arch/um/kernel/maccess.c

   1 /*
   2  * Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/uaccess.h>
  10 #include <linux/kernel.h>
  11 #include <os.h>
  12
  13 long probe_kernel_read(void *dst, const void *src, size_t size)
  14 {
  15         void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE);
  16
  17         if ((unsigned long)src < PAGE_SIZE || size <= 0)
  18                 return -EFAULT;
  19
  20         if (os_mincore(psrc, size + src - psrc) <= 0)
  21                 return -EFAULT;
  22
  23         return __probe_kernel_read(dst, src, size);
  24 }