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authorAnthony Liguori <aliguori@us.ibm.com>2008-08-19 02:15:31 +0400
committerRusty Russell <rusty@rustcorp.com.au>2008-08-25 18:19:25 +0400
commit532a6086e35fa3b5761e68af36d4e42a550eba15 (patch)
treec1d8ab4df9db25e0efd89dab64dda98f84df1fa6 /drivers/virtio
parent83097aca8567a0bd593534853b71fe0fa9a75d69 (diff)
downloadlinux-532a6086e35fa3b5761e68af36d4e42a550eba15.tar.xz
virtio_balloon: fix towards_target when deflating balloon
Both v and vb->num_pages are u32 and unsigned int respectively. If v is less than vb->num_pages (and it is, when deflating the balloon), the result is a very large 32-bit number. Since we're returning a s64, instead of getting the same negative number we desire, we get a very large positive number. This handles the case where v < vb->num_pages and ensures we get a small, negative, s64 as the result. Rusty: please push this for 2.6.27-rc4. It's probably appropriate for the stable tree too as it will cause an unexpected OOM when ballooning. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (simplified)
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_balloon.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index bfef604160d1..62eab43152d2 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -158,7 +158,7 @@ static inline s64 towards_target(struct virtio_balloon *vb)
vb->vdev->config->get(vb->vdev,
offsetof(struct virtio_balloon_config, num_pages),
&v, sizeof(v));
- return v - vb->num_pages;
+ return (s64)v - vb->num_pages;
}
static void update_balloon_size(struct virtio_balloon *vb)