as can be seen by the following gdb trace:

 (gdb) where
 #0  tcache_put (tc_idx=0, chunk=0x156cc30) at malloc.c:2940
 #1  _int_free (av=0x3fffd49ee80 <main_arena>, p=0x156cc30,
		     have_lock=<optimized out>) at malloc.c:4222
 #2  0x00000000012d5e78 in cpu_map__delete (map=0x156cc40) at cpumap.c:31
 #3  0x00000000012d5f7a in perf_cpu_map__put (map=0x156cc40) at cpumap.c:45
 #4  0x00000000012d723a in perf_cpu_map__merge (orig=0x156cc40,
     other=0x156cc60) at cpumap.c:343
 #5  0x000000000110cdd0 in test__cpu_map_merge (
     test=0x14ea6c8 <generic_tests+2856>, subtest=-1) at tests/cpumap.c:128

Thus the perf_cpu_map__put(a) (see (1) above) frees map 'a'
a second time and causes the failure. Fix this be removing that
function call.

Output after:
  [root@m35lp76 perf]# ./perf test -Fvvvvv 52
  52: Merge cpu map                                         :
  --- start ---
  cpumask list: 1-2,4-5,7
  ---- end ----
  Merge cpu map: Ok
  [root@m35lp76 perf]#

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: sumanthk@linux.ibm.com
Link: http://lore.kernel.org/lkml/20200120132011.64698-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-01-30 11:55:02 +01:00

138 lines
3.9 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "tests.h"
#include <stdio.h>
#include "cpumap.h"
#include "event.h"
#include "util/synthetic-events.h"
#include <string.h>
#include <linux/bitops.h>
#include <perf/cpumap.h>
#include "debug.h"
struct machine;
static int process_event_mask(struct perf_tool *tool __maybe_unused,
union perf_event *event,
struct perf_sample *sample __maybe_unused,
struct machine *machine __maybe_unused)
{
struct perf_record_cpu_map *map_event = &event->cpu_map;
struct perf_record_record_cpu_map *mask;
struct perf_record_cpu_map_data *data;
struct perf_cpu_map *map;
int i;
data = &map_event->data;
TEST_ASSERT_VAL("wrong type", data->type == PERF_CPU_MAP__MASK);
mask = (struct perf_record_record_cpu_map *)data->data;
TEST_ASSERT_VAL("wrong nr", mask->nr == 1);
for (i = 0; i < 20; i++) {
TEST_ASSERT_VAL("wrong cpu", test_bit(i, mask->mask));
}
map = cpu_map__new_data(data);
TEST_ASSERT_VAL("wrong nr", map->nr == 20);
for (i = 0; i < 20; i++) {
TEST_ASSERT_VAL("wrong cpu", map->map[i] == i);
}
perf_cpu_map__put(map);
return 0;
}
static int process_event_cpus(struct perf_tool *tool __maybe_unused,
union perf_event *event,
struct perf_sample *sample __maybe_unused,
struct machine *machine __maybe_unused)
{
struct perf_record_cpu_map *map_event = &event->cpu_map;
struct cpu_map_entries *cpus;
struct perf_record_cpu_map_data *data;
struct perf_cpu_map *map;
data = &map_event->data;
TEST_ASSERT_VAL("wrong type", data->type == PERF_CPU_MAP__CPUS);
cpus = (struct cpu_map_entries *)data->data;
TEST_ASSERT_VAL("wrong nr", cpus->nr == 2);
TEST_ASSERT_VAL("wrong cpu", cpus->cpu[0] == 1);
TEST_ASSERT_VAL("wrong cpu", cpus->cpu[1] == 256);
map = cpu_map__new_data(data);
TEST_ASSERT_VAL("wrong nr", map->nr == 2);
TEST_ASSERT_VAL("wrong cpu", map->map[0] == 1);
TEST_ASSERT_VAL("wrong cpu", map->map[1] == 256);
TEST_ASSERT_VAL("wrong refcnt", refcount_read(&map->refcnt) == 1);
perf_cpu_map__put(map);
return 0;
}
int test__cpu_map_synthesize(struct test *test __maybe_unused, int subtest __maybe_unused)
{
struct perf_cpu_map *cpus;
/* This one is better stores in mask. */
cpus = perf_cpu_map__new("0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19");
TEST_ASSERT_VAL("failed to synthesize map",
!perf_event__synthesize_cpu_map(NULL, cpus, process_event_mask, NULL));
perf_cpu_map__put(cpus);
/* This one is better stores in cpu values. */
cpus = perf_cpu_map__new("1,256");
TEST_ASSERT_VAL("failed to synthesize map",
!perf_event__synthesize_cpu_map(NULL, cpus, process_event_cpus, NULL));
perf_cpu_map__put(cpus);
return 0;
}
static int cpu_map_print(const char *str)
{
struct perf_cpu_map *map = perf_cpu_map__new(str);
char buf[100];
if (!map)
return -1;
cpu_map__snprint(map, buf, sizeof(buf));
return !strcmp(buf, str);
}
int test__cpu_map_print(struct test *test __maybe_unused, int subtest __maybe_unused)
{
TEST_ASSERT_VAL("failed to convert map", cpu_map_print("1"));
TEST_ASSERT_VAL("failed to convert map", cpu_map_print("1,5"));
TEST_ASSERT_VAL("failed to convert map", cpu_map_print("1,3,5,7,9,11,13,15,17,19,21-40"));
TEST_ASSERT_VAL("failed to convert map", cpu_map_print("2-5"));
TEST_ASSERT_VAL("failed to convert map", cpu_map_print("1,3-6,8-10,24,35-37"));
TEST_ASSERT_VAL("failed to convert map", cpu_map_print("1,3-6,8-10,24,35-37"));
TEST_ASSERT_VAL("failed to convert map", cpu_map_print("1-10,12-20,22-30,32-40"));
return 0;
}
int test__cpu_map_merge(struct test *test __maybe_unused, int subtest __maybe_unused)
{
struct perf_cpu_map *a = perf_cpu_map__new("4,2,1");
struct perf_cpu_map *b = perf_cpu_map__new("4,5,7");
struct perf_cpu_map *c = perf_cpu_map__merge(a, b);
char buf[100];
TEST_ASSERT_VAL("failed to merge map: bad nr", c->nr == 5);
cpu_map__snprint(c, buf, sizeof(buf));
TEST_ASSERT_VAL("failed to merge map: bad result", !strcmp(buf, "1-2,4-5,7"));
perf_cpu_map__put(b);
perf_cpu_map__put(c);
return 0;
}