LXR linux/arch/x86/um/mem

   1/*
   2 * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 */
   8
   9#include <linux/mm.h>
  10#include <asm/elf.h>
  11
  12static struct vm_area_struct gate_vma;
  13
  14static int __init gate_vma_init(void)
  15{
  16        if (!FIXADDR_USER_START)
  17                return 0;
  18
  19        gate_vma.vm_mm = NULL;
  20        gate_vma.vm_start = FIXADDR_USER_START;
  21        gate_vma.vm_end = FIXADDR_USER_END;
  22        gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
  23        gate_vma.vm_page_prot = __P101;
  24
  25        return 0;
  26}
  27__initcall(gate_vma_init);
  28
  29struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
  30{
  31        return FIXADDR_USER_START ? &gate_vma : NULL;
  32}
  33
  34int in_gate_area_no_mm(unsigned long addr)
  35{
  36        if (!FIXADDR_USER_START)
  37                return 0;
  38
  39        if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
  40                return 1;
  41
  42        return 0;
  43}
  44
  45int in_gate_area(struct mm_struct *mm, unsigned long addr)
  46{
  47        struct vm_area_struct *vma = get_gate_vma(mm);
  48
  49        if (!vma)
  50                return 0;
  51
  52        return (addr >= vma->vm_start) && (addr < vma->vm_end);
  53}
  54