original_kernel/arch/x86/um/mem_32.c

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/*
* Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/mm.h>
#include <asm/page.h>
#include <asm/mman.h>
static struct vm_area_struct gate_vma;
static int __init gate_vma_init(void)
{
if (!FIXADDR_USER_START)
return 0;
gate_vma.vm_mm = NULL;
gate_vma.vm_start = FIXADDR_USER_START;
gate_vma.vm_end = FIXADDR_USER_END;
gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
gate_vma.vm_page_prot = __P101;
return 0;
}
__initcall(gate_vma_init);
struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
return FIXADDR_USER_START ? &gate_vma : NULL;
}
int in_gate_area_no_mm(unsigned long addr)
{
if (!FIXADDR_USER_START)
return 0;
if ((addr >= FIXADDR_USER_START) && (addr < FIXADDR_USER_END))
return 1;
return 0;
}
int in_gate_area(struct mm_struct *mm, unsigned long addr)
{
struct vm_area_struct *vma = get_gate_vma(mm);
if (!vma)
return 0;
return (addr >= vma->vm_start) && (addr < vma->vm_end);
}