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@kiryl
Last active February 7, 2017 14:06
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diff --git a/mm/mprotect.c b/mm/mprotect.c
index f9c07f54dd62..187c14c001fd 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -33,34 +33,6 @@
#include "internal.h"
-/*
- * For a prot_numa update we only hold mmap_sem for read so there is a
- * potential race with faulting where a pmd was temporarily none. This
- * function checks for a transhuge pmd under the appropriate lock. It
- * returns a pte if it was successfully locked or NULL if it raced with
- * a transhuge insertion.
- */
-static pte_t *lock_pte_protection(struct vm_area_struct *vma, pmd_t *pmd,
- unsigned long addr, int prot_numa, spinlock_t **ptl)
-{
- pte_t *pte;
- spinlock_t *pmdl;
-
- /* !prot_numa is protected by mmap_sem held for write */
- if (!prot_numa)
- return pte_offset_map_lock(vma->vm_mm, pmd, addr, ptl);
-
- pmdl = pmd_lock(vma->vm_mm, pmd);
- if (unlikely(pmd_trans_huge(*pmd) || pmd_none(*pmd))) {
- spin_unlock(pmdl);
- return NULL;
- }
-
- pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, ptl);
- spin_unlock(pmdl);
- return pte;
-}
-
static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long addr, unsigned long end, pgprot_t newprot,
int dirty_accountable, int prot_numa)
@@ -71,7 +43,7 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long pages = 0;
int target_node = NUMA_NO_NODE;
- pte = lock_pte_protection(vma, pmd, addr, prot_numa, &ptl);
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
if (!pte)
return 0;
@@ -177,8 +149,6 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) {
if (next - addr != HPAGE_PMD_SIZE) {
__split_huge_pmd(vma, pmd, addr, false, NULL);
- if (pmd_trans_unstable(pmd))
- continue;
} else {
int nr_ptes = change_huge_pmd(vma, pmd, addr,
newprot, prot_numa);
@@ -195,6 +165,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
}
/* fall through, the trans huge pmd just split */
}
+ if (pmd_trans_unstable(pmd))
+ continue;
this_pages = change_pte_range(vma, pmd, addr, next, newprot,
dirty_accountable, prot_numa);
pages += this_pages;
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