From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754229AbdCHSry (ORCPT ); Wed, 8 Mar 2017 13:47:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51992 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753944AbdCHSrt (ORCPT ); Wed, 8 Mar 2017 13:47:49 -0500 Date: Wed, 8 Mar 2017 10:47:40 -0800 From: Chris Leech 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 22/29] drivers, scsi: convert iscsi_task.refcount from atomic_t to refcount_t Message-ID: <20170308184740.4gueok5csdkt7u62@straylight.hirudinean.org> Mail-Followup-To: Chris Leech , Elena Reshetova , 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 References: <1488810076-3754-1-git-send-email-elena.reshetova@intel.com> <1488810076-3754-23-git-send-email-elena.reshetova@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1488810076-3754-23-git-send-email-elena.reshetova@intel.com> User-Agent: NeoMutt/20170306 (1.8.0) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 08 Mar 2017 18:47:49 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 06, 2017 at 04:21:09PM +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. > > Signed-off-by: Elena Reshetova > Signed-off-by: Hans Liljestrand > Signed-off-by: Kees Cook > Signed-off-by: David Windsor This looks OK to me. Acked-by: Chris Leech > --- > drivers/scsi/libiscsi.c | 8 ++++---- > drivers/scsi/qedi/qedi_iscsi.c | 2 +- > include/scsi/libiscsi.h | 3 ++- > 3 files changed, 7 insertions(+), 6 deletions(-) > > diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c > index 834d121..7eb1d2c 100644 > --- a/drivers/scsi/libiscsi.c > +++ b/drivers/scsi/libiscsi.c > @@ -516,13 +516,13 @@ static void iscsi_free_task(struct iscsi_task *task) > > void __iscsi_get_task(struct iscsi_task *task) > { > - atomic_inc(&task->refcount); > + refcount_inc(&task->refcount); > } > EXPORT_SYMBOL_GPL(__iscsi_get_task); > > void __iscsi_put_task(struct iscsi_task *task) > { > - if (atomic_dec_and_test(&task->refcount)) > + if (refcount_dec_and_test(&task->refcount)) > iscsi_free_task(task); > } > EXPORT_SYMBOL_GPL(__iscsi_put_task); > @@ -744,7 +744,7 @@ __iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr, > * released by the lld when it has transmitted the task for > * pdus we do not expect a response for. > */ > - atomic_set(&task->refcount, 1); > + refcount_set(&task->refcount, 1); > task->conn = conn; > task->sc = NULL; > INIT_LIST_HEAD(&task->running); > @@ -1616,7 +1616,7 @@ static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn, > sc->SCp.phase = conn->session->age; > sc->SCp.ptr = (char *) task; > > - atomic_set(&task->refcount, 1); > + refcount_set(&task->refcount, 1); > task->state = ISCSI_TASK_PENDING; > task->conn = conn; > task->sc = sc; > diff --git a/drivers/scsi/qedi/qedi_iscsi.c b/drivers/scsi/qedi/qedi_iscsi.c > index b9f79d3..3895bd5 100644 > --- a/drivers/scsi/qedi/qedi_iscsi.c > +++ b/drivers/scsi/qedi/qedi_iscsi.c > @@ -1372,7 +1372,7 @@ static void qedi_cleanup_task(struct iscsi_task *task) > { > if (!task->sc || task->state == ISCSI_TASK_PENDING) { > QEDI_INFO(NULL, QEDI_LOG_IO, "Returning ref_cnt=%d\n", > - atomic_read(&task->refcount)); > + refcount_read(&task->refcount)); > return; > } > > diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h > index b0e275d..24d74b5 100644 > --- a/include/scsi/libiscsi.h > +++ b/include/scsi/libiscsi.h > @@ -29,6 +29,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -139,7 +140,7 @@ struct iscsi_task { > > /* state set/tested under session->lock */ > int state; > - atomic_t refcount; > + refcount_t refcount; > struct list_head running; /* running cmd list */ > void *dd_data; /* driver/transport data */ > }; > -- > 2.7.4 >