[PATCH 4.2.y-ckt 151/305] vhost: relax log address alignment

From: Kamal Mostafa
Date: Fri Jan 15 2016 - 19:52:38 EST


4.2.8-ckt2 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: "Michael S. Tsirkin" <mst@xxxxxxxxxx>

commit d542483876f6ed720f573de3fbb1d8e60ccd0d6e upstream.

commit 5d9a07b0de512b77bf28d2401e5fe3351f00a240 ("vhost: relax used
address alignment") fixed the alignment for the used virtual address,
but not for the physical address used for logging.

That's a mistake: alignment should clearly be the same for virtual and
physical addresses,

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/vhost/vhost.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index eec2f11..080422f 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -819,7 +819,7 @@ long vhost_vring_ioctl(struct vhost_dev *d, int ioctl, void __user *argp)
BUILD_BUG_ON(__alignof__ *vq->used > VRING_USED_ALIGN_SIZE);
if ((a.avail_user_addr & (VRING_AVAIL_ALIGN_SIZE - 1)) ||
(a.used_user_addr & (VRING_USED_ALIGN_SIZE - 1)) ||
- (a.log_guest_addr & (sizeof(u64) - 1))) {
+ (a.log_guest_addr & (VRING_USED_ALIGN_SIZE - 1))) {
r = -EINVAL;
break;
}
--
1.9.1