2 * Copyright (c) 2014, The Linux Foundation. All rights reserved.
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.
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.
13 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/sched.h>
18 #include <asm/pgtable.h>
19 #include <asm/tlbflush.h>
21 struct page_change_data {
26 static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr,
29 struct page_change_data *cdata = data;
32 pte = clear_pte_bit(pte, cdata->clear_mask);
33 pte = set_pte_bit(pte, cdata->set_mask);
39 static int change_memory_common(unsigned long addr, int numpages,
40 pgprot_t set_mask, pgprot_t clear_mask)
42 unsigned long start = addr;
43 unsigned long size = PAGE_SIZE*numpages;
44 unsigned long end = start + size;
46 struct page_change_data data;
48 if (!PAGE_ALIGNED(addr)) {
54 if (start < MODULES_VADDR || start >= MODULES_END)
57 if (end < MODULES_VADDR || end >= MODULES_END)
60 data.set_mask = set_mask;
61 data.clear_mask = clear_mask;
63 ret = apply_to_page_range(&init_mm, start, size, change_page_range,
66 flush_tlb_kernel_range(start, end);
70 int set_memory_ro(unsigned long addr, int numpages)
72 return change_memory_common(addr, numpages,
77 int set_memory_rw(unsigned long addr, int numpages)
79 return change_memory_common(addr, numpages,
81 __pgprot(PTE_RDONLY));
84 int set_memory_nx(unsigned long addr, int numpages)
86 return change_memory_common(addr, numpages,
90 EXPORT_SYMBOL_GPL(set_memory_nx);
92 int set_memory_x(unsigned long addr, int numpages)
94 return change_memory_common(addr, numpages,
98 EXPORT_SYMBOL_GPL(set_memory_x);