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 split_huge_page_pmd(walk->mm, pmd); 38 if (pmd_none_or_clear_bad(pmd)) { 39 if (walk->pte_hole) 40 err = walk->pte_hole(addr, next, walk); 41 if (err) 42 break; 43 continue; 44 } 45 if (walk->pmd_entry) 46 err = walk->pmd_entry(pmd, addr, next, walk); 47 if (!err && walk->pte_entry) 48 err = walk_pte_range(pmd, addr, next, walk); 49 if (err) 50 break; 51 } while (pmd++, addr = next, addr != end); 52 53 return err; 54 } 55 56 static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end, 57 struct mm_walk *walk) 58 { 59 pud_t *pud; 60 unsigned long next; 61 int err = 0; 62 63 pud = pud_offset(pgd, addr); 64 do { 65 next = pud_addr_end(addr, end); 66 if (pud_none_or_clear_bad(pud)) { 67 if (walk->pte_hole) 68 err = walk->pte_hole(addr, next, walk); 69 if (err) 70 break; 71 continue; 72 } 73 if (walk->pud_entry) 74 err = walk->pud_entry(pud, addr, next, walk); 75 if (!err && (walk->pmd_entry || walk->pte_entry)) 76 err = walk_pmd_range(pud, addr, next, walk); 77 if (err) 78 break; 79 } while (pud++, addr = next, addr != end); 80 81 return err; 82 } 83 84 #ifdef CONFIG_HUGETLB_PAGE 85 static unsigned long hugetlb_entry_end(struct hstate *h, unsigned long addr, 86 unsigned long end) 87 { 88 unsigned long boundary = (addr & huge_page_mask(h)) + huge_page_size(h); 89 return boundary < end ? boundary : end; 90 } 91 92 static int walk_hugetlb_range(struct vm_area_struct *vma, 93 unsigned long addr, unsigned long end, 94 struct mm_walk *walk) 95 { 96 struct hstate *h = hstate_vma(vma); 97 unsigned long next; 98 unsigned long hmask = huge_page_mask(h); 99 pte_t *pte; 100 int err = 0; 101 102 do { 103 next = hugetlb_entry_end(h, addr, end); 104 pte = huge_pte_offset(walk->mm, addr & hmask); 105 if (pte && walk->hugetlb_entry) 106 err = walk->hugetlb_entry(pte, hmask, addr, next, walk); 107 if (err) 108 return err; 109 } while (addr = next, addr != end); 110 111 return 0; 112 } 113 #endif 114 115 /** 116 * walk_page_range - walk a memory map's page tables with a callback 117 * @mm: memory map to walk 118 * @addr: starting address 119 * @end: ending address 120 * @walk: set of callbacks to invoke for each level of the tree 121 * 122 * Recursively walk the page table for the memory area in a VMA, 123 * calling supplied callbacks. Callbacks are called in-order (first 124 * PGD, first PUD, first PMD, first PTE, second PTE... second PMD, 125 * etc.). If lower-level callbacks are omitted, walking depth is reduced. 126 * 127 * Each callback receives an entry pointer and the start and end of the 128 * associated range, and a copy of the original mm_walk for access to 129 * the ->private or ->mm fields. 130 * 131 * No locks are taken, but the bottom level iterator will map PTE 132 * directories from highmem if necessary. 133 * 134 * If any callback returns a non-zero value, the walk is aborted and 135 * the return value is propagated back to the caller. Otherwise 0 is returned. 136 */ 137 int walk_page_range(unsigned long addr, unsigned long end, 138 struct mm_walk *walk) 139 { 140 pgd_t *pgd; 141 unsigned long next; 142 int err = 0; 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 struct vm_area_struct *uninitialized_var(vma); 153 154 next = pgd_addr_end(addr, end); 155 156 #ifdef CONFIG_HUGETLB_PAGE 157 /* 158 * handle hugetlb vma individually because pagetable walk for 159 * the hugetlb page is dependent on the architecture and 160 * we can't handled it in the same manner as non-huge pages. 161 */ 162 vma = find_vma(walk->mm, addr); 163 if (vma && is_vm_hugetlb_page(vma)) { 164 if (vma->vm_end < next) 165 next = vma->vm_end; 166 /* 167 * Hugepage is very tightly coupled with vma, so 168 * walk through hugetlb entries within a given vma. 169 */ 170 err = walk_hugetlb_range(vma, addr, next, walk); 171 if (err) 172 break; 173 pgd = pgd_offset(walk->mm, next); 174 continue; 175 } 176 #endif 177 if (pgd_none_or_clear_bad(pgd)) { 178 if (walk->pte_hole) 179 err = walk->pte_hole(addr, next, walk); 180 if (err) 181 break; 182 pgd++; 183 continue; 184 } 185 if (walk->pgd_entry) 186 err = walk->pgd_entry(pgd, addr, next, walk); 187 if (!err && 188 (walk->pud_entry || walk->pmd_entry || walk->pte_entry)) 189 err = walk_pud_range(pgd, addr, next, walk); 190 if (err) 191 break; 192 pgd++; 193 } while (addr = next, addr != end); 194 195 return err; 196 } 197