Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/ipc/msgutil.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 2417 byte(s)
Wed Mar 4 11:03:09 2009 UTC (15 years, 3 months ago) by niro
File MIME type: text/plain
File size: 2417 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * linux/ipc/util.c |
3 | * Copyright (C) 1999, 2004 Manfred Spraul |
4 | * |
5 | * This file is released under GNU General Public Licence version 2 or |
6 | * (at your option) any later version. |
7 | * |
8 | * See the file COPYING for more details. |
9 | */ |
10 | |
11 | #include <linux/spinlock.h> |
12 | #include <linux/init.h> |
13 | #include <linux/security.h> |
14 | #include <linux/slab.h> |
15 | #include <linux/ipc.h> |
16 | #include <asm/uaccess.h> |
17 | |
18 | #include "util.h" |
19 | |
20 | struct msg_msgseg { |
21 | struct msg_msgseg* next; |
22 | /* the next part of the message follows immediately */ |
23 | }; |
24 | |
25 | #define DATALEN_MSG (PAGE_SIZE-sizeof(struct msg_msg)) |
26 | #define DATALEN_SEG (PAGE_SIZE-sizeof(struct msg_msgseg)) |
27 | |
28 | struct msg_msg *load_msg(const void __user *src, int len) |
29 | { |
30 | struct msg_msg *msg; |
31 | struct msg_msgseg **pseg; |
32 | int err; |
33 | int alen; |
34 | |
35 | alen = len; |
36 | if (alen > DATALEN_MSG) |
37 | alen = DATALEN_MSG; |
38 | |
39 | msg = (struct msg_msg *)kmalloc(sizeof(*msg) + alen, GFP_KERNEL); |
40 | if (msg == NULL) |
41 | return ERR_PTR(-ENOMEM); |
42 | |
43 | msg->next = NULL; |
44 | msg->security = NULL; |
45 | |
46 | if (copy_from_user(msg + 1, src, alen)) { |
47 | err = -EFAULT; |
48 | goto out_err; |
49 | } |
50 | |
51 | len -= alen; |
52 | src = ((char __user *)src) + alen; |
53 | pseg = &msg->next; |
54 | while (len > 0) { |
55 | struct msg_msgseg *seg; |
56 | alen = len; |
57 | if (alen > DATALEN_SEG) |
58 | alen = DATALEN_SEG; |
59 | seg = (struct msg_msgseg *)kmalloc(sizeof(*seg) + alen, |
60 | GFP_KERNEL); |
61 | if (seg == NULL) { |
62 | err = -ENOMEM; |
63 | goto out_err; |
64 | } |
65 | *pseg = seg; |
66 | seg->next = NULL; |
67 | if (copy_from_user(seg + 1, src, alen)) { |
68 | err = -EFAULT; |
69 | goto out_err; |
70 | } |
71 | pseg = &seg->next; |
72 | len -= alen; |
73 | src = ((char __user *)src) + alen; |
74 | } |
75 | |
76 | err = security_msg_msg_alloc(msg); |
77 | if (err) |
78 | goto out_err; |
79 | |
80 | return msg; |
81 | |
82 | out_err: |
83 | free_msg(msg); |
84 | return ERR_PTR(err); |
85 | } |
86 | |
87 | int store_msg(void __user *dest, struct msg_msg *msg, int len) |
88 | { |
89 | int alen; |
90 | struct msg_msgseg *seg; |
91 | |
92 | alen = len; |
93 | if (alen > DATALEN_MSG) |
94 | alen = DATALEN_MSG; |
95 | if (copy_to_user(dest, msg + 1, alen)) |
96 | return -1; |
97 | |
98 | len -= alen; |
99 | dest = ((char __user *)dest) + alen; |
100 | seg = msg->next; |
101 | while (len > 0) { |
102 | alen = len; |
103 | if (alen > DATALEN_SEG) |
104 | alen = DATALEN_SEG; |
105 | if (copy_to_user(dest, seg + 1, alen)) |
106 | return -1; |
107 | len -= alen; |
108 | dest = ((char __user *)dest) + alen; |
109 | seg = seg->next; |
110 | } |
111 | return 0; |
112 | } |
113 | |
114 | void free_msg(struct msg_msg *msg) |
115 | { |
116 | struct msg_msgseg *seg; |
117 | |
118 | security_msg_msg_free(msg); |
119 | |
120 | seg = msg->next; |
121 | kfree(msg); |
122 | while (seg != NULL) { |
123 | struct msg_msgseg *tmp = seg->next; |
124 | kfree(seg); |
125 | seg = tmp; |
126 | } |
127 | } |