perf thread_map: Convert thread_map.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/1487691303-31858-10-git-send-email-elena.reshetova@intel.com
[ Did missing tests/thread-map.c conversion ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/tests/thread-map.c b/tools/perf/tests/thread-map.c
index f2d2e54..a63d694 100644 (file)
--- a/tools/perf/tests/thread-map.c
+++ b/tools/perf/tests/thread-map.c
@@ -29,7 +29,7 @@ int test__thread_map(int subtest __maybe_unused)
                        thread_map__comm(map, 0) &&
                        !strcmp(thread_map__comm(map, 0), NAME));
        TEST_ASSERT_VAL("wrong refcnt",
-                       atomic_read(&map->refcnt) == 1);
+                       refcount_read(&map->refcnt) == 1);
        thread_map__put(map);
 
        /* test dummy pid */
@@ -44,7 +44,7 @@ int test__thread_map(int subtest __maybe_unused)
                        thread_map__comm(map, 0) &&
                        !strcmp(thread_map__comm(map, 0), "dummy"));
        TEST_ASSERT_VAL("wrong refcnt",
-                       atomic_read(&map->refcnt) == 1);
+                       refcount_read(&map->refcnt) == 1);
        thread_map__put(map);
        return 0;
 }
@@ -71,7 +71,7 @@ static int process_event(struct perf_tool *tool __maybe_unused,
                        thread_map__comm(threads, 0) &&
                        !strcmp(thread_map__comm(threads, 0), NAME));
        TEST_ASSERT_VAL("wrong refcnt",
-                       atomic_read(&threads->refcnt) == 1);
+                       refcount_read(&threads->refcnt) == 1);
        thread_map__put(threads);
        return 0;
 }

diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c
index 7c3fcc5..9026408 100644 (file)
--- a/tools/perf/util/thread_map.c
+++ b/tools/perf/util/thread_map.c
@@ -66,7 +66,7 @@ struct thread_map *thread_map__new_by_pid(pid_t pid)
                for (i = 0; i < items; i++)
                        thread_map__set_pid(threads, i, atoi(namelist[i]->d_name));
                threads->nr = items;
-               atomic_set(&threads->refcnt, 1);
+               refcount_set(&threads->refcnt, 1);
        }
 
        for (i=0; i<items; i++)
@@ -83,7 +83,7 @@ struct thread_map *thread_map__new_by_tid(pid_t tid)
        if (threads != NULL) {
                thread_map__set_pid(threads, 0, tid);
                threads->nr = 1;
-               atomic_set(&threads->refcnt, 1);
+               refcount_set(&threads->refcnt, 1);
        }
 
        return threads;
@@ -105,7 +105,7 @@ struct thread_map *thread_map__new_by_uid(uid_t uid)
                goto out_free_threads;
 
        threads->nr = 0;
-       atomic_set(&threads->refcnt, 1);
+       refcount_set(&threads->refcnt, 1);
 
        while ((dirent = readdir(proc)) != NULL) {
                char *end;
@@ -235,7 +235,7 @@ static struct thread_map *thread_map__new_by_pid_str(const char *pid_str)
 out:
        strlist__delete(slist);
        if (threads)
-               atomic_set(&threads->refcnt, 1);
+               refcount_set(&threads->refcnt, 1);
        return threads;
 
 out_free_namelist:
@@ -255,7 +255,7 @@ struct thread_map *thread_map__new_dummy(void)
        if (threads != NULL) {
                thread_map__set_pid(threads, 0, -1);
                threads->nr = 1;
-               atomic_set(&threads->refcnt, 1);
+               refcount_set(&threads->refcnt, 1);
        }
        return threads;
 }
@@ -300,7 +300,7 @@ struct thread_map *thread_map__new_by_tid_str(const char *tid_str)
        }
 out:
        if (threads)
-               atomic_set(&threads->refcnt, 1);
+               refcount_set(&threads->refcnt, 1);
        return threads;
 
 out_free_threads:
@@ -326,7 +326,7 @@ static void thread_map__delete(struct thread_map *threads)
        if (threads) {
                int i;
 
-               WARN_ONCE(atomic_read(&threads->refcnt) != 0,
+               WARN_ONCE(refcount_read(&threads->refcnt) != 0,
                          "thread map refcnt unbalanced\n");
                for (i = 0; i < threads->nr; i++)
                        free(thread_map__comm(threads, i));
@@ -337,13 +337,13 @@ static void thread_map__delete(struct thread_map *threads)
 struct thread_map *thread_map__get(struct thread_map *map)
 {
        if (map)
-               atomic_inc(&map->refcnt);
+               refcount_inc(&map->refcnt);
        return map;
 }
 
 void thread_map__put(struct thread_map *map)
 {
-       if (map && atomic_dec_and_test(&map->refcnt))
+       if (map && refcount_dec_and_test(&map->refcnt))
                thread_map__delete(map);
 }
 
@@ -423,7 +423,7 @@ static void thread_map__copy_event(struct thread_map *threads,
                threads->map[i].comm = strndup(event->entries[i].comm, 16);
        }
 
-       atomic_set(&threads->refcnt, 1);
+       refcount_set(&threads->refcnt, 1);
 }
 
 struct thread_map *thread_map__new_event(struct thread_map_event *event)

diff --git a/tools/perf/util/thread_map.h b/tools/perf/util/thread_map.h
index ea0ef08..bd34d7a 100644 (file)
--- a/tools/perf/util/thread_map.h
+++ b/tools/perf/util/thread_map.h
@@ -3,7 +3,7 @@
 
 #include <sys/types.h>
 #include <stdio.h>
-#include <linux/atomic.h>
+#include <linux/refcount.h>
 
 struct thread_map_data {
        pid_t    pid;
@@ -11,7 +11,7 @@ struct thread_map_data {
 };
 
 struct thread_map {
-       atomic_t refcnt;
+       refcount_t refcnt;
        int nr;
        struct thread_map_data map[];
 };