perf thread: convert thread.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/1487691303-31858-9-git-send-email-elena.reshetova@intel.com
[ Did missing conversion in __machine__remove_thread() ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 71c9720d4973..b9974fe41bc1 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1439,7 +1439,7 @@ static void __machine__remove_thread(struct machine *machine, struct thread *th,
         if (machine->last_match == th)
                 machine->last_match = NULL;
 
-        BUG_ON(atomic_read(&th->refcnt) == 0);
+        BUG_ON(refcount_read(&th->refcnt) == 0);
         if (lock)
                 pthread_rwlock_wrlock(&machine->threads_lock);
         rb_erase_init(&th->rb_node, &machine->threads);