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/pgtable.h>
 9#include <asm/tlbflush.h>
10#include <asm/set_memory.h>
11
12struct page_change_data {
13	pgprot_t set_mask;
14	pgprot_t clear_mask;
15};
16
17static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
18{
19	struct page_change_data *cdata = data;
20	pte_t pte = *ptep;
21
22	pte = clear_pte_bit(pte, cdata->clear_mask);
23	pte = set_pte_bit(pte, cdata->set_mask);
24
25	set_pte_ext(ptep, pte, 0);
26	return 0;
27}
28
29static bool in_range(unsigned long start, unsigned long size,
30	unsigned long range_start, unsigned long range_end)
31{
32	return start >= range_start && start < range_end &&
33		size <= range_end - start;
34}
35
36static int change_memory_common(unsigned long addr, int numpages,
37				pgprot_t set_mask, pgprot_t clear_mask)
38{
39	unsigned long start = addr & PAGE_MASK;
40	unsigned long end = PAGE_ALIGN(addr) + numpages * PAGE_SIZE;
41	unsigned long size = end - start;
42	int ret;
43	struct page_change_data data;
44
45	WARN_ON_ONCE(start != addr);
46
47	if (!size)
48		return 0;
49
50	if (!in_range(start, size, MODULES_VADDR, MODULES_END) &&
51	    !in_range(start, size, VMALLOC_START, VMALLOC_END))
52		return -EINVAL;
53
54	data.set_mask = set_mask;
55	data.clear_mask = clear_mask;
56
57	ret = apply_to_page_range(&init_mm, start, size, change_page_range,
58					&data);
59
60	flush_tlb_kernel_range(start, end);
61	return ret;
62}
63
64int set_memory_ro(unsigned long addr, int numpages)
65{
66	return change_memory_common(addr, numpages,
67					__pgprot(L_PTE_RDONLY),
68					__pgprot(0));
69}
70
71int set_memory_rw(unsigned long addr, int numpages)
72{
73	return change_memory_common(addr, numpages,
74					__pgprot(0),
75					__pgprot(L_PTE_RDONLY));
76}
77
78int set_memory_nx(unsigned long addr, int numpages)
79{
80	return change_memory_common(addr, numpages,
81					__pgprot(L_PTE_XN),
82					__pgprot(0));
83}
84
85int set_memory_x(unsigned long addr, int numpages)
86{
87	return change_memory_common(addr, numpages,
88					__pgprot(0),
89					__pgprot(L_PTE_XN));
90}