| Submitter | Herton Ronaldo Krzesinski |
|---|---|
| Date | Jan. 8, 2013, 8:56 p.m. |
| Message ID | <1357678594-19339-1-git-send-email-herton.krzesinski@canonical.com> |
| Download | mbox | patch |
| Permalink | /patch/210497/ |
| State | New |
| Headers | show |
Comments
Patch
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 5aa43c3..52bfd07 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -132,6 +132,13 @@ static int vring_add_indirect(struct vring_virtqueue *vq, unsigned head; int i; + /* + * We require lowmem mappings for the descriptors because + * otherwise virt_to_phys will give us bogus addresses in the + * virtqueue. + */ + gfp &= ~(__GFP_HIGHMEM | __GFP_HIGH); + desc = kmalloc((out + in) * sizeof(struct vring_desc), gfp); if (!desc) return -ENOMEM;
This is a note to let you know that I have just added a patch titled virtio: force vring descriptors to be allocated from to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From 4c08598a6cdf9aad46730478c303142d0256fd45 Mon Sep 17 00:00:00 2001 From: Will Deacon <will.deacon@arm.com> Date: Fri, 19 Oct 2012 14:03:33 +0100 Subject: [PATCH 01/27] virtio: force vring descriptors to be allocated from lowmem commit b92b1b89a33c172c075edccf6afb0edc41d851fd upstream. Virtio devices may attempt to add descriptors to a virtqueue from atomic context using GFP_ATOMIC allocation. This is problematic because such allocations can fall outside of the lowmem mapping, causing virt_to_phys to report bogus physical addresses which are subsequently passed to userspace via the buffers for the virtual device. This patch masks out __GFP_HIGH and __GFP_HIGHMEM from the requested flags when allocating descriptors for a virtqueue. If an atomic allocation is requested and later fails, we will return -ENOSPC which will be handled by the driver. Cc: Sasha Levin <levinsasha928@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- drivers/virtio/virtio_ring.c | 7 +++++++ 1 file changed, 7 insertions(+) -- 1.7.9.5