vhost: Fix the calculation in vhost_overflow()

[linux-2.6-microblaze.git] / drivers / vhost / vhost.c

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 5ccb070..59edb5a 100644 (file)
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -231,7 +231,7 @@ void vhost_poll_stop(struct vhost_poll *poll)
 }
 EXPORT_SYMBOL_GPL(vhost_poll_stop);
 
-void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
+void vhost_work_dev_flush(struct vhost_dev *dev)
 {
        struct vhost_flush_struct flush;
 
@@ -243,13 +243,13 @@ void vhost_work_flush(struct vhost_dev *dev, struct vhost_work *work)
                wait_for_completion(&flush.wait_event);
        }
 }
-EXPORT_SYMBOL_GPL(vhost_work_flush);
+EXPORT_SYMBOL_GPL(vhost_work_dev_flush);
 
 /* Flush any work that has been scheduled. When calling this, don't hold any
  * locks that are also used by the callback. */
 void vhost_poll_flush(struct vhost_poll *poll)
 {
-       vhost_work_flush(poll->dev, &poll->work);
+       vhost_work_dev_flush(poll->dev);
 }
 EXPORT_SYMBOL_GPL(vhost_poll_flush);
 
@@ -538,7 +538,7 @@ static int vhost_attach_cgroups(struct vhost_dev *dev)
        attach.owner = current;
        vhost_work_init(&attach.work, vhost_attach_cgroups_work);
        vhost_work_queue(dev, &attach.work);
-       vhost_work_flush(dev, &attach.work);
+       vhost_work_dev_flush(dev);
        return attach.ret;
 }
 
@@ -735,10 +735,16 @@ static bool log_access_ok(void __user *log_base, u64 addr, unsigned long sz)
                         (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8);
 }
 
+/* Make sure 64 bit math will not overflow. */
 static bool vhost_overflow(u64 uaddr, u64 size)
 {
-       /* Make sure 64 bit math will not overflow. */
-       return uaddr > ULONG_MAX || size > ULONG_MAX || uaddr > ULONG_MAX - size;
+       if (uaddr > ULONG_MAX || size > ULONG_MAX)
+               return true;
+
+       if (!size)
+               return false;
+
+       return uaddr > ULONG_MAX - size + 1;
 }
 
 /* Caller should have vq mutex and device mutex. */