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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Uwe Zeisbergerf30c2262006-10-03 23:01:26 +02002 * linux/ipc/msgutil.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 * 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>
Al Viro40401532012-02-13 03:58:52 +000016#include <linux/msg.h>
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070017#include <linux/ipc_namespace.h>
Al Viro40401532012-02-13 03:58:52 +000018#include <linux/utsname.h>
Eric W. Biederman98f842e2011-06-15 10:21:48 -070019#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/uaccess.h>
21
22#include "util.h"
23
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070024DEFINE_SPINLOCK(mq_lock);
25
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070026/*
27 * The next 2 defines are here bc this is the only file
28 * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
29 * and not CONFIG_IPC_NS.
30 */
31struct ipc_namespace init_ipc_ns = {
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070032 .count = ATOMIC_INIT(1),
Serge E. Hallynb5154982011-03-23 16:43:23 -070033 .user_ns = &init_user_ns,
Eric W. Biederman98f842e2011-06-15 10:21:48 -070034 .proc_inum = PROC_IPC_INIT_INO,
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070035};
36
37atomic_t nr_ipc_ns = ATOMIC_INIT(1);
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039struct msg_msgseg {
40 struct msg_msgseg* next;
41 /* the next part of the message follows immediately */
42};
43
44#define DATALEN_MSG (PAGE_SIZE-sizeof(struct msg_msg))
45#define DATALEN_SEG (PAGE_SIZE-sizeof(struct msg_msgseg))
46
47struct msg_msg *load_msg(const void __user *src, int len)
48{
49 struct msg_msg *msg;
50 struct msg_msgseg **pseg;
51 int err;
52 int alen;
53
54 alen = len;
55 if (alen > DATALEN_MSG)
56 alen = DATALEN_MSG;
57
Robert P. J. Day5cbded52006-12-13 00:35:56 -080058 msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 if (msg == NULL)
60 return ERR_PTR(-ENOMEM);
61
62 msg->next = NULL;
63 msg->security = NULL;
64
65 if (copy_from_user(msg + 1, src, alen)) {
66 err = -EFAULT;
67 goto out_err;
68 }
69
70 len -= alen;
71 src = ((char __user *)src) + alen;
72 pseg = &msg->next;
73 while (len > 0) {
74 struct msg_msgseg *seg;
75 alen = len;
76 if (alen > DATALEN_SEG)
77 alen = DATALEN_SEG;
Robert P. J. Day5cbded52006-12-13 00:35:56 -080078 seg = kmalloc(sizeof(*seg) + alen,
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 GFP_KERNEL);
80 if (seg == NULL) {
81 err = -ENOMEM;
82 goto out_err;
83 }
84 *pseg = seg;
85 seg->next = NULL;
86 if (copy_from_user(seg + 1, src, alen)) {
87 err = -EFAULT;
88 goto out_err;
89 }
90 pseg = &seg->next;
91 len -= alen;
92 src = ((char __user *)src) + alen;
93 }
94
95 err = security_msg_msg_alloc(msg);
96 if (err)
97 goto out_err;
98
99 return msg;
100
101out_err:
102 free_msg(msg);
103 return ERR_PTR(err);
104}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800105#ifdef CONFIG_CHECKPOINT_RESTORE
106struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
107{
108 struct msg_msgseg *dst_pseg, *src_pseg;
109 int len = src->m_ts;
110 int alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800112 BUG_ON(dst == NULL);
113 if (src->m_ts > dst->m_ts)
114 return ERR_PTR(-EINVAL);
115
116 alen = len;
117 if (alen > DATALEN_MSG)
118 alen = DATALEN_MSG;
119
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800120 memcpy(dst + 1, src + 1, alen);
121
122 len -= alen;
123 dst_pseg = dst->next;
124 src_pseg = src->next;
125 while (len > 0) {
126 alen = len;
127 if (alen > DATALEN_SEG)
128 alen = DATALEN_SEG;
129 memcpy(dst_pseg + 1, src_pseg + 1, alen);
130 dst_pseg = dst_pseg->next;
131 len -= alen;
132 src_pseg = src_pseg->next;
133 }
134
135 dst->m_type = src->m_type;
136 dst->m_ts = src->m_ts;
137
138 return dst;
139}
Stanislav Kinsbursky51eeaca2013-01-04 15:35:01 -0800140#else
141struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
142{
143 return ERR_PTR(-ENOSYS);
144}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800145#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146int store_msg(void __user *dest, struct msg_msg *msg, int len)
147{
148 int alen;
149 struct msg_msgseg *seg;
150
151 alen = len;
152 if (alen > DATALEN_MSG)
153 alen = DATALEN_MSG;
154 if (copy_to_user(dest, msg + 1, alen))
155 return -1;
156
157 len -= alen;
158 dest = ((char __user *)dest) + alen;
159 seg = msg->next;
160 while (len > 0) {
161 alen = len;
162 if (alen > DATALEN_SEG)
163 alen = DATALEN_SEG;
164 if (copy_to_user(dest, seg + 1, alen))
165 return -1;
166 len -= alen;
167 dest = ((char __user *)dest) + alen;
168 seg = seg->next;
169 }
170 return 0;
171}
172
173void free_msg(struct msg_msg *msg)
174{
175 struct msg_msgseg *seg;
176
177 security_msg_msg_free(msg);
178
179 seg = msg->next;
180 kfree(msg);
181 while (seg != NULL) {
182 struct msg_msgseg *tmp = seg->next;
183 kfree(seg);
184 seg = tmp;
185 }
186}