From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933857AbdBVUh6 (ORCPT ); Wed, 22 Feb 2017 15:37:58 -0500 Received: from mail.kernel.org ([198.145.29.136]:53798 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933524AbdBVUhe (ORCPT ); Wed, 22 Feb 2017 15:37:34 -0500 Date: Wed, 22 Feb 2017 17:29:40 -0300 From: Arnaldo Carvalho de Melo To: Elena Reshetova Cc: linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org, peterz@infradead.org, gregkh@linuxfoundation.org, mingo@redhat.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, mark.rutland@arm.com, akpm@linux-foundation.org, matija.glavinic-pecotic.ext@nokia.com, Hans Liljestrand , Kees Cook , David Windsor Subject: Re: [PATCH 2/9] tools: convert cpu_map.refcnt from atomic_t to refcount_t Message-ID: <20170222202940.GD20447@kernel.org> References: <1487691303-31858-1-git-send-email-elena.reshetova@intel.com> <1487691303-31858-3-git-send-email-elena.reshetova@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1487691303-31858-3-git-send-email-elena.reshetova@intel.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.7.1 (2016-10-04) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Tue, Feb 21, 2017 at 05:34:56PM +0200, Elena Reshetova escreveu: > 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. The following patch was needed for this one to build: diff --git a/tools/perf/tests/cpumap.c b/tools/perf/tests/cpumap.c index f168a85992d0..4478773cdb97 100644 --- a/tools/perf/tests/cpumap.c +++ b/tools/perf/tests/cpumap.c @@ -66,7 +66,7 @@ static int process_event_cpus(struct perf_tool *tool __maybe_unused, TEST_ASSERT_VAL("wrong nr", map->nr == 2); TEST_ASSERT_VAL("wrong cpu", map->map[0] == 1); TEST_ASSERT_VAL("wrong cpu", map->map[1] == 256); - TEST_ASSERT_VAL("wrong refcnt", atomic_read(&map->refcnt) == 1); + TEST_ASSERT_VAL("wrong refcnt", refcount_read(&map->refcnt) == 1); cpu_map__put(map); return 0; } diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h index e84491636c1b..ab1aeed8cd5d 100644 --- a/tools/perf/util/cpumap.h +++ b/tools/perf/util/cpumap.h @@ -3,10 +3,10 @@ #include #include -#include #include "perf.h" #include "util/debug.h" +#include struct cpu_map { refcount_t refcnt; > Signed-off-by: Elena Reshetova > Signed-off-by: Hans Liljestrand > Signed-off-by: Kees Cook > Signed-off-by: David Windsor > --- > tools/perf/util/cpumap.c | 16 ++++++++-------- > tools/perf/util/cpumap.h | 4 ++-- > 2 files changed, 10 insertions(+), 10 deletions(-) > > diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c > index 2c0b522..0e21e28 100644 > --- a/tools/perf/util/cpumap.c > +++ b/tools/perf/util/cpumap.c > @@ -28,7 +28,7 @@ static struct cpu_map *cpu_map__default_new(void) > cpus->map[i] = i; > > cpus->nr = nr_cpus; > - atomic_set(&cpus->refcnt, 1); > + refcount_set(&cpus->refcnt, 1); > } > > return cpus; > @@ -42,7 +42,7 @@ static struct cpu_map *cpu_map__trim_new(int nr_cpus, int *tmp_cpus) > if (cpus != NULL) { > cpus->nr = nr_cpus; > memcpy(cpus->map, tmp_cpus, payload_size); > - atomic_set(&cpus->refcnt, 1); > + refcount_set(&cpus->refcnt, 1); > } > > return cpus; > @@ -251,7 +251,7 @@ struct cpu_map *cpu_map__dummy_new(void) > if (cpus != NULL) { > cpus->nr = 1; > cpus->map[0] = -1; > - atomic_set(&cpus->refcnt, 1); > + refcount_set(&cpus->refcnt, 1); > } > > return cpus; > @@ -268,7 +268,7 @@ struct cpu_map *cpu_map__empty_new(int nr) > for (i = 0; i < nr; i++) > cpus->map[i] = -1; > > - atomic_set(&cpus->refcnt, 1); > + refcount_set(&cpus->refcnt, 1); > } > > return cpus; > @@ -277,7 +277,7 @@ struct cpu_map *cpu_map__empty_new(int nr) > static void cpu_map__delete(struct cpu_map *map) > { > if (map) { > - WARN_ONCE(atomic_read(&map->refcnt) != 0, > + WARN_ONCE(refcount_read(&map->refcnt) != 0, > "cpu_map refcnt unbalanced\n"); > free(map); > } > @@ -286,13 +286,13 @@ static void cpu_map__delete(struct cpu_map *map) > struct cpu_map *cpu_map__get(struct cpu_map *map) > { > if (map) > - atomic_inc(&map->refcnt); > + refcount_inc(&map->refcnt); > return map; > } > > void cpu_map__put(struct cpu_map *map) > { > - if (map && atomic_dec_and_test(&map->refcnt)) > + if (map && refcount_dec_and_test(&map->refcnt)) > cpu_map__delete(map); > } > > @@ -356,7 +356,7 @@ int cpu_map__build_map(struct cpu_map *cpus, struct cpu_map **res, > /* ensure we process id in increasing order */ > qsort(c->map, c->nr, sizeof(int), cmp_ids); > > - atomic_set(&c->refcnt, 1); > + refcount_set(&c->refcnt, 1); > *res = c; > return 0; > } > diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h > index 06bd689..4f12a01 100644 > --- a/tools/perf/util/cpumap.h > +++ b/tools/perf/util/cpumap.h > @@ -3,13 +3,13 @@ > > #include > #include > -#include > +#include > > #include "perf.h" > #include "util/debug.h" > > struct cpu_map { > - atomic_t refcnt; > + refcount_t refcnt; > int nr; > int map[]; > }; > -- > 2.7.4