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Commit | Line | Data |
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1da177e4 | 1 | /* |
f30c2269 | 2 | * linux/ipc/msgutil.c |
1da177e4 LT |
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> | |
40401530 | 16 | #include <linux/msg.h> |
614b84cf | 17 | #include <linux/ipc_namespace.h> |
40401530 | 18 | #include <linux/utsname.h> |
0bb80f24 | 19 | #include <linux/proc_ns.h> |
1e3c941c | 20 | #include <linux/uaccess.h> |
d6a2946a | 21 | #include <linux/sched.h> |
1da177e4 LT |
22 | |
23 | #include "util.h" | |
24 | ||
7eafd7c7 SH |
25 | DEFINE_SPINLOCK(mq_lock); |
26 | ||
614b84cf SH |
27 | /* |
28 | * The next 2 defines are here bc this is the only file | |
29 | * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE | |
30 | * and not CONFIG_IPC_NS. | |
31 | */ | |
32 | struct ipc_namespace init_ipc_ns = { | |
a2e0602c | 33 | .count = REFCOUNT_INIT(1), |
b515498f | 34 | .user_ns = &init_user_ns, |
435d5f4b | 35 | .ns.inum = PROC_IPC_INIT_INO, |
33c42940 AV |
36 | #ifdef CONFIG_IPC_NS |
37 | .ns.ops = &ipcns_operations, | |
38 | #endif | |
614b84cf SH |
39 | }; |
40 | ||
1da177e4 | 41 | struct msg_msgseg { |
1e3c941c | 42 | struct msg_msgseg *next; |
1da177e4 LT |
43 | /* the next part of the message follows immediately */ |
44 | }; | |
45 | ||
4e9b45a1 MK |
46 | #define DATALEN_MSG ((size_t)PAGE_SIZE-sizeof(struct msg_msg)) |
47 | #define DATALEN_SEG ((size_t)PAGE_SIZE-sizeof(struct msg_msgseg)) | |
1da177e4 | 48 | |
be5f4b33 | 49 | |
4e9b45a1 | 50 | static struct msg_msg *alloc_msg(size_t len) |
1da177e4 LT |
51 | { |
52 | struct msg_msg *msg; | |
53 | struct msg_msgseg **pseg; | |
4e9b45a1 | 54 | size_t alen; |
1da177e4 | 55 | |
3d8fa456 | 56 | alen = min(len, DATALEN_MSG); |
8c8d4d45 | 57 | msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL_ACCOUNT); |
1da177e4 | 58 | if (msg == NULL) |
be5f4b33 | 59 | return NULL; |
1da177e4 LT |
60 | |
61 | msg->next = NULL; | |
62 | msg->security = NULL; | |
63 | ||
be5f4b33 PH |
64 | len -= alen; |
65 | pseg = &msg->next; | |
66 | while (len > 0) { | |
67 | struct msg_msgseg *seg; | |
d6a2946a LR |
68 | |
69 | cond_resched(); | |
70 | ||
be5f4b33 | 71 | alen = min(len, DATALEN_SEG); |
8c8d4d45 | 72 | seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL_ACCOUNT); |
be5f4b33 PH |
73 | if (seg == NULL) |
74 | goto out_err; | |
75 | *pseg = seg; | |
76 | seg->next = NULL; | |
77 | pseg = &seg->next; | |
78 | len -= alen; | |
79 | } | |
80 | ||
81 | return msg; | |
82 | ||
83 | out_err: | |
84 | free_msg(msg); | |
85 | return NULL; | |
86 | } | |
87 | ||
4e9b45a1 | 88 | struct msg_msg *load_msg(const void __user *src, size_t len) |
be5f4b33 PH |
89 | { |
90 | struct msg_msg *msg; | |
91 | struct msg_msgseg *seg; | |
2b3097a2 | 92 | int err = -EFAULT; |
4e9b45a1 | 93 | size_t alen; |
be5f4b33 PH |
94 | |
95 | msg = alloc_msg(len); | |
96 | if (msg == NULL) | |
97 | return ERR_PTR(-ENOMEM); | |
98 | ||
99 | alen = min(len, DATALEN_MSG); | |
2b3097a2 | 100 | if (copy_from_user(msg + 1, src, alen)) |
1da177e4 | 101 | goto out_err; |
1da177e4 | 102 | |
da085d45 PH |
103 | for (seg = msg->next; seg != NULL; seg = seg->next) { |
104 | len -= alen; | |
105 | src = (char __user *)src + alen; | |
3d8fa456 | 106 | alen = min(len, DATALEN_SEG); |
2b3097a2 | 107 | if (copy_from_user(seg + 1, src, alen)) |
1da177e4 | 108 | goto out_err; |
1da177e4 LT |
109 | } |
110 | ||
111 | err = security_msg_msg_alloc(msg); | |
112 | if (err) | |
113 | goto out_err; | |
114 | ||
115 | return msg; | |
116 | ||
117 | out_err: | |
118 | free_msg(msg); | |
119 | return ERR_PTR(err); | |
120 | } | |
4a674f34 SK |
121 | #ifdef CONFIG_CHECKPOINT_RESTORE |
122 | struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst) | |
123 | { | |
124 | struct msg_msgseg *dst_pseg, *src_pseg; | |
4e9b45a1 MK |
125 | size_t len = src->m_ts; |
126 | size_t alen; | |
4a674f34 | 127 | |
4a674f34 SK |
128 | if (src->m_ts > dst->m_ts) |
129 | return ERR_PTR(-EINVAL); | |
130 | ||
3d8fa456 | 131 | alen = min(len, DATALEN_MSG); |
4a674f34 SK |
132 | memcpy(dst + 1, src + 1, alen); |
133 | ||
da085d45 PH |
134 | for (dst_pseg = dst->next, src_pseg = src->next; |
135 | src_pseg != NULL; | |
136 | dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) { | |
137 | ||
138 | len -= alen; | |
3d8fa456 | 139 | alen = min(len, DATALEN_SEG); |
4a674f34 | 140 | memcpy(dst_pseg + 1, src_pseg + 1, alen); |
4a674f34 SK |
141 | } |
142 | ||
143 | dst->m_type = src->m_type; | |
144 | dst->m_ts = src->m_ts; | |
145 | ||
146 | return dst; | |
147 | } | |
51eeacaa SK |
148 | #else |
149 | struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst) | |
150 | { | |
151 | return ERR_PTR(-ENOSYS); | |
152 | } | |
4a674f34 | 153 | #endif |
4e9b45a1 | 154 | int store_msg(void __user *dest, struct msg_msg *msg, size_t len) |
1da177e4 | 155 | { |
4e9b45a1 | 156 | size_t alen; |
1da177e4 LT |
157 | struct msg_msgseg *seg; |
158 | ||
3d8fa456 | 159 | alen = min(len, DATALEN_MSG); |
1da177e4 LT |
160 | if (copy_to_user(dest, msg + 1, alen)) |
161 | return -1; | |
162 | ||
da085d45 PH |
163 | for (seg = msg->next; seg != NULL; seg = seg->next) { |
164 | len -= alen; | |
165 | dest = (char __user *)dest + alen; | |
3d8fa456 | 166 | alen = min(len, DATALEN_SEG); |
1da177e4 LT |
167 | if (copy_to_user(dest, seg + 1, alen)) |
168 | return -1; | |
1da177e4 LT |
169 | } |
170 | return 0; | |
171 | } | |
172 | ||
173 | void 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; | |
d6a2946a LR |
183 | |
184 | cond_resched(); | |
1da177e4 LT |
185 | kfree(seg); |
186 | seg = tmp; | |
187 | } | |
188 | } |