release/src-rt-6.x.4708/linux/linux-2.6.36/arch/um/kernel/uaccess.c

   1 /*
   2  * Copyright (C) 2001 Chris Emerson (cemerson@chiark.greenend.org.uk)
   3  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   4  * Licensed under the GPL
   5  */
   6
   7 /*
   8  * These are here rather than tt/uaccess.c because skas mode needs them in
   9  * order to do SIGBUS recovery when a tmpfs mount runs out of room.
  10  */
  11
  12 #include <linux/string.h>
  13 #include "os.h"
  14
  15 static void __do_copy(void *to, const void *from, int n)
  16 {
  17         memcpy(to, from, n);
  18 }
  19
  20
  21 int __do_copy_to_user(void *to, const void *from, int n,
  22                       void **fault_addr, jmp_buf **fault_catcher)
  23 {
  24         unsigned long fault;
  25         int faulted;
  26
  27         fault = __do_user_copy(to, from, n, fault_addr, fault_catcher,
  28                                __do_copy, &faulted);
  29         if (!faulted)
  30                 return 0;
  31         else
  32                 return n - (fault - (unsigned long) to);
  33 }