arch/um/include/asm/uaccess.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   4  * Copyright (C) 2015 Richard Weinberger (richard@nod.at)
   5  */
   6
   7 #ifndef __UM_UACCESS_H
   8 #define __UM_UACCESS_H
   9
  10 #include <asm/elf.h>
  11
  12 #define __under_task_size(addr, size) \
  13         (((unsigned long) (addr) < TASK_SIZE) && \
  14          (((unsigned long) (addr) + (size)) < TASK_SIZE))
  15
  16 #define __access_ok_vsyscall(addr, size) \
  17           (((unsigned long) (addr) >= FIXADDR_USER_START) && \
  18           ((unsigned long) (addr) + (size) <= FIXADDR_USER_END) && \
  19           ((unsigned long) (addr) + (size) >= (unsigned long)(addr)))
  20
  21 #define __addr_range_nowrap(addr, size) \
  22         ((unsigned long) (addr) <= ((unsigned long) (addr) + (size)))
  23
  24 extern unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n);
  25 extern unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n);
  26 extern long __strncpy_from_user(char *dst, const char __user *src, long count);
  27 extern long __strnlen_user(const void __user *str, long len);
  28 extern unsigned long __clear_user(void __user *mem, unsigned long len);
  29 static inline int __access_ok(unsigned long addr, unsigned long size);
  30
  31 /* Teach asm-generic/uaccess.h that we have C functions for these. */
  32 #define __access_ok __access_ok
  33 #define __clear_user __clear_user
  34 #define __strnlen_user __strnlen_user
  35 #define __strncpy_from_user __strncpy_from_user
  36 #define INLINE_COPY_FROM_USER
  37 #define INLINE_COPY_TO_USER
  38
  39 #include <asm-generic/uaccess.h>
  40
  41 static inline int __access_ok(unsigned long addr, unsigned long size)
  42 {
  43         return __addr_range_nowrap(addr, size) &&
  44                 (__under_task_size(addr, size) ||
  45                 __access_ok_vsyscall(addr, size) ||
  46                 uaccess_kernel());
  47 }
  48
  49 #endif