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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>
David Howells0bb80f22013-04-12 01:50:06 +010019#include <linux/proc_ns.h>
HoSung Jung1e3c9412013-04-30 19:15:09 -070020#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
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,
Al Viro435d5f42014-10-31 22:56:04 -040034 .ns.inum = PROC_IPC_INIT_INO,
Al Viro33c42942014-11-01 02:32:53 -040035#ifdef CONFIG_IPC_NS
36 .ns.ops = &ipcns_operations,
37#endif
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070038};
39
40atomic_t nr_ipc_ns = ATOMIC_INIT(1);
41
Linus Torvalds1da177e2005-04-16 15:20:36 -070042struct msg_msgseg {
HoSung Jung1e3c9412013-04-30 19:15:09 -070043 struct msg_msgseg *next;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 /* the next part of the message follows immediately */
45};
46
Mathias Krause4e9b45a2013-11-12 15:11:47 -080047#define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg))
48#define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Peter Hurleybe5f4b32013-04-30 19:14:31 -070050
Mathias Krause4e9b45a2013-11-12 15:11:47 -080051static struct msg_msg *alloc_msg(size_t len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070052{
53 struct msg_msg *msg;
54 struct msg_msgseg **pseg;
Mathias Krause4e9b45a2013-11-12 15:11:47 -080055 size_t alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
Peter Hurley3d8fa452013-04-30 19:14:25 -070057 alen = min(len, DATALEN_MSG);
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)
Peter Hurleybe5f4b32013-04-30 19:14:31 -070060 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62 msg->next = NULL;
63 msg->security = NULL;
64
Peter Hurleybe5f4b32013-04-30 19:14:31 -070065 len -= alen;
66 pseg = &msg->next;
67 while (len > 0) {
68 struct msg_msgseg *seg;
69 alen = min(len, DATALEN_SEG);
70 seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL);
71 if (seg == NULL)
72 goto out_err;
73 *pseg = seg;
74 seg->next = NULL;
75 pseg = &seg->next;
76 len -= alen;
77 }
78
79 return msg;
80
81out_err:
82 free_msg(msg);
83 return NULL;
84}
85
Mathias Krause4e9b45a2013-11-12 15:11:47 -080086struct msg_msg *load_msg(const void __user *src, size_t len)
Peter Hurleybe5f4b32013-04-30 19:14:31 -070087{
88 struct msg_msg *msg;
89 struct msg_msgseg *seg;
Peter Hurley2b3097a2013-04-30 19:14:42 -070090 int err = -EFAULT;
Mathias Krause4e9b45a2013-11-12 15:11:47 -080091 size_t alen;
Peter Hurleybe5f4b32013-04-30 19:14:31 -070092
93 msg = alloc_msg(len);
94 if (msg == NULL)
95 return ERR_PTR(-ENOMEM);
96
97 alen = min(len, DATALEN_MSG);
Peter Hurley2b3097a2013-04-30 19:14:42 -070098 if (copy_from_user(msg + 1, src, alen))
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Peter Hurleyda085d42013-04-30 19:14:37 -0700101 for (seg = msg->next; seg != NULL; seg = seg->next) {
102 len -= alen;
103 src = (char __user *)src + alen;
Peter Hurley3d8fa452013-04-30 19:14:25 -0700104 alen = min(len, DATALEN_SEG);
Peter Hurley2b3097a2013-04-30 19:14:42 -0700105 if (copy_from_user(seg + 1, src, alen))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 }
108
109 err = security_msg_msg_alloc(msg);
110 if (err)
111 goto out_err;
112
113 return msg;
114
115out_err:
116 free_msg(msg);
117 return ERR_PTR(err);
118}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800119#ifdef CONFIG_CHECKPOINT_RESTORE
120struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
121{
122 struct msg_msgseg *dst_pseg, *src_pseg;
Mathias Krause4e9b45a2013-11-12 15:11:47 -0800123 size_t len = src->m_ts;
124 size_t alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Davidlohr Buesod0edd852015-09-09 15:39:20 -0700126 WARN_ON(dst == NULL);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800127 if (src->m_ts > dst->m_ts)
128 return ERR_PTR(-EINVAL);
129
Peter Hurley3d8fa452013-04-30 19:14:25 -0700130 alen = min(len, DATALEN_MSG);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800131 memcpy(dst + 1, src + 1, alen);
132
Peter Hurleyda085d42013-04-30 19:14:37 -0700133 for (dst_pseg = dst->next, src_pseg = src->next;
134 src_pseg != NULL;
135 dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
136
137 len -= alen;
Peter Hurley3d8fa452013-04-30 19:14:25 -0700138 alen = min(len, DATALEN_SEG);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800139 memcpy(dst_pseg + 1, src_pseg + 1, alen);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800140 }
141
142 dst->m_type = src->m_type;
143 dst->m_ts = src->m_ts;
144
145 return dst;
146}
Stanislav Kinsbursky51eeaca2013-01-04 15:35:01 -0800147#else
148struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
149{
150 return ERR_PTR(-ENOSYS);
151}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800152#endif
Mathias Krause4e9b45a2013-11-12 15:11:47 -0800153int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154{
Mathias Krause4e9b45a2013-11-12 15:11:47 -0800155 size_t alen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 struct msg_msgseg *seg;
157
Peter Hurley3d8fa452013-04-30 19:14:25 -0700158 alen = min(len, DATALEN_MSG);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 if (copy_to_user(dest, msg + 1, alen))
160 return -1;
161
Peter Hurleyda085d42013-04-30 19:14:37 -0700162 for (seg = msg->next; seg != NULL; seg = seg->next) {
163 len -= alen;
164 dest = (char __user *)dest + alen;
Peter Hurley3d8fa452013-04-30 19:14:25 -0700165 alen = min(len, DATALEN_SEG);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 if (copy_to_user(dest, seg + 1, alen))
167 return -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 }
169 return 0;
170}
171
172void free_msg(struct msg_msg *msg)
173{
174 struct msg_msgseg *seg;
175
176 security_msg_msg_free(msg);
177
178 seg = msg->next;
179 kfree(msg);
180 while (seg != NULL) {
181 struct msg_msgseg *tmp = seg->next;
182 kfree(seg);
183 seg = tmp;
184 }
185}