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 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 }