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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/ipc/msg.c | |
5a06a363 | 3 | * Copyright (C) 1992 Krishna Balasubramanian |
1da177e4 LT |
4 | * |
5 | * Removed all the remaining kerneld mess | |
6 | * Catch the -EFAULT stuff properly | |
7 | * Use GFP_KERNEL for messages as in 1.2 | |
8 | * Fixed up the unchecked user space derefs | |
9 | * Copyright (C) 1998 Alan Cox & Andi Kleen | |
10 | * | |
11 | * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com> | |
12 | * | |
13 | * mostly rewritten, threaded and wake-one semantics added | |
14 | * MSGMAX limit removed, sysctl's added | |
624dffcb | 15 | * (c) 1999 Manfred Spraul <manfred@colorfullife.com> |
073115d6 SG |
16 | * |
17 | * support for audit of ipc object properties and permission changes | |
18 | * Dustin Kirkland <dustin.kirkland@us.ibm.com> | |
1e786937 KK |
19 | * |
20 | * namespaces support | |
21 | * OpenVZ, SWsoft Inc. | |
22 | * Pavel Emelianov <xemul@openvz.org> | |
1da177e4 LT |
23 | */ |
24 | ||
c59ede7b | 25 | #include <linux/capability.h> |
1da177e4 LT |
26 | #include <linux/msg.h> |
27 | #include <linux/spinlock.h> | |
28 | #include <linux/init.h> | |
f7bf3df8 | 29 | #include <linux/mm.h> |
1da177e4 LT |
30 | #include <linux/proc_fs.h> |
31 | #include <linux/list.h> | |
32 | #include <linux/security.h> | |
33 | #include <linux/sched.h> | |
34 | #include <linux/syscalls.h> | |
35 | #include <linux/audit.h> | |
19b4946c | 36 | #include <linux/seq_file.h> |
3e148c79 | 37 | #include <linux/rwsem.h> |
1e786937 | 38 | #include <linux/nsproxy.h> |
ae5e1b22 | 39 | #include <linux/ipc_namespace.h> |
5f921ae9 | 40 | |
1da177e4 | 41 | #include <asm/current.h> |
7153e402 | 42 | #include <linux/uaccess.h> |
1da177e4 LT |
43 | #include "util.h" |
44 | ||
5a06a363 IM |
45 | /* |
46 | * one msg_receiver structure for each sleeping receiver: | |
47 | */ | |
1da177e4 | 48 | struct msg_receiver { |
5a06a363 IM |
49 | struct list_head r_list; |
50 | struct task_struct *r_tsk; | |
1da177e4 | 51 | |
5a06a363 IM |
52 | int r_mode; |
53 | long r_msgtype; | |
54 | long r_maxsize; | |
1da177e4 | 55 | |
80491eb9 | 56 | struct msg_msg *volatile r_msg; |
1da177e4 LT |
57 | }; |
58 | ||
59 | /* one msg_sender for each sleeping sender */ | |
60 | struct msg_sender { | |
5a06a363 IM |
61 | struct list_head list; |
62 | struct task_struct *tsk; | |
1da177e4 LT |
63 | }; |
64 | ||
65 | #define SEARCH_ANY 1 | |
66 | #define SEARCH_EQUAL 2 | |
67 | #define SEARCH_NOTEQUAL 3 | |
68 | #define SEARCH_LESSEQUAL 4 | |
8ac6ed58 | 69 | #define SEARCH_NUMBER 5 |
1da177e4 | 70 | |
ed2ddbf8 | 71 | #define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS]) |
1da177e4 | 72 | |
a5001a0d DB |
73 | static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id) |
74 | { | |
75 | struct kern_ipc_perm *ipcp = ipc_obtain_object(&msg_ids(ns), id); | |
76 | ||
77 | if (IS_ERR(ipcp)) | |
78 | return ERR_CAST(ipcp); | |
79 | ||
80 | return container_of(ipcp, struct msg_queue, q_perm); | |
81 | } | |
82 | ||
83 | static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns, | |
84 | int id) | |
85 | { | |
86 | struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id); | |
87 | ||
88 | if (IS_ERR(ipcp)) | |
89 | return ERR_CAST(ipcp); | |
90 | ||
91 | return container_of(ipcp, struct msg_queue, q_perm); | |
92 | } | |
93 | ||
7ca7e564 ND |
94 | static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) |
95 | { | |
96 | ipc_rmid(&msg_ids(ns), &s->q_perm); | |
97 | } | |
98 | ||
53dad6d3 DB |
99 | static void msg_rcu_free(struct rcu_head *head) |
100 | { | |
101 | struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu); | |
102 | struct msg_queue *msq = ipc_rcu_to_struct(p); | |
103 | ||
104 | security_msg_queue_free(msq); | |
105 | ipc_rcu_free(head); | |
106 | } | |
107 | ||
f4566f04 ND |
108 | /** |
109 | * newque - Create a new msg queue | |
110 | * @ns: namespace | |
111 | * @params: ptr to the structure that contains the key and msgflg | |
112 | * | |
d9a605e4 | 113 | * Called with msg_ids.rwsem held (writer) |
f4566f04 | 114 | */ |
7748dbfa | 115 | static int newque(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 116 | { |
1da177e4 | 117 | struct msg_queue *msq; |
5a06a363 | 118 | int id, retval; |
7748dbfa ND |
119 | key_t key = params->key; |
120 | int msgflg = params->flg; | |
1da177e4 | 121 | |
5a06a363 IM |
122 | msq = ipc_rcu_alloc(sizeof(*msq)); |
123 | if (!msq) | |
1da177e4 LT |
124 | return -ENOMEM; |
125 | ||
5a06a363 | 126 | msq->q_perm.mode = msgflg & S_IRWXUGO; |
1da177e4 LT |
127 | msq->q_perm.key = key; |
128 | ||
129 | msq->q_perm.security = NULL; | |
130 | retval = security_msg_queue_alloc(msq); | |
131 | if (retval) { | |
53dad6d3 | 132 | ipc_rcu_putref(msq, ipc_rcu_free); |
1da177e4 LT |
133 | return retval; |
134 | } | |
135 | ||
dbfcd91f | 136 | /* ipc_addid() locks msq upon success. */ |
1e786937 | 137 | id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); |
283bb7fa | 138 | if (id < 0) { |
53dad6d3 | 139 | ipc_rcu_putref(msq, msg_rcu_free); |
283bb7fa | 140 | return id; |
1da177e4 LT |
141 | } |
142 | ||
143 | msq->q_stime = msq->q_rtime = 0; | |
144 | msq->q_ctime = get_seconds(); | |
145 | msq->q_cbytes = msq->q_qnum = 0; | |
1e786937 | 146 | msq->q_qbytes = ns->msg_ctlmnb; |
1da177e4 LT |
147 | msq->q_lspid = msq->q_lrpid = 0; |
148 | INIT_LIST_HEAD(&msq->q_messages); | |
149 | INIT_LIST_HEAD(&msq->q_receivers); | |
150 | INIT_LIST_HEAD(&msq->q_senders); | |
7ca7e564 | 151 | |
cf9d5d78 | 152 | ipc_unlock_object(&msq->q_perm); |
dbfcd91f | 153 | rcu_read_unlock(); |
1da177e4 | 154 | |
7ca7e564 | 155 | return msq->q_perm.id; |
1da177e4 LT |
156 | } |
157 | ||
5a06a363 | 158 | static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss) |
1da177e4 | 159 | { |
5a06a363 | 160 | mss->tsk = current; |
f75a2f35 | 161 | __set_current_state(TASK_INTERRUPTIBLE); |
5a06a363 | 162 | list_add_tail(&mss->list, &msq->q_senders); |
1da177e4 LT |
163 | } |
164 | ||
5a06a363 | 165 | static inline void ss_del(struct msg_sender *mss) |
1da177e4 | 166 | { |
5a06a363 | 167 | if (mss->list.next != NULL) |
1da177e4 LT |
168 | list_del(&mss->list); |
169 | } | |
170 | ||
5a06a363 | 171 | static void ss_wakeup(struct list_head *h, int kill) |
1da177e4 | 172 | { |
41239fe8 | 173 | struct msg_sender *mss, *t; |
1da177e4 | 174 | |
41239fe8 | 175 | list_for_each_entry_safe(mss, t, h, list) { |
5a06a363 IM |
176 | if (kill) |
177 | mss->list.next = NULL; | |
1da177e4 LT |
178 | wake_up_process(mss->tsk); |
179 | } | |
180 | } | |
181 | ||
5a06a363 | 182 | static void expunge_all(struct msg_queue *msq, int res) |
1da177e4 | 183 | { |
41239fe8 | 184 | struct msg_receiver *msr, *t; |
5a06a363 | 185 | |
41239fe8 | 186 | list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) { |
ffa571da | 187 | msr->r_msg = NULL; /* initialize expunge ordering */ |
1da177e4 | 188 | wake_up_process(msr->r_tsk); |
ffa571da DB |
189 | /* |
190 | * Ensure that the wakeup is visible before setting r_msg as | |
191 | * the receiving end depends on it: either spinning on a nil, | |
192 | * or dealing with -EAGAIN cases. See lockless receive part 1 | |
193 | * and 2 in do_msgrcv(). | |
194 | */ | |
1da177e4 LT |
195 | smp_mb(); |
196 | msr->r_msg = ERR_PTR(res); | |
197 | } | |
198 | } | |
5a06a363 IM |
199 | |
200 | /* | |
201 | * freeque() wakes up waiters on the sender and receiver waiting queue, | |
f4566f04 ND |
202 | * removes the message queue from message queue ID IDR, and cleans up all the |
203 | * messages associated with this queue. | |
1da177e4 | 204 | * |
d9a605e4 DB |
205 | * msg_ids.rwsem (writer) and the spinlock for this message queue are held |
206 | * before freeque() is called. msg_ids.rwsem remains locked on exit. | |
1da177e4 | 207 | */ |
01b8b07a | 208 | static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
1da177e4 | 209 | { |
41239fe8 | 210 | struct msg_msg *msg, *t; |
01b8b07a | 211 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); |
1da177e4 | 212 | |
5a06a363 IM |
213 | expunge_all(msq, -EIDRM); |
214 | ss_wakeup(&msq->q_senders, 1); | |
7ca7e564 | 215 | msg_rmid(ns, msq); |
4718787d DB |
216 | ipc_unlock_object(&msq->q_perm); |
217 | rcu_read_unlock(); | |
5a06a363 | 218 | |
41239fe8 | 219 | list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) { |
3ac88a41 | 220 | atomic_dec(&ns->msg_hdrs); |
1da177e4 LT |
221 | free_msg(msg); |
222 | } | |
3ac88a41 | 223 | atomic_sub(msq->q_cbytes, &ns->msg_bytes); |
53dad6d3 | 224 | ipc_rcu_putref(msq, msg_rcu_free); |
1da177e4 LT |
225 | } |
226 | ||
f4566f04 | 227 | /* |
d9a605e4 | 228 | * Called with msg_ids.rwsem and ipcp locked. |
f4566f04 | 229 | */ |
03f02c76 | 230 | static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg) |
7748dbfa | 231 | { |
03f02c76 ND |
232 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); |
233 | ||
234 | return security_msg_queue_associate(msq, msgflg); | |
7748dbfa ND |
235 | } |
236 | ||
e48fbb69 | 237 | SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg) |
1da177e4 | 238 | { |
1e786937 | 239 | struct ipc_namespace *ns; |
eb66ec44 MK |
240 | static const struct ipc_ops msg_ops = { |
241 | .getnew = newque, | |
242 | .associate = msg_security, | |
243 | }; | |
7748dbfa | 244 | struct ipc_params msg_params; |
1e786937 KK |
245 | |
246 | ns = current->nsproxy->ipc_ns; | |
7ca7e564 | 247 | |
7748dbfa ND |
248 | msg_params.key = key; |
249 | msg_params.flg = msgflg; | |
5a06a363 | 250 | |
7748dbfa | 251 | return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params); |
1da177e4 LT |
252 | } |
253 | ||
5a06a363 IM |
254 | static inline unsigned long |
255 | copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version) | |
1da177e4 | 256 | { |
239521f3 | 257 | switch (version) { |
1da177e4 | 258 | case IPC_64: |
5a06a363 | 259 | return copy_to_user(buf, in, sizeof(*in)); |
1da177e4 | 260 | case IPC_OLD: |
5a06a363 | 261 | { |
1da177e4 LT |
262 | struct msqid_ds out; |
263 | ||
5a06a363 | 264 | memset(&out, 0, sizeof(out)); |
1da177e4 LT |
265 | |
266 | ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); | |
267 | ||
268 | out.msg_stime = in->msg_stime; | |
269 | out.msg_rtime = in->msg_rtime; | |
270 | out.msg_ctime = in->msg_ctime; | |
271 | ||
4be929be AD |
272 | if (in->msg_cbytes > USHRT_MAX) |
273 | out.msg_cbytes = USHRT_MAX; | |
1da177e4 LT |
274 | else |
275 | out.msg_cbytes = in->msg_cbytes; | |
276 | out.msg_lcbytes = in->msg_cbytes; | |
277 | ||
4be929be AD |
278 | if (in->msg_qnum > USHRT_MAX) |
279 | out.msg_qnum = USHRT_MAX; | |
1da177e4 LT |
280 | else |
281 | out.msg_qnum = in->msg_qnum; | |
282 | ||
4be929be AD |
283 | if (in->msg_qbytes > USHRT_MAX) |
284 | out.msg_qbytes = USHRT_MAX; | |
1da177e4 LT |
285 | else |
286 | out.msg_qbytes = in->msg_qbytes; | |
287 | out.msg_lqbytes = in->msg_qbytes; | |
288 | ||
289 | out.msg_lspid = in->msg_lspid; | |
290 | out.msg_lrpid = in->msg_lrpid; | |
291 | ||
5a06a363 IM |
292 | return copy_to_user(buf, &out, sizeof(out)); |
293 | } | |
1da177e4 LT |
294 | default: |
295 | return -EINVAL; | |
296 | } | |
297 | } | |
298 | ||
5a06a363 | 299 | static inline unsigned long |
016d7132 | 300 | copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version) |
1da177e4 | 301 | { |
239521f3 | 302 | switch (version) { |
1da177e4 | 303 | case IPC_64: |
016d7132 | 304 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 305 | return -EFAULT; |
1da177e4 | 306 | return 0; |
1da177e4 | 307 | case IPC_OLD: |
5a06a363 | 308 | { |
1da177e4 LT |
309 | struct msqid_ds tbuf_old; |
310 | ||
5a06a363 | 311 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) |
1da177e4 LT |
312 | return -EFAULT; |
313 | ||
239521f3 MS |
314 | out->msg_perm.uid = tbuf_old.msg_perm.uid; |
315 | out->msg_perm.gid = tbuf_old.msg_perm.gid; | |
316 | out->msg_perm.mode = tbuf_old.msg_perm.mode; | |
1da177e4 | 317 | |
5a06a363 | 318 | if (tbuf_old.msg_qbytes == 0) |
016d7132 | 319 | out->msg_qbytes = tbuf_old.msg_lqbytes; |
1da177e4 | 320 | else |
016d7132 | 321 | out->msg_qbytes = tbuf_old.msg_qbytes; |
1da177e4 LT |
322 | |
323 | return 0; | |
5a06a363 | 324 | } |
1da177e4 LT |
325 | default: |
326 | return -EINVAL; | |
327 | } | |
328 | } | |
329 | ||
a0d092fc | 330 | /* |
d9a605e4 | 331 | * This function handles some msgctl commands which require the rwsem |
a0d092fc | 332 | * to be held in write mode. |
d9a605e4 | 333 | * NOTE: no locks must be held, the rwsem is taken inside this function. |
a0d092fc PP |
334 | */ |
335 | static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd, | |
336 | struct msqid_ds __user *buf, int version) | |
1da177e4 | 337 | { |
1da177e4 | 338 | struct kern_ipc_perm *ipcp; |
f1970c48 | 339 | struct msqid64_ds uninitialized_var(msqid64); |
a0d092fc PP |
340 | struct msg_queue *msq; |
341 | int err; | |
342 | ||
343 | if (cmd == IPC_SET) { | |
016d7132 | 344 | if (copy_msqid_from_user(&msqid64, buf, version)) |
a0d092fc PP |
345 | return -EFAULT; |
346 | } | |
347 | ||
d9a605e4 | 348 | down_write(&msg_ids(ns).rwsem); |
7b4cc5d8 DB |
349 | rcu_read_lock(); |
350 | ||
15724ecb DB |
351 | ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd, |
352 | &msqid64.msg_perm, msqid64.msg_qbytes); | |
7b4cc5d8 DB |
353 | if (IS_ERR(ipcp)) { |
354 | err = PTR_ERR(ipcp); | |
7b4cc5d8 DB |
355 | goto out_unlock1; |
356 | } | |
a0d092fc | 357 | |
a5f75e7f | 358 | msq = container_of(ipcp, struct msg_queue, q_perm); |
a0d092fc PP |
359 | |
360 | err = security_msg_queue_msgctl(msq, cmd); | |
361 | if (err) | |
15724ecb | 362 | goto out_unlock1; |
a0d092fc PP |
363 | |
364 | switch (cmd) { | |
365 | case IPC_RMID: | |
15724ecb | 366 | ipc_lock_object(&msq->q_perm); |
7b4cc5d8 | 367 | /* freeque unlocks the ipc object and rcu */ |
a0d092fc PP |
368 | freeque(ns, ipcp); |
369 | goto out_up; | |
370 | case IPC_SET: | |
016d7132 | 371 | if (msqid64.msg_qbytes > ns->msg_ctlmnb && |
a0d092fc PP |
372 | !capable(CAP_SYS_RESOURCE)) { |
373 | err = -EPERM; | |
15724ecb | 374 | goto out_unlock1; |
a0d092fc PP |
375 | } |
376 | ||
15724ecb | 377 | ipc_lock_object(&msq->q_perm); |
1efdb69b EB |
378 | err = ipc_update_perm(&msqid64.msg_perm, ipcp); |
379 | if (err) | |
7b4cc5d8 | 380 | goto out_unlock0; |
1efdb69b | 381 | |
016d7132 | 382 | msq->q_qbytes = msqid64.msg_qbytes; |
a0d092fc | 383 | |
a0d092fc PP |
384 | msq->q_ctime = get_seconds(); |
385 | /* sleeping receivers might be excluded by | |
386 | * stricter permissions. | |
387 | */ | |
388 | expunge_all(msq, -EAGAIN); | |
389 | /* sleeping senders might be able to send | |
390 | * due to a larger queue size. | |
391 | */ | |
392 | ss_wakeup(&msq->q_senders, 0); | |
393 | break; | |
394 | default: | |
395 | err = -EINVAL; | |
15724ecb | 396 | goto out_unlock1; |
a0d092fc | 397 | } |
7b4cc5d8 DB |
398 | |
399 | out_unlock0: | |
400 | ipc_unlock_object(&msq->q_perm); | |
401 | out_unlock1: | |
402 | rcu_read_unlock(); | |
a0d092fc | 403 | out_up: |
d9a605e4 | 404 | up_write(&msg_ids(ns).rwsem); |
a0d092fc PP |
405 | return err; |
406 | } | |
407 | ||
2cafed30 DB |
408 | static int msgctl_nolock(struct ipc_namespace *ns, int msqid, |
409 | int cmd, int version, void __user *buf) | |
a0d092fc | 410 | { |
2cafed30 | 411 | int err; |
5a06a363 | 412 | struct msg_queue *msq; |
1da177e4 LT |
413 | |
414 | switch (cmd) { | |
5a06a363 IM |
415 | case IPC_INFO: |
416 | case MSG_INFO: | |
417 | { | |
1da177e4 LT |
418 | struct msginfo msginfo; |
419 | int max_id; | |
5a06a363 | 420 | |
1da177e4 LT |
421 | if (!buf) |
422 | return -EFAULT; | |
2cafed30 | 423 | |
5a06a363 IM |
424 | /* |
425 | * We must not return kernel stack data. | |
1da177e4 LT |
426 | * due to padding, it's not enough |
427 | * to set all member fields. | |
428 | */ | |
1da177e4 LT |
429 | err = security_msg_queue_msgctl(NULL, cmd); |
430 | if (err) | |
431 | return err; | |
432 | ||
5a06a363 | 433 | memset(&msginfo, 0, sizeof(msginfo)); |
1e786937 KK |
434 | msginfo.msgmni = ns->msg_ctlmni; |
435 | msginfo.msgmax = ns->msg_ctlmax; | |
436 | msginfo.msgmnb = ns->msg_ctlmnb; | |
1da177e4 LT |
437 | msginfo.msgssz = MSGSSZ; |
438 | msginfo.msgseg = MSGSEG; | |
d9a605e4 | 439 | down_read(&msg_ids(ns).rwsem); |
1da177e4 | 440 | if (cmd == MSG_INFO) { |
1e786937 | 441 | msginfo.msgpool = msg_ids(ns).in_use; |
3ac88a41 KK |
442 | msginfo.msgmap = atomic_read(&ns->msg_hdrs); |
443 | msginfo.msgtql = atomic_read(&ns->msg_bytes); | |
1da177e4 LT |
444 | } else { |
445 | msginfo.msgmap = MSGMAP; | |
446 | msginfo.msgpool = MSGPOOL; | |
447 | msginfo.msgtql = MSGTQL; | |
448 | } | |
7ca7e564 | 449 | max_id = ipc_get_maxid(&msg_ids(ns)); |
d9a605e4 | 450 | up_read(&msg_ids(ns).rwsem); |
5a06a363 | 451 | if (copy_to_user(buf, &msginfo, sizeof(struct msginfo))) |
1da177e4 | 452 | return -EFAULT; |
5a06a363 | 453 | return (max_id < 0) ? 0 : max_id; |
1da177e4 | 454 | } |
2cafed30 DB |
455 | |
456 | case MSG_STAT: | |
1da177e4 LT |
457 | case IPC_STAT: |
458 | { | |
459 | struct msqid64_ds tbuf; | |
460 | int success_return; | |
5a06a363 | 461 | |
1da177e4 LT |
462 | if (!buf) |
463 | return -EFAULT; | |
1da177e4 | 464 | |
ac0ba20e DB |
465 | memset(&tbuf, 0, sizeof(tbuf)); |
466 | ||
467 | rcu_read_lock(); | |
5a06a363 | 468 | if (cmd == MSG_STAT) { |
ac0ba20e DB |
469 | msq = msq_obtain_object(ns, msqid); |
470 | if (IS_ERR(msq)) { | |
471 | err = PTR_ERR(msq); | |
472 | goto out_unlock; | |
473 | } | |
7ca7e564 | 474 | success_return = msq->q_perm.id; |
1da177e4 | 475 | } else { |
ac0ba20e DB |
476 | msq = msq_obtain_object_check(ns, msqid); |
477 | if (IS_ERR(msq)) { | |
478 | err = PTR_ERR(msq); | |
479 | goto out_unlock; | |
480 | } | |
1da177e4 LT |
481 | success_return = 0; |
482 | } | |
ac0ba20e | 483 | |
1da177e4 | 484 | err = -EACCES; |
b0e77598 | 485 | if (ipcperms(ns, &msq->q_perm, S_IRUGO)) |
1da177e4 LT |
486 | goto out_unlock; |
487 | ||
488 | err = security_msg_queue_msgctl(msq, cmd); | |
489 | if (err) | |
490 | goto out_unlock; | |
491 | ||
492 | kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm); | |
493 | tbuf.msg_stime = msq->q_stime; | |
494 | tbuf.msg_rtime = msq->q_rtime; | |
495 | tbuf.msg_ctime = msq->q_ctime; | |
496 | tbuf.msg_cbytes = msq->q_cbytes; | |
497 | tbuf.msg_qnum = msq->q_qnum; | |
498 | tbuf.msg_qbytes = msq->q_qbytes; | |
499 | tbuf.msg_lspid = msq->q_lspid; | |
500 | tbuf.msg_lrpid = msq->q_lrpid; | |
ac0ba20e DB |
501 | rcu_read_unlock(); |
502 | ||
1da177e4 LT |
503 | if (copy_msqid_to_user(buf, &tbuf, version)) |
504 | return -EFAULT; | |
505 | return success_return; | |
506 | } | |
2cafed30 | 507 | |
1da177e4 | 508 | default: |
2cafed30 | 509 | return -EINVAL; |
1da177e4 LT |
510 | } |
511 | ||
2cafed30 | 512 | return err; |
1da177e4 | 513 | out_unlock: |
ac0ba20e | 514 | rcu_read_unlock(); |
1da177e4 LT |
515 | return err; |
516 | } | |
517 | ||
2cafed30 DB |
518 | SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf) |
519 | { | |
520 | int version; | |
521 | struct ipc_namespace *ns; | |
522 | ||
523 | if (msqid < 0 || cmd < 0) | |
524 | return -EINVAL; | |
525 | ||
526 | version = ipc_parse_version(&cmd); | |
527 | ns = current->nsproxy->ipc_ns; | |
528 | ||
529 | switch (cmd) { | |
530 | case IPC_INFO: | |
531 | case MSG_INFO: | |
532 | case MSG_STAT: /* msqid is an index rather than a msg queue id */ | |
533 | case IPC_STAT: | |
534 | return msgctl_nolock(ns, msqid, cmd, version, buf); | |
535 | case IPC_SET: | |
536 | case IPC_RMID: | |
537 | return msgctl_down(ns, msqid, cmd, buf, version); | |
538 | default: | |
539 | return -EINVAL; | |
540 | } | |
541 | } | |
542 | ||
5a06a363 | 543 | static int testmsg(struct msg_msg *msg, long type, int mode) |
1da177e4 | 544 | { |
46c0a8ca PM |
545 | switch (mode) { |
546 | case SEARCH_ANY: | |
547 | case SEARCH_NUMBER: | |
548 | return 1; | |
549 | case SEARCH_LESSEQUAL: | |
550 | if (msg->m_type <= type) | |
551 | return 1; | |
552 | break; | |
553 | case SEARCH_EQUAL: | |
554 | if (msg->m_type == type) | |
1da177e4 | 555 | return 1; |
46c0a8ca PM |
556 | break; |
557 | case SEARCH_NOTEQUAL: | |
558 | if (msg->m_type != type) | |
559 | return 1; | |
560 | break; | |
1da177e4 LT |
561 | } |
562 | return 0; | |
563 | } | |
564 | ||
5a06a363 | 565 | static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg) |
1da177e4 | 566 | { |
41239fe8 | 567 | struct msg_receiver *msr, *t; |
5a06a363 | 568 | |
41239fe8 | 569 | list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) { |
5a06a363 IM |
570 | if (testmsg(msg, msr->r_msgtype, msr->r_mode) && |
571 | !security_msg_queue_msgrcv(msq, msg, msr->r_tsk, | |
572 | msr->r_msgtype, msr->r_mode)) { | |
573 | ||
1da177e4 | 574 | list_del(&msr->r_list); |
5a06a363 | 575 | if (msr->r_maxsize < msg->m_ts) { |
ffa571da | 576 | /* initialize pipelined send ordering */ |
1da177e4 LT |
577 | msr->r_msg = NULL; |
578 | wake_up_process(msr->r_tsk); | |
ffa571da | 579 | smp_mb(); /* see barrier comment below */ |
1da177e4 LT |
580 | msr->r_msg = ERR_PTR(-E2BIG); |
581 | } else { | |
582 | msr->r_msg = NULL; | |
b488893a | 583 | msq->q_lrpid = task_pid_vnr(msr->r_tsk); |
1da177e4 LT |
584 | msq->q_rtime = get_seconds(); |
585 | wake_up_process(msr->r_tsk); | |
ffa571da DB |
586 | /* |
587 | * Ensure that the wakeup is visible before | |
588 | * setting r_msg, as the receiving end depends | |
589 | * on it. See lockless receive part 1 and 2 in | |
590 | * do_msgrcv(). | |
591 | */ | |
1da177e4 LT |
592 | smp_mb(); |
593 | msr->r_msg = msg; | |
5a06a363 | 594 | |
1da177e4 LT |
595 | return 1; |
596 | } | |
597 | } | |
598 | } | |
ffa571da | 599 | |
1da177e4 LT |
600 | return 0; |
601 | } | |
602 | ||
651971cb | 603 | long do_msgsnd(int msqid, long mtype, void __user *mtext, |
604 | size_t msgsz, int msgflg) | |
1da177e4 LT |
605 | { |
606 | struct msg_queue *msq; | |
607 | struct msg_msg *msg; | |
1da177e4 | 608 | int err; |
1e786937 KK |
609 | struct ipc_namespace *ns; |
610 | ||
611 | ns = current->nsproxy->ipc_ns; | |
5a06a363 | 612 | |
1e786937 | 613 | if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0) |
1da177e4 | 614 | return -EINVAL; |
1da177e4 LT |
615 | if (mtype < 1) |
616 | return -EINVAL; | |
617 | ||
651971cb | 618 | msg = load_msg(mtext, msgsz); |
5a06a363 | 619 | if (IS_ERR(msg)) |
1da177e4 LT |
620 | return PTR_ERR(msg); |
621 | ||
622 | msg->m_type = mtype; | |
623 | msg->m_ts = msgsz; | |
624 | ||
3dd1f784 DB |
625 | rcu_read_lock(); |
626 | msq = msq_obtain_object_check(ns, msqid); | |
023a5355 ND |
627 | if (IS_ERR(msq)) { |
628 | err = PTR_ERR(msq); | |
3dd1f784 | 629 | goto out_unlock1; |
023a5355 | 630 | } |
1da177e4 | 631 | |
bebcb928 MS |
632 | ipc_lock_object(&msq->q_perm); |
633 | ||
1da177e4 LT |
634 | for (;;) { |
635 | struct msg_sender s; | |
636 | ||
5a06a363 | 637 | err = -EACCES; |
b0e77598 | 638 | if (ipcperms(ns, &msq->q_perm, S_IWUGO)) |
bebcb928 | 639 | goto out_unlock0; |
1da177e4 | 640 | |
4271b05a | 641 | /* raced with RMID? */ |
0f3d2b01 | 642 | if (!ipc_valid_object(&msq->q_perm)) { |
4271b05a DB |
643 | err = -EIDRM; |
644 | goto out_unlock0; | |
645 | } | |
646 | ||
1da177e4 LT |
647 | err = security_msg_queue_msgsnd(msq, msg, msgflg); |
648 | if (err) | |
bebcb928 | 649 | goto out_unlock0; |
1da177e4 | 650 | |
5a06a363 | 651 | if (msgsz + msq->q_cbytes <= msq->q_qbytes && |
1da177e4 LT |
652 | 1 + msq->q_qnum <= msq->q_qbytes) { |
653 | break; | |
654 | } | |
655 | ||
656 | /* queue full, wait: */ | |
5a06a363 IM |
657 | if (msgflg & IPC_NOWAIT) { |
658 | err = -EAGAIN; | |
bebcb928 | 659 | goto out_unlock0; |
1da177e4 | 660 | } |
3dd1f784 | 661 | |
ffa571da | 662 | /* enqueue the sender and prepare to block */ |
1da177e4 | 663 | ss_add(msq, &s); |
6062a8dc RR |
664 | |
665 | if (!ipc_rcu_getref(msq)) { | |
666 | err = -EIDRM; | |
3dd1f784 | 667 | goto out_unlock0; |
6062a8dc RR |
668 | } |
669 | ||
3dd1f784 DB |
670 | ipc_unlock_object(&msq->q_perm); |
671 | rcu_read_unlock(); | |
1da177e4 LT |
672 | schedule(); |
673 | ||
3dd1f784 DB |
674 | rcu_read_lock(); |
675 | ipc_lock_object(&msq->q_perm); | |
676 | ||
53dad6d3 | 677 | ipc_rcu_putref(msq, ipc_rcu_free); |
0f3d2b01 RA |
678 | /* raced with RMID? */ |
679 | if (!ipc_valid_object(&msq->q_perm)) { | |
1da177e4 | 680 | err = -EIDRM; |
3dd1f784 | 681 | goto out_unlock0; |
1da177e4 | 682 | } |
3dd1f784 | 683 | |
1da177e4 | 684 | ss_del(&s); |
5a06a363 | 685 | |
1da177e4 | 686 | if (signal_pending(current)) { |
5a06a363 | 687 | err = -ERESTARTNOHAND; |
3dd1f784 | 688 | goto out_unlock0; |
1da177e4 | 689 | } |
3dd1f784 | 690 | |
1da177e4 | 691 | } |
b488893a | 692 | msq->q_lspid = task_tgid_vnr(current); |
1da177e4 LT |
693 | msq->q_stime = get_seconds(); |
694 | ||
5a06a363 | 695 | if (!pipelined_send(msq, msg)) { |
25985edc | 696 | /* no one is waiting for this message, enqueue it */ |
5a06a363 | 697 | list_add_tail(&msg->m_list, &msq->q_messages); |
1da177e4 LT |
698 | msq->q_cbytes += msgsz; |
699 | msq->q_qnum++; | |
3ac88a41 KK |
700 | atomic_add(msgsz, &ns->msg_bytes); |
701 | atomic_inc(&ns->msg_hdrs); | |
1da177e4 | 702 | } |
5a06a363 | 703 | |
1da177e4 LT |
704 | err = 0; |
705 | msg = NULL; | |
706 | ||
3dd1f784 DB |
707 | out_unlock0: |
708 | ipc_unlock_object(&msq->q_perm); | |
709 | out_unlock1: | |
710 | rcu_read_unlock(); | |
5a06a363 | 711 | if (msg != NULL) |
1da177e4 LT |
712 | free_msg(msg); |
713 | return err; | |
714 | } | |
715 | ||
e48fbb69 HC |
716 | SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz, |
717 | int, msgflg) | |
651971cb | 718 | { |
719 | long mtype; | |
720 | ||
721 | if (get_user(mtype, &msgp->mtype)) | |
722 | return -EFAULT; | |
723 | return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg); | |
724 | } | |
725 | ||
5a06a363 | 726 | static inline int convert_mode(long *msgtyp, int msgflg) |
1da177e4 | 727 | { |
8ac6ed58 PH |
728 | if (msgflg & MSG_COPY) |
729 | return SEARCH_NUMBER; | |
5a06a363 | 730 | /* |
1da177e4 LT |
731 | * find message of correct type. |
732 | * msgtyp = 0 => get first. | |
733 | * msgtyp > 0 => get first message of matching type. | |
5a06a363 | 734 | * msgtyp < 0 => get message with least type must be < abs(msgtype). |
1da177e4 | 735 | */ |
5a06a363 | 736 | if (*msgtyp == 0) |
1da177e4 | 737 | return SEARCH_ANY; |
5a06a363 IM |
738 | if (*msgtyp < 0) { |
739 | *msgtyp = -*msgtyp; | |
1da177e4 LT |
740 | return SEARCH_LESSEQUAL; |
741 | } | |
5a06a363 | 742 | if (msgflg & MSG_EXCEPT) |
1da177e4 LT |
743 | return SEARCH_NOTEQUAL; |
744 | return SEARCH_EQUAL; | |
745 | } | |
746 | ||
f9dd87f4 SK |
747 | static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz) |
748 | { | |
749 | struct msgbuf __user *msgp = dest; | |
750 | size_t msgsz; | |
751 | ||
752 | if (put_user(msg->m_type, &msgp->mtype)) | |
753 | return -EFAULT; | |
754 | ||
755 | msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz; | |
756 | if (store_msg(msgp->mtext, msg, msgsz)) | |
757 | return -EFAULT; | |
758 | return msgsz; | |
759 | } | |
760 | ||
4a674f34 | 761 | #ifdef CONFIG_CHECKPOINT_RESTORE |
3fcfe786 SK |
762 | /* |
763 | * This function creates new kernel message structure, large enough to store | |
764 | * bufsz message bytes. | |
765 | */ | |
8ac6ed58 | 766 | static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz) |
4a674f34 SK |
767 | { |
768 | struct msg_msg *copy; | |
769 | ||
4a674f34 SK |
770 | /* |
771 | * Create dummy message to copy real message to. | |
772 | */ | |
773 | copy = load_msg(buf, bufsz); | |
774 | if (!IS_ERR(copy)) | |
775 | copy->m_ts = bufsz; | |
776 | return copy; | |
777 | } | |
778 | ||
85398aa8 | 779 | static inline void free_copy(struct msg_msg *copy) |
4a674f34 | 780 | { |
85398aa8 | 781 | if (copy) |
4a674f34 SK |
782 | free_msg(copy); |
783 | } | |
784 | #else | |
8ac6ed58 | 785 | static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz) |
b30efe27 SK |
786 | { |
787 | return ERR_PTR(-ENOSYS); | |
788 | } | |
789 | ||
85398aa8 SK |
790 | static inline void free_copy(struct msg_msg *copy) |
791 | { | |
792 | } | |
4a674f34 SK |
793 | #endif |
794 | ||
daaf74cf PH |
795 | static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode) |
796 | { | |
368ae537 | 797 | struct msg_msg *msg, *found = NULL; |
daaf74cf PH |
798 | long count = 0; |
799 | ||
800 | list_for_each_entry(msg, &msq->q_messages, m_list) { | |
801 | if (testmsg(msg, *msgtyp, mode) && | |
802 | !security_msg_queue_msgrcv(msq, msg, current, | |
803 | *msgtyp, mode)) { | |
804 | if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) { | |
805 | *msgtyp = msg->m_type - 1; | |
368ae537 | 806 | found = msg; |
daaf74cf PH |
807 | } else if (mode == SEARCH_NUMBER) { |
808 | if (*msgtyp == count) | |
809 | return msg; | |
810 | } else | |
811 | return msg; | |
812 | count++; | |
813 | } | |
814 | } | |
815 | ||
368ae537 | 816 | return found ?: ERR_PTR(-EAGAIN); |
daaf74cf PH |
817 | } |
818 | ||
41a0d523 | 819 | long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg, |
f9dd87f4 | 820 | long (*msg_handler)(void __user *, struct msg_msg *, size_t)) |
1da177e4 | 821 | { |
1da177e4 | 822 | int mode; |
41a0d523 | 823 | struct msg_queue *msq; |
1e786937 | 824 | struct ipc_namespace *ns; |
41a0d523 | 825 | struct msg_msg *msg, *copy = NULL; |
1da177e4 | 826 | |
88b9e456 PH |
827 | ns = current->nsproxy->ipc_ns; |
828 | ||
f9dd87f4 | 829 | if (msqid < 0 || (long) bufsz < 0) |
1da177e4 | 830 | return -EINVAL; |
41a0d523 | 831 | |
4a674f34 | 832 | if (msgflg & MSG_COPY) { |
4f87dac3 MK |
833 | if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT)) |
834 | return -EINVAL; | |
8ac6ed58 | 835 | copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax)); |
4a674f34 SK |
836 | if (IS_ERR(copy)) |
837 | return PTR_ERR(copy); | |
838 | } | |
5a06a363 | 839 | mode = convert_mode(&msgtyp, msgflg); |
1da177e4 | 840 | |
41a0d523 DB |
841 | rcu_read_lock(); |
842 | msq = msq_obtain_object_check(ns, msqid); | |
4a674f34 | 843 | if (IS_ERR(msq)) { |
41a0d523 | 844 | rcu_read_unlock(); |
85398aa8 | 845 | free_copy(copy); |
023a5355 | 846 | return PTR_ERR(msq); |
4a674f34 | 847 | } |
1da177e4 LT |
848 | |
849 | for (;;) { | |
850 | struct msg_receiver msr_d; | |
1da177e4 LT |
851 | |
852 | msg = ERR_PTR(-EACCES); | |
b0e77598 | 853 | if (ipcperms(ns, &msq->q_perm, S_IRUGO)) |
41a0d523 | 854 | goto out_unlock1; |
1da177e4 | 855 | |
41a0d523 | 856 | ipc_lock_object(&msq->q_perm); |
4271b05a DB |
857 | |
858 | /* raced with RMID? */ | |
0f3d2b01 | 859 | if (!ipc_valid_object(&msq->q_perm)) { |
4271b05a DB |
860 | msg = ERR_PTR(-EIDRM); |
861 | goto out_unlock0; | |
862 | } | |
863 | ||
daaf74cf | 864 | msg = find_msg(msq, &msgtyp, mode); |
5a06a363 IM |
865 | if (!IS_ERR(msg)) { |
866 | /* | |
867 | * Found a suitable message. | |
868 | * Unlink it from the queue. | |
869 | */ | |
f9dd87f4 | 870 | if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) { |
1da177e4 | 871 | msg = ERR_PTR(-E2BIG); |
41a0d523 | 872 | goto out_unlock0; |
1da177e4 | 873 | } |
3fcfe786 SK |
874 | /* |
875 | * If we are copying, then do not unlink message and do | |
876 | * not update queue parameters. | |
877 | */ | |
852028af PH |
878 | if (msgflg & MSG_COPY) { |
879 | msg = copy_msg(msg, copy); | |
41a0d523 | 880 | goto out_unlock0; |
852028af | 881 | } |
41a0d523 | 882 | |
1da177e4 LT |
883 | list_del(&msg->m_list); |
884 | msq->q_qnum--; | |
885 | msq->q_rtime = get_seconds(); | |
b488893a | 886 | msq->q_lrpid = task_tgid_vnr(current); |
1da177e4 | 887 | msq->q_cbytes -= msg->m_ts; |
3ac88a41 KK |
888 | atomic_sub(msg->m_ts, &ns->msg_bytes); |
889 | atomic_dec(&ns->msg_hdrs); | |
5a06a363 | 890 | ss_wakeup(&msq->q_senders, 0); |
41a0d523 DB |
891 | |
892 | goto out_unlock0; | |
1da177e4 | 893 | } |
41a0d523 | 894 | |
1da177e4 LT |
895 | /* No message waiting. Wait for a message */ |
896 | if (msgflg & IPC_NOWAIT) { | |
897 | msg = ERR_PTR(-ENOMSG); | |
41a0d523 | 898 | goto out_unlock0; |
1da177e4 | 899 | } |
41a0d523 | 900 | |
5a06a363 | 901 | list_add_tail(&msr_d.r_list, &msq->q_receivers); |
1da177e4 LT |
902 | msr_d.r_tsk = current; |
903 | msr_d.r_msgtype = msgtyp; | |
904 | msr_d.r_mode = mode; | |
5a06a363 | 905 | if (msgflg & MSG_NOERROR) |
1da177e4 | 906 | msr_d.r_maxsize = INT_MAX; |
5a06a363 | 907 | else |
f9dd87f4 | 908 | msr_d.r_maxsize = bufsz; |
1da177e4 | 909 | msr_d.r_msg = ERR_PTR(-EAGAIN); |
f75a2f35 | 910 | __set_current_state(TASK_INTERRUPTIBLE); |
1da177e4 | 911 | |
41a0d523 DB |
912 | ipc_unlock_object(&msq->q_perm); |
913 | rcu_read_unlock(); | |
1da177e4 LT |
914 | schedule(); |
915 | ||
916 | /* Lockless receive, part 1: | |
917 | * Disable preemption. We don't hold a reference to the queue | |
918 | * and getting a reference would defeat the idea of a lockless | |
919 | * operation, thus the code relies on rcu to guarantee the | |
25985edc | 920 | * existence of msq: |
1da177e4 LT |
921 | * Prior to destruction, expunge_all(-EIRDM) changes r_msg. |
922 | * Thus if r_msg is -EAGAIN, then the queue not yet destroyed. | |
923 | * rcu_read_lock() prevents preemption between reading r_msg | |
41a0d523 | 924 | * and acquiring the q_perm.lock in ipc_lock_object(). |
1da177e4 LT |
925 | */ |
926 | rcu_read_lock(); | |
927 | ||
928 | /* Lockless receive, part 2: | |
929 | * Wait until pipelined_send or expunge_all are outside of | |
930 | * wake_up_process(). There is a race with exit(), see | |
931 | * ipc/mqueue.c for the details. | |
932 | */ | |
239521f3 | 933 | msg = (struct msg_msg *)msr_d.r_msg; |
1da177e4 LT |
934 | while (msg == NULL) { |
935 | cpu_relax(); | |
5a06a363 | 936 | msg = (struct msg_msg *)msr_d.r_msg; |
1da177e4 LT |
937 | } |
938 | ||
939 | /* Lockless receive, part 3: | |
940 | * If there is a message or an error then accept it without | |
941 | * locking. | |
942 | */ | |
41a0d523 DB |
943 | if (msg != ERR_PTR(-EAGAIN)) |
944 | goto out_unlock1; | |
1da177e4 LT |
945 | |
946 | /* Lockless receive, part 3: | |
947 | * Acquire the queue spinlock. | |
948 | */ | |
41a0d523 | 949 | ipc_lock_object(&msq->q_perm); |
1da177e4 LT |
950 | |
951 | /* Lockless receive, part 4: | |
952 | * Repeat test after acquiring the spinlock. | |
953 | */ | |
239521f3 | 954 | msg = (struct msg_msg *)msr_d.r_msg; |
5a06a363 | 955 | if (msg != ERR_PTR(-EAGAIN)) |
41a0d523 | 956 | goto out_unlock0; |
1da177e4 LT |
957 | |
958 | list_del(&msr_d.r_list); | |
959 | if (signal_pending(current)) { | |
960 | msg = ERR_PTR(-ERESTARTNOHAND); | |
41a0d523 | 961 | goto out_unlock0; |
1da177e4 | 962 | } |
41a0d523 DB |
963 | |
964 | ipc_unlock_object(&msq->q_perm); | |
1da177e4 | 965 | } |
41a0d523 DB |
966 | |
967 | out_unlock0: | |
968 | ipc_unlock_object(&msq->q_perm); | |
969 | out_unlock1: | |
970 | rcu_read_unlock(); | |
4a674f34 | 971 | if (IS_ERR(msg)) { |
85398aa8 | 972 | free_copy(copy); |
5a06a363 | 973 | return PTR_ERR(msg); |
4a674f34 | 974 | } |
1da177e4 | 975 | |
f9dd87f4 | 976 | bufsz = msg_handler(buf, msg, bufsz); |
1da177e4 | 977 | free_msg(msg); |
5a06a363 | 978 | |
f9dd87f4 | 979 | return bufsz; |
1da177e4 LT |
980 | } |
981 | ||
e48fbb69 HC |
982 | SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz, |
983 | long, msgtyp, int, msgflg) | |
651971cb | 984 | { |
f9dd87f4 | 985 | return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill); |
651971cb | 986 | } |
987 | ||
3440a6bd DB |
988 | /* |
989 | * Scale msgmni with the available lowmem size: the memory dedicated to msg | |
990 | * queues should occupy at most 1/MSG_MEM_SCALE of lowmem. | |
991 | * Also take into account the number of nsproxies created so far. | |
992 | * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range. | |
993 | */ | |
994 | void recompute_msgmni(struct ipc_namespace *ns) | |
995 | { | |
996 | struct sysinfo i; | |
997 | unsigned long allowed; | |
998 | int nb_ns; | |
999 | ||
1000 | si_meminfo(&i); | |
1001 | allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit) | |
1002 | / MSGMNB; | |
1003 | nb_ns = atomic_read(&nr_ipc_ns); | |
1004 | allowed /= nb_ns; | |
1005 | ||
1006 | if (allowed < MSGMNI) { | |
1007 | ns->msg_ctlmni = MSGMNI; | |
1008 | return; | |
1009 | } | |
1010 | ||
1011 | if (allowed > IPCMNI / nb_ns) { | |
1012 | ns->msg_ctlmni = IPCMNI / nb_ns; | |
1013 | return; | |
1014 | } | |
1015 | ||
1016 | ns->msg_ctlmni = allowed; | |
1017 | } | |
1018 | ||
1019 | void msg_init_ns(struct ipc_namespace *ns) | |
1020 | { | |
1021 | ns->msg_ctlmax = MSGMAX; | |
1022 | ns->msg_ctlmnb = MSGMNB; | |
1023 | ||
1024 | recompute_msgmni(ns); | |
1025 | ||
1026 | atomic_set(&ns->msg_bytes, 0); | |
1027 | atomic_set(&ns->msg_hdrs, 0); | |
1028 | ipc_init_ids(&ns->ids[IPC_MSG_IDS]); | |
1029 | } | |
1030 | ||
1031 | #ifdef CONFIG_IPC_NS | |
1032 | void msg_exit_ns(struct ipc_namespace *ns) | |
1033 | { | |
1034 | free_ipcs(ns, &msg_ids(ns), freeque); | |
1035 | idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr); | |
1036 | } | |
1037 | #endif | |
1038 | ||
1da177e4 | 1039 | #ifdef CONFIG_PROC_FS |
19b4946c | 1040 | static int sysvipc_msg_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1041 | { |
1efdb69b | 1042 | struct user_namespace *user_ns = seq_user_ns(s); |
19b4946c MW |
1043 | struct msg_queue *msq = it; |
1044 | ||
1045 | return seq_printf(s, | |
5a06a363 IM |
1046 | "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n", |
1047 | msq->q_perm.key, | |
7ca7e564 | 1048 | msq->q_perm.id, |
5a06a363 IM |
1049 | msq->q_perm.mode, |
1050 | msq->q_cbytes, | |
1051 | msq->q_qnum, | |
1052 | msq->q_lspid, | |
1053 | msq->q_lrpid, | |
1efdb69b EB |
1054 | from_kuid_munged(user_ns, msq->q_perm.uid), |
1055 | from_kgid_munged(user_ns, msq->q_perm.gid), | |
1056 | from_kuid_munged(user_ns, msq->q_perm.cuid), | |
1057 | from_kgid_munged(user_ns, msq->q_perm.cgid), | |
5a06a363 IM |
1058 | msq->q_stime, |
1059 | msq->q_rtime, | |
1060 | msq->q_ctime); | |
1da177e4 LT |
1061 | } |
1062 | #endif | |
3440a6bd DB |
1063 | |
1064 | void __init msg_init(void) | |
1065 | { | |
1066 | msg_init_ns(&init_ipc_ns); | |
1067 | ||
1068 | printk(KERN_INFO "msgmni has been set to %d\n", | |
1069 | init_ipc_ns.msg_ctlmni); | |
1070 | ||
1071 | ipc_init_proc_interface("sysvipc/msg", | |
1072 | " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n", | |
1073 | IPC_MSG_IDS, sysvipc_msg_proc_show); | |
1074 | } |