[PATCH] drm/amdgpu: revert allow write access to mapped userptrs"

[Alex Deucher]

On Mon, Jun 24, 2024 at 5:17 AM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> This reverts commit 358c258a816baed4c6997b59c2117578a1360498.
>
> Jerome actually pointed out why that stuff doesn't work in 2016:
> https://lists.freedesktop.org/archives/dri-devel/2016-March/103062.html
>
> Unfortunately the revert somehow got lost.
>
> Signed-off-by: Christian König <christian.koenig at amd.com>
> Fixes: 358c258a816baed4c6997b59c2117578a1360498

Fixes: 358c258a816b ("drm/amdgpu: allow write access to mapped userptrs")

Acked-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> index 3adaa4670103..331969b96a5a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
> @@ -433,10 +433,12 @@ int amdgpu_gem_userptr_ioctl(struct drm_device *dev, void *data,
>             AMDGPU_GEM_USERPTR_REGISTER))
>                 return -EINVAL;
>
> -       if (!(args->flags & AMDGPU_GEM_USERPTR_READONLY) &&
> -            !(args->flags & AMDGPU_GEM_USERPTR_REGISTER)) {
> +       if (!(args->flags & AMDGPU_GEM_USERPTR_READONLY) && (
> +            !(args->flags & AMDGPU_GEM_USERPTR_ANONONLY) ||
> +            !(args->flags & AMDGPU_GEM_USERPTR_REGISTER))) {
>
> -               /* if we want to write to it we must install a MMU notifier */
> +               /* if we want to write to it we must require anonymous
> +                  memory and install a MMU notifier */
>                 return -EACCES;
>         }
>
> --
> 2.34.1
>