arch/sparc64/lib/user_fixup.c

   1 /* user_fixup.c: Fix up user copy faults.
   2  *
   3  * Copyright (C) 2004 David S. Miller <davem@redhat.com>
   4  */
   5
   6 #include <linux/compiler.h>
   7 #include <linux/kernel.h>
   8 #include <linux/string.h>
   9 #include <linux/errno.h>
  10 #include <asm/uaccess.h>
  11
  12 /* Calculating the exact fault address when using
  13  * block loads and stores can be very complicated.
  14  * Instead of trying to be clever and handling all
  15  * of the cases, just fix things up simply here.
  16  */
  17
  18 unsigned long copy_from_user_fixup(void *to, const void __user *from, unsigned long size)
  19 {
  20         char *dst = to;
  21         const char __user *src = from;
  22
  23         while (size) {
  24                 if (__get_user(*dst, src))
  25                         break;
  26                 dst++;
  27                 src++;
  28                 size--;
  29         }
  30
  31         if (size)
  32                 memset(dst, 0, size);
  33
  34         return size;
  35 }
  36
  37 unsigned long copy_to_user_fixup(void __user *to, const void *from, unsigned long size)
  38 {
  39         char __user *dst = to;
  40         const char *src = from;
  41
  42         while (size) {
  43                 if (__put_user(*src, dst))
  44                         break;
  45                 dst++;
  46                 src++;
  47                 size--;
  48         }
  49
  50         return size;
  51 }
  52
  53 unsigned long copy_in_user_fixup(void __user *to, void __user *from, unsigned long size)
  54 {
  55         char __user *dst = to;
  56         char __user *src = from;
  57
  58         while (size) {
  59                 char tmp;
  60
  61                 if (__get_user(tmp, src))
  62                         break;
  63                 if (__put_user(tmp, dst))
  64                         break;
  65                 dst++;
  66                 src++;
  67                 size--;
  68         }
  69
  70         return size;
  71 }