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 11 struct page_change_data { 12 pgprot_t set_mask; 13 pgprot_t clear_mask; 14 }; 15 16 static 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 28 static 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 35 /* 36 * This function assumes that the range is mapped with PAGE_SIZE pages. 37 */ 38 static 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 54 static 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 (!in_range(start, size, MODULES_VADDR, MODULES_END) && 67 !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 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 } 100 101 int 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