ARM: kvm: rename cpu_reset to avoid name clash
[linux-2.6.git] / ipc / msgutil.c
blob491e71f2a1b862a72e78a54e7b16e08812a13f3d
1 /*
2 * linux/ipc/msgutil.c
3 * Copyright (C) 1999, 2004 Manfred Spraul
5 * This file is released under GNU General Public Licence version 2 or
6 * (at your option) any later version.
8 * See the file COPYING for more details.
9 */
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 <linux/msg.h>
17 #include <linux/ipc_namespace.h>
18 #include <linux/utsname.h>
19 #include <linux/proc_ns.h>
20 #include <linux/uaccess.h>
22 #include "util.h"
24 DEFINE_SPINLOCK(mq_lock);
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.
31 struct ipc_namespace init_ipc_ns = {
32 .count = ATOMIC_INIT(1),
33 .user_ns = &init_user_ns,
34 .proc_inum = PROC_IPC_INIT_INO,
37 atomic_t nr_ipc_ns = ATOMIC_INIT(1);
39 struct msg_msgseg {
40 struct msg_msgseg *next;
41 /* the next part of the message follows immediately */
44 #define DATALEN_MSG (int)(PAGE_SIZE-sizeof(struct msg_msg))
45 #define DATALEN_SEG (int)(PAGE_SIZE-sizeof(struct msg_msgseg))
48 static struct msg_msg *alloc_msg(int len)
50 struct msg_msg *msg;
51 struct msg_msgseg **pseg;
52 int alen;
54 alen = min(len, DATALEN_MSG);
55 msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
56 if (msg == NULL)
57 return NULL;
59 msg->next = NULL;
60 msg->security = NULL;
62 len -= alen;
63 pseg = &msg->next;
64 while (len > 0) {
65 struct msg_msgseg *seg;
66 alen = min(len, DATALEN_SEG);
67 seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL);
68 if (seg == NULL)
69 goto out_err;
70 *pseg = seg;
71 seg->next = NULL;
72 pseg = &seg->next;
73 len -= alen;
76 return msg;
78 out_err:
79 free_msg(msg);
80 return NULL;
83 struct msg_msg *load_msg(const void __user *src, int len)
85 struct msg_msg *msg;
86 struct msg_msgseg *seg;
87 int err = -EFAULT;
88 int alen;
90 msg = alloc_msg(len);
91 if (msg == NULL)
92 return ERR_PTR(-ENOMEM);
94 alen = min(len, DATALEN_MSG);
95 if (copy_from_user(msg + 1, src, alen))
96 goto out_err;
98 for (seg = msg->next; seg != NULL; seg = seg->next) {
99 len -= alen;
100 src = (char __user *)src + alen;
101 alen = min(len, DATALEN_SEG);
102 if (copy_from_user(seg + 1, src, alen))
103 goto out_err;
106 err = security_msg_msg_alloc(msg);
107 if (err)
108 goto out_err;
110 return msg;
112 out_err:
113 free_msg(msg);
114 return ERR_PTR(err);
116 #ifdef CONFIG_CHECKPOINT_RESTORE
117 struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
119 struct msg_msgseg *dst_pseg, *src_pseg;
120 int len = src->m_ts;
121 int alen;
123 BUG_ON(dst == NULL);
124 if (src->m_ts > dst->m_ts)
125 return ERR_PTR(-EINVAL);
127 alen = min(len, DATALEN_MSG);
128 memcpy(dst + 1, src + 1, alen);
130 for (dst_pseg = dst->next, src_pseg = src->next;
131 src_pseg != NULL;
132 dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {
134 len -= alen;
135 alen = min(len, DATALEN_SEG);
136 memcpy(dst_pseg + 1, src_pseg + 1, alen);
139 dst->m_type = src->m_type;
140 dst->m_ts = src->m_ts;
142 return dst;
144 #else
145 struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
147 return ERR_PTR(-ENOSYS);
149 #endif
150 int store_msg(void __user *dest, struct msg_msg *msg, int len)
152 int alen;
153 struct msg_msgseg *seg;
155 alen = min(len, DATALEN_MSG);
156 if (copy_to_user(dest, msg + 1, alen))
157 return -1;
159 for (seg = msg->next; seg != NULL; seg = seg->next) {
160 len -= alen;
161 dest = (char __user *)dest + alen;
162 alen = min(len, DATALEN_SEG);
163 if (copy_to_user(dest, seg + 1, alen))
164 return -1;
166 return 0;
169 void free_msg(struct msg_msg *msg)
171 struct msg_msgseg *seg;
173 security_msg_msg_free(msg);
175 seg = msg->next;
176 kfree(msg);
177 while (seg != NULL) {
178 struct msg_msgseg *tmp = seg->next;
179 kfree(seg);
180 seg = tmp;