xref: /kernel/linux/linux-6.6/arch/arm/mm/pageattr.c (revision 62306a36) 
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
11struct page_change_data {
12	pgprot_t set_mask;
13	pgprot_t clear_mask;
14};
15
16static 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
28static 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 */
38static 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
54static 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
73int 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
80int 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
87int 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
94int 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
101int 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