mirror of https://gitee.com/openkylin/linux.git
72 lines
1.2 KiB
C
72 lines
1.2 KiB
C
/* user_fixup.c: Fix up user copy faults.
|
|
*
|
|
* Copyright (C) 2004 David S. Miller <davem@redhat.com>
|
|
*/
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/string.h>
|
|
#include <linux/errno.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
/* Calculating the exact fault address when using
|
|
* block loads and stores can be very complicated.
|
|
* Instead of trying to be clever and handling all
|
|
* of the cases, just fix things up simply here.
|
|
*/
|
|
|
|
unsigned long copy_from_user_fixup(void *to, const void __user *from, unsigned long size)
|
|
{
|
|
char *dst = to;
|
|
const char __user *src = from;
|
|
|
|
while (size) {
|
|
if (__get_user(*dst, src))
|
|
break;
|
|
dst++;
|
|
src++;
|
|
size--;
|
|
}
|
|
|
|
if (size)
|
|
memset(dst, 0, size);
|
|
|
|
return size;
|
|
}
|
|
|
|
unsigned long copy_to_user_fixup(void __user *to, const void *from, unsigned long size)
|
|
{
|
|
char __user *dst = to;
|
|
const char *src = from;
|
|
|
|
while (size) {
|
|
if (__put_user(*src, dst))
|
|
break;
|
|
dst++;
|
|
src++;
|
|
size--;
|
|
}
|
|
|
|
return size;
|
|
}
|
|
|
|
unsigned long copy_in_user_fixup(void __user *to, void __user *from, unsigned long size)
|
|
{
|
|
char __user *dst = to;
|
|
char __user *src = from;
|
|
|
|
while (size) {
|
|
char tmp;
|
|
|
|
if (__get_user(tmp, src))
|
|
break;
|
|
if (__put_user(tmp, dst))
|
|
break;
|
|
dst++;
|
|
src++;
|
|
size--;
|
|
}
|
|
|
|
return size;
|
|
}
|