From 9386fac34c7cbe39013410b01348e284652ca1cf Mon Sep 17 00:00:00 2001 From: Punit Agrawal Date: Thu, 6 Jul 2017 15:39:46 -0700 Subject: [PATCH] mm/hugetlb: allow architectures to override huge_pte_clear() When unmapping a hugepage range, huge_pte_clear() is used to clear the page table entries that are marked as not present. huge_pte_clear() internally just ends up calling pte_clear() which does not correctly deal with hugepages consisting of contiguous page table entries. Add a size argument to address this issue and allow architectures to override huge_pte_clear() by wrapping it in a #ifndef block. Update s390 implementation with the size parameter as well. Note that the change only affects huge_pte_clear() - the other generic hugetlb functions don't need any change. Link: http://lkml.kernel.org/r/20170522162555.4313-1-punit.agrawal@arm.com Signed-off-by: Punit Agrawal Acked-by: Martin Schwidefsky [s390 bits] Cc: Heiko Carstens Cc: Arnd Bergmann Cc: "Aneesh Kumar K.V" Cc: Mike Kravetz Cc: Catalin Marinas Cc: Will Deacon Cc: Naoya Horiguchi Cc: "Kirill A. Shutemov" Cc: Steve Capper Cc: Mark Rutland Cc: Hillf Danton Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/include/asm/hugetlb.h | 2 +- include/asm-generic/hugetlb.h | 4 +++- mm/hugetlb.c | 2 +- 3 files changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h index 89057b2..d95869c 100644 --- a/arch/s390/include/asm/hugetlb.h +++ b/arch/s390/include/asm/hugetlb.h @@ -39,7 +39,7 @@ static inline int prepare_hugepage_range(struct file *file, #define arch_clear_hugepage_flags(page) do { } while (0) static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr, - pte_t *ptep) + pte_t *ptep, unsigned long sz) { if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) pte_val(*ptep) = _REGION3_ENTRY_EMPTY; diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h index 99b490b..540354f 100644 --- a/include/asm-generic/hugetlb.h +++ b/include/asm-generic/hugetlb.h @@ -31,10 +31,12 @@ static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot) return pte_modify(pte, newprot); } +#ifndef huge_pte_clear static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr, - pte_t *ptep) + pte_t *ptep, unsigned long sz) { pte_clear(mm, addr, ptep); } +#endif #endif /* _ASM_GENERIC_HUGETLB_H */ diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 0753455323..3dbe3e2 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3351,7 +3351,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, * unmapped and its refcount is dropped, so just clear pte here. */ if (unlikely(!pte_present(pte))) { - huge_pte_clear(mm, address, ptep); + huge_pte_clear(mm, address, ptep, sz); spin_unlock(ptl); continue; } -- 2.7.4