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e6473092 MM |
1 | #include <linux/mm.h> |
2 | #include <linux/highmem.h> | |
3 | #include <linux/sched.h> | |
4 | ||
5 | static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, | |
6 | const struct mm_walk *walk, void *private) | |
7 | { | |
8 | pte_t *pte; | |
9 | int err = 0; | |
10 | ||
11 | pte = pte_offset_map(pmd, addr); | |
12 | do { | |
13 | err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, private); | |
14 | if (err) | |
15 | break; | |
16 | } while (pte++, addr += PAGE_SIZE, addr != end); | |
17 | ||
18 | pte_unmap(pte); | |
19 | return err; | |
20 | } | |
21 | ||
22 | static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, | |
23 | const struct mm_walk *walk, void *private) | |
24 | { | |
25 | pmd_t *pmd; | |
26 | unsigned long next; | |
27 | int err = 0; | |
28 | ||
29 | pmd = pmd_offset(pud, addr); | |
30 | do { | |
31 | next = pmd_addr_end(addr, end); | |
32 | if (pmd_none_or_clear_bad(pmd)) { | |
33 | if (walk->pte_hole) | |
34 | err = walk->pte_hole(addr, next, private); | |
35 | if (err) | |
36 | break; | |
37 | continue; | |
38 | } | |
39 | if (walk->pmd_entry) | |
40 | err = walk->pmd_entry(pmd, addr, next, private); | |
41 | if (!err && walk->pte_entry) | |
42 | err = walk_pte_range(pmd, addr, next, walk, private); | |
43 | if (err) | |
44 | break; | |
45 | } while (pmd++, addr = next, addr != end); | |
46 | ||
47 | return err; | |
48 | } | |
49 | ||
50 | static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end, | |
51 | const struct mm_walk *walk, void *private) | |
52 | { | |
53 | pud_t *pud; | |
54 | unsigned long next; | |
55 | int err = 0; | |
56 | ||
57 | pud = pud_offset(pgd, addr); | |
58 | do { | |
59 | next = pud_addr_end(addr, end); | |
60 | if (pud_none_or_clear_bad(pud)) { | |
61 | if (walk->pte_hole) | |
62 | err = walk->pte_hole(addr, next, private); | |
63 | if (err) | |
64 | break; | |
65 | continue; | |
66 | } | |
67 | if (walk->pud_entry) | |
68 | err = walk->pud_entry(pud, addr, next, private); | |
69 | if (!err && (walk->pmd_entry || walk->pte_entry)) | |
70 | err = walk_pmd_range(pud, addr, next, walk, private); | |
71 | if (err) | |
72 | break; | |
73 | } while (pud++, addr = next, addr != end); | |
74 | ||
75 | return err; | |
76 | } | |
77 | ||
78 | /** | |
79 | * walk_page_range - walk a memory map's page tables with a callback | |
80 | * @mm - memory map to walk | |
81 | * @addr - starting address | |
82 | * @end - ending address | |
83 | * @walk - set of callbacks to invoke for each level of the tree | |
84 | * @private - private data passed to the callback function | |
85 | * | |
86 | * Recursively walk the page table for the memory area in a VMA, | |
87 | * calling supplied callbacks. Callbacks are called in-order (first | |
88 | * PGD, first PUD, first PMD, first PTE, second PTE... second PMD, | |
89 | * etc.). If lower-level callbacks are omitted, walking depth is reduced. | |
90 | * | |
91 | * Each callback receives an entry pointer, the start and end of the | |
92 | * associated range, and a caller-supplied private data pointer. | |
93 | * | |
94 | * No locks are taken, but the bottom level iterator will map PTE | |
95 | * directories from highmem if necessary. | |
96 | * | |
97 | * If any callback returns a non-zero value, the walk is aborted and | |
98 | * the return value is propagated back to the caller. Otherwise 0 is returned. | |
99 | */ | |
100 | int walk_page_range(const struct mm_struct *mm, | |
101 | unsigned long addr, unsigned long end, | |
102 | const struct mm_walk *walk, void *private) | |
103 | { | |
104 | pgd_t *pgd; | |
105 | unsigned long next; | |
106 | int err = 0; | |
107 | ||
108 | if (addr >= end) | |
109 | return err; | |
110 | ||
111 | pgd = pgd_offset(mm, addr); | |
112 | do { | |
113 | next = pgd_addr_end(addr, end); | |
114 | if (pgd_none_or_clear_bad(pgd)) { | |
115 | if (walk->pte_hole) | |
116 | err = walk->pte_hole(addr, next, private); | |
117 | if (err) | |
118 | break; | |
119 | continue; | |
120 | } | |
121 | if (walk->pgd_entry) | |
122 | err = walk->pgd_entry(pgd, addr, next, private); | |
123 | if (!err && | |
124 | (walk->pud_entry || walk->pmd_entry || walk->pte_entry)) | |
125 | err = walk_pud_range(pgd, addr, next, walk, private); | |
126 | if (err) | |
127 | break; | |
128 | } while (pgd++, addr = next, addr != end); | |
129 | ||
130 | return err; | |
131 | } |