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 #ifdef CONFIG_HUGETLB_PAGE 84 static unsigned long hugetlb_entry_end(struct hstate *h, unsigned long addr, 85 unsigned long end) 86 { 87 unsigned long boundary = (addr & huge_page_mask(h)) + huge_page_size(h); 88 return boundary < end ? boundary : end; 89 } 90 91 static int walk_hugetlb_range(struct vm_area_struct *vma, 92 unsigned long addr, unsigned long end, 93 struct mm_walk *walk) 94 { 95 struct hstate *h = hstate_vma(vma); 96 unsigned long next; 97 unsigned long hmask = huge_page_mask(h); 98 pte_t *pte; 99 int err = 0; 100 101 do { 102 next = hugetlb_entry_end(h, addr, end); 103 pte = huge_pte_offset(walk->mm, addr & hmask); 104 if (pte && walk->hugetlb_entry) 105 err = walk->hugetlb_entry(pte, hmask, addr, next, walk); 106 if (err) 107 return err; 108 } while (addr = next, addr != end); 109 110 return 0; 111 } 112 #endif 113 114 /** 115 * walk_page_range - walk a memory map's page tables with a callback 116 * @mm: memory map to walk 117 * @addr: starting address 118 * @end: ending address 119 * @walk: set of callbacks to invoke for each level of the tree 120 * 121 * Recursively walk the page table for the memory area in a VMA, 122 * calling supplied callbacks. Callbacks are called in-order (first 123 * PGD, first PUD, first PMD, first PTE, second PTE... second PMD, 124 * etc.). If lower-level callbacks are omitted, walking depth is reduced. 125 * 126 * Each callback receives an entry pointer and the start and end of the 127 * associated range, and a copy of the original mm_walk for access to 128 * the ->private or ->mm fields. 129 * 130 * No locks are taken, but the bottom level iterator will map PTE 131 * directories from highmem if necessary. 132 * 133 * If any callback returns a non-zero value, the walk is aborted and 134 * the return value is propagated back to the caller. Otherwise 0 is returned. 135 */ 136 int walk_page_range(unsigned long addr, unsigned long end, 137 struct mm_walk *walk) 138 { 139 pgd_t *pgd; 140 unsigned long next; 141 int err = 0; 142 struct vm_area_struct *vma; 143 144 if (addr >= end) 145 return err; 146 147 if (!walk->mm) 148 return -EINVAL; 149 150 pgd = pgd_offset(walk->mm, addr); 151 do { 152 next = pgd_addr_end(addr, end); 153 154 /* 155 * handle hugetlb vma individually because pagetable walk for 156 * the hugetlb page is dependent on the architecture and 157 * we can't handled it in the same manner as non-huge pages. 158 */ 159 vma = find_vma(walk->mm, addr); 160 #ifdef CONFIG_HUGETLB_PAGE 161 if (vma && is_vm_hugetlb_page(vma)) { 162 if (vma->vm_end < next) 163 next = vma->vm_end; 164 /* 165 * Hugepage is very tightly coupled with vma, so 166 * walk through hugetlb entries within a given vma. 167 */ 168 err = walk_hugetlb_range(vma, addr, next, walk); 169 if (err) 170 break; 171 pgd = pgd_offset(walk->mm, next); 172 continue; 173 } 174 #endif 175 if (pgd_none_or_clear_bad(pgd)) { 176 if (walk->pte_hole) 177 err = walk->pte_hole(addr, next, walk); 178 if (err) 179 break; 180 pgd++; 181 continue; 182 } 183 if (walk->pgd_entry) 184 err = walk->pgd_entry(pgd, addr, next, walk); 185 if (!err && 186 (walk->pud_entry || walk->pmd_entry || walk->pte_entry)) 187 err = walk_pud_range(pgd, addr, next, walk); 188 if (err) 189 break; 190 pgd++; 191 } while (addr = next, addr != end); 192 193 return err; 194 } 195