LinuxLists.cc - [PATCH] iommu/virtio: reverse arguments to list

2020-05-05 19:31:28

Subject: [PATCH] iommu/virtio: reverse arguments to list_add

Elsewhere in the file, there is a list_for_each_entry with
&vdev->resv_regions as the second argument, suggesting that
&vdev->resv_regions is the list head. So exchange the
arguments on the list_add call to put the list head in the
second argument.

Fixes: 2a5a31487445 ("iommu/virtio: Add probe request")
Signed-off-by: Julia Lawall <[email protected]>

---
drivers/iommu/virtio-iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index d5cac4f46ca5..4e1d11af23c8 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -453,7 +453,7 @@ static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
if (!region)
return -ENOMEM;

- list_add(&vdev->resv_regions, &region->list);
+ list_add(&region->list, &vdev->resv_regions);
return 0;
}

2020-05-06 09:37:52

by Jean-Philippe Brucker

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Subject: Re: [PATCH] iommu/virtio: reverse arguments to list_add

On Tue, May 05, 2020 at 08:47:47PM +0200, Julia Lawall wrote:
> Elsewhere in the file, there is a list_for_each_entry with
> &vdev->resv_regions as the second argument, suggesting that
> &vdev->resv_regions is the list head. So exchange the
> arguments on the list_add call to put the list head in the
> second argument.
>
> Fixes: 2a5a31487445 ("iommu/virtio: Add probe request")
> Signed-off-by: Julia Lawall <[email protected]>

Thanks for the fix. The reason this hasn't blown up so far is
iommu_alloc_resv_region() initializes region->list, but adding more than
one item would break the list.

Reviewed-by: Jean-Philippe Brucker <[email protected]>

> ---
> drivers/iommu/virtio-iommu.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
> index d5cac4f46ca5..4e1d11af23c8 100644
> --- a/drivers/iommu/virtio-iommu.c
> +++ b/drivers/iommu/virtio-iommu.c
> @@ -453,7 +453,7 @@ static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
> if (!region)
> return -ENOMEM;
>
> - list_add(&vdev->resv_regions, &region->list);
> + list_add(&region->list, &vdev->resv_regions);
> return 0;
> }
>
>

2020-05-08 15:34:19

by Joerg Roedel

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