xref: /linux/ipc/msg.c (revision 0d97a82b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/ipc/msg.c
4  * Copyright (C) 1992 Krishna Balasubramanian
5  *
6  * Removed all the remaining kerneld mess
7  * Catch the -EFAULT stuff properly
8  * Use GFP_KERNEL for messages as in 1.2
9  * Fixed up the unchecked user space derefs
10  * Copyright (C) 1998 Alan Cox & Andi Kleen
11  *
12  * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
13  *
14  * mostly rewritten, threaded and wake-one semantics added
15  * MSGMAX limit removed, sysctl's added
16  * (c) 1999 Manfred Spraul <manfred@colorfullife.com>
17  *
18  * support for audit of ipc object properties and permission changes
19  * Dustin Kirkland <dustin.kirkland@us.ibm.com>
20  *
21  * namespaces support
22  * OpenVZ, SWsoft Inc.
23  * Pavel Emelianov <xemul@openvz.org>
24  */
25 
26 #include <linux/capability.h>
27 #include <linux/msg.h>
28 #include <linux/spinlock.h>
29 #include <linux/init.h>
30 #include <linux/mm.h>
31 #include <linux/proc_fs.h>
32 #include <linux/list.h>
33 #include <linux/security.h>
34 #include <linux/sched/wake_q.h>
35 #include <linux/syscalls.h>
36 #include <linux/audit.h>
37 #include <linux/seq_file.h>
38 #include <linux/rwsem.h>
39 #include <linux/nsproxy.h>
40 #include <linux/ipc_namespace.h>
41 #include <linux/rhashtable.h>
42 
43 #include <asm/current.h>
44 #include <linux/uaccess.h>
45 #include "util.h"
46 
47 /* one msq_queue structure for each present queue on the system */
48 struct msg_queue {
49 	struct kern_ipc_perm q_perm;
50 	time64_t q_stime;		/* last msgsnd time */
51 	time64_t q_rtime;		/* last msgrcv time */
52 	time64_t q_ctime;		/* last change time */
53 	unsigned long q_cbytes;		/* current number of bytes on queue */
54 	unsigned long q_qnum;		/* number of messages in queue */
55 	unsigned long q_qbytes;		/* max number of bytes on queue */
56 	struct pid *q_lspid;		/* pid of last msgsnd */
57 	struct pid *q_lrpid;		/* last receive pid */
58 
59 	struct list_head q_messages;
60 	struct list_head q_receivers;
61 	struct list_head q_senders;
62 } __randomize_layout;
63 
64 /*
65  * MSG_BARRIER Locking:
66  *
67  * Similar to the optimization used in ipc/mqueue.c, one syscall return path
68  * does not acquire any locks when it sees that a message exists in
69  * msg_receiver.r_msg. Therefore r_msg is set using smp_store_release()
70  * and accessed using READ_ONCE()+smp_acquire__after_ctrl_dep(). In addition,
71  * wake_q_add_safe() is used. See ipc/mqueue.c for more details
72  */
73 
74 /* one msg_receiver structure for each sleeping receiver */
75 struct msg_receiver {
76 	struct list_head	r_list;
77 	struct task_struct	*r_tsk;
78 
79 	int			r_mode;
80 	long			r_msgtype;
81 	long			r_maxsize;
82 
83 	struct msg_msg		*r_msg;
84 };
85 
86 /* one msg_sender for each sleeping sender */
87 struct msg_sender {
88 	struct list_head	list;
89 	struct task_struct	*tsk;
90 	size_t                  msgsz;
91 };
92 
93 #define SEARCH_ANY		1
94 #define SEARCH_EQUAL		2
95 #define SEARCH_NOTEQUAL		3
96 #define SEARCH_LESSEQUAL	4
97 #define SEARCH_NUMBER		5
98 
99 #define msg_ids(ns)	((ns)->ids[IPC_MSG_IDS])
100 
101 static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id)
102 {
103 	struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&msg_ids(ns), id);
104 
105 	if (IS_ERR(ipcp))
106 		return ERR_CAST(ipcp);
107 
108 	return container_of(ipcp, struct msg_queue, q_perm);
109 }
110 
111 static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns,
112 							int id)
113 {
114 	struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id);
115 
116 	if (IS_ERR(ipcp))
117 		return ERR_CAST(ipcp);
118 
119 	return container_of(ipcp, struct msg_queue, q_perm);
120 }
121 
122 static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
123 {
124 	ipc_rmid(&msg_ids(ns), &s->q_perm);
125 }
126 
127 static void msg_rcu_free(struct rcu_head *head)
128 {
129 	struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu);
130 	struct msg_queue *msq = container_of(p, struct msg_queue, q_perm);
131 
132 	security_msg_queue_free(&msq->q_perm);
133 	kvfree(msq);
134 }
135 
136 /**
137  * newque - Create a new msg queue
138  * @ns: namespace
139  * @params: ptr to the structure that contains the key and msgflg
140  *
141  * Called with msg_ids.rwsem held (writer)
142  */
143 static int newque(struct ipc_namespace *ns, struct ipc_params *params)
144 {
145 	struct msg_queue *msq;
146 	int retval;
147 	key_t key = params->key;
148 	int msgflg = params->flg;
149 
150 	msq = kvmalloc(sizeof(*msq), GFP_KERNEL);
151 	if (unlikely(!msq))
152 		return -ENOMEM;
153 
154 	msq->q_perm.mode = msgflg & S_IRWXUGO;
155 	msq->q_perm.key = key;
156 
157 	msq->q_perm.security = NULL;
158 	retval = security_msg_queue_alloc(&msq->q_perm);
159 	if (retval) {
160 		kvfree(msq);
161 		return retval;
162 	}
163 
164 	msq->q_stime = msq->q_rtime = 0;
165 	msq->q_ctime = ktime_get_real_seconds();
166 	msq->q_cbytes = msq->q_qnum = 0;
167 	msq->q_qbytes = ns->msg_ctlmnb;
168 	msq->q_lspid = msq->q_lrpid = NULL;
169 	INIT_LIST_HEAD(&msq->q_messages);
170 	INIT_LIST_HEAD(&msq->q_receivers);
171 	INIT_LIST_HEAD(&msq->q_senders);
172 
173 	/* ipc_addid() locks msq upon success. */
174 	retval = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
175 	if (retval < 0) {
176 		ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
177 		return retval;
178 	}
179 
180 	ipc_unlock_object(&msq->q_perm);
181 	rcu_read_unlock();
182 
183 	return msq->q_perm.id;
184 }
185 
186 static inline bool msg_fits_inqueue(struct msg_queue *msq, size_t msgsz)
187 {
188 	return msgsz + msq->q_cbytes <= msq->q_qbytes &&
189 		1 + msq->q_qnum <= msq->q_qbytes;
190 }
191 
192 static inline void ss_add(struct msg_queue *msq,
193 			  struct msg_sender *mss, size_t msgsz)
194 {
195 	mss->tsk = current;
196 	mss->msgsz = msgsz;
197 	/*
198 	 * No memory barrier required: we did ipc_lock_object(),
199 	 * and the waker obtains that lock before calling wake_q_add().
200 	 */
201 	__set_current_state(TASK_INTERRUPTIBLE);
202 	list_add_tail(&mss->list, &msq->q_senders);
203 }
204 
205 static inline void ss_del(struct msg_sender *mss)
206 {
207 	if (mss->list.next)
208 		list_del(&mss->list);
209 }
210 
211 static void ss_wakeup(struct msg_queue *msq,
212 		      struct wake_q_head *wake_q, bool kill)
213 {
214 	struct msg_sender *mss, *t;
215 	struct task_struct *stop_tsk = NULL;
216 	struct list_head *h = &msq->q_senders;
217 
218 	list_for_each_entry_safe(mss, t, h, list) {
219 		if (kill)
220 			mss->list.next = NULL;
221 
222 		/*
223 		 * Stop at the first task we don't wakeup,
224 		 * we've already iterated the original
225 		 * sender queue.
226 		 */
227 		else if (stop_tsk == mss->tsk)
228 			break;
229 		/*
230 		 * We are not in an EIDRM scenario here, therefore
231 		 * verify that we really need to wakeup the task.
232 		 * To maintain current semantics and wakeup order,
233 		 * move the sender to the tail on behalf of the
234 		 * blocked task.
235 		 */
236 		else if (!msg_fits_inqueue(msq, mss->msgsz)) {
237 			if (!stop_tsk)
238 				stop_tsk = mss->tsk;
239 
240 			list_move_tail(&mss->list, &msq->q_senders);
241 			continue;
242 		}
243 
244 		wake_q_add(wake_q, mss->tsk);
245 	}
246 }
247 
248 static void expunge_all(struct msg_queue *msq, int res,
249 			struct wake_q_head *wake_q)
250 {
251 	struct msg_receiver *msr, *t;
252 
253 	list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
254 		get_task_struct(msr->r_tsk);
255 
256 		/* see MSG_BARRIER for purpose/pairing */
257 		smp_store_release(&msr->r_msg, ERR_PTR(res));
258 		wake_q_add_safe(wake_q, msr->r_tsk);
259 	}
260 }
261 
262 /*
263  * freeque() wakes up waiters on the sender and receiver waiting queue,
264  * removes the message queue from message queue ID IDR, and cleans up all the
265  * messages associated with this queue.
266  *
267  * msg_ids.rwsem (writer) and the spinlock for this message queue are held
268  * before freeque() is called. msg_ids.rwsem remains locked on exit.
269  */
270 static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
271 {
272 	struct msg_msg *msg, *t;
273 	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
274 	DEFINE_WAKE_Q(wake_q);
275 
276 	expunge_all(msq, -EIDRM, &wake_q);
277 	ss_wakeup(msq, &wake_q, true);
278 	msg_rmid(ns, msq);
279 	ipc_unlock_object(&msq->q_perm);
280 	wake_up_q(&wake_q);
281 	rcu_read_unlock();
282 
283 	list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
284 		atomic_dec(&ns->msg_hdrs);
285 		free_msg(msg);
286 	}
287 	atomic_sub(msq->q_cbytes, &ns->msg_bytes);
288 	ipc_update_pid(&msq->q_lspid, NULL);
289 	ipc_update_pid(&msq->q_lrpid, NULL);
290 	ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
291 }
292 
293 long ksys_msgget(key_t key, int msgflg)
294 {
295 	struct ipc_namespace *ns;
296 	static const struct ipc_ops msg_ops = {
297 		.getnew = newque,
298 		.associate = security_msg_queue_associate,
299 	};
300 	struct ipc_params msg_params;
301 
302 	ns = current->nsproxy->ipc_ns;
303 
304 	msg_params.key = key;
305 	msg_params.flg = msgflg;
306 
307 	return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
308 }
309 
310 SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
311 {
312 	return ksys_msgget(key, msgflg);
313 }
314 
315 static inline unsigned long
316 copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
317 {
318 	switch (version) {
319 	case IPC_64:
320 		return copy_to_user(buf, in, sizeof(*in));
321 	case IPC_OLD:
322 	{
323 		struct msqid_ds out;
324 
325 		memset(&out, 0, sizeof(out));
326 
327 		ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
328 
329 		out.msg_stime		= in->msg_stime;
330 		out.msg_rtime		= in->msg_rtime;
331 		out.msg_ctime		= in->msg_ctime;
332 
333 		if (in->msg_cbytes > USHRT_MAX)
334 			out.msg_cbytes	= USHRT_MAX;
335 		else
336 			out.msg_cbytes	= in->msg_cbytes;
337 		out.msg_lcbytes		= in->msg_cbytes;
338 
339 		if (in->msg_qnum > USHRT_MAX)
340 			out.msg_qnum	= USHRT_MAX;
341 		else
342 			out.msg_qnum	= in->msg_qnum;
343 
344 		if (in->msg_qbytes > USHRT_MAX)
345 			out.msg_qbytes	= USHRT_MAX;
346 		else
347 			out.msg_qbytes	= in->msg_qbytes;
348 		out.msg_lqbytes		= in->msg_qbytes;
349 
350 		out.msg_lspid		= in->msg_lspid;
351 		out.msg_lrpid		= in->msg_lrpid;
352 
353 		return copy_to_user(buf, &out, sizeof(out));
354 	}
355 	default:
356 		return -EINVAL;
357 	}
358 }
359 
360 static inline unsigned long
361 copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
362 {
363 	switch (version) {
364 	case IPC_64:
365 		if (copy_from_user(out, buf, sizeof(*out)))
366 			return -EFAULT;
367 		return 0;
368 	case IPC_OLD:
369 	{
370 		struct msqid_ds tbuf_old;
371 
372 		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
373 			return -EFAULT;
374 
375 		out->msg_perm.uid	= tbuf_old.msg_perm.uid;
376 		out->msg_perm.gid	= tbuf_old.msg_perm.gid;
377 		out->msg_perm.mode	= tbuf_old.msg_perm.mode;
378 
379 		if (tbuf_old.msg_qbytes == 0)
380 			out->msg_qbytes	= tbuf_old.msg_lqbytes;
381 		else
382 			out->msg_qbytes	= tbuf_old.msg_qbytes;
383 
384 		return 0;
385 	}
386 	default:
387 		return -EINVAL;
388 	}
389 }
390 
391 /*
392  * This function handles some msgctl commands which require the rwsem
393  * to be held in write mode.
394  * NOTE: no locks must be held, the rwsem is taken inside this function.
395  */
396 static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
397 			struct msqid64_ds *msqid64)
398 {
399 	struct kern_ipc_perm *ipcp;
400 	struct msg_queue *msq;
401 	int err;
402 
403 	down_write(&msg_ids(ns).rwsem);
404 	rcu_read_lock();
405 
406 	ipcp = ipcctl_obtain_check(ns, &msg_ids(ns), msqid, cmd,
407 				      &msqid64->msg_perm, msqid64->msg_qbytes);
408 	if (IS_ERR(ipcp)) {
409 		err = PTR_ERR(ipcp);
410 		goto out_unlock1;
411 	}
412 
413 	msq = container_of(ipcp, struct msg_queue, q_perm);
414 
415 	err = security_msg_queue_msgctl(&msq->q_perm, cmd);
416 	if (err)
417 		goto out_unlock1;
418 
419 	switch (cmd) {
420 	case IPC_RMID:
421 		ipc_lock_object(&msq->q_perm);
422 		/* freeque unlocks the ipc object and rcu */
423 		freeque(ns, ipcp);
424 		goto out_up;
425 	case IPC_SET:
426 	{
427 		DEFINE_WAKE_Q(wake_q);
428 
429 		if (msqid64->msg_qbytes > ns->msg_ctlmnb &&
430 		    !capable(CAP_SYS_RESOURCE)) {
431 			err = -EPERM;
432 			goto out_unlock1;
433 		}
434 
435 		ipc_lock_object(&msq->q_perm);
436 		err = ipc_update_perm(&msqid64->msg_perm, ipcp);
437 		if (err)
438 			goto out_unlock0;
439 
440 		msq->q_qbytes = msqid64->msg_qbytes;
441 
442 		msq->q_ctime = ktime_get_real_seconds();
443 		/*
444 		 * Sleeping receivers might be excluded by
445 		 * stricter permissions.
446 		 */
447 		expunge_all(msq, -EAGAIN, &wake_q);
448 		/*
449 		 * Sleeping senders might be able to send
450 		 * due to a larger queue size.
451 		 */
452 		ss_wakeup(msq, &wake_q, false);
453 		ipc_unlock_object(&msq->q_perm);
454 		wake_up_q(&wake_q);
455 
456 		goto out_unlock1;
457 	}
458 	default:
459 		err = -EINVAL;
460 		goto out_unlock1;
461 	}
462 
463 out_unlock0:
464 	ipc_unlock_object(&msq->q_perm);
465 out_unlock1:
466 	rcu_read_unlock();
467 out_up:
468 	up_write(&msg_ids(ns).rwsem);
469 	return err;
470 }
471 
472 static int msgctl_info(struct ipc_namespace *ns, int msqid,
473 			 int cmd, struct msginfo *msginfo)
474 {
475 	int err;
476 	int max_idx;
477 
478 	/*
479 	 * We must not return kernel stack data.
480 	 * due to padding, it's not enough
481 	 * to set all member fields.
482 	 */
483 	err = security_msg_queue_msgctl(NULL, cmd);
484 	if (err)
485 		return err;
486 
487 	memset(msginfo, 0, sizeof(*msginfo));
488 	msginfo->msgmni = ns->msg_ctlmni;
489 	msginfo->msgmax = ns->msg_ctlmax;
490 	msginfo->msgmnb = ns->msg_ctlmnb;
491 	msginfo->msgssz = MSGSSZ;
492 	msginfo->msgseg = MSGSEG;
493 	down_read(&msg_ids(ns).rwsem);
494 	if (cmd == MSG_INFO) {
495 		msginfo->msgpool = msg_ids(ns).in_use;
496 		msginfo->msgmap = atomic_read(&ns->msg_hdrs);
497 		msginfo->msgtql = atomic_read(&ns->msg_bytes);
498 	} else {
499 		msginfo->msgmap = MSGMAP;
500 		msginfo->msgpool = MSGPOOL;
501 		msginfo->msgtql = MSGTQL;
502 	}
503 	max_idx = ipc_get_maxidx(&msg_ids(ns));
504 	up_read(&msg_ids(ns).rwsem);
505 	return (max_idx < 0) ? 0 : max_idx;
506 }
507 
508 static int msgctl_stat(struct ipc_namespace *ns, int msqid,
509 			 int cmd, struct msqid64_ds *p)
510 {
511 	struct msg_queue *msq;
512 	int err;
513 
514 	memset(p, 0, sizeof(*p));
515 
516 	rcu_read_lock();
517 	if (cmd == MSG_STAT || cmd == MSG_STAT_ANY) {
518 		msq = msq_obtain_object(ns, msqid);
519 		if (IS_ERR(msq)) {
520 			err = PTR_ERR(msq);
521 			goto out_unlock;
522 		}
523 	} else { /* IPC_STAT */
524 		msq = msq_obtain_object_check(ns, msqid);
525 		if (IS_ERR(msq)) {
526 			err = PTR_ERR(msq);
527 			goto out_unlock;
528 		}
529 	}
530 
531 	/* see comment for SHM_STAT_ANY */
532 	if (cmd == MSG_STAT_ANY)
533 		audit_ipc_obj(&msq->q_perm);
534 	else {
535 		err = -EACCES;
536 		if (ipcperms(ns, &msq->q_perm, S_IRUGO))
537 			goto out_unlock;
538 	}
539 
540 	err = security_msg_queue_msgctl(&msq->q_perm, cmd);
541 	if (err)
542 		goto out_unlock;
543 
544 	ipc_lock_object(&msq->q_perm);
545 
546 	if (!ipc_valid_object(&msq->q_perm)) {
547 		ipc_unlock_object(&msq->q_perm);
548 		err = -EIDRM;
549 		goto out_unlock;
550 	}
551 
552 	kernel_to_ipc64_perm(&msq->q_perm, &p->msg_perm);
553 	p->msg_stime  = msq->q_stime;
554 	p->msg_rtime  = msq->q_rtime;
555 	p->msg_ctime  = msq->q_ctime;
556 #ifndef CONFIG_64BIT
557 	p->msg_stime_high = msq->q_stime >> 32;
558 	p->msg_rtime_high = msq->q_rtime >> 32;
559 	p->msg_ctime_high = msq->q_ctime >> 32;
560 #endif
561 	p->msg_cbytes = msq->q_cbytes;
562 	p->msg_qnum   = msq->q_qnum;
563 	p->msg_qbytes = msq->q_qbytes;
564 	p->msg_lspid  = pid_vnr(msq->q_lspid);
565 	p->msg_lrpid  = pid_vnr(msq->q_lrpid);
566 
567 	if (cmd == IPC_STAT) {
568 		/*
569 		 * As defined in SUS:
570 		 * Return 0 on success
571 		 */
572 		err = 0;
573 	} else {
574 		/*
575 		 * MSG_STAT and MSG_STAT_ANY (both Linux specific)
576 		 * Return the full id, including the sequence number
577 		 */
578 		err = msq->q_perm.id;
579 	}
580 
581 	ipc_unlock_object(&msq->q_perm);
582 out_unlock:
583 	rcu_read_unlock();
584 	return err;
585 }
586 
587 static long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf, int version)
588 {
589 	struct ipc_namespace *ns;
590 	struct msqid64_ds msqid64;
591 	int err;
592 
593 	if (msqid < 0 || cmd < 0)
594 		return -EINVAL;
595 
596 	ns = current->nsproxy->ipc_ns;
597 
598 	switch (cmd) {
599 	case IPC_INFO:
600 	case MSG_INFO: {
601 		struct msginfo msginfo;
602 		err = msgctl_info(ns, msqid, cmd, &msginfo);
603 		if (err < 0)
604 			return err;
605 		if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
606 			err = -EFAULT;
607 		return err;
608 	}
609 	case MSG_STAT:	/* msqid is an index rather than a msg queue id */
610 	case MSG_STAT_ANY:
611 	case IPC_STAT:
612 		err = msgctl_stat(ns, msqid, cmd, &msqid64);
613 		if (err < 0)
614 			return err;
615 		if (copy_msqid_to_user(buf, &msqid64, version))
616 			err = -EFAULT;
617 		return err;
618 	case IPC_SET:
619 		if (copy_msqid_from_user(&msqid64, buf, version))
620 			return -EFAULT;
621 		/* fallthru */
622 	case IPC_RMID:
623 		return msgctl_down(ns, msqid, cmd, &msqid64);
624 	default:
625 		return  -EINVAL;
626 	}
627 }
628 
629 SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
630 {
631 	return ksys_msgctl(msqid, cmd, buf, IPC_64);
632 }
633 
634 #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
635 long ksys_old_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
636 {
637 	int version = ipc_parse_version(&cmd);
638 
639 	return ksys_msgctl(msqid, cmd, buf, version);
640 }
641 
642 SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
643 {
644 	return ksys_old_msgctl(msqid, cmd, buf);
645 }
646 #endif
647 
648 #ifdef CONFIG_COMPAT
649 
650 struct compat_msqid_ds {
651 	struct compat_ipc_perm msg_perm;
652 	compat_uptr_t msg_first;
653 	compat_uptr_t msg_last;
654 	old_time32_t msg_stime;
655 	old_time32_t msg_rtime;
656 	old_time32_t msg_ctime;
657 	compat_ulong_t msg_lcbytes;
658 	compat_ulong_t msg_lqbytes;
659 	unsigned short msg_cbytes;
660 	unsigned short msg_qnum;
661 	unsigned short msg_qbytes;
662 	compat_ipc_pid_t msg_lspid;
663 	compat_ipc_pid_t msg_lrpid;
664 };
665 
666 static int copy_compat_msqid_from_user(struct msqid64_ds *out, void __user *buf,
667 					int version)
668 {
669 	memset(out, 0, sizeof(*out));
670 	if (version == IPC_64) {
671 		struct compat_msqid64_ds __user *p = buf;
672 		if (get_compat_ipc64_perm(&out->msg_perm, &p->msg_perm))
673 			return -EFAULT;
674 		if (get_user(out->msg_qbytes, &p->msg_qbytes))
675 			return -EFAULT;
676 	} else {
677 		struct compat_msqid_ds __user *p = buf;
678 		if (get_compat_ipc_perm(&out->msg_perm, &p->msg_perm))
679 			return -EFAULT;
680 		if (get_user(out->msg_qbytes, &p->msg_qbytes))
681 			return -EFAULT;
682 	}
683 	return 0;
684 }
685 
686 static int copy_compat_msqid_to_user(void __user *buf, struct msqid64_ds *in,
687 					int version)
688 {
689 	if (version == IPC_64) {
690 		struct compat_msqid64_ds v;
691 		memset(&v, 0, sizeof(v));
692 		to_compat_ipc64_perm(&v.msg_perm, &in->msg_perm);
693 		v.msg_stime	 = lower_32_bits(in->msg_stime);
694 		v.msg_stime_high = upper_32_bits(in->msg_stime);
695 		v.msg_rtime	 = lower_32_bits(in->msg_rtime);
696 		v.msg_rtime_high = upper_32_bits(in->msg_rtime);
697 		v.msg_ctime	 = lower_32_bits(in->msg_ctime);
698 		v.msg_ctime_high = upper_32_bits(in->msg_ctime);
699 		v.msg_cbytes = in->msg_cbytes;
700 		v.msg_qnum = in->msg_qnum;
701 		v.msg_qbytes = in->msg_qbytes;
702 		v.msg_lspid = in->msg_lspid;
703 		v.msg_lrpid = in->msg_lrpid;
704 		return copy_to_user(buf, &v, sizeof(v));
705 	} else {
706 		struct compat_msqid_ds v;
707 		memset(&v, 0, sizeof(v));
708 		to_compat_ipc_perm(&v.msg_perm, &in->msg_perm);
709 		v.msg_stime = in->msg_stime;
710 		v.msg_rtime = in->msg_rtime;
711 		v.msg_ctime = in->msg_ctime;
712 		v.msg_cbytes = in->msg_cbytes;
713 		v.msg_qnum = in->msg_qnum;
714 		v.msg_qbytes = in->msg_qbytes;
715 		v.msg_lspid = in->msg_lspid;
716 		v.msg_lrpid = in->msg_lrpid;
717 		return copy_to_user(buf, &v, sizeof(v));
718 	}
719 }
720 
721 static long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr, int version)
722 {
723 	struct ipc_namespace *ns;
724 	int err;
725 	struct msqid64_ds msqid64;
726 
727 	ns = current->nsproxy->ipc_ns;
728 
729 	if (msqid < 0 || cmd < 0)
730 		return -EINVAL;
731 
732 	switch (cmd & (~IPC_64)) {
733 	case IPC_INFO:
734 	case MSG_INFO: {
735 		struct msginfo msginfo;
736 		err = msgctl_info(ns, msqid, cmd, &msginfo);
737 		if (err < 0)
738 			return err;
739 		if (copy_to_user(uptr, &msginfo, sizeof(struct msginfo)))
740 			err = -EFAULT;
741 		return err;
742 	}
743 	case IPC_STAT:
744 	case MSG_STAT:
745 	case MSG_STAT_ANY:
746 		err = msgctl_stat(ns, msqid, cmd, &msqid64);
747 		if (err < 0)
748 			return err;
749 		if (copy_compat_msqid_to_user(uptr, &msqid64, version))
750 			err = -EFAULT;
751 		return err;
752 	case IPC_SET:
753 		if (copy_compat_msqid_from_user(&msqid64, uptr, version))
754 			return -EFAULT;
755 		/* fallthru */
756 	case IPC_RMID:
757 		return msgctl_down(ns, msqid, cmd, &msqid64);
758 	default:
759 		return -EINVAL;
760 	}
761 }
762 
763 COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr)
764 {
765 	return compat_ksys_msgctl(msqid, cmd, uptr, IPC_64);
766 }
767 
768 #ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
769 long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr)
770 {
771 	int version = compat_ipc_parse_version(&cmd);
772 
773 	return compat_ksys_msgctl(msqid, cmd, uptr, version);
774 }
775 
776 COMPAT_SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, void __user *, uptr)
777 {
778 	return compat_ksys_old_msgctl(msqid, cmd, uptr);
779 }
780 #endif
781 #endif
782 
783 static int testmsg(struct msg_msg *msg, long type, int mode)
784 {
785 	switch (mode) {
786 	case SEARCH_ANY:
787 	case SEARCH_NUMBER:
788 		return 1;
789 	case SEARCH_LESSEQUAL:
790 		if (msg->m_type <= type)
791 			return 1;
792 		break;
793 	case SEARCH_EQUAL:
794 		if (msg->m_type == type)
795 			return 1;
796 		break;
797 	case SEARCH_NOTEQUAL:
798 		if (msg->m_type != type)
799 			return 1;
800 		break;
801 	}
802 	return 0;
803 }
804 
805 static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg,
806 				 struct wake_q_head *wake_q)
807 {
808 	struct msg_receiver *msr, *t;
809 
810 	list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
811 		if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
812 		    !security_msg_queue_msgrcv(&msq->q_perm, msg, msr->r_tsk,
813 					       msr->r_msgtype, msr->r_mode)) {
814 
815 			list_del(&msr->r_list);
816 			if (msr->r_maxsize < msg->m_ts) {
817 				wake_q_add(wake_q, msr->r_tsk);
818 
819 				/* See expunge_all regarding memory barrier */
820 				smp_store_release(&msr->r_msg, ERR_PTR(-E2BIG));
821 			} else {
822 				ipc_update_pid(&msq->q_lrpid, task_pid(msr->r_tsk));
823 				msq->q_rtime = ktime_get_real_seconds();
824 
825 				wake_q_add(wake_q, msr->r_tsk);
826 
827 				/* See expunge_all regarding memory barrier */
828 				smp_store_release(&msr->r_msg, msg);
829 				return 1;
830 			}
831 		}
832 	}
833 
834 	return 0;
835 }
836 
837 static long do_msgsnd(int msqid, long mtype, void __user *mtext,
838 		size_t msgsz, int msgflg)
839 {
840 	struct msg_queue *msq;
841 	struct msg_msg *msg;
842 	int err;
843 	struct ipc_namespace *ns;
844 	DEFINE_WAKE_Q(wake_q);
845 
846 	ns = current->nsproxy->ipc_ns;
847 
848 	if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
849 		return -EINVAL;
850 	if (mtype < 1)
851 		return -EINVAL;
852 
853 	msg = load_msg(mtext, msgsz);
854 	if (IS_ERR(msg))
855 		return PTR_ERR(msg);
856 
857 	msg->m_type = mtype;
858 	msg->m_ts = msgsz;
859 
860 	rcu_read_lock();
861 	msq = msq_obtain_object_check(ns, msqid);
862 	if (IS_ERR(msq)) {
863 		err = PTR_ERR(msq);
864 		goto out_unlock1;
865 	}
866 
867 	ipc_lock_object(&msq->q_perm);
868 
869 	for (;;) {
870 		struct msg_sender s;
871 
872 		err = -EACCES;
873 		if (ipcperms(ns, &msq->q_perm, S_IWUGO))
874 			goto out_unlock0;
875 
876 		/* raced with RMID? */
877 		if (!ipc_valid_object(&msq->q_perm)) {
878 			err = -EIDRM;
879 			goto out_unlock0;
880 		}
881 
882 		err = security_msg_queue_msgsnd(&msq->q_perm, msg, msgflg);
883 		if (err)
884 			goto out_unlock0;
885 
886 		if (msg_fits_inqueue(msq, msgsz))
887 			break;
888 
889 		/* queue full, wait: */
890 		if (msgflg & IPC_NOWAIT) {
891 			err = -EAGAIN;
892 			goto out_unlock0;
893 		}
894 
895 		/* enqueue the sender and prepare to block */
896 		ss_add(msq, &s, msgsz);
897 
898 		if (!ipc_rcu_getref(&msq->q_perm)) {
899 			err = -EIDRM;
900 			goto out_unlock0;
901 		}
902 
903 		ipc_unlock_object(&msq->q_perm);
904 		rcu_read_unlock();
905 		schedule();
906 
907 		rcu_read_lock();
908 		ipc_lock_object(&msq->q_perm);
909 
910 		ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
911 		/* raced with RMID? */
912 		if (!ipc_valid_object(&msq->q_perm)) {
913 			err = -EIDRM;
914 			goto out_unlock0;
915 		}
916 		ss_del(&s);
917 
918 		if (signal_pending(current)) {
919 			err = -ERESTARTNOHAND;
920 			goto out_unlock0;
921 		}
922 
923 	}
924 
925 	ipc_update_pid(&msq->q_lspid, task_tgid(current));
926 	msq->q_stime = ktime_get_real_seconds();
927 
928 	if (!pipelined_send(msq, msg, &wake_q)) {
929 		/* no one is waiting for this message, enqueue it */
930 		list_add_tail(&msg->m_list, &msq->q_messages);
931 		msq->q_cbytes += msgsz;
932 		msq->q_qnum++;
933 		atomic_add(msgsz, &ns->msg_bytes);
934 		atomic_inc(&ns->msg_hdrs);
935 	}
936 
937 	err = 0;
938 	msg = NULL;
939 
940 out_unlock0:
941 	ipc_unlock_object(&msq->q_perm);
942 	wake_up_q(&wake_q);
943 out_unlock1:
944 	rcu_read_unlock();
945 	if (msg != NULL)
946 		free_msg(msg);
947 	return err;
948 }
949 
950 long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
951 		 int msgflg)
952 {
953 	long mtype;
954 
955 	if (get_user(mtype, &msgp->mtype))
956 		return -EFAULT;
957 	return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
958 }
959 
960 SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
961 		int, msgflg)
962 {
963 	return ksys_msgsnd(msqid, msgp, msgsz, msgflg);
964 }
965 
966 #ifdef CONFIG_COMPAT
967 
968 struct compat_msgbuf {
969 	compat_long_t mtype;
970 	char mtext[1];
971 };
972 
973 long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
974 		       compat_ssize_t msgsz, int msgflg)
975 {
976 	struct compat_msgbuf __user *up = compat_ptr(msgp);
977 	compat_long_t mtype;
978 
979 	if (get_user(mtype, &up->mtype))
980 		return -EFAULT;
981 	return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg);
982 }
983 
984 COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
985 		       compat_ssize_t, msgsz, int, msgflg)
986 {
987 	return compat_ksys_msgsnd(msqid, msgp, msgsz, msgflg);
988 }
989 #endif
990 
991 static inline int convert_mode(long *msgtyp, int msgflg)
992 {
993 	if (msgflg & MSG_COPY)
994 		return SEARCH_NUMBER;
995 	/*
996 	 *  find message of correct type.
997 	 *  msgtyp = 0 => get first.
998 	 *  msgtyp > 0 => get first message of matching type.
999 	 *  msgtyp < 0 => get message with least type must be < abs(msgtype).
1000 	 */
1001 	if (*msgtyp == 0)
1002 		return SEARCH_ANY;
1003 	if (*msgtyp < 0) {
1004 		if (*msgtyp == LONG_MIN) /* -LONG_MIN is undefined */
1005 			*msgtyp = LONG_MAX;
1006 		else
1007 			*msgtyp = -*msgtyp;
1008 		return SEARCH_LESSEQUAL;
1009 	}
1010 	if (msgflg & MSG_EXCEPT)
1011 		return SEARCH_NOTEQUAL;
1012 	return SEARCH_EQUAL;
1013 }
1014 
1015 static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
1016 {
1017 	struct msgbuf __user *msgp = dest;
1018 	size_t msgsz;
1019 
1020 	if (put_user(msg->m_type, &msgp->mtype))
1021 		return -EFAULT;
1022 
1023 	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
1024 	if (store_msg(msgp->mtext, msg, msgsz))
1025 		return -EFAULT;
1026 	return msgsz;
1027 }
1028 
1029 #ifdef CONFIG_CHECKPOINT_RESTORE
1030 /*
1031  * This function creates new kernel message structure, large enough to store
1032  * bufsz message bytes.
1033  */
1034 static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
1035 {
1036 	struct msg_msg *copy;
1037 
1038 	/*
1039 	 * Create dummy message to copy real message to.
1040 	 */
1041 	copy = load_msg(buf, bufsz);
1042 	if (!IS_ERR(copy))
1043 		copy->m_ts = bufsz;
1044 	return copy;
1045 }
1046 
1047 static inline void free_copy(struct msg_msg *copy)
1048 {
1049 	if (copy)
1050 		free_msg(copy);
1051 }
1052 #else
1053 static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
1054 {
1055 	return ERR_PTR(-ENOSYS);
1056 }
1057 
1058 static inline void free_copy(struct msg_msg *copy)
1059 {
1060 }
1061 #endif
1062 
1063 static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
1064 {
1065 	struct msg_msg *msg, *found = NULL;
1066 	long count = 0;
1067 
1068 	list_for_each_entry(msg, &msq->q_messages, m_list) {
1069 		if (testmsg(msg, *msgtyp, mode) &&
1070 		    !security_msg_queue_msgrcv(&msq->q_perm, msg, current,
1071 					       *msgtyp, mode)) {
1072 			if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
1073 				*msgtyp = msg->m_type - 1;
1074 				found = msg;
1075 			} else if (mode == SEARCH_NUMBER) {
1076 				if (*msgtyp == count)
1077 					return msg;
1078 			} else
1079 				return msg;
1080 			count++;
1081 		}
1082 	}
1083 
1084 	return found ?: ERR_PTR(-EAGAIN);
1085 }
1086 
1087 static long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
1088 	       long (*msg_handler)(void __user *, struct msg_msg *, size_t))
1089 {
1090 	int mode;
1091 	struct msg_queue *msq;
1092 	struct ipc_namespace *ns;
1093 	struct msg_msg *msg, *copy = NULL;
1094 	DEFINE_WAKE_Q(wake_q);
1095 
1096 	ns = current->nsproxy->ipc_ns;
1097 
1098 	if (msqid < 0 || (long) bufsz < 0)
1099 		return -EINVAL;
1100 
1101 	if (msgflg & MSG_COPY) {
1102 		if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT))
1103 			return -EINVAL;
1104 		copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
1105 		if (IS_ERR(copy))
1106 			return PTR_ERR(copy);
1107 	}
1108 	mode = convert_mode(&msgtyp, msgflg);
1109 
1110 	rcu_read_lock();
1111 	msq = msq_obtain_object_check(ns, msqid);
1112 	if (IS_ERR(msq)) {
1113 		rcu_read_unlock();
1114 		free_copy(copy);
1115 		return PTR_ERR(msq);
1116 	}
1117 
1118 	for (;;) {
1119 		struct msg_receiver msr_d;
1120 
1121 		msg = ERR_PTR(-EACCES);
1122 		if (ipcperms(ns, &msq->q_perm, S_IRUGO))
1123 			goto out_unlock1;
1124 
1125 		ipc_lock_object(&msq->q_perm);
1126 
1127 		/* raced with RMID? */
1128 		if (!ipc_valid_object(&msq->q_perm)) {
1129 			msg = ERR_PTR(-EIDRM);
1130 			goto out_unlock0;
1131 		}
1132 
1133 		msg = find_msg(msq, &msgtyp, mode);
1134 		if (!IS_ERR(msg)) {
1135 			/*
1136 			 * Found a suitable message.
1137 			 * Unlink it from the queue.
1138 			 */
1139 			if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
1140 				msg = ERR_PTR(-E2BIG);
1141 				goto out_unlock0;
1142 			}
1143 			/*
1144 			 * If we are copying, then do not unlink message and do
1145 			 * not update queue parameters.
1146 			 */
1147 			if (msgflg & MSG_COPY) {
1148 				msg = copy_msg(msg, copy);
1149 				goto out_unlock0;
1150 			}
1151 
1152 			list_del(&msg->m_list);
1153 			msq->q_qnum--;
1154 			msq->q_rtime = ktime_get_real_seconds();
1155 			ipc_update_pid(&msq->q_lrpid, task_tgid(current));
1156 			msq->q_cbytes -= msg->m_ts;
1157 			atomic_sub(msg->m_ts, &ns->msg_bytes);
1158 			atomic_dec(&ns->msg_hdrs);
1159 			ss_wakeup(msq, &wake_q, false);
1160 
1161 			goto out_unlock0;
1162 		}
1163 
1164 		/* No message waiting. Wait for a message */
1165 		if (msgflg & IPC_NOWAIT) {
1166 			msg = ERR_PTR(-ENOMSG);
1167 			goto out_unlock0;
1168 		}
1169 
1170 		list_add_tail(&msr_d.r_list, &msq->q_receivers);
1171 		msr_d.r_tsk = current;
1172 		msr_d.r_msgtype = msgtyp;
1173 		msr_d.r_mode = mode;
1174 		if (msgflg & MSG_NOERROR)
1175 			msr_d.r_maxsize = INT_MAX;
1176 		else
1177 			msr_d.r_maxsize = bufsz;
1178 
1179 		/* memory barrier not require due to ipc_lock_object() */
1180 		WRITE_ONCE(msr_d.r_msg, ERR_PTR(-EAGAIN));
1181 
1182 		/* memory barrier not required, we own ipc_lock_object() */
1183 		__set_current_state(TASK_INTERRUPTIBLE);
1184 
1185 		ipc_unlock_object(&msq->q_perm);
1186 		rcu_read_unlock();
1187 		schedule();
1188 
1189 		/*
1190 		 * Lockless receive, part 1:
1191 		 * We don't hold a reference to the queue and getting a
1192 		 * reference would defeat the idea of a lockless operation,
1193 		 * thus the code relies on rcu to guarantee the existence of
1194 		 * msq:
1195 		 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
1196 		 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
1197 		 */
1198 		rcu_read_lock();
1199 
1200 		/*
1201 		 * Lockless receive, part 2:
1202 		 * The work in pipelined_send() and expunge_all():
1203 		 * - Set pointer to message
1204 		 * - Queue the receiver task for later wakeup
1205 		 * - Wake up the process after the lock is dropped.
1206 		 *
1207 		 * Should the process wake up before this wakeup (due to a
1208 		 * signal) it will either see the message and continue ...
1209 		 */
1210 		msg = READ_ONCE(msr_d.r_msg);
1211 		if (msg != ERR_PTR(-EAGAIN)) {
1212 			/* see MSG_BARRIER for purpose/pairing */
1213 			smp_acquire__after_ctrl_dep();
1214 
1215 			goto out_unlock1;
1216 		}
1217 
1218 		 /*
1219 		  * ... or see -EAGAIN, acquire the lock to check the message
1220 		  * again.
1221 		  */
1222 		ipc_lock_object(&msq->q_perm);
1223 
1224 		msg = READ_ONCE(msr_d.r_msg);
1225 		if (msg != ERR_PTR(-EAGAIN))
1226 			goto out_unlock0;
1227 
1228 		list_del(&msr_d.r_list);
1229 		if (signal_pending(current)) {
1230 			msg = ERR_PTR(-ERESTARTNOHAND);
1231 			goto out_unlock0;
1232 		}
1233 
1234 		ipc_unlock_object(&msq->q_perm);
1235 	}
1236 
1237 out_unlock0:
1238 	ipc_unlock_object(&msq->q_perm);
1239 	wake_up_q(&wake_q);
1240 out_unlock1:
1241 	rcu_read_unlock();
1242 	if (IS_ERR(msg)) {
1243 		free_copy(copy);
1244 		return PTR_ERR(msg);
1245 	}
1246 
1247 	bufsz = msg_handler(buf, msg, bufsz);
1248 	free_msg(msg);
1249 
1250 	return bufsz;
1251 }
1252 
1253 long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
1254 		 long msgtyp, int msgflg)
1255 {
1256 	return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
1257 }
1258 
1259 SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
1260 		long, msgtyp, int, msgflg)
1261 {
1262 	return ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg);
1263 }
1264 
1265 #ifdef CONFIG_COMPAT
1266 static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
1267 {
1268 	struct compat_msgbuf __user *msgp = dest;
1269 	size_t msgsz;
1270 
1271 	if (put_user(msg->m_type, &msgp->mtype))
1272 		return -EFAULT;
1273 
1274 	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
1275 	if (store_msg(msgp->mtext, msg, msgsz))
1276 		return -EFAULT;
1277 	return msgsz;
1278 }
1279 
1280 long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
1281 			compat_long_t msgtyp, int msgflg)
1282 {
1283 	return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp,
1284 			 msgflg, compat_do_msg_fill);
1285 }
1286 
1287 COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp,
1288 		       compat_ssize_t, msgsz, compat_long_t, msgtyp,
1289 		       int, msgflg)
1290 {
1291 	return compat_ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg);
1292 }
1293 #endif
1294 
1295 void msg_init_ns(struct ipc_namespace *ns)
1296 {
1297 	ns->msg_ctlmax = MSGMAX;
1298 	ns->msg_ctlmnb = MSGMNB;
1299 	ns->msg_ctlmni = MSGMNI;
1300 
1301 	atomic_set(&ns->msg_bytes, 0);
1302 	atomic_set(&ns->msg_hdrs, 0);
1303 	ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
1304 }
1305 
1306 #ifdef CONFIG_IPC_NS
1307 void msg_exit_ns(struct ipc_namespace *ns)
1308 {
1309 	free_ipcs(ns, &msg_ids(ns), freeque);
1310 	idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
1311 	rhashtable_destroy(&ns->ids[IPC_MSG_IDS].key_ht);
1312 }
1313 #endif
1314 
1315 #ifdef CONFIG_PROC_FS
1316 static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
1317 {
1318 	struct pid_namespace *pid_ns = ipc_seq_pid_ns(s);
1319 	struct user_namespace *user_ns = seq_user_ns(s);
1320 	struct kern_ipc_perm *ipcp = it;
1321 	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
1322 
1323 	seq_printf(s,
1324 		   "%10d %10d  %4o  %10lu %10lu %5u %5u %5u %5u %5u %5u %10llu %10llu %10llu\n",
1325 		   msq->q_perm.key,
1326 		   msq->q_perm.id,
1327 		   msq->q_perm.mode,
1328 		   msq->q_cbytes,
1329 		   msq->q_qnum,
1330 		   pid_nr_ns(msq->q_lspid, pid_ns),
1331 		   pid_nr_ns(msq->q_lrpid, pid_ns),
1332 		   from_kuid_munged(user_ns, msq->q_perm.uid),
1333 		   from_kgid_munged(user_ns, msq->q_perm.gid),
1334 		   from_kuid_munged(user_ns, msq->q_perm.cuid),
1335 		   from_kgid_munged(user_ns, msq->q_perm.cgid),
1336 		   msq->q_stime,
1337 		   msq->q_rtime,
1338 		   msq->q_ctime);
1339 
1340 	return 0;
1341 }
1342 #endif
1343 
1344 void __init msg_init(void)
1345 {
1346 	msg_init_ns(&init_ipc_ns);
1347 
1348 	ipc_init_proc_interface("sysvipc/msg",
1349 				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
1350 				IPC_MSG_IDS, sysvipc_msg_proc_show);
1351 }
1352