Re: [PATCH v1] vfio/type1: Remove the almost unused check in vfio_iommu_type1_unpin_pages

2021-04-06 Thread Alex Williamson
On Tue, 6 Apr 2021 21:50:09 +0800
Shenming Lu  wrote:

> The check i > npage at the end of vfio_iommu_type1_unpin_pages is unused
> unless npage < 0, but if npage < 0, this function will return npage, which
> should return -EINVAL instead. So let's just check the parameter npage at
> the start of the function. By the way, replace unpin_exit with break.
> 
> Signed-off-by: Shenming Lu 
> ---
>  drivers/vfio/vfio_iommu_type1.c | 8 
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
> index 45cbfd4879a5..fd4213c41743 100644
> --- a/drivers/vfio/vfio_iommu_type1.c
> +++ b/drivers/vfio/vfio_iommu_type1.c
> @@ -960,7 +960,7 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data,
>   bool do_accounting;
>   int i;
>  
> - if (!iommu || !user_pfn)
> + if (!iommu || !user_pfn || npage <= 0)
>   return -EINVAL;
>  
>   /* Supported for v2 version only */
> @@ -977,13 +977,13 @@ static int vfio_iommu_type1_unpin_pages(void 
> *iommu_data,
>   iova = user_pfn[i] << PAGE_SHIFT;
>   dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
>   if (!dma)
> - goto unpin_exit;
> + break;
> +
>   vfio_unpin_page_external(dma, iova, do_accounting);
>   }
>  
> -unpin_exit:
>   mutex_unlock(>lock);
> - return i > npage ? npage : (i > 0 ? i : -EINVAL);
> + return i > 0 ? i : -EINVAL;
>  }
>  
>  static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,

Very odd behavior previously.  Applied to vfio next branch for v5.13.
Thanks,

Alex



[PATCH v1] vfio/type1: Remove the almost unused check in vfio_iommu_type1_unpin_pages

2021-04-06 Thread Shenming Lu
The check i > npage at the end of vfio_iommu_type1_unpin_pages is unused
unless npage < 0, but if npage < 0, this function will return npage, which
should return -EINVAL instead. So let's just check the parameter npage at
the start of the function. By the way, replace unpin_exit with break.

Signed-off-by: Shenming Lu 
---
 drivers/vfio/vfio_iommu_type1.c | 8 
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 45cbfd4879a5..fd4213c41743 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -960,7 +960,7 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data,
bool do_accounting;
int i;
 
-   if (!iommu || !user_pfn)
+   if (!iommu || !user_pfn || npage <= 0)
return -EINVAL;
 
/* Supported for v2 version only */
@@ -977,13 +977,13 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data,
iova = user_pfn[i] << PAGE_SHIFT;
dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
if (!dma)
-   goto unpin_exit;
+   break;
+
vfio_unpin_page_external(dma, iova, do_accounting);
}
 
-unpin_exit:
mutex_unlock(>lock);
-   return i > npage ? npage : (i > 0 ? i : -EINVAL);
+   return i > 0 ? i : -EINVAL;
 }
 
 static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,
-- 
2.19.1