* Vlastimil Babka <vbabka@xxxxxxx> [220119 12:39]:
> On 12/1/21 15:30, Liam Howlett wrote:
> > From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
>
> Empty message.
>
> > Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> > ---
> > mm/gup.c | 7 +++----
> > 1 file changed, 3 insertions(+), 4 deletions(-)
> >
> > diff --git a/mm/gup.c b/mm/gup.c
> > index 2c51e9748a6a..60892e5df6a2 100644
> > --- a/mm/gup.c
> > +++ b/mm/gup.c
> > @@ -1570,7 +1570,6 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
> > long ret = 0;
> >
> > end = start + len;
> > -
> > for (nstart = start; nstart < end; nstart = nend) {
> > /*
> > * We want to fault in pages for [nstart; end) address range.
> > @@ -1579,10 +1578,10 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
> > if (!locked) {
> > locked = 1;
> > mmap_read_lock(mm);
> > - vma = find_vma(mm, nstart);
> > + vma = find_vma_intersection(mm, start, end);
>
> Is it ok to use start instead of nstart? At least theoretically,
> populate_vma_page_range() called later can reset locked to 0, so !locked
> doesn't guarantee we are in the first iteration?
It is not okay to use start instead of nstart, I will fix this patch.
>
> > } else if (nstart >= vma->vm_end)
> > - vma = vma->vm_next;
> > - if (!vma || vma->vm_start >= end)
> > + vma = find_vma(mm, vma->vm_end);
> > + if (!vma)
> > break;
> > /*
> > * Set [nstart; nend) to intersection of desired address
>
