On Tue, 13 Jul 2021 13:29:20 -0700 Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote: > On 7/13/21 8:24 AM, Joao Martins wrote: > > > The syzbot repro no longer reproduces after this patch. Additionally, ran > > the libhugetlbfs tests (which were passing without this), gup_test and an > > extra gup_test extension that take an offset to exercise gup() starting > > address not being page aligned. > > --- > > mm/hugetlb.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > > index 924553aa8f78..dfc940d5221d 100644 > > --- a/mm/hugetlb.c > > +++ b/mm/hugetlb.c > > @@ -5440,8 +5440,9 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, > > continue; > > } > > > > - refs = min3(pages_per_huge_page(h) - pfn_offset, > > - (vma->vm_end - vaddr) >> PAGE_SHIFT, remainder); > > + /* vaddr may not be aligned to PAGE_SIZE */ > > + refs = min3(pages_per_huge_page(h) - pfn_offset, remainder, > > + (vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT); > > > > if (pages || vmas) > > record_subpages_vmas(mem_map_offset(page, pfn_offset), > > > > Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> I'll add cc:stable to this.
