On Tue, Jul 20, 2021 at 11:37:36PM +0800, kernel test robot wrote: > config: s390-randconfig-r023-20210716 (attached as .config) [...] > >> mm/hugetlb.c:5063:29: error: implicit declaration of function 'huge_pte_uffd_wp' [-Werror,-Wimplicit-function-declaration] > if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) && > ^ > 12 warnings and 1 error generated. I remember I raised this question once on why s390 redefines a lot of huge pte operations on its own even if they're defined the same in generic hugetlb.h.. I think there was a plan to rework that but definitely not landed yet. Will sqaush below into the patch "mm/hugetlb: Introduce huge pte version of uffd-wp helpers": ---8<--- diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h index 60f9241e5e4a..19c4b4431d27 100644 --- a/arch/s390/include/asm/hugetlb.h +++ b/arch/s390/include/asm/hugetlb.h @@ -115,6 +115,21 @@ static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot) return pte_modify(pte, newprot); } +static inline pte_t huge_pte_mkuffd_wp(pte_t pte) +{ + return pte; +} + +static inline pte_t huge_pte_clear_uffd_wp(pte_t pte) +{ + return pte; +} + +static inline int huge_pte_uffd_wp(pte_t pte) +{ + return 0; +} + static inline bool gigantic_page_runtime_supported(void) { return true; ---8<--- Thanks, -- Peter Xu