[PATCH] drm/amd/amdgpu: fix offset into page with amdgpu_iomem debugfs file

[ckoenig.leichtzumerken@xxxxxxxxx (Christian König)]

Am 20.03.2018 um 14:16 schrieb Tom St Denis:
> The offset inside the page wasn't included in the copy call meaning
> the start of the page was being read/written instead.
>
> Reported-by: Jay Cornwall <Jay.Cornwall at amd.com>
> Signed-off-by: Tom St Denis <tom.stdenis at amd.com>

Good catch, patch is Reviewed-by: Christian König 
<christian.koenig at amd.com>.

Regards,
Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 291dd3d600cd..d2ab40494a4c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1996,7 +1996,7 @@ static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,
>   			return -EPERM;
>   
>   		ptr = kmap(p);
> -		r = copy_to_user(buf, ptr, bytes);
> +		r = copy_to_user(buf, ptr + off, bytes);
>   		kunmap(p);
>   		if (r)
>   			return -EFAULT;
> @@ -2040,7 +2040,7 @@ static ssize_t amdgpu_iomem_write(struct file *f, const char __user *buf,
>   			return -EPERM;
>   
>   		ptr = kmap(p);
> -		r = copy_from_user(ptr, buf, bytes);
> +		r = copy_from_user(ptr + off, buf, bytes);
>   		kunmap(p);
>   		if (r)
>   			return -EFAULT;