Jungseung Lee | 4e802cf | 2014-11-29 03:02:11 +0100 | [diff] [blame] | 1 | /* |
Shiraz Hashim | e7acf69 | 2017-08-11 17:49:28 +0530 | [diff] [blame] | 2 | * Copyright (c) 2014,2017 The Linux Foundation. All rights reserved. |
Jungseung Lee | 4e802cf | 2014-11-29 03:02:11 +0100 | [diff] [blame] | 3 | * |
| 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. |
| 7 | * |
| 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. |
| 12 | */ |
| 13 | #include <linux/mm.h> |
| 14 | #include <linux/module.h> |
| 15 | |
| 16 | #include <asm/pgtable.h> |
| 17 | #include <asm/tlbflush.h> |
| 18 | |
| 19 | struct page_change_data { |
| 20 | pgprot_t set_mask; |
| 21 | pgprot_t clear_mask; |
| 22 | }; |
| 23 | |
| 24 | static int change_page_range(pte_t *ptep, pgtable_t token, unsigned long addr, |
| 25 | void *data) |
| 26 | { |
| 27 | struct page_change_data *cdata = data; |
| 28 | pte_t pte = *ptep; |
| 29 | |
| 30 | pte = clear_pte_bit(pte, cdata->clear_mask); |
| 31 | pte = set_pte_bit(pte, cdata->set_mask); |
| 32 | |
| 33 | set_pte_ext(ptep, pte, 0); |
| 34 | return 0; |
| 35 | } |
| 36 | |
| 37 | static int change_memory_common(unsigned long addr, int numpages, |
| 38 | pgprot_t set_mask, pgprot_t clear_mask) |
| 39 | { |
| 40 | unsigned long start = addr; |
| 41 | unsigned long size = PAGE_SIZE*numpages; |
| 42 | unsigned long end = start + size; |
| 43 | int ret; |
| 44 | struct page_change_data data; |
| 45 | |
| 46 | if (!IS_ALIGNED(addr, PAGE_SIZE)) { |
| 47 | start &= PAGE_MASK; |
| 48 | end = start + size; |
| 49 | WARN_ON_ONCE(1); |
| 50 | } |
| 51 | |
Mika Penttilä | f474c8c | 2016-02-22 17:56:52 +0100 | [diff] [blame] | 52 | if (!numpages) |
| 53 | return 0; |
| 54 | |
Laura Abbott | 460ad2e | 2014-04-14 19:42:04 -0700 | [diff] [blame] | 55 | if (!IS_ENABLED(CONFIG_FORCE_PAGES)) { |
| 56 | if (start < MODULES_VADDR || start >= MODULES_END) |
| 57 | return -EINVAL; |
Laura Abbott | f2ca09f | 2015-03-13 21:41:45 +0100 | [diff] [blame] | 58 | |
Laura Abbott | 460ad2e | 2014-04-14 19:42:04 -0700 | [diff] [blame] | 59 | if (end < MODULES_VADDR || start >= MODULES_END) |
| 60 | return -EINVAL; |
| 61 | } |
Jungseung Lee | 4e802cf | 2014-11-29 03:02:11 +0100 | [diff] [blame] | 62 | |
| 63 | data.set_mask = set_mask; |
| 64 | data.clear_mask = clear_mask; |
| 65 | |
| 66 | ret = apply_to_page_range(&init_mm, start, size, change_page_range, |
| 67 | &data); |
| 68 | |
| 69 | flush_tlb_kernel_range(start, end); |
| 70 | return ret; |
| 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 | } |
Shiraz Hashim | e7acf69 | 2017-08-11 17:49:28 +0530 | [diff] [blame] | 100 | |
| 101 | #ifdef CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC |
| 102 | void __kernel_map_pages(struct page *page, int numpages, int enable) |
| 103 | { |
| 104 | unsigned long addr; |
| 105 | |
| 106 | if (PageHighMem(page)) |
| 107 | return; |
| 108 | |
| 109 | addr = (unsigned long) page_address(page); |
| 110 | if (enable) |
| 111 | set_memory_rw(addr, numpages); |
| 112 | else |
| 113 | set_memory_ro(addr, numpages); |
| 114 | } |
| 115 | #endif |