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 static 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 63 int 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 70 int 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 77 int 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 84 int 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 } 90