[PATCH 03/16] mm: add vma_desc_size(), vma_desc_pages() helpers

[Lorenzo Stoakes]

On Mon, Sep 08, 2025 at 09:51:01AM -0300, Jason Gunthorpe wrote:
> On Mon, Sep 08, 2025 at 12:10:34PM +0100, Lorenzo Stoakes wrote:
> >  static int secretmem_mmap_prepare(struct vm_area_desc *desc)
> >  {
> > -	const unsigned long len = desc->end - desc->start;
> > +	const unsigned long len = vma_desc_size(desc);
> >
> >  	if ((desc->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
> >  		return -EINVAL;
>
> I wonder if we should have some helper for this shared check too, it
> is a bit tricky with the two flags. Forced-shared checks are pretty
> common.

Sure can add.

>
> vma_desc_must_be_shared(desc) ?

Maybe _could_be_shared()?

>
> Also 'must not be exec' is common too.

Right, will have a look! :)

>
> Jason