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11d91a77 LA |
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/kernel.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/sched.h> | |
17 | ||
18 | #include <asm/pgtable.h> | |
19 | #include <asm/tlbflush.h> | |
20 | ||
21 | struct page_change_data { | |
22 | pgprot_t set_mask; | |
23 | pgprot_t clear_mask; | |
24 | }; | |
25 | ||
26 | static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr, | |
27 | void *data) | |
28 | { | |
29 | struct page_change_data *cdata = data; | |
30 | pte_t pte = *ptep; | |
31 | ||
32 | pte = clear_pte_bit(pte, cdata->clear_mask); | |
33 | pte = set_pte_bit(pte, cdata->set_mask); | |
34 | ||
35 | set_pte(ptep, pte); | |
36 | return 0; | |
37 | } | |
38 | ||
39 | static int change_memory_common(unsigned long addr, int numpages, | |
40 | pgprot_t set_mask, pgprot_t clear_mask) | |
41 | { | |
42 | unsigned long start = addr; | |
43 | unsigned long size = PAGE_SIZE*numpages; | |
44 | unsigned long end = start + size; | |
45 | int ret; | |
46 | struct page_change_data data; | |
47 | ||
48 | if (!IS_ALIGNED(addr, PAGE_SIZE)) { | |
b4da1840 LA |
49 | start &= PAGE_MASK; |
50 | end = start + size; | |
11d91a77 LA |
51 | WARN_ON_ONCE(1); |
52 | } | |
53 | ||
8b5f5a07 LA |
54 | if (start < MODULES_VADDR || start >= MODULES_END) |
55 | return -EINVAL; | |
56 | ||
57 | if (end < MODULES_VADDR || end >= MODULES_END) | |
11d91a77 LA |
58 | return -EINVAL; |
59 | ||
60 | data.set_mask = set_mask; | |
61 | data.clear_mask = clear_mask; | |
62 | ||
63 | ret = apply_to_page_range(&init_mm, start, size, change_page_range, | |
64 | &data); | |
65 | ||
66 | flush_tlb_kernel_range(start, end); | |
67 | return ret; | |
68 | } | |
69 | ||
70 | int set_memory_ro(unsigned long addr, int numpages) | |
71 | { | |
72 | return change_memory_common(addr, numpages, | |
73 | __pgprot(PTE_RDONLY), | |
74 | __pgprot(PTE_WRITE)); | |
75 | } | |
76 | EXPORT_SYMBOL_GPL(set_memory_ro); | |
77 | ||
78 | int set_memory_rw(unsigned long addr, int numpages) | |
79 | { | |
80 | return change_memory_common(addr, numpages, | |
81 | __pgprot(PTE_WRITE), | |
82 | __pgprot(PTE_RDONLY)); | |
83 | } | |
84 | EXPORT_SYMBOL_GPL(set_memory_rw); | |
85 | ||
86 | int set_memory_nx(unsigned long addr, int numpages) | |
87 | { | |
88 | return change_memory_common(addr, numpages, | |
89 | __pgprot(PTE_PXN), | |
90 | __pgprot(0)); | |
91 | } | |
92 | EXPORT_SYMBOL_GPL(set_memory_nx); | |
93 | ||
94 | int set_memory_x(unsigned long addr, int numpages) | |
95 | { | |
96 | return change_memory_common(addr, numpages, | |
97 | __pgprot(0), | |
98 | __pgprot(PTE_PXN)); | |
99 | } | |
100 | EXPORT_SYMBOL_GPL(set_memory_x); |