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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, | |
2165009b | 6 | struct mm_walk *walk) |
e6473092 MM |
7 | { |
8 | pte_t *pte; | |
9 | int err = 0; | |
10 | ||
11 | pte = pte_offset_map(pmd, addr); | |
556637cd | 12 | for (;;) { |
2165009b | 13 | err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, walk); |
e6473092 MM |
14 | if (err) |
15 | break; | |
556637cd JW |
16 | addr += PAGE_SIZE; |
17 | if (addr == end) | |
18 | break; | |
19 | pte++; | |
20 | } | |
e6473092 MM |
21 | |
22 | pte_unmap(pte); | |
23 | return err; | |
24 | } | |
25 | ||
26 | static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, | |
2165009b | 27 | struct mm_walk *walk) |
e6473092 MM |
28 | { |
29 | pmd_t *pmd; | |
30 | unsigned long next; | |
31 | int err = 0; | |
32 | ||
33 | pmd = pmd_offset(pud, addr); | |
34 | do { | |
35 | next = pmd_addr_end(addr, end); | |
36 | if (pmd_none_or_clear_bad(pmd)) { | |
37 | if (walk->pte_hole) | |
2165009b | 38 | err = walk->pte_hole(addr, next, walk); |
e6473092 MM |
39 | if (err) |
40 | break; | |
41 | continue; | |
42 | } | |
43 | if (walk->pmd_entry) | |
2165009b | 44 | err = walk->pmd_entry(pmd, addr, next, walk); |
e6473092 | 45 | if (!err && walk->pte_entry) |
2165009b | 46 | err = walk_pte_range(pmd, addr, next, walk); |
e6473092 MM |
47 | if (err) |
48 | break; | |
49 | } while (pmd++, addr = next, addr != end); | |
50 | ||
51 | return err; | |
52 | } | |
53 | ||
54 | static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end, | |
2165009b | 55 | struct mm_walk *walk) |
e6473092 MM |
56 | { |
57 | pud_t *pud; | |
58 | unsigned long next; | |
59 | int err = 0; | |
60 | ||
61 | pud = pud_offset(pgd, addr); | |
62 | do { | |
63 | next = pud_addr_end(addr, end); | |
64 | if (pud_none_or_clear_bad(pud)) { | |
65 | if (walk->pte_hole) | |
2165009b | 66 | err = walk->pte_hole(addr, next, walk); |
e6473092 MM |
67 | if (err) |
68 | break; | |
69 | continue; | |
70 | } | |
71 | if (walk->pud_entry) | |
2165009b | 72 | err = walk->pud_entry(pud, addr, next, walk); |
e6473092 | 73 | if (!err && (walk->pmd_entry || walk->pte_entry)) |
2165009b | 74 | err = walk_pmd_range(pud, addr, next, walk); |
e6473092 MM |
75 | if (err) |
76 | break; | |
77 | } while (pud++, addr = next, addr != end); | |
78 | ||
79 | return err; | |
80 | } | |
81 | ||
82 | /** | |
83 | * walk_page_range - walk a memory map's page tables with a callback | |
7682486b RD |
84 | * @mm: memory map to walk |
85 | * @addr: starting address | |
86 | * @end: ending address | |
87 | * @walk: set of callbacks to invoke for each level of the tree | |
e6473092 MM |
88 | * |
89 | * Recursively walk the page table for the memory area in a VMA, | |
90 | * calling supplied callbacks. Callbacks are called in-order (first | |
91 | * PGD, first PUD, first PMD, first PTE, second PTE... second PMD, | |
92 | * etc.). If lower-level callbacks are omitted, walking depth is reduced. | |
93 | * | |
2165009b DH |
94 | * Each callback receives an entry pointer and the start and end of the |
95 | * associated range, and a copy of the original mm_walk for access to | |
96 | * the ->private or ->mm fields. | |
e6473092 MM |
97 | * |
98 | * No locks are taken, but the bottom level iterator will map PTE | |
99 | * directories from highmem if necessary. | |
100 | * | |
101 | * If any callback returns a non-zero value, the walk is aborted and | |
102 | * the return value is propagated back to the caller. Otherwise 0 is returned. | |
103 | */ | |
2165009b DH |
104 | int walk_page_range(unsigned long addr, unsigned long end, |
105 | struct mm_walk *walk) | |
e6473092 MM |
106 | { |
107 | pgd_t *pgd; | |
108 | unsigned long next; | |
109 | int err = 0; | |
110 | ||
111 | if (addr >= end) | |
112 | return err; | |
113 | ||
2165009b DH |
114 | if (!walk->mm) |
115 | return -EINVAL; | |
116 | ||
117 | pgd = pgd_offset(walk->mm, addr); | |
e6473092 MM |
118 | do { |
119 | next = pgd_addr_end(addr, end); | |
120 | if (pgd_none_or_clear_bad(pgd)) { | |
121 | if (walk->pte_hole) | |
2165009b | 122 | err = walk->pte_hole(addr, next, walk); |
e6473092 MM |
123 | if (err) |
124 | break; | |
125 | continue; | |
126 | } | |
127 | if (walk->pgd_entry) | |
2165009b | 128 | err = walk->pgd_entry(pgd, addr, next, walk); |
e6473092 MM |
129 | if (!err && |
130 | (walk->pud_entry || walk->pmd_entry || walk->pte_entry)) | |
2165009b | 131 | err = walk_pud_range(pgd, addr, next, walk); |
e6473092 MM |
132 | if (err) |
133 | break; | |
134 | } while (pgd++, addr = next, addr != end); | |
135 | ||
136 | return err; | |
137 | } |