1 #include <linux/mm.h> 2 #include <linux/highmem.h> 3 #include <linux/sched.h> 4 #include <linux/hugetlb.h> 5 6 static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, 7 struct mm_walk *walk) 8 { 9 pte_t *pte; 10 int err = 0; 11 12 pte = pte_offset_map(pmd, addr); 13 for (;;) { 14 err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, walk); 15 if (err) 16 break; 17 addr += PAGE_SIZE; 18 if (addr == end) 19 break; 20 pte++; 21 } 22 23 pte_unmap(pte); 24 return err; 25 } 26 27 static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, 28 struct mm_walk *walk) 29 { 30 pmd_t *pmd; 31 unsigned long next; 32 int err = 0; 33 34 pmd = pmd_offset(pud, addr); 35 do { 36 next = pmd_addr_end(addr, end); 37 if (pmd_none_or_clear_bad(pmd)) { 38 if (walk->pte_hole) 39 err = walk->pte_hole(addr, next, walk); 40 if (err) 41 break; 42 continue; 43 } 44 if (walk->pmd_entry) 45 err = walk->pmd_entry(pmd, addr, next, walk); 46 if (!err && walk->pte_entry) 47 err = walk_pte_range(pmd, addr, next, walk); 48 if (err) 49 break; 50 } while (pmd++, addr = next, addr != end); 51 52 return err; 53 } 54 55 static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end, 56 struct mm_walk *walk) 57 { 58 pud_t *pud; 59 unsigned long next; 60 int err = 0; 61 62 pud = pud_offset(pgd, addr); 63 do { 64 next = pud_addr_end(addr, end); 65 if (pud_none_or_clear_bad(pud)) { 66 if (walk->pte_hole) 67 err = walk->pte_hole(addr, next, walk); 68 if (err) 69 break; 70 continue; 71 } 72 if (walk->pud_entry) 73 err = walk->pud_entry(pud, addr, next, walk); 74 if (!err && (walk->pmd_entry || walk->pte_entry)) 75 err = walk_pmd_range(pud, addr, next, walk); 76 if (err) 77 break; 78 } while (pud++, addr = next, addr != end); 79 80 return err; 81 } 82 83 /** 84 * walk_page_range - walk a memory map's page tables with a callback 85 * @mm: memory map to walk 86 * @addr: starting address 87 * @end: ending address 88 * @walk: set of callbacks to invoke for each level of the tree 89 * 90 * Recursively walk the page table for the memory area in a VMA, 91 * calling supplied callbacks. Callbacks are called in-order (first 92 * PGD, first PUD, first PMD, first PTE, second PTE... second PMD, 93 * etc.). If lower-level callbacks are omitted, walking depth is reduced. 94 * 95 * Each callback receives an entry pointer and the start and end of the 96 * associated range, and a copy of the original mm_walk for access to 97 * the ->private or ->mm fields. 98 * 99 * No locks are taken, but the bottom level iterator will map PTE 100 * directories from highmem if necessary. 101 * 102 * If any callback returns a non-zero value, the walk is aborted and 103 * the return value is propagated back to the caller. Otherwise 0 is returned. 104 */ 105 int walk_page_range(unsigned long addr, unsigned long end, 106 struct mm_walk *walk) 107 { 108 pgd_t *pgd; 109 unsigned long next; 110 int err = 0; 111 struct vm_area_struct *vma; 112 113 if (addr >= end) 114 return err; 115 116 if (!walk->mm) 117 return -EINVAL; 118 119 pgd = pgd_offset(walk->mm, addr); 120 do { 121 next = pgd_addr_end(addr, end); 122 123 /* 124 * handle hugetlb vma individually because pagetable walk for 125 * the hugetlb page is dependent on the architecture and 126 * we can't handled it in the same manner as non-huge pages. 127 */ 128 vma = find_vma(walk->mm, addr); 129 #ifdef CONFIG_HUGETLB_PAGE 130 if (vma && is_vm_hugetlb_page(vma)) { 131 pte_t *pte; 132 struct hstate *hs; 133 134 if (vma->vm_end < next) 135 next = vma->vm_end; 136 hs = hstate_vma(vma); 137 pte = huge_pte_offset(walk->mm, 138 addr & huge_page_mask(hs)); 139 if (pte && !huge_pte_none(huge_ptep_get(pte)) 140 && walk->hugetlb_entry) 141 err = walk->hugetlb_entry(pte, addr, 142 next, walk); 143 if (err) 144 break; 145 continue; 146 } 147 #endif 148 if (pgd_none_or_clear_bad(pgd)) { 149 if (walk->pte_hole) 150 err = walk->pte_hole(addr, next, walk); 151 if (err) 152 break; 153 pgd++; 154 continue; 155 } 156 if (walk->pgd_entry) 157 err = walk->pgd_entry(pgd, addr, next, walk); 158 if (!err && 159 (walk->pud_entry || walk->pmd_entry || walk->pte_entry)) 160 err = walk_pud_range(pgd, addr, next, walk); 161 if (err) 162 break; 163 pgd++; 164 } while (addr = next, addr != end); 165 166 return err; 167 } 168