Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Optimized memory copy routines.
4 *
5 * Copyright (C) 2004 Randolph Chung <tausq@debian.org>
6 * Copyright (C) 2013-2017 Helge Deller <deller@gmx.de>
7 *
8 * Portions derived from the GNU C Library
9 * Copyright (C) 1991, 1997, 2003 Free Software Foundation, Inc.
10 */
11
12#include <linux/module.h>
13#include <linux/compiler.h>
14#include <linux/uaccess.h>
15#include <linux/mm.h>
16
17#define get_user_space() mfsp(SR_USER)
18#define get_kernel_space() SR_KERNEL
19
20/* Returns 0 for success, otherwise, returns number of bytes not transferred. */
21extern unsigned long pa_memcpy(void *dst, const void *src,
22 unsigned long len);
23
24unsigned long raw_copy_to_user(void __user *dst, const void *src,
25 unsigned long len)
26{
27 mtsp(get_kernel_space(), SR_TEMP1);
28 mtsp(get_user_space(), SR_TEMP2);
29 return pa_memcpy((void __force *)dst, src, len);
30}
31EXPORT_SYMBOL(raw_copy_to_user);
32
33unsigned long raw_copy_from_user(void *dst, const void __user *src,
34 unsigned long len)
35{
36 unsigned long start = (unsigned long) src;
37 unsigned long end = start + len;
38 unsigned long newlen = len;
39
40 mtsp(get_user_space(), SR_TEMP1);
41 mtsp(get_kernel_space(), SR_TEMP2);
42
43 /* Check region is user accessible */
44 while (start < end) {
45 if (!prober_user(SR_TEMP1, start)) {
46 newlen = (start - (unsigned long) src);
47 break;
48 }
49 start += PAGE_SIZE;
50 /* align to page boundry which may have different permission */
51 start = PAGE_ALIGN_DOWN(start);
52 }
53 return len - newlen + pa_memcpy(dst, (void __force *)src, newlen);
54}
55EXPORT_SYMBOL(raw_copy_from_user);
56
57void * memcpy(void * dst,const void *src, size_t count)
58{
59 mtsp(get_kernel_space(), SR_TEMP1);
60 mtsp(get_kernel_space(), SR_TEMP2);
61 pa_memcpy(dst, src, count);
62 return dst;
63}
64
65EXPORT_SYMBOL(memcpy);
66
67bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
68{
69 if ((unsigned long)unsafe_src < PAGE_SIZE)
70 return false;
71 /* check for I/O space F_EXTEND(0xfff00000) access as well? */
72 return true;
73}