Re: [PATCH] drm/panthor: check bo offset alignment in vm bind

[Boris Brezillon <boris.brezillon@collabora.com>]

On Thu, 28 Aug 2025 13:01:16 -0700
Chia-I Wu <olvaffe@gmail.com> wrote:

> Fail early from panthor_vm_bind_prepare_op_ctx instead of late from
> ops->map_pages.
> 
> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
> ---
>  drivers/gpu/drm/panthor/panthor_mmu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
> index bad720f23eb70..6dec4354e3789 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -1222,7 +1222,7 @@ static int panthor_vm_prepare_map_op_ctx(struct panthor_vm_op_ctx *op_ctx,
>  	    (flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) != DRM_PANTHOR_VM_BIND_OP_TYPE_MAP)
>  		return -EINVAL;
>  
> -	/* Make sure the VA and size are aligned and in-bounds. */
> +	/* Make sure the VA and size are in-bounds. */
>  	if (size > bo->base.base.size || offset > bo->base.base.size - size)
>  		return -EINVAL;
>  
> @@ -2447,7 +2447,7 @@ panthor_vm_bind_prepare_op_ctx(struct drm_file *file,
>  	int ret;
>  
>  	/* Aligned on page size. */
> -	if (!IS_ALIGNED(op->va | op->size, vm_pgsz))
> +	if (!IS_ALIGNED(op->va | op->size | op->bo_offset, vm_pgsz))
>  		return -EINVAL;

Now that I look at this, I think we'd be better moving this alignment
check to panthor_vm_prepare_[un]map_op_ctx() to cover the in-kernel
users.

>  
>  	switch (op->flags & DRM_PANTHOR_VM_BIND_OP_TYPE_MASK) {