[PATCH V2 4/5] mm/hugetlb: Add prot_modify_start/commit sequence for hugetlb update

From: Aneesh Kumar K.V
Date: Wed Nov 28 2018 - 09:35:21 EST


Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
---
include/linux/hugetlb.h | 18 ++++++++++++++++++
mm/hugetlb.c | 8 +++++---
2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 087fd5f48c91..e2a3b0c854eb 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -543,6 +543,24 @@ static inline void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr
set_huge_pte_at(mm, addr, ptep, pte);
}
#endif
+
+#ifndef huge_ptep_modify_prot_start
+static inline pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+}
+#endif
+
+#ifndef huge_ptep_modify_prot_commit
+static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t old_pte, pte_t pte)
+{
+ set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+}
+#endif
+
#else /* CONFIG_HUGETLB_PAGE */
struct hstate {};
#define alloc_huge_page(v, a, r) NULL
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7f2a28ab46d5..e5f5cda14f28 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4388,10 +4388,12 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
continue;
}
if (!huge_pte_none(pte)) {
- pte = huge_ptep_get_and_clear(mm, address, ptep);
- pte = pte_mkhuge(huge_pte_modify(pte, newprot));
+ pte_t old_pte;
+
+ old_pte = huge_ptep_modify_prot_start(vma, address, ptep);
+ pte = pte_mkhuge(huge_pte_modify(old_pte, newprot));
pte = arch_make_huge_pte(pte, vma, NULL, 0);
- set_huge_pte_at(mm, address, ptep, pte);
+ huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte);
pages++;
}
spin_unlock(ptl);
--
2.19.1