From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756093AbdCGTLY (ORCPT ); Tue, 7 Mar 2017 14:11:24 -0500 Received: from mail.kernel.org ([198.145.29.136]:52794 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756048AbdCGTLU (ORCPT ); Tue, 7 Mar 2017 14:11:20 -0500 Date: Tue, 7 Mar 2017 11:04:49 -0800 From: Shaohua Li To: Elena Reshetova Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, netdev@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-bcache@vger.kernel.org, linux-raid@vger.kernel.org, linux-media@vger.kernel.org, devel@linuxdriverproject.org, linux-pci@vger.kernel.org, linux-s390@vger.kernel.org, fcoe-devel@open-fcoe.org, linux-scsi@vger.kernel.org, open-iscsi@googlegroups.com, devel@driverdev.osuosl.org, target-devel@vger.kernel.org, linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, peterz@infradead.org, Hans Liljestrand , Kees Cook , David Windsor Subject: Re: [PATCH 08/29] drivers, md: convert mddev.active from atomic_t to refcount_t Message-ID: <20170307190449.baceyzzngsz776x7@kernel.org> References: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> <1488810076-3754-9-git-send-email-elena.reshetova@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1488810076-3754-9-git-send-email-elena.reshetova@intel.com> User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 06, 2017 at 04:20:55PM +0200, Elena Reshetova wrote: > 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. Looks good. Let me know how do you want to route the patch to upstream. > Signed-off-by: Elena Reshetova > Signed-off-by: Hans Liljestrand > Signed-off-by: Kees Cook > Signed-off-by: David Windsor > --- > drivers/md/md.c | 6 +++--- > drivers/md/md.h | 3 ++- > 2 files changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/md/md.c b/drivers/md/md.c > index 985374f..94c8ebf 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -449,7 +449,7 @@ EXPORT_SYMBOL(md_unplug); > > static inline struct mddev *mddev_get(struct mddev *mddev) > { > - atomic_inc(&mddev->active); > + refcount_inc(&mddev->active); > return mddev; > } > > @@ -459,7 +459,7 @@ static void mddev_put(struct mddev *mddev) > { > struct bio_set *bs = NULL; > > - if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock)) > + if (!refcount_dec_and_lock(&mddev->active, &all_mddevs_lock)) > return; > if (!mddev->raid_disks && list_empty(&mddev->disks) && > mddev->ctime == 0 && !mddev->hold_active) { > @@ -495,7 +495,7 @@ void mddev_init(struct mddev *mddev) > INIT_LIST_HEAD(&mddev->all_mddevs); > setup_timer(&mddev->safemode_timer, md_safemode_timeout, > (unsigned long) mddev); > - atomic_set(&mddev->active, 1); > + refcount_set(&mddev->active, 1); > atomic_set(&mddev->openers, 0); > atomic_set(&mddev->active_io, 0); > spin_lock_init(&mddev->lock); > diff --git a/drivers/md/md.h b/drivers/md/md.h > index b8859cb..4811663 100644 > --- a/drivers/md/md.h > +++ b/drivers/md/md.h > @@ -22,6 +22,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -360,7 +361,7 @@ struct mddev { > */ > struct mutex open_mutex; > struct mutex reconfig_mutex; > - atomic_t active; /* general refcount */ > + refcount_t active; /* general refcount */ > atomic_t openers; /* number of active opens */ > > int changed; /* True if we might need to > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html