arch/arm/mm/pageattr.c

   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 }