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 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
35static int change_memory_common(unsigned long addr, int numpages,
36				pgprot_t set_mask, pgprot_t clear_mask)
37{
38	unsigned long start = addr & PAGE_MASK;
39	unsigned long end = PAGE_ALIGN(addr) + numpages * PAGE_SIZE;
40	unsigned long size = end - start;
41	int ret;
42	struct page_change_data data;
43
44	WARN_ON_ONCE(start != addr);
45
46	if (!size)
47		return 0;
48
49	if (!in_range(start, size, MODULES_VADDR, MODULES_END) &&
50	    !in_range(start, size, VMALLOC_START, VMALLOC_END))
51		return -EINVAL;
52
53	data.set_mask = set_mask;
54	data.clear_mask = clear_mask;
55
56	ret = apply_to_page_range(&init_mm, start, size, change_page_range,
57					&data);
58
59	flush_tlb_kernel_range(start, end);
60	return ret;
61}
62
63int set_memory_ro(unsigned long addr, int numpages)
64{
65	return change_memory_common(addr, numpages,
66					__pgprot(L_PTE_RDONLY),
67					__pgprot(0));
68}
69
70int set_memory_rw(unsigned long addr, int numpages)
71{
72	return change_memory_common(addr, numpages,
73					__pgprot(0),
74					__pgprot(L_PTE_RDONLY));
75}
76
77int set_memory_nx(unsigned long addr, int numpages)
78{
79	return change_memory_common(addr, numpages,
80					__pgprot(L_PTE_XN),
81					__pgprot(0));
82}
83
84int set_memory_x(unsigned long addr, int numpages)
85{
86	return change_memory_common(addr, numpages,
87					__pgprot(0),
88					__pgprot(L_PTE_XN));
89}