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 12 struct page_change_data { 13 pgprot_t set_mask; 14 pgprot_t clear_mask; 15 }; 16 17 static 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 29 static 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 36 static 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 64 int 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 71 int 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 78 int 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 85 int 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 } 91