Re: [PATCH v4 12/21] misc: open-dice: replace deprecated mmap hook with mmap_prepare

["Vlastimil Babka (SUSE)" <vbabka@kernel.org>]

On 3/20/26 23:39, Lorenzo Stoakes (Oracle) wrote:
> The f_op->mmap interface is deprecated, so update driver to use its
> successor, mmap_prepare.
> 
> The driver previously used vm_iomap_memory(), so this change replaces it
> with its mmap_prepare equivalent, mmap_action_simple_ioremap().
> 
> Reviewed-by: Suren Baghdasaryan <surenb@google.com>
> Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>

Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>

> ---
>  drivers/misc/open-dice.c | 19 +++++++++++--------
>  1 file changed, 11 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/misc/open-dice.c b/drivers/misc/open-dice.c
> index 24c29e0f00ef..45060fb4ea27 100644
> --- a/drivers/misc/open-dice.c
> +++ b/drivers/misc/open-dice.c
> @@ -86,29 +86,32 @@ static ssize_t open_dice_write(struct file *filp, const char __user *ptr,
>  /*
>   * Creates a mapping of the reserved memory region in user address space.
>   */
> -static int open_dice_mmap(struct file *filp, struct vm_area_struct *vma)
> +static int open_dice_mmap_prepare(struct vm_area_desc *desc)
>  {
> +	struct file *filp = desc->file;
>  	struct open_dice_drvdata *drvdata = to_open_dice_drvdata(filp);
>  
> -	if (vma->vm_flags & VM_MAYSHARE) {
> +	if (vma_desc_test(desc, VMA_MAYSHARE_BIT)) {
>  		/* Do not allow userspace to modify the underlying data. */
> -		if (vma->vm_flags & VM_WRITE)
> +		if (vma_desc_test(desc, VMA_WRITE_BIT))
>  			return -EPERM;
>  		/* Ensure userspace cannot acquire VM_WRITE later. */
> -		vm_flags_clear(vma, VM_MAYWRITE);
> +		vma_desc_clear_flags(desc, VMA_MAYWRITE_BIT);
>  	}
>  
>  	/* Create write-combine mapping so all clients observe a wipe. */
> -	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
> -	vm_flags_set(vma, VM_DONTCOPY | VM_DONTDUMP);
> -	return vm_iomap_memory(vma, drvdata->rmem->base, drvdata->rmem->size);
> +	desc->page_prot = pgprot_writecombine(desc->page_prot);
> +	vma_desc_set_flags(desc, VMA_DONTCOPY_BIT, VMA_DONTDUMP_BIT);
> +	mmap_action_simple_ioremap(desc, drvdata->rmem->base,
> +				   drvdata->rmem->size);
> +	return 0;
>  }
>  
>  static const struct file_operations open_dice_fops = {
>  	.owner = THIS_MODULE,
>  	.read = open_dice_read,
>  	.write = open_dice_write,
> -	.mmap = open_dice_mmap,
> +	.mmap_prepare = open_dice_mmap_prepare,
>  };
>  
>  static int __init open_dice_probe(struct platform_device *pdev)