linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jiang Liu <liuj97@gmail.com>
To: Alex Williamson <alex.williamson@redhat.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiang Liu <jiang.liu@huawei.com>,
	Joerg Roedel <joerg.roedel@amd.com>,
	Yinghai Lu <yinghai@kernel.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Hanjun Guo <guohanjun@huawei.com>
Subject: [RFC PATCH 3/6] VFIO: unregister IOMMU notifier on error recovery path
Date: Sat, 10 Nov 2012 21:57:16 +0800	[thread overview]
Message-ID: <1352555839-18961-3-git-send-email-jiang.liu@huawei.com> (raw)
In-Reply-To: <1352555839-18961-1-git-send-email-jiang.liu@huawei.com>

 From: Jiang Liu <jiang.liu@huawei.com>

On error recovery path in function vfio_create_group(), it should
unregister the IOMMU notifier for the new VFIO group. Otherwise it may
cause invalid memory access later when handling bus notifications.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
---
 drivers/vfio/vfio.c |   31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 17830c9..3359ec2 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -191,6 +191,17 @@ static void vfio_container_put(struct vfio_container *container)
 	kref_put(&container->kref, vfio_container_release);
 }
 
+static void vfio_group_unlock_and_free(struct vfio_group *group)
+{
+	mutex_unlock(&vfio.group_lock);
+	/*
+	 * Unregister outside of lock.  A spurious callback is harmless now
+	 * that the group is no longer in vfio.group_list.
+	 */
+	iommu_group_unregister_notifier(group->iommu_group, &group->nb);
+	kfree(group);
+}
+
 /**
  * Group objects - create, release, get, put, search
  */
@@ -229,8 +240,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
 
 	minor = vfio_alloc_group_minor(group);
 	if (minor < 0) {
-		mutex_unlock(&vfio.group_lock);
-		kfree(group);
+		vfio_group_unlock_and_free(group);
 		return ERR_PTR(minor);
 	}
 
@@ -239,8 +249,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
 		if (tmp->iommu_group == iommu_group) {
 			vfio_group_get(tmp);
 			vfio_free_group_minor(minor);
-			mutex_unlock(&vfio.group_lock);
-			kfree(group);
+			vfio_group_unlock_and_free(group);
 			return tmp;
 		}
 	}
@@ -249,8 +258,7 @@ static struct vfio_group *vfio_create_group(struct iommu_group *iommu_group)
 			    group, "%d", iommu_group_id(iommu_group));
 	if (IS_ERR(dev)) {
 		vfio_free_group_minor(minor);
-		mutex_unlock(&vfio.group_lock);
-		kfree(group);
+		vfio_group_unlock_and_free(group);
 		return (struct vfio_group *)dev; /* ERR_PTR */
 	}
 
@@ -274,16 +282,7 @@ static void vfio_group_release(struct kref *kref)
 	device_destroy(vfio.class, MKDEV(MAJOR(vfio.devt), group->minor));
 	list_del(&group->vfio_next);
 	vfio_free_group_minor(group->minor);
-
-	mutex_unlock(&vfio.group_lock);
-
-	/*
-	 * Unregister outside of lock.  A spurious callback is harmless now
-	 * that the group is no longer in vfio.group_list.
-	 */
-	iommu_group_unregister_notifier(group->iommu_group, &group->nb);
-
-	kfree(group);
+	vfio_group_unlock_and_free(group);
 }
 
 static void vfio_group_put(struct vfio_group *group)
-- 
1.7.9.5


  parent reply	other threads:[~2012-11-10 13:59 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-10 13:57 [RFC PATCH 1/6] driver core: add a bus notification to temporarily reject driver binding Jiang Liu
2012-11-10 13:57 ` [RFC PATCH 2/6] iommu: pass on BUS_NOTIFY_QUERY_BINDING to iommu group notifier clients Jiang Liu
2012-11-10 13:57 ` Jiang Liu [this message]
2012-11-13 18:15   ` [RFC PATCH 3/6] VFIO: unregister IOMMU notifier on error recovery path Alex Williamson
2012-11-10 13:57 ` [RFC PATCH 4/6] VFIO: reject binding driver to devices belonging to active VFIO groups Jiang Liu
2012-11-10 13:57 ` [RFC PATCH 5/6] VFIO: simplify IOMMU group notification handler Jiang Liu
2012-11-10 13:57 ` [RFC PATCH 6/6] VFIO: use ACCESS_ONCE() to guard access to dev->driver Jiang Liu
2012-11-11  5:21 ` [RFC PATCH 1/6] driver core: add a bus notification to temporarily reject driver binding Greg Kroah-Hartman
2012-11-13 16:02   ` Jiang Liu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1352555839-18961-3-git-send-email-jiang.liu@huawei.com \
    --to=liuj97@gmail.com \
    --cc=alex.williamson@redhat.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=guohanjun@huawei.com \
    --cc=jiang.liu@huawei.com \
    --cc=joerg.roedel@amd.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=yinghai@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).