 0b0968a3e6
			
		
	
	
	0b0968a3e6
	
	
	
		
			
			If we move a mapping from one virtual address to another, and this changes the virtual color of the mapping to those pages, we can see corrupt data due to D-cache aliasing. Check for and deal with this by overriding the move_pte() macro. Set things up so that other platforms can cleanly override the move_pte() macro too. Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			235 lines
		
	
	
	
		
			6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			235 lines
		
	
	
	
		
			6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef _ASM_GENERIC_PGTABLE_H
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| #define _ASM_GENERIC_PGTABLE_H
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| 
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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 the pte 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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
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| struct mm_struct;
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| #ifndef __HAVE_ARCH_MOVE_PTE
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| #define move_pte(pte, prot, old_addr, new_addr)	(pte)
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| #endif
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| #endif /* _ASM_GENERIC_PGTABLE_H */
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