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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 | } |