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
  25 extern long __copy_from_user(void *to, const void __user *from, unsigned long n);
  26 extern long __copy_to_user(void __user *to, const void *from, unsigned long n);
  27 extern long __strncpy_from_user(char *dst, const char __user *src, long count);
  28 extern long __strnlen_user(const void __user *str, long len);
  29 extern unsigned long __clear_user(void __user *mem, unsigned long len);
  30 static 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
  44 static 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