Re: [PATCHv2 1/2] x86/mm: Do not allow non-MAP_FIXED mapping across DEFAULT_MAP_WINDOW border

From: Thomas Gleixner
Date: Wed Nov 15 2017 - 09:23:49 EST


On Wed, 15 Nov 2017, Kirill A. Shutemov wrote:
> On Wed, Nov 15, 2017 at 05:04:26PM +0300, Kirill A. Shutemov wrote:
> /* requesting a specific address */
> if (addr) {
> - addr = PAGE_ALIGN(addr);
> + addr &= PAGE_MASK;
> if (!mmap_address_hint_valid(addr, len))
> goto get_unmapped_area;
>
> diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
> index 92db903c3dad..00b296617ca4 100644
> --- a/arch/x86/mm/hugetlbpage.c
> +++ b/arch/x86/mm/hugetlbpage.c
> @@ -166,7 +166,7 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
> }
>
> if (addr) {
> - addr = ALIGN(addr, huge_page_size(h));
> + addr &= huge_page_mask(h);
> if (!mmap_address_hint_valid(addr, len))
> goto get_unmapped_area;

That should work. Care to pickup my variant, make the fixups and resend
along with the selftest which covers both normal and huge mappings?

Thanks,

tglx