perf map: Convert map_groups.refcnt from atomic_t to refcount_t

The refcount_t type and corresponding API should be used instead of
atomic_t when the variable is used as a reference counter.

This allows to avoid accidental refcounter overflows that might lead to
use-after-free situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Kook <keescook@chromium.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Windsor <dwindsor@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hans Liljestrand <ishkamiel@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kees Kook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matija Glavinic Pecotic <matija.glavinic-pecotic.ext@nokia.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: alsa-devel@alsa-project.org
Link: http://lkml.kernel.org/r/1487691303-31858-7-git-send-email-elena.reshetova@intel.com
[ Did the missing conversion of tests/thread-mg-share.c too ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Elena Reshetova 2017-02-21 17:35:00 +02:00 committed by Arnaldo Carvalho de Melo
parent e3a42cdd3e
commit ead05e8f3f
3 changed files with 10 additions and 10 deletions

View File

@ -43,7 +43,7 @@ int test__thread_mg_share(int subtest __maybe_unused)
leader && t1 && t2 && t3 && other);
mg = leader->mg;
TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 4);
TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&mg->refcnt), 4);
/* test the map groups pointer is shared */
TEST_ASSERT_VAL("map groups don't match", mg == t1->mg);
@ -71,25 +71,25 @@ int test__thread_mg_share(int subtest __maybe_unused)
machine__remove_thread(machine, other_leader);
other_mg = other->mg;
TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&other_mg->refcnt), 2);
TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&other_mg->refcnt), 2);
TEST_ASSERT_VAL("map groups don't match", other_mg == other_leader->mg);
/* release thread group */
thread__put(leader);
TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 3);
TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&mg->refcnt), 3);
thread__put(t1);
TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 2);
TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&mg->refcnt), 2);
thread__put(t2);
TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 1);
TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&mg->refcnt), 1);
thread__put(t3);
/* release other group */
thread__put(other_leader);
TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&other_mg->refcnt), 1);
TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(&other_mg->refcnt), 1);
thread__put(other);

View File

@ -485,7 +485,7 @@ void map_groups__init(struct map_groups *mg, struct machine *machine)
maps__init(&mg->maps[i]);
}
mg->machine = machine;
atomic_set(&mg->refcnt, 1);
refcount_set(&mg->refcnt, 1);
}
static void __maps__purge(struct maps *maps)
@ -547,7 +547,7 @@ void map_groups__delete(struct map_groups *mg)
void map_groups__put(struct map_groups *mg)
{
if (mg && atomic_dec_and_test(&mg->refcnt))
if (mg && refcount_dec_and_test(&mg->refcnt))
map_groups__delete(mg);
}

View File

@ -67,7 +67,7 @@ struct maps {
struct map_groups {
struct maps maps[MAP__NR_TYPES];
struct machine *machine;
atomic_t refcnt;
refcount_t refcnt;
};
struct map_groups *map_groups__new(struct machine *machine);
@ -77,7 +77,7 @@ bool map_groups__empty(struct map_groups *mg);
static inline struct map_groups *map_groups__get(struct map_groups *mg)
{
if (mg)
atomic_inc(&mg->refcnt);
refcount_inc(&mg->refcnt);
return mg;
}