On Wed 22-03-17 10:09:43, Jiri Slaby wrote:
[...]
> @@ -1245,6 +1254,10 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
>
> page = pmd_page(*pmd);
> VM_BUG_ON(!PageHead(page));
> +
> + if (flags & FOLL_WRITE && !can_follow_write_pmd(*pmd, page, flags))
> + goto out;
> +
> if (flags & FOLL_TOUCH) {
> pmd_t _pmd;
> /*
I have just noticed that this patch is not correct fo 3.12 because we
should return NULL rather than the page in this case. 3.2 is wrong as
well AFAICS.
--
Michal Hocko
SUSE Labs
