From: Elena Reshetova elena.reshetova@intel.com

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/1487691303-31858-5-git-send-email-elena.reshetova@i... Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com --- tools/perf/util/dso.c | 6 +++--- tools/perf/util/dso.h | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c index d38b62a700ca..42db00d78573 100644 --- a/tools/perf/util/dso.c +++ b/tools/perf/util/dso.c @@ -1109,7 +1109,7 @@ struct dso *dso__new(const char *name) INIT_LIST_HEAD(&dso->node); INIT_LIST_HEAD(&dso->data.open_entry); pthread_mutex_init(&dso->lock, NULL); - atomic_set(&dso->refcnt, 1); + refcount_set(&dso->refcnt, 1); }

return dso; @@ -1147,13 +1147,13 @@ void dso__delete(struct dso *dso) struct dso *dso__get(struct dso *dso) { if (dso) - atomic_inc(&dso->refcnt); + refcount_inc(&dso->refcnt); return dso; }

void dso__put(struct dso *dso) { - if (dso && atomic_dec_and_test(&dso->refcnt)) + if (dso && refcount_dec_and_test(&dso->refcnt)) dso__delete(dso); }

diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h index ecc4bbd3f82e..12350b171727 100644 --- a/tools/perf/util/dso.h +++ b/tools/perf/util/dso.h @@ -1,7 +1,7 @@ #ifndef __PERF_DSO #define __PERF_DSO

-#include <linux/atomic.h> +#include <linux/refcount.h> #include <linux/types.h> #include <linux/rbtree.h> #include <sys/types.h> @@ -187,7 +187,7 @@ struct dso { void *priv; u64 db_id; }; - atomic_t refcnt; + refcount_t refcnt; char name[0]; };