LXR linux/arch/um/include/asm/uaccess.h

   1/* 
   2 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3 * Copyright (C) 2015 Richard Weinberger (richard@nod.at)
   4 * Licensed under the GPL
   5 */
   6
   7#ifndef __UM_UACCESS_H
   8#define __UM_UACCESS_H
   9
  10#include <asm/thread_info.h>
  11#include <asm/elf.h>
  12
  13#define __under_task_size(addr, size) \
  14        (((unsigned long) (addr) < TASK_SIZE) && \
  15         (((unsigned long) (addr) + (size)) < TASK_SIZE))
  16
  17#define __access_ok_vsyscall(addr, size) \
  18          (((unsigned long) (addr) >= FIXADDR_USER_START) && \
  19          ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
  20          ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
  21
  22#define __addr_range_nowrap(addr, size) \
  23        ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
  24
  25extern long __copy_from_user(void *to, const void __user *from, unsigned long n);
  26extern long __copy_to_user(void __user *to, const void *from, unsigned long n);
  27extern long __strncpy_from_user(char *dst, const char __user *src, long count);
  28extern long __strnlen_user(const void __user *str, long len);
  29extern unsigned long __clear_user(void __user *mem, unsigned long len);
  30static inline int __access_ok(unsigned long addr, unsigned long size);
  31
  32/* Teach asm-generic/uaccess.h that we have C functions for these. */
  33#define __access_ok __access_ok
  34#define __clear_user __clear_user
  35#define __copy_to_user __copy_to_user
  36#define __copy_from_user __copy_from_user
  37#define __strnlen_user __strnlen_user
  38#define __strncpy_from_user __strncpy_from_user
  39#define __copy_to_user_inatomic __copy_to_user
  40#define __copy_from_user_inatomic __copy_from_user
  41
  42#include <asm-generic/uaccess.h>
  43
  44static inline int __access_ok(unsigned long addr, unsigned long size)
  45{
  46        return __addr_range_nowrap(addr, size) &&
  47                (__under_task_size(addr, size) ||
  48                __access_ok_vsyscall(addr, size) ||
  49                segment_eq(get_fs(), KERNEL_DS));
  50}
  51
  52#endif
  53