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4e802cfd JL |
1 | /* |
2 | * Copyright (c) 2014, The Linux Foundation. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 and | |
6 | * only version 2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
11 | * GNU General Public License for more details. | |
12 | */ | |
13 | #include <linux/mm.h> | |
14 | #include <linux/module.h> | |
15 | ||
16 | #include <asm/pgtable.h> | |
17 | #include <asm/tlbflush.h> | |
18 | ||
19 | struct page_change_data { | |
20 | pgprot_t set_mask; | |
21 | pgprot_t clear_mask; | |
22 | }; | |
23 | ||
24 | static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr, | |
25 | void *data) | |
26 | { | |
27 | struct page_change_data *cdata = data; | |
28 | pte_t pte = *ptep; | |
29 | ||
30 | pte = clear_pte_bit(pte, cdata->clear_mask); | |
31 | pte = set_pte_bit(pte, cdata->set_mask); | |
32 | ||
33 | set_pte_ext(ptep, pte, 0); | |
34 | return 0; | |
35 | } | |
36 | ||
37 | static int change_memory_common(unsigned long addr, int numpages, | |
38 | pgprot_t set_mask, pgprot_t clear_mask) | |
39 | { | |
40 | unsigned long start = addr; | |
41 | unsigned long size = PAGE_SIZE*numpages; | |
42 | unsigned long end = start + size; | |
43 | int ret; | |
44 | struct page_change_data data; | |
45 | ||
46 | if (!IS_ALIGNED(addr, PAGE_SIZE)) { | |
47 | start &= PAGE_MASK; | |
48 | end = start + size; | |
49 | WARN_ON_ONCE(1); | |
50 | } | |
51 | ||
f474c8c8 MP |
52 | if (!numpages) |
53 | return 0; | |
54 | ||
f2ca09f3 LA |
55 | if (start < MODULES_VADDR || start >= MODULES_END) |
56 | return -EINVAL; | |
57 | ||
58 | if (end < MODULES_VADDR || start >= MODULES_END) | |
4e802cfd JL |
59 | return -EINVAL; |
60 | ||
61 | data.set_mask = set_mask; | |
62 | data.clear_mask = clear_mask; | |
63 | ||
64 | ret = apply_to_page_range(&init_mm, start, size, change_page_range, | |
65 | &data); | |
66 | ||
67 | flush_tlb_kernel_range(start, end); | |
68 | return ret; | |
69 | } | |
70 | ||
71 | int set_memory_ro(unsigned long addr, int numpages) | |
72 | { | |
73 | return change_memory_common(addr, numpages, | |
74 | __pgprot(L_PTE_RDONLY), | |
75 | __pgprot(0)); | |
76 | } | |
77 | ||
78 | int set_memory_rw(unsigned long addr, int numpages) | |
79 | { | |
80 | return change_memory_common(addr, numpages, | |
81 | __pgprot(0), | |
82 | __pgprot(L_PTE_RDONLY)); | |
83 | } | |
84 | ||
85 | int set_memory_nx(unsigned long addr, int numpages) | |
86 | { | |
87 | return change_memory_common(addr, numpages, | |
88 | __pgprot(L_PTE_XN), | |
89 | __pgprot(0)); | |
90 | } | |
91 | ||
92 | int set_memory_x(unsigned long addr, int numpages) | |
93 | { | |
94 | return change_memory_common(addr, numpages, | |
95 | __pgprot(0), | |
96 | __pgprot(L_PTE_XN)); | |
97 | } |