On Tue, Mar 05, 2024 at 12:37:46PM +0800, peterx@xxxxxxxxxx wrote:
> From: Peter Xu <peterx@xxxxxxxxxx>
>
> There is an old trick in shadow_mapped() to use pXd_bad() to detect huge
> pages. After commit 93fab1b22ef7 ("mm: add generic p?d_leaf() macros") we
> have a global API for huge mappings. Use that to replace the trick.
>
> Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
> Cc: Alexander Potapenko <glider@xxxxxxxxxx>
> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
> Cc: kasan-dev@xxxxxxxxxxxxxxxx
> Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Reviewed-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
> ---
> mm/kasan/shadow.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
> index 9ef84f31833f..d6210ca48dda 100644
> --- a/mm/kasan/shadow.c
> +++ b/mm/kasan/shadow.c
> @@ -199,19 +199,12 @@ static bool shadow_mapped(unsigned long addr)
> pud = pud_offset(p4d, addr);
> if (pud_none(*pud))
> return false;
> -
> - /*
> - * We can't use pud_large() or pud_huge(), the first one is
> - * arch-specific, the last one depends on HUGETLB_PAGE. So let's abuse
> - * pud_bad(), if pud is bad then it's bad because it's huge.
> - */
> - if (pud_bad(*pud))
> + if (pud_leaf(*pud))
> return true;
> pmd = pmd_offset(pud, addr);
> if (pmd_none(*pmd))
> return false;
> -
> - if (pmd_bad(*pmd))
> + if (pmd_leaf(*pmd))
> return true;
> pte = pte_offset_kernel(pmd, addr);
> return !pte_none(ptep_get(pte));
> --
> 2.44.0
>
>
--
Sincerely yours,
Mike.
