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/page.h>
  11#include <asm/mman.h>
  12
  13static struct vm_area_struct gate_vma;
  14
  15static int __init gate_vma_init(void)
  16{
  17        if (!FIXADDR_USER_START)
  18                return 0;
  19
  20        gate_vma.vm_mm = NULL;
  21        gate_vma.vm_start = FIXADDR_USER_START;
  22        gate_vma.vm_end = FIXADDR_USER_END;
  23        gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
  24        gate_vma.vm_page_prot = __P101;
  25
  26        return 0;
  27}
  28__initcall(gate_vma_init);
  29
  30struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
  31{
  32        return FIXADDR_USER_START ? &gate_vma : NULL;
  33}
  34
  35int in_gate_area_no_mm(unsigned long addr)
  36{
  37        if (!FIXADDR_USER_START)
  38                return 0;
  39
  40        if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
  41                return 1;
  42
  43        return 0;
  44}
  45
  46int in_gate_area(struct mm_struct *mm, unsigned long addr)
  47{
  48        struct vm_area_struct *vma = get_gate_vma(mm);
  49
  50        if (!vma)
  51                return 0;
  52
  53        return (addr >= vma->vm_start) && (addr < vma->vm_end);
  54}
  55