LXR linux/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/pgtable.h>
   9#include <asm/tlbflush.h>
  10#include <asm/set_memory.h>
  11
  12struct page_change_data {
  13        pgprot_t set_mask;
  14        pgprot_t clear_mask;
  15};
  16
  17static 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
  29static 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
  36static 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
  64int 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
  71int 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
  78int 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
  85int 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