LXR linux/arch/x86/um/mem

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
   4 */
   5
   6#include <linux/mm.h>
   7#include <asm/elf.h>
   8
   9static struct vm_area_struct gate_vma;
  10
  11static int __init gate_vma_init(void)
  12{
  13        if (!FIXADDR_USER_START)
  14                return 0;
  15
  16        vma_init(&gate_vma, NULL);
  17        gate_vma.vm_start = FIXADDR_USER_START;
  18        gate_vma.vm_end = FIXADDR_USER_END;
  19        gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
  20        gate_vma.vm_page_prot = __P101;
  21
  22        return 0;
  23}
  24__initcall(gate_vma_init);
  25
  26struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
  27{
  28        return FIXADDR_USER_START ? &gate_vma : NULL;
  29}
  30
  31int in_gate_area_no_mm(unsigned long addr)
  32{
  33        if (!FIXADDR_USER_START)
  34                return 0;
  35
  36        if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
  37                return 1;
  38
  39        return 0;
  40}
  41
  42int in_gate_area(struct mm_struct *mm, unsigned long addr)
  43{
  44        struct vm_area_struct *vma = get_gate_vma(mm);
  45
  46        if (!vma)
  47                return 0;
  48
  49        return (addr >= vma->vm_start) && (addr < vma->vm_end);
  50}
  51