1 /*
2 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
3 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without modification,
6 * are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this list of
9 * conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
12 * of conditions and the following disclaimer in the documentation and/or other materials
13 * provided with the distribution.
14 *
15 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
16 * to endorse or promote products derived from this software without specific prior written
17 * permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
21 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "los_strncpy_from_user.h"
33 #include "los_user_get.h"
34 #include "los_vm_map.h"
35
36
LOS_StrncpyFromUser(CHAR * dst,const CHAR * src,INT32 count)37 INT32 LOS_StrncpyFromUser(CHAR *dst, const CHAR *src, INT32 count)
38 {
39 CHAR character;
40 INT32 i;
41 INT32 maxCount;
42 size_t offset = 0;
43
44 if ((!LOS_IsKernelAddress((VADDR_T)(UINTPTR)dst)) || (!LOS_IsUserAddress((VADDR_T)(UINTPTR)src)) || (count <= 0)) {
45 return -EFAULT;
46 }
47
48 maxCount = (LOS_IsUserAddressRange((VADDR_T)(UINTPTR)src, (size_t)count)) ? \
49 count : (INT32)(USER_ASPACE_TOP_MAX - (UINTPTR)src);
50
51 for (i = 0; i < maxCount; ++i) {
52 if (LOS_GetUser(&character, src + offset) != LOS_OK) {
53 return -EFAULT;
54 }
55 *(CHAR *)(dst + offset) = character;
56 if (character == '\0') {
57 return offset;
58 }
59 ++offset;
60 }
61
62 return offset;
63 }
64
65