1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2014, The Linux Foundation. All rights reserved.
4 */
5 #include <linux/mm.h>
6 #include <linux/module.h>
7
8 #include <asm/tlbflush.h>
9 #include <asm/set_memory.h>
10
11 struct page_change_data {
12 pgprot_t set_mask;
13 pgprot_t clear_mask;
14 };
15
16 static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
17 {
18 struct page_change_data *cdata = data;
19 pte_t pte = *ptep;
20
21 pte = clear_pte_bit(pte, cdata->clear_mask);
22 pte = set_pte_bit(pte, cdata->set_mask);
23
24 set_pte_ext(ptep, pte, 0);
25 return 0;
26 }
27
28 static bool range_in_range(unsigned long start, unsigned long size,
29 unsigned long range_start, unsigned long range_end)
30 {
31 return start >= range_start && start < range_end &&
32 size <= range_end - start;
33 }
34
35 /*
36 * This function assumes that the range is mapped with PAGE_SIZE pages.
37 */
38 static int __change_memory_common(unsigned long start, unsigned long size,
39 pgprot_t set_mask, pgprot_t clear_mask)
40 {
41 struct page_change_data data;
42 int ret;
43
44 data.set_mask = set_mask;
45 data.clear_mask = clear_mask;
46
47 ret = apply_to_page_range(&init_mm, start, size, change_page_range,
48 &data);
49
50 flush_tlb_kernel_range(start, start + size);
51 return ret;
52 }
53
54 static int change_memory_common(unsigned long addr, int numpages,
55 pgprot_t set_mask, pgprot_t clear_mask)
56 {
57 unsigned long start = addr & PAGE_MASK;
58 unsigned long end = PAGE_ALIGN(addr) + numpages * PAGE_SIZE;
59 unsigned long size = end - start;
60
61 WARN_ON_ONCE(start != addr);
62
63 if (!size)
64 return 0;
65
66 if (!range_in_range(start, size, MODULES_VADDR, MODULES_END) &&
67 !range_in_range(start, size, VMALLOC_START, VMALLOC_END))
68 return -EINVAL;
69
70 return __change_memory_common(start, size, set_mask, clear_mask);
71 }
72
73 int set_memory_ro(unsigned long addr, int numpages)
74 {
75 return change_memory_common(addr, numpages,
76 __pgprot(L_PTE_RDONLY),
77 __pgprot(0));
78 }
79
80 int set_memory_rw(unsigned long addr, int numpages)
81 {
82 return change_memory_common(addr, numpages,
83 __pgprot(0),
84 __pgprot(L_PTE_RDONLY));
85 }
86
87 int set_memory_nx(unsigned long addr, int numpages)
88 {
89 return change_memory_common(addr, numpages,
90 __pgprot(L_PTE_XN),
91 __pgprot(0));
92 }
93
94 int set_memory_x(unsigned long addr, int numpages)
95 {
96 return change_memory_common(addr, numpages,
97 __pgprot(0),
98 __pgprot(L_PTE_XN));
99 }
100
101 int set_memory_valid(unsigned long addr, int numpages, int enable)
102 {
103 if (enable)
104 return __change_memory_common(addr, PAGE_SIZE * numpages,
105 __pgprot(L_PTE_VALID),
106 __pgprot(0));
107 else
108 return __change_memory_common(addr, PAGE_SIZE * numpages,
109 __pgprot(0),
110 __pgprot(L_PTE_VALID));
111 }
112
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