8b1f312461
Move the ZERO_PAGE remapping complexity to the move_pte macro in asm-generic, have it conditionally depend on __HAVE_ARCH_MULTIPLE_ZERO_PAGE, which gets defined for MIPS. For architectures without __HAVE_ARCH_MULTIPLE_ZERO_PAGE, move_pte becomes a noop. From: Hugh Dickins <hugh@veritas.com> Fix nasty little bug we've missed in Nick's mremap move ZERO_PAGE patch. The "pte" at that point may be a swap entry or a pte_file entry: we must check pte_present before perhaps corrupting such an entry. Patch below against 2.6.14-rc2-mm1, but the same bug is in 2.6.14-rc2's mm/mremap.c, and more dangerous there since it's affecting all arches: I think the safest course is to send Nick's patch and Yoichi's build fix and this fix (build tested) on to Linus - so only MIPS can be affected. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
244 lines
6.3 KiB
C
244 lines
6.3 KiB
C
#ifndef _ASM_GENERIC_PGTABLE_H
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#define _ASM_GENERIC_PGTABLE_H
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#ifndef __HAVE_ARCH_PTEP_ESTABLISH
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/*
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* Establish a new mapping:
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* - flush the old one
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* - update the page tables
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* - inform the TLB about the new one
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*
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* We hold the mm semaphore for reading and vma->vm_mm->page_table_lock.
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*
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* Note: the old pte is known to not be writable, so we don't need to
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* worry about dirty bits etc getting lost.
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*/
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#ifndef __HAVE_ARCH_SET_PTE_ATOMIC
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#define ptep_establish(__vma, __address, __ptep, __entry) \
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do { \
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set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
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flush_tlb_page(__vma, __address); \
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} while (0)
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#else /* __HAVE_ARCH_SET_PTE_ATOMIC */
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#define ptep_establish(__vma, __address, __ptep, __entry) \
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do { \
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set_pte_atomic(__ptep, __entry); \
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flush_tlb_page(__vma, __address); \
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} while (0)
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#endif /* __HAVE_ARCH_SET_PTE_ATOMIC */
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#endif
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#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
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/*
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* Largely same as above, but only sets the access flags (dirty,
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* accessed, and writable). Furthermore, we know it always gets set
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* to a "more permissive" setting, which allows most architectures
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* to optimize this.
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*/
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#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
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do { \
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set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
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flush_tlb_page(__vma, __address); \
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} while (0)
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#endif
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#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
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#define ptep_test_and_clear_young(__vma, __address, __ptep) \
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({ \
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pte_t __pte = *(__ptep); \
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int r = 1; \
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if (!pte_young(__pte)) \
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r = 0; \
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else \
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set_pte_at((__vma)->vm_mm, (__address), \
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(__ptep), pte_mkold(__pte)); \
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r; \
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})
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#endif
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#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
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#define ptep_clear_flush_young(__vma, __address, __ptep) \
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({ \
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int __young; \
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__young = ptep_test_and_clear_young(__vma, __address, __ptep); \
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if (__young) \
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flush_tlb_page(__vma, __address); \
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__young; \
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})
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#endif
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#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
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#define ptep_test_and_clear_dirty(__vma, __address, __ptep) \
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({ \
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pte_t __pte = *__ptep; \
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int r = 1; \
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if (!pte_dirty(__pte)) \
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r = 0; \
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else \
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set_pte_at((__vma)->vm_mm, (__address), (__ptep), \
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pte_mkclean(__pte)); \
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r; \
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})
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#endif
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#ifndef __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
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#define ptep_clear_flush_dirty(__vma, __address, __ptep) \
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({ \
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int __dirty; \
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__dirty = ptep_test_and_clear_dirty(__vma, __address, __ptep); \
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if (__dirty) \
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flush_tlb_page(__vma, __address); \
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__dirty; \
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})
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#endif
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#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
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#define ptep_get_and_clear(__mm, __address, __ptep) \
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({ \
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pte_t __pte = *(__ptep); \
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pte_clear((__mm), (__address), (__ptep)); \
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__pte; \
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})
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#endif
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#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
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#define ptep_get_and_clear_full(__mm, __address, __ptep, __full) \
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({ \
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pte_t __pte; \
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__pte = ptep_get_and_clear((__mm), (__address), (__ptep)); \
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__pte; \
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})
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#endif
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#ifndef __HAVE_ARCH_PTE_CLEAR_FULL
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#define pte_clear_full(__mm, __address, __ptep, __full) \
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do { \
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pte_clear((__mm), (__address), (__ptep)); \
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} while (0)
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#endif
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#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
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#define ptep_clear_flush(__vma, __address, __ptep) \
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({ \
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pte_t __pte; \
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__pte = ptep_get_and_clear((__vma)->vm_mm, __address, __ptep); \
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flush_tlb_page(__vma, __address); \
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__pte; \
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})
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#endif
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#ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
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static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
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{
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pte_t old_pte = *ptep;
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set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
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}
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#endif
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#ifndef __HAVE_ARCH_PTE_SAME
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#define pte_same(A,B) (pte_val(A) == pte_val(B))
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#endif
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#ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
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#define page_test_and_clear_dirty(page) (0)
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#define pte_maybe_dirty(pte) pte_dirty(pte)
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#else
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#define pte_maybe_dirty(pte) (1)
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#endif
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#ifndef __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
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#define page_test_and_clear_young(page) (0)
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#endif
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#ifndef __HAVE_ARCH_PGD_OFFSET_GATE
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#define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
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#endif
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#ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
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#define lazy_mmu_prot_update(pte) do { } while (0)
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#endif
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#ifndef __HAVE_ARCH_MULTIPLE_ZERO_PAGE
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#define move_pte(pte, prot, old_addr, new_addr) (pte)
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#else
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#define move_pte(pte, prot, old_addr, new_addr) \
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({ \
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pte_t newpte = (pte); \
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if (pte_present(pte) && pfn_valid(pte_pfn(pte)) && \
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pte_page(pte) == ZERO_PAGE(old_addr)) \
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newpte = mk_pte(ZERO_PAGE(new_addr), (prot)); \
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newpte; \
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})
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#endif
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/*
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* When walking page tables, get the address of the next boundary,
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* or the end address of the range if that comes earlier. Although no
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* vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
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*/
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#define pgd_addr_end(addr, end) \
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({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \
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(__boundary - 1 < (end) - 1)? __boundary: (end); \
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})
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#ifndef pud_addr_end
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#define pud_addr_end(addr, end) \
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({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \
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(__boundary - 1 < (end) - 1)? __boundary: (end); \
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})
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#endif
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#ifndef pmd_addr_end
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#define pmd_addr_end(addr, end) \
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({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
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(__boundary - 1 < (end) - 1)? __boundary: (end); \
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})
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#endif
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#ifndef __ASSEMBLY__
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/*
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* When walking page tables, we usually want to skip any p?d_none entries;
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* and any p?d_bad entries - reporting the error before resetting to none.
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* Do the tests inline, but report and clear the bad entry in mm/memory.c.
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*/
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void pgd_clear_bad(pgd_t *);
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void pud_clear_bad(pud_t *);
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void pmd_clear_bad(pmd_t *);
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static inline int pgd_none_or_clear_bad(pgd_t *pgd)
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{
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if (pgd_none(*pgd))
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return 1;
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if (unlikely(pgd_bad(*pgd))) {
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pgd_clear_bad(pgd);
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return 1;
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}
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return 0;
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}
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static inline int pud_none_or_clear_bad(pud_t *pud)
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{
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if (pud_none(*pud))
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return 1;
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if (unlikely(pud_bad(*pud))) {
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pud_clear_bad(pud);
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return 1;
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}
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return 0;
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}
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static inline int pmd_none_or_clear_bad(pmd_t *pmd)
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{
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if (pmd_none(*pmd))
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return 1;
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if (unlikely(pmd_bad(*pmd))) {
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pmd_clear_bad(pmd);
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return 1;
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}
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return 0;
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}
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#endif /* !__ASSEMBLY__ */
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#endif /* _ASM_GENERIC_PGTABLE_H */
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