From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753496AbdBUPgE (ORCPT ); Tue, 21 Feb 2017 10:36:04 -0500 Received: from mga02.intel.com ([134.134.136.20]:33064 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752838AbdBUPfY (ORCPT ); Tue, 21 Feb 2017 10:35:24 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,190,1484035200"; d="scan'208";a="826820514" From: Elena Reshetova To: linux-kernel@vger.kernel.org Cc: alsa-devel@alsa-project.org, peterz@infradead.org, gregkh@linuxfoundation.org, mingo@redhat.com, acme@kernel.org, alexander.shishkin@linux.intel.com, jolsa@kernel.org, mark.rutland@arm.com, akpm@linux-foundation.org, matija.glavinic-pecotic.ext@nokia.com, Elena Reshetova , Hans Liljestrand , Kees Cook , David Windsor Subject: [PATCH 3/9] tools: convert comm_str.refcnt from atomic_t to refcount_t Date: Tue, 21 Feb 2017 17:34:57 +0200 Message-Id: <1487691303-31858-4-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1487691303-31858-1-git-send-email-elena.reshetova@intel.com> References: <1487691303-31858-1-git-send-email-elena.reshetova@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- tools/perf/util/comm.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/comm.c b/tools/perf/util/comm.c index 21b7ff3..0fd3d70 100644 --- a/tools/perf/util/comm.c +++ b/tools/perf/util/comm.c @@ -2,12 +2,12 @@ #include "util.h" #include #include -#include +#include struct comm_str { char *str; struct rb_node rb_node; - atomic_t refcnt; + refcount_t refcnt; }; /* Should perhaps be moved to struct machine */ @@ -16,13 +16,13 @@ static struct rb_root comm_str_root; static struct comm_str *comm_str__get(struct comm_str *cs) { if (cs) - atomic_inc(&cs->refcnt); + refcount_inc(&cs->refcnt); return cs; } static void comm_str__put(struct comm_str *cs) { - if (cs && atomic_dec_and_test(&cs->refcnt)) { + if (cs && refcount_dec_and_test(&cs->refcnt)) { rb_erase(&cs->rb_node, &comm_str_root); zfree(&cs->str); free(cs); @@ -43,7 +43,7 @@ static struct comm_str *comm_str__alloc(const char *str) return NULL; } - atomic_set(&cs->refcnt, 0); + refcount_set(&cs->refcnt, 1); return cs; } @@ -95,8 +95,6 @@ struct comm *comm__new(const char *str, u64 timestamp, bool exec) return NULL; } - comm_str__get(comm->comm_str); - return comm; } @@ -108,7 +106,6 @@ int comm__override(struct comm *comm, const char *str, u64 timestamp, bool exec) if (!new) return -ENOMEM; - comm_str__get(new); comm_str__put(old); comm->comm_str = new; comm->start = timestamp; -- 2.7.4