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mm, ksm: convert write_protect_page() to use page_vma_mapped_walk()
For consistency, it worth converting all page_check_address() to page_vma_mapped_walk(), so we could drop the former. Link: http://lkml.kernel.org/r/20170129173858.45174-9-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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parent
c7ab0d2fdc
commit
36eaff3364
34
mm/ksm.c
34
mm/ksm.c
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@ -856,33 +856,35 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
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pte_t *orig_pte)
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{
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struct mm_struct *mm = vma->vm_mm;
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unsigned long addr;
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pte_t *ptep;
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spinlock_t *ptl;
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struct page_vma_mapped_walk pvmw = {
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.page = page,
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.vma = vma,
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};
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int swapped;
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int err = -EFAULT;
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unsigned long mmun_start; /* For mmu_notifiers */
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unsigned long mmun_end; /* For mmu_notifiers */
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addr = page_address_in_vma(page, vma);
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if (addr == -EFAULT)
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pvmw.address = page_address_in_vma(page, vma);
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if (pvmw.address == -EFAULT)
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goto out;
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BUG_ON(PageTransCompound(page));
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mmun_start = addr;
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mmun_end = addr + PAGE_SIZE;
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mmun_start = pvmw.address;
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mmun_end = pvmw.address + PAGE_SIZE;
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mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
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ptep = page_check_address(page, mm, addr, &ptl, 0);
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if (!ptep)
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if (!page_vma_mapped_walk(&pvmw))
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goto out_mn;
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if (WARN_ONCE(!pvmw.pte, "Unexpected PMD mapping?"))
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goto out_unlock;
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if (pte_write(*ptep) || pte_dirty(*ptep)) {
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if (pte_write(*pvmw.pte) || pte_dirty(*pvmw.pte)) {
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pte_t entry;
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swapped = PageSwapCache(page);
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flush_cache_page(vma, addr, page_to_pfn(page));
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flush_cache_page(vma, pvmw.address, page_to_pfn(page));
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/*
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* Ok this is tricky, when get_user_pages_fast() run it doesn't
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* take any lock, therefore the check that we are going to make
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@ -892,25 +894,25 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
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* this assure us that no O_DIRECT can happen after the check
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* or in the middle of the check.
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*/
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entry = ptep_clear_flush_notify(vma, addr, ptep);
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entry = ptep_clear_flush_notify(vma, pvmw.address, pvmw.pte);
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/*
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* Check that no O_DIRECT or similar I/O is in progress on the
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* page
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*/
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if (page_mapcount(page) + 1 + swapped != page_count(page)) {
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set_pte_at(mm, addr, ptep, entry);
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set_pte_at(mm, pvmw.address, pvmw.pte, entry);
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goto out_unlock;
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}
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if (pte_dirty(entry))
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set_page_dirty(page);
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entry = pte_mkclean(pte_wrprotect(entry));
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set_pte_at_notify(mm, addr, ptep, entry);
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set_pte_at_notify(mm, pvmw.address, pvmw.pte, entry);
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}
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*orig_pte = *ptep;
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*orig_pte = *pvmw.pte;
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err = 0;
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out_unlock:
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pte_unmap_unlock(ptep, ptl);
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page_vma_mapped_walk_done(&pvmw);
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out_mn:
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mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
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out:
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