aboutsummaryrefslogtreecommitdiff
path: root/drivers/vfio
diff options
context:
space:
mode:
authorAl Viro <viro@zeniv.linux.org.uk>2012-08-17 21:29:06 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-08-22 10:26:13 -0400
commit90b1253e4139776e8257914ae9e2292d0de2fecc (patch)
tree47ed9f35d8f58d42f6e3c8614d355b1edc86f51b /drivers/vfio
parent6d2cd3ce815b302e885b44ca1bdbe3c7db321c7a (diff)
downloadlinux-90b1253e4139776e8257914ae9e2292d0de2fecc.tar.gz
vfio: get rid of vfio_device_put()/vfio_group_get_device* races
we really need to make sure that dropping the last reference happens under the group->device_lock; otherwise a loop (under device_lock) might find vfio_device instance that is being freed right now, has already dropped the last reference and waits on device_lock to exclude the sucker from the list. Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/vfio.c3
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 92b85676e6b..887ae43276b 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -396,7 +396,6 @@ static void vfio_device_release(struct kref *kref)
struct vfio_device, kref);
struct vfio_group *group = device->group;
- mutex_lock(&group->device_lock);
list_del(&device->group_next);
mutex_unlock(&group->device_lock);
@@ -412,7 +411,7 @@ static void vfio_device_release(struct kref *kref)
static void vfio_device_put(struct vfio_device *device)
{
struct vfio_group *group = device->group;
- kref_put(&device->kref, vfio_device_release);
+ kref_put_mutex(&device->kref, vfio_device_release, &group->device_lock);
vfio_group_put(group);
}