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-rw-r--r--mm/ksm.c34
1 files changed, 18 insertions, 16 deletions
diff --git a/mm/ksm.c b/mm/ksm.c
index 28bc5ab2b979..8960f6ecbc12 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -856,33 +856,35 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
pte_t *orig_pte)
{
struct mm_struct *mm = vma->vm_mm;
- unsigned long addr;
- pte_t *ptep;
- spinlock_t *ptl;
+ struct page_vma_mapped_walk pvmw = {
+ .page = page,
+ .vma = vma,
+ };
int swapped;
int err = -EFAULT;
unsigned long mmun_start; /* For mmu_notifiers */
unsigned long mmun_end; /* For mmu_notifiers */
- addr = page_address_in_vma(page, vma);
- if (addr == -EFAULT)
+ pvmw.address = page_address_in_vma(page, vma);
+ if (pvmw.address == -EFAULT)
goto out;
BUG_ON(PageTransCompound(page));
- mmun_start = addr;
- mmun_end = addr + PAGE_SIZE;
+ mmun_start = pvmw.address;
+ mmun_end = pvmw.address + PAGE_SIZE;
mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
- ptep = page_check_address(page, mm, addr, &ptl, 0);
- if (!ptep)
+ if (!page_vma_mapped_walk(&pvmw))
goto out_mn;
+ if (WARN_ONCE(!pvmw.pte, "Unexpected PMD mapping?"))
+ goto out_unlock;
- if (pte_write(*ptep) || pte_dirty(*ptep)) {
+ if (pte_write(*pvmw.pte) || pte_dirty(*pvmw.pte)) {
pte_t entry;
swapped = PageSwapCache(page);
- flush_cache_page(vma, addr, page_to_pfn(page));
+ flush_cache_page(vma, pvmw.address, page_to_pfn(page));
/*
* Ok this is tricky, when get_user_pages_fast() run it doesn't
* take any lock, therefore the check that we are going to make
@@ -892,25 +894,25 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
* this assure us that no O_DIRECT can happen after the check
* or in the middle of the check.
*/
- entry = ptep_clear_flush_notify(vma, addr, ptep);
+ entry = ptep_clear_flush_notify(vma, pvmw.address, pvmw.pte);
/*
* Check that no O_DIRECT or similar I/O is in progress on the
* page
*/
if (page_mapcount(page) + 1 + swapped != page_count(page)) {
- set_pte_at(mm, addr, ptep, entry);
+ set_pte_at(mm, pvmw.address, pvmw.pte, entry);
goto out_unlock;
}
if (pte_dirty(entry))
set_page_dirty(page);
entry = pte_mkclean(pte_wrprotect(entry));
- set_pte_at_notify(mm, addr, ptep, entry);
+ set_pte_at_notify(mm, pvmw.address, pvmw.pte, entry);
}
- *orig_pte = *ptep;
+ *orig_pte = *pvmw.pte;
err = 0;
out_unlock:
- pte_unmap_unlock(ptep, ptl);
+ page_vma_mapped_walk_done(&pvmw);
out_mn:
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
out:
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