On Tue, Oct 15, 2019 at 01:48:12PM -0700, Ralph Campbell wrote:
> +static bool hmm_range_needs_fault(unsigned long addr, unsigned long end,
> + const struct hmm_vma_walk *hmm_vma_walk)
This has a very similar name to hmm_range_need_fault(), and seems like
it does the same thing?
> +static int hmm_vma_walk_test(unsigned long start, unsigned long end,
> + struct mm_walk *walk)
> +{
> + struct hmm_vma_walk *hmm_vma_walk = walk->private;
> + struct hmm_range *range = hmm_vma_walk->range;
> + struct vm_area_struct *vma = walk->vma;
> +
> + /* If range is no longer valid, force retry. */
> + if (!range->valid)
> + return -EBUSY;
> +
> + /*
> + * Skip vma ranges that don't have struct page backing them or
> + * map I/O devices directly.
> + */
> + if (vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP))
> + return -EFAULT;
> +
> + /*
> + * If the vma does not allow read access, then assume that it does not
> + * allow write access either. HMM does not support architectures
> + * that allow write without read.
> + */
> + if (!(vma->vm_flags & VM_READ)) {
> + /*
> + * Check to see if a fault is requested for any page in the
> + * range.
> + */
> + if (hmm_range_needs_fault(start, end, hmm_vma_walk))
> + return -EFAULT;
Is this change to call hmm_range_needs_fault another bug fix?
Jason
