xref: /openbmc/linux/ipc/msg.c (revision 519b58bb)
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 #include <linux/percpu_counter.h>
43 
44 #include <asm/current.h>
45 #include <linux/uaccess.h>
46 #include "util.h"
47 
48 /* one msq_queue structure for each present queue on the system */
49 struct msg_queue {
50 	struct kern_ipc_perm q_perm;
51 	time64_t q_stime;		/* last msgsnd time */
52 	time64_t q_rtime;		/* last msgrcv time */
53 	time64_t q_ctime;		/* last change time */
54 	unsigned long q_cbytes;		/* current number of bytes on queue */
55 	unsigned long q_qnum;		/* number of messages in queue */
56 	unsigned long q_qbytes;		/* max number of bytes on queue */
57 	struct pid *q_lspid;		/* pid of last msgsnd */
58 	struct pid *q_lrpid;		/* last receive pid */
59 
60 	struct list_head q_messages;
61 	struct list_head q_receivers;
62 	struct list_head q_senders;
63 } __randomize_layout;
64 
65 /*
66  * MSG_BARRIER Locking:
67  *
68  * Similar to the optimization used in ipc/mqueue.c, one syscall return path
69  * does not acquire any locks when it sees that a message exists in
70  * msg_receiver.r_msg. Therefore r_msg is set using smp_store_release()
71  * and accessed using READ_ONCE()+smp_acquire__after_ctrl_dep(). In addition,
72  * wake_q_add_safe() is used. See ipc/mqueue.c for more details
73  */
74 
75 /* one msg_receiver structure for each sleeping receiver */
76 struct msg_receiver {
77 	struct list_head	r_list;
78 	struct task_struct	*r_tsk;
79 
80 	int			r_mode;
81 	long			r_msgtype;
82 	long			r_maxsize;
83 
84 	struct msg_msg		*r_msg;
85 };
86 
87 /* one msg_sender for each sleeping sender */
88 struct msg_sender {
89 	struct list_head	list;
90 	struct task_struct	*tsk;
91 	size_t                  msgsz;
92 };
93 
94 #define SEARCH_ANY		1
95 #define SEARCH_EQUAL		2
96 #define SEARCH_NOTEQUAL		3
97 #define SEARCH_LESSEQUAL	4
98 #define SEARCH_NUMBER		5
99 
100 #define msg_ids(ns)	((ns)->ids[IPC_MSG_IDS])
101 
102 static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id)
103 {
104 	struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&msg_ids(ns), id);
105 
106 	if (IS_ERR(ipcp))
107 		return ERR_CAST(ipcp);
108 
109 	return container_of(ipcp, struct msg_queue, q_perm);
110 }
111 
112 static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns,
113 							int id)
114 {
115 	struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id);
116 
117 	if (IS_ERR(ipcp))
118 		return ERR_CAST(ipcp);
119 
120 	return container_of(ipcp, struct msg_queue, q_perm);
121 }
122 
123 static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
124 {
125 	ipc_rmid(&msg_ids(ns), &s->q_perm);
126 }
127 
128 static void msg_rcu_free(struct rcu_head *head)
129 {
130 	struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu);
131 	struct msg_queue *msq = container_of(p, struct msg_queue, q_perm);
132 
133 	security_msg_queue_free(&msq->q_perm);
134 	kfree(msq);
135 }
136 
137 /**
138  * newque - Create a new msg queue
139  * @ns: namespace
140  * @params: ptr to the structure that contains the key and msgflg
141  *
142  * Called with msg_ids.rwsem held (writer)
143  */
144 static int newque(struct ipc_namespace *ns, struct ipc_params *params)
145 {
146 	struct msg_queue *msq;
147 	int retval;
148 	key_t key = params->key;
149 	int msgflg = params->flg;
150 
151 	msq = kmalloc(sizeof(*msq), GFP_KERNEL_ACCOUNT);
152 	if (unlikely(!msq))
153 		return -ENOMEM;
154 
155 	msq->q_perm.mode = msgflg & S_IRWXUGO;
156 	msq->q_perm.key = key;
157 
158 	msq->q_perm.security = NULL;
159 	retval = security_msg_queue_alloc(&msq->q_perm);
160 	if (retval) {
161 		kfree(msq);
162 		return retval;
163 	}
164 
165 	msq->q_stime = msq->q_rtime = 0;
166 	msq->q_ctime = ktime_get_real_seconds();
167 	msq->q_cbytes = msq->q_qnum = 0;
168 	msq->q_qbytes = ns->msg_ctlmnb;
169 	msq->q_lspid = msq->q_lrpid = NULL;
170 	INIT_LIST_HEAD(&msq->q_messages);
171 	INIT_LIST_HEAD(&msq->q_receivers);
172 	INIT_LIST_HEAD(&msq->q_senders);
173 
174 	/* ipc_addid() locks msq upon success. */
175 	retval = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
176 	if (retval < 0) {
177 		ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
178 		return retval;
179 	}
180 
181 	ipc_unlock_object(&msq->q_perm);
182 	rcu_read_unlock();
183 
184 	return msq->q_perm.id;
185 }
186 
187 static inline bool msg_fits_inqueue(struct msg_queue *msq, size_t msgsz)
188 {
189 	return msgsz + msq->q_cbytes <= msq->q_qbytes &&
190 		1 + msq->q_qnum <= msq->q_qbytes;
191 }
192 
193 static inline void ss_add(struct msg_queue *msq,
194 			  struct msg_sender *mss, size_t msgsz)
195 {
196 	mss->tsk = current;
197 	mss->msgsz = msgsz;
198 	/*
199 	 * No memory barrier required: we did ipc_lock_object(),
200 	 * and the waker obtains that lock before calling wake_q_add().
201 	 */
202 	__set_current_state(TASK_INTERRUPTIBLE);
203 	list_add_tail(&mss->list, &msq->q_senders);
204 }
205 
206 static inline void ss_del(struct msg_sender *mss)
207 {
208 	if (mss->list.next)
209 		list_del(&mss->list);
210 }
211 
212 static void ss_wakeup(struct msg_queue *msq,
213 		      struct wake_q_head *wake_q, bool kill)
214 {
215 	struct msg_sender *mss, *t;
216 	struct task_struct *stop_tsk = NULL;
217 	struct list_head *h = &msq->q_senders;
218 
219 	list_for_each_entry_safe(mss, t, h, list) {
220 		if (kill)
221 			mss->list.next = NULL;
222 
223 		/*
224 		 * Stop at the first task we don't wakeup,
225 		 * we've already iterated the original
226 		 * sender queue.
227 		 */
228 		else if (stop_tsk == mss->tsk)
229 			break;
230 		/*
231 		 * We are not in an EIDRM scenario here, therefore
232 		 * verify that we really need to wakeup the task.
233 		 * To maintain current semantics and wakeup order,
234 		 * move the sender to the tail on behalf of the
235 		 * blocked task.
236 		 */
237 		else if (!msg_fits_inqueue(msq, mss->msgsz)) {
238 			if (!stop_tsk)
239 				stop_tsk = mss->tsk;
240 
241 			list_move_tail(&mss->list, &msq->q_senders);
242 			continue;
243 		}
244 
245 		wake_q_add(wake_q, mss->tsk);
246 	}
247 }
248 
249 static void expunge_all(struct msg_queue *msq, int res,
250 			struct wake_q_head *wake_q)
251 {
252 	struct msg_receiver *msr, *t;
253 
254 	list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
255 		struct task_struct *r_tsk;
256 
257 		r_tsk = get_task_struct(msr->r_tsk);
258 
259 		/* see MSG_BARRIER for purpose/pairing */
260 		smp_store_release(&msr->r_msg, ERR_PTR(res));
261 		wake_q_add_safe(wake_q, r_tsk);
262 	}
263 }
264 
265 /*
266  * freeque() wakes up waiters on the sender and receiver waiting queue,
267  * removes the message queue from message queue ID IDR, and cleans up all the
268  * messages associated with this queue.
269  *
270  * msg_ids.rwsem (writer) and the spinlock for this message queue are held
271  * before freeque() is called. msg_ids.rwsem remains locked on exit.
272  */
273 static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
274 	__releases(RCU)
275 	__releases(&msq->q_perm)
276 {
277 	struct msg_msg *msg, *t;
278 	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
279 	DEFINE_WAKE_Q(wake_q);
280 
281 	expunge_all(msq, -EIDRM, &wake_q);
282 	ss_wakeup(msq, &wake_q, true);
283 	msg_rmid(ns, msq);
284 	ipc_unlock_object(&msq->q_perm);
285 	wake_up_q(&wake_q);
286 	rcu_read_unlock();
287 
288 	list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
289 		percpu_counter_sub_local(&ns->percpu_msg_hdrs, 1);
290 		free_msg(msg);
291 	}
292 	percpu_counter_sub_local(&ns->percpu_msg_bytes, msq->q_cbytes);
293 	ipc_update_pid(&msq->q_lspid, NULL);
294 	ipc_update_pid(&msq->q_lrpid, NULL);
295 	ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
296 }
297 
298 long ksys_msgget(key_t key, int msgflg)
299 {
300 	struct ipc_namespace *ns;
301 	static const struct ipc_ops msg_ops = {
302 		.getnew = newque,
303 		.associate = security_msg_queue_associate,
304 	};
305 	struct ipc_params msg_params;
306 
307 	ns = current->nsproxy->ipc_ns;
308 
309 	msg_params.key = key;
310 	msg_params.flg = msgflg;
311 
312 	return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
313 }
314 
315 SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
316 {
317 	return ksys_msgget(key, msgflg);
318 }
319 
320 static inline unsigned long
321 copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
322 {
323 	switch (version) {
324 	case IPC_64:
325 		return copy_to_user(buf, in, sizeof(*in));
326 	case IPC_OLD:
327 	{
328 		struct msqid_ds out;
329 
330 		memset(&out, 0, sizeof(out));
331 
332 		ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
333 
334 		out.msg_stime		= in->msg_stime;
335 		out.msg_rtime		= in->msg_rtime;
336 		out.msg_ctime		= in->msg_ctime;
337 
338 		if (in->msg_cbytes > USHRT_MAX)
339 			out.msg_cbytes	= USHRT_MAX;
340 		else
341 			out.msg_cbytes	= in->msg_cbytes;
342 		out.msg_lcbytes		= in->msg_cbytes;
343 
344 		if (in->msg_qnum > USHRT_MAX)
345 			out.msg_qnum	= USHRT_MAX;
346 		else
347 			out.msg_qnum	= in->msg_qnum;
348 
349 		if (in->msg_qbytes > USHRT_MAX)
350 			out.msg_qbytes	= USHRT_MAX;
351 		else
352 			out.msg_qbytes	= in->msg_qbytes;
353 		out.msg_lqbytes		= in->msg_qbytes;
354 
355 		out.msg_lspid		= in->msg_lspid;
356 		out.msg_lrpid		= in->msg_lrpid;
357 
358 		return copy_to_user(buf, &out, sizeof(out));
359 	}
360 	default:
361 		return -EINVAL;
362 	}
363 }
364 
365 static inline unsigned long
366 copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
367 {
368 	switch (version) {
369 	case IPC_64:
370 		if (copy_from_user(out, buf, sizeof(*out)))
371 			return -EFAULT;
372 		return 0;
373 	case IPC_OLD:
374 	{
375 		struct msqid_ds tbuf_old;
376 
377 		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
378 			return -EFAULT;
379 
380 		out->msg_perm.uid	= tbuf_old.msg_perm.uid;
381 		out->msg_perm.gid	= tbuf_old.msg_perm.gid;
382 		out->msg_perm.mode	= tbuf_old.msg_perm.mode;
383 
384 		if (tbuf_old.msg_qbytes == 0)
385 			out->msg_qbytes	= tbuf_old.msg_lqbytes;
386 		else
387 			out->msg_qbytes	= tbuf_old.msg_qbytes;
388 
389 		return 0;
390 	}
391 	default:
392 		return -EINVAL;
393 	}
394 }
395 
396 /*
397  * This function handles some msgctl commands which require the rwsem
398  * to be held in write mode.
399  * NOTE: no locks must be held, the rwsem is taken inside this function.
400  */
401 static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
402 			struct ipc64_perm *perm, int msg_qbytes)
403 {
404 	struct kern_ipc_perm *ipcp;
405 	struct msg_queue *msq;
406 	int err;
407 
408 	down_write(&msg_ids(ns).rwsem);
409 	rcu_read_lock();
410 
411 	ipcp = ipcctl_obtain_check(ns, &msg_ids(ns), msqid, cmd,
412 				      perm, msg_qbytes);
413 	if (IS_ERR(ipcp)) {
414 		err = PTR_ERR(ipcp);
415 		goto out_unlock1;
416 	}
417 
418 	msq = container_of(ipcp, struct msg_queue, q_perm);
419 
420 	err = security_msg_queue_msgctl(&msq->q_perm, cmd);
421 	if (err)
422 		goto out_unlock1;
423 
424 	switch (cmd) {
425 	case IPC_RMID:
426 		ipc_lock_object(&msq->q_perm);
427 		/* freeque unlocks the ipc object and rcu */
428 		freeque(ns, ipcp);
429 		goto out_up;
430 	case IPC_SET:
431 	{
432 		DEFINE_WAKE_Q(wake_q);
433 
434 		if (msg_qbytes > ns->msg_ctlmnb &&
435 		    !capable(CAP_SYS_RESOURCE)) {
436 			err = -EPERM;
437 			goto out_unlock1;
438 		}
439 
440 		ipc_lock_object(&msq->q_perm);
441 		err = ipc_update_perm(perm, ipcp);
442 		if (err)
443 			goto out_unlock0;
444 
445 		msq->q_qbytes = msg_qbytes;
446 
447 		msq->q_ctime = ktime_get_real_seconds();
448 		/*
449 		 * Sleeping receivers might be excluded by
450 		 * stricter permissions.
451 		 */
452 		expunge_all(msq, -EAGAIN, &wake_q);
453 		/*
454 		 * Sleeping senders might be able to send
455 		 * due to a larger queue size.
456 		 */
457 		ss_wakeup(msq, &wake_q, false);
458 		ipc_unlock_object(&msq->q_perm);
459 		wake_up_q(&wake_q);
460 
461 		goto out_unlock1;
462 	}
463 	default:
464 		err = -EINVAL;
465 		goto out_unlock1;
466 	}
467 
468 out_unlock0:
469 	ipc_unlock_object(&msq->q_perm);
470 out_unlock1:
471 	rcu_read_unlock();
472 out_up:
473 	up_write(&msg_ids(ns).rwsem);
474 	return err;
475 }
476 
477 static int msgctl_info(struct ipc_namespace *ns, int msqid,
478 			 int cmd, struct msginfo *msginfo)
479 {
480 	int err;
481 	int max_idx;
482 
483 	/*
484 	 * We must not return kernel stack data.
485 	 * due to padding, it's not enough
486 	 * to set all member fields.
487 	 */
488 	err = security_msg_queue_msgctl(NULL, cmd);
489 	if (err)
490 		return err;
491 
492 	memset(msginfo, 0, sizeof(*msginfo));
493 	msginfo->msgmni = ns->msg_ctlmni;
494 	msginfo->msgmax = ns->msg_ctlmax;
495 	msginfo->msgmnb = ns->msg_ctlmnb;
496 	msginfo->msgssz = MSGSSZ;
497 	msginfo->msgseg = MSGSEG;
498 	down_read(&msg_ids(ns).rwsem);
499 	if (cmd == MSG_INFO)
500 		msginfo->msgpool = msg_ids(ns).in_use;
501 	max_idx = ipc_get_maxidx(&msg_ids(ns));
502 	up_read(&msg_ids(ns).rwsem);
503 	if (cmd == MSG_INFO) {
504 		msginfo->msgmap = min_t(int,
505 				     percpu_counter_sum(&ns->percpu_msg_hdrs),
506 				     INT_MAX);
507 		msginfo->msgtql = min_t(int,
508 		                     percpu_counter_sum(&ns->percpu_msg_bytes),
509 				     INT_MAX);
510 	} else {
511 		msginfo->msgmap = MSGMAP;
512 		msginfo->msgpool = MSGPOOL;
513 		msginfo->msgtql = MSGTQL;
514 	}
515 	return (max_idx < 0) ? 0 : max_idx;
516 }
517 
518 static int msgctl_stat(struct ipc_namespace *ns, int msqid,
519 			 int cmd, struct msqid64_ds *p)
520 {
521 	struct msg_queue *msq;
522 	int err;
523 
524 	memset(p, 0, sizeof(*p));
525 
526 	rcu_read_lock();
527 	if (cmd == MSG_STAT || cmd == MSG_STAT_ANY) {
528 		msq = msq_obtain_object(ns, msqid);
529 		if (IS_ERR(msq)) {
530 			err = PTR_ERR(msq);
531 			goto out_unlock;
532 		}
533 	} else { /* IPC_STAT */
534 		msq = msq_obtain_object_check(ns, msqid);
535 		if (IS_ERR(msq)) {
536 			err = PTR_ERR(msq);
537 			goto out_unlock;
538 		}
539 	}
540 
541 	/* see comment for SHM_STAT_ANY */
542 	if (cmd == MSG_STAT_ANY)
543 		audit_ipc_obj(&msq->q_perm);
544 	else {
545 		err = -EACCES;
546 		if (ipcperms(ns, &msq->q_perm, S_IRUGO))
547 			goto out_unlock;
548 	}
549 
550 	err = security_msg_queue_msgctl(&msq->q_perm, cmd);
551 	if (err)
552 		goto out_unlock;
553 
554 	ipc_lock_object(&msq->q_perm);
555 
556 	if (!ipc_valid_object(&msq->q_perm)) {
557 		ipc_unlock_object(&msq->q_perm);
558 		err = -EIDRM;
559 		goto out_unlock;
560 	}
561 
562 	kernel_to_ipc64_perm(&msq->q_perm, &p->msg_perm);
563 	p->msg_stime  = msq->q_stime;
564 	p->msg_rtime  = msq->q_rtime;
565 	p->msg_ctime  = msq->q_ctime;
566 #ifndef CONFIG_64BIT
567 	p->msg_stime_high = msq->q_stime >> 32;
568 	p->msg_rtime_high = msq->q_rtime >> 32;
569 	p->msg_ctime_high = msq->q_ctime >> 32;
570 #endif
571 	p->msg_cbytes = msq->q_cbytes;
572 	p->msg_qnum   = msq->q_qnum;
573 	p->msg_qbytes = msq->q_qbytes;
574 	p->msg_lspid  = pid_vnr(msq->q_lspid);
575 	p->msg_lrpid  = pid_vnr(msq->q_lrpid);
576 
577 	if (cmd == IPC_STAT) {
578 		/*
579 		 * As defined in SUS:
580 		 * Return 0 on success
581 		 */
582 		err = 0;
583 	} else {
584 		/*
585 		 * MSG_STAT and MSG_STAT_ANY (both Linux specific)
586 		 * Return the full id, including the sequence number
587 		 */
588 		err = msq->q_perm.id;
589 	}
590 
591 	ipc_unlock_object(&msq->q_perm);
592 out_unlock:
593 	rcu_read_unlock();
594 	return err;
595 }
596 
597 static long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf, int version)
598 {
599 	struct ipc_namespace *ns;
600 	struct msqid64_ds msqid64;
601 	int err;
602 
603 	if (msqid < 0 || cmd < 0)
604 		return -EINVAL;
605 
606 	ns = current->nsproxy->ipc_ns;
607 
608 	switch (cmd) {
609 	case IPC_INFO:
610 	case MSG_INFO: {
611 		struct msginfo msginfo;
612 		err = msgctl_info(ns, msqid, cmd, &msginfo);
613 		if (err < 0)
614 			return err;
615 		if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
616 			err = -EFAULT;
617 		return err;
618 	}
619 	case MSG_STAT:	/* msqid is an index rather than a msg queue id */
620 	case MSG_STAT_ANY:
621 	case IPC_STAT:
622 		err = msgctl_stat(ns, msqid, cmd, &msqid64);
623 		if (err < 0)
624 			return err;
625 		if (copy_msqid_to_user(buf, &msqid64, version))
626 			err = -EFAULT;
627 		return err;
628 	case IPC_SET:
629 		if (copy_msqid_from_user(&msqid64, buf, version))
630 			return -EFAULT;
631 		return msgctl_down(ns, msqid, cmd, &msqid64.msg_perm,
632 				   msqid64.msg_qbytes);
633 	case IPC_RMID:
634 		return msgctl_down(ns, msqid, cmd, NULL, 0);
635 	default:
636 		return  -EINVAL;
637 	}
638 }
639 
640 SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
641 {
642 	return ksys_msgctl(msqid, cmd, buf, IPC_64);
643 }
644 
645 #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
646 long ksys_old_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
647 {
648 	int version = ipc_parse_version(&cmd);
649 
650 	return ksys_msgctl(msqid, cmd, buf, version);
651 }
652 
653 SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
654 {
655 	return ksys_old_msgctl(msqid, cmd, buf);
656 }
657 #endif
658 
659 #ifdef CONFIG_COMPAT
660 
661 struct compat_msqid_ds {
662 	struct compat_ipc_perm msg_perm;
663 	compat_uptr_t msg_first;
664 	compat_uptr_t msg_last;
665 	old_time32_t msg_stime;
666 	old_time32_t msg_rtime;
667 	old_time32_t msg_ctime;
668 	compat_ulong_t msg_lcbytes;
669 	compat_ulong_t msg_lqbytes;
670 	unsigned short msg_cbytes;
671 	unsigned short msg_qnum;
672 	unsigned short msg_qbytes;
673 	compat_ipc_pid_t msg_lspid;
674 	compat_ipc_pid_t msg_lrpid;
675 };
676 
677 static int copy_compat_msqid_from_user(struct msqid64_ds *out, void __user *buf,
678 					int version)
679 {
680 	memset(out, 0, sizeof(*out));
681 	if (version == IPC_64) {
682 		struct compat_msqid64_ds __user *p = buf;
683 		if (get_compat_ipc64_perm(&out->msg_perm, &p->msg_perm))
684 			return -EFAULT;
685 		if (get_user(out->msg_qbytes, &p->msg_qbytes))
686 			return -EFAULT;
687 	} else {
688 		struct compat_msqid_ds __user *p = buf;
689 		if (get_compat_ipc_perm(&out->msg_perm, &p->msg_perm))
690 			return -EFAULT;
691 		if (get_user(out->msg_qbytes, &p->msg_qbytes))
692 			return -EFAULT;
693 	}
694 	return 0;
695 }
696 
697 static int copy_compat_msqid_to_user(void __user *buf, struct msqid64_ds *in,
698 					int version)
699 {
700 	if (version == IPC_64) {
701 		struct compat_msqid64_ds v;
702 		memset(&v, 0, sizeof(v));
703 		to_compat_ipc64_perm(&v.msg_perm, &in->msg_perm);
704 		v.msg_stime	 = lower_32_bits(in->msg_stime);
705 		v.msg_stime_high = upper_32_bits(in->msg_stime);
706 		v.msg_rtime	 = lower_32_bits(in->msg_rtime);
707 		v.msg_rtime_high = upper_32_bits(in->msg_rtime);
708 		v.msg_ctime	 = lower_32_bits(in->msg_ctime);
709 		v.msg_ctime_high = upper_32_bits(in->msg_ctime);
710 		v.msg_cbytes = in->msg_cbytes;
711 		v.msg_qnum = in->msg_qnum;
712 		v.msg_qbytes = in->msg_qbytes;
713 		v.msg_lspid = in->msg_lspid;
714 		v.msg_lrpid = in->msg_lrpid;
715 		return copy_to_user(buf, &v, sizeof(v));
716 	} else {
717 		struct compat_msqid_ds v;
718 		memset(&v, 0, sizeof(v));
719 		to_compat_ipc_perm(&v.msg_perm, &in->msg_perm);
720 		v.msg_stime = in->msg_stime;
721 		v.msg_rtime = in->msg_rtime;
722 		v.msg_ctime = in->msg_ctime;
723 		v.msg_cbytes = in->msg_cbytes;
724 		v.msg_qnum = in->msg_qnum;
725 		v.msg_qbytes = in->msg_qbytes;
726 		v.msg_lspid = in->msg_lspid;
727 		v.msg_lrpid = in->msg_lrpid;
728 		return copy_to_user(buf, &v, sizeof(v));
729 	}
730 }
731 
732 static long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr, int version)
733 {
734 	struct ipc_namespace *ns;
735 	int err;
736 	struct msqid64_ds msqid64;
737 
738 	ns = current->nsproxy->ipc_ns;
739 
740 	if (msqid < 0 || cmd < 0)
741 		return -EINVAL;
742 
743 	switch (cmd & (~IPC_64)) {
744 	case IPC_INFO:
745 	case MSG_INFO: {
746 		struct msginfo msginfo;
747 		err = msgctl_info(ns, msqid, cmd, &msginfo);
748 		if (err < 0)
749 			return err;
750 		if (copy_to_user(uptr, &msginfo, sizeof(struct msginfo)))
751 			err = -EFAULT;
752 		return err;
753 	}
754 	case IPC_STAT:
755 	case MSG_STAT:
756 	case MSG_STAT_ANY:
757 		err = msgctl_stat(ns, msqid, cmd, &msqid64);
758 		if (err < 0)
759 			return err;
760 		if (copy_compat_msqid_to_user(uptr, &msqid64, version))
761 			err = -EFAULT;
762 		return err;
763 	case IPC_SET:
764 		if (copy_compat_msqid_from_user(&msqid64, uptr, version))
765 			return -EFAULT;
766 		return msgctl_down(ns, msqid, cmd, &msqid64.msg_perm, msqid64.msg_qbytes);
767 	case IPC_RMID:
768 		return msgctl_down(ns, msqid, cmd, NULL, 0);
769 	default:
770 		return -EINVAL;
771 	}
772 }
773 
774 COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr)
775 {
776 	return compat_ksys_msgctl(msqid, cmd, uptr, IPC_64);
777 }
778 
779 #ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
780 long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr)
781 {
782 	int version = compat_ipc_parse_version(&cmd);
783 
784 	return compat_ksys_msgctl(msqid, cmd, uptr, version);
785 }
786 
787 COMPAT_SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, void __user *, uptr)
788 {
789 	return compat_ksys_old_msgctl(msqid, cmd, uptr);
790 }
791 #endif
792 #endif
793 
794 static int testmsg(struct msg_msg *msg, long type, int mode)
795 {
796 	switch (mode) {
797 	case SEARCH_ANY:
798 	case SEARCH_NUMBER:
799 		return 1;
800 	case SEARCH_LESSEQUAL:
801 		if (msg->m_type <= type)
802 			return 1;
803 		break;
804 	case SEARCH_EQUAL:
805 		if (msg->m_type == type)
806 			return 1;
807 		break;
808 	case SEARCH_NOTEQUAL:
809 		if (msg->m_type != type)
810 			return 1;
811 		break;
812 	}
813 	return 0;
814 }
815 
816 static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg,
817 				 struct wake_q_head *wake_q)
818 {
819 	struct msg_receiver *msr, *t;
820 
821 	list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
822 		if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
823 		    !security_msg_queue_msgrcv(&msq->q_perm, msg, msr->r_tsk,
824 					       msr->r_msgtype, msr->r_mode)) {
825 
826 			list_del(&msr->r_list);
827 			if (msr->r_maxsize < msg->m_ts) {
828 				wake_q_add(wake_q, msr->r_tsk);
829 
830 				/* See expunge_all regarding memory barrier */
831 				smp_store_release(&msr->r_msg, ERR_PTR(-E2BIG));
832 			} else {
833 				ipc_update_pid(&msq->q_lrpid, task_pid(msr->r_tsk));
834 				msq->q_rtime = ktime_get_real_seconds();
835 
836 				wake_q_add(wake_q, msr->r_tsk);
837 
838 				/* See expunge_all regarding memory barrier */
839 				smp_store_release(&msr->r_msg, msg);
840 				return 1;
841 			}
842 		}
843 	}
844 
845 	return 0;
846 }
847 
848 static long do_msgsnd(int msqid, long mtype, void __user *mtext,
849 		size_t msgsz, int msgflg)
850 {
851 	struct msg_queue *msq;
852 	struct msg_msg *msg;
853 	int err;
854 	struct ipc_namespace *ns;
855 	DEFINE_WAKE_Q(wake_q);
856 
857 	ns = current->nsproxy->ipc_ns;
858 
859 	if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
860 		return -EINVAL;
861 	if (mtype < 1)
862 		return -EINVAL;
863 
864 	msg = load_msg(mtext, msgsz);
865 	if (IS_ERR(msg))
866 		return PTR_ERR(msg);
867 
868 	msg->m_type = mtype;
869 	msg->m_ts = msgsz;
870 
871 	rcu_read_lock();
872 	msq = msq_obtain_object_check(ns, msqid);
873 	if (IS_ERR(msq)) {
874 		err = PTR_ERR(msq);
875 		goto out_unlock1;
876 	}
877 
878 	ipc_lock_object(&msq->q_perm);
879 
880 	for (;;) {
881 		struct msg_sender s;
882 
883 		err = -EACCES;
884 		if (ipcperms(ns, &msq->q_perm, S_IWUGO))
885 			goto out_unlock0;
886 
887 		/* raced with RMID? */
888 		if (!ipc_valid_object(&msq->q_perm)) {
889 			err = -EIDRM;
890 			goto out_unlock0;
891 		}
892 
893 		err = security_msg_queue_msgsnd(&msq->q_perm, msg, msgflg);
894 		if (err)
895 			goto out_unlock0;
896 
897 		if (msg_fits_inqueue(msq, msgsz))
898 			break;
899 
900 		/* queue full, wait: */
901 		if (msgflg & IPC_NOWAIT) {
902 			err = -EAGAIN;
903 			goto out_unlock0;
904 		}
905 
906 		/* enqueue the sender and prepare to block */
907 		ss_add(msq, &s, msgsz);
908 
909 		if (!ipc_rcu_getref(&msq->q_perm)) {
910 			err = -EIDRM;
911 			goto out_unlock0;
912 		}
913 
914 		ipc_unlock_object(&msq->q_perm);
915 		rcu_read_unlock();
916 		schedule();
917 
918 		rcu_read_lock();
919 		ipc_lock_object(&msq->q_perm);
920 
921 		ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
922 		/* raced with RMID? */
923 		if (!ipc_valid_object(&msq->q_perm)) {
924 			err = -EIDRM;
925 			goto out_unlock0;
926 		}
927 		ss_del(&s);
928 
929 		if (signal_pending(current)) {
930 			err = -ERESTARTNOHAND;
931 			goto out_unlock0;
932 		}
933 
934 	}
935 
936 	ipc_update_pid(&msq->q_lspid, task_tgid(current));
937 	msq->q_stime = ktime_get_real_seconds();
938 
939 	if (!pipelined_send(msq, msg, &wake_q)) {
940 		/* no one is waiting for this message, enqueue it */
941 		list_add_tail(&msg->m_list, &msq->q_messages);
942 		msq->q_cbytes += msgsz;
943 		msq->q_qnum++;
944 		percpu_counter_add_local(&ns->percpu_msg_bytes, msgsz);
945 		percpu_counter_add_local(&ns->percpu_msg_hdrs, 1);
946 	}
947 
948 	err = 0;
949 	msg = NULL;
950 
951 out_unlock0:
952 	ipc_unlock_object(&msq->q_perm);
953 	wake_up_q(&wake_q);
954 out_unlock1:
955 	rcu_read_unlock();
956 	if (msg != NULL)
957 		free_msg(msg);
958 	return err;
959 }
960 
961 long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
962 		 int msgflg)
963 {
964 	long mtype;
965 
966 	if (get_user(mtype, &msgp->mtype))
967 		return -EFAULT;
968 	return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
969 }
970 
971 SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
972 		int, msgflg)
973 {
974 	return ksys_msgsnd(msqid, msgp, msgsz, msgflg);
975 }
976 
977 #ifdef CONFIG_COMPAT
978 
979 struct compat_msgbuf {
980 	compat_long_t mtype;
981 	char mtext[1];
982 };
983 
984 long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
985 		       compat_ssize_t msgsz, int msgflg)
986 {
987 	struct compat_msgbuf __user *up = compat_ptr(msgp);
988 	compat_long_t mtype;
989 
990 	if (get_user(mtype, &up->mtype))
991 		return -EFAULT;
992 	return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg);
993 }
994 
995 COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
996 		       compat_ssize_t, msgsz, int, msgflg)
997 {
998 	return compat_ksys_msgsnd(msqid, msgp, msgsz, msgflg);
999 }
1000 #endif
1001 
1002 static inline int convert_mode(long *msgtyp, int msgflg)
1003 {
1004 	if (msgflg & MSG_COPY)
1005 		return SEARCH_NUMBER;
1006 	/*
1007 	 *  find message of correct type.
1008 	 *  msgtyp = 0 => get first.
1009 	 *  msgtyp > 0 => get first message of matching type.
1010 	 *  msgtyp < 0 => get message with least type must be < abs(msgtype).
1011 	 */
1012 	if (*msgtyp == 0)
1013 		return SEARCH_ANY;
1014 	if (*msgtyp < 0) {
1015 		if (*msgtyp == LONG_MIN) /* -LONG_MIN is undefined */
1016 			*msgtyp = LONG_MAX;
1017 		else
1018 			*msgtyp = -*msgtyp;
1019 		return SEARCH_LESSEQUAL;
1020 	}
1021 	if (msgflg & MSG_EXCEPT)
1022 		return SEARCH_NOTEQUAL;
1023 	return SEARCH_EQUAL;
1024 }
1025 
1026 static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
1027 {
1028 	struct msgbuf __user *msgp = dest;
1029 	size_t msgsz;
1030 
1031 	if (put_user(msg->m_type, &msgp->mtype))
1032 		return -EFAULT;
1033 
1034 	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
1035 	if (store_msg(msgp->mtext, msg, msgsz))
1036 		return -EFAULT;
1037 	return msgsz;
1038 }
1039 
1040 #ifdef CONFIG_CHECKPOINT_RESTORE
1041 /*
1042  * This function creates new kernel message structure, large enough to store
1043  * bufsz message bytes.
1044  */
1045 static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
1046 {
1047 	struct msg_msg *copy;
1048 
1049 	/*
1050 	 * Create dummy message to copy real message to.
1051 	 */
1052 	copy = load_msg(buf, bufsz);
1053 	if (!IS_ERR(copy))
1054 		copy->m_ts = bufsz;
1055 	return copy;
1056 }
1057 
1058 static inline void free_copy(struct msg_msg *copy)
1059 {
1060 	if (copy)
1061 		free_msg(copy);
1062 }
1063 #else
1064 static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
1065 {
1066 	return ERR_PTR(-ENOSYS);
1067 }
1068 
1069 static inline void free_copy(struct msg_msg *copy)
1070 {
1071 }
1072 #endif
1073 
1074 static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
1075 {
1076 	struct msg_msg *msg, *found = NULL;
1077 	long count = 0;
1078 
1079 	list_for_each_entry(msg, &msq->q_messages, m_list) {
1080 		if (testmsg(msg, *msgtyp, mode) &&
1081 		    !security_msg_queue_msgrcv(&msq->q_perm, msg, current,
1082 					       *msgtyp, mode)) {
1083 			if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
1084 				*msgtyp = msg->m_type - 1;
1085 				found = msg;
1086 			} else if (mode == SEARCH_NUMBER) {
1087 				if (*msgtyp == count)
1088 					return msg;
1089 			} else
1090 				return msg;
1091 			count++;
1092 		}
1093 	}
1094 
1095 	return found ?: ERR_PTR(-EAGAIN);
1096 }
1097 
1098 static long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
1099 	       long (*msg_handler)(void __user *, struct msg_msg *, size_t))
1100 {
1101 	int mode;
1102 	struct msg_queue *msq;
1103 	struct ipc_namespace *ns;
1104 	struct msg_msg *msg, *copy = NULL;
1105 	DEFINE_WAKE_Q(wake_q);
1106 
1107 	ns = current->nsproxy->ipc_ns;
1108 
1109 	if (msqid < 0 || (long) bufsz < 0)
1110 		return -EINVAL;
1111 
1112 	if (msgflg & MSG_COPY) {
1113 		if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT))
1114 			return -EINVAL;
1115 		copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
1116 		if (IS_ERR(copy))
1117 			return PTR_ERR(copy);
1118 	}
1119 	mode = convert_mode(&msgtyp, msgflg);
1120 
1121 	rcu_read_lock();
1122 	msq = msq_obtain_object_check(ns, msqid);
1123 	if (IS_ERR(msq)) {
1124 		rcu_read_unlock();
1125 		free_copy(copy);
1126 		return PTR_ERR(msq);
1127 	}
1128 
1129 	for (;;) {
1130 		struct msg_receiver msr_d;
1131 
1132 		msg = ERR_PTR(-EACCES);
1133 		if (ipcperms(ns, &msq->q_perm, S_IRUGO))
1134 			goto out_unlock1;
1135 
1136 		ipc_lock_object(&msq->q_perm);
1137 
1138 		/* raced with RMID? */
1139 		if (!ipc_valid_object(&msq->q_perm)) {
1140 			msg = ERR_PTR(-EIDRM);
1141 			goto out_unlock0;
1142 		}
1143 
1144 		msg = find_msg(msq, &msgtyp, mode);
1145 		if (!IS_ERR(msg)) {
1146 			/*
1147 			 * Found a suitable message.
1148 			 * Unlink it from the queue.
1149 			 */
1150 			if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
1151 				msg = ERR_PTR(-E2BIG);
1152 				goto out_unlock0;
1153 			}
1154 			/*
1155 			 * If we are copying, then do not unlink message and do
1156 			 * not update queue parameters.
1157 			 */
1158 			if (msgflg & MSG_COPY) {
1159 				msg = copy_msg(msg, copy);
1160 				goto out_unlock0;
1161 			}
1162 
1163 			list_del(&msg->m_list);
1164 			msq->q_qnum--;
1165 			msq->q_rtime = ktime_get_real_seconds();
1166 			ipc_update_pid(&msq->q_lrpid, task_tgid(current));
1167 			msq->q_cbytes -= msg->m_ts;
1168 			percpu_counter_sub_local(&ns->percpu_msg_bytes, msg->m_ts);
1169 			percpu_counter_sub_local(&ns->percpu_msg_hdrs, 1);
1170 			ss_wakeup(msq, &wake_q, false);
1171 
1172 			goto out_unlock0;
1173 		}
1174 
1175 		/* No message waiting. Wait for a message */
1176 		if (msgflg & IPC_NOWAIT) {
1177 			msg = ERR_PTR(-ENOMSG);
1178 			goto out_unlock0;
1179 		}
1180 
1181 		list_add_tail(&msr_d.r_list, &msq->q_receivers);
1182 		msr_d.r_tsk = current;
1183 		msr_d.r_msgtype = msgtyp;
1184 		msr_d.r_mode = mode;
1185 		if (msgflg & MSG_NOERROR)
1186 			msr_d.r_maxsize = INT_MAX;
1187 		else
1188 			msr_d.r_maxsize = bufsz;
1189 
1190 		/* memory barrier not require due to ipc_lock_object() */
1191 		WRITE_ONCE(msr_d.r_msg, ERR_PTR(-EAGAIN));
1192 
1193 		/* memory barrier not required, we own ipc_lock_object() */
1194 		__set_current_state(TASK_INTERRUPTIBLE);
1195 
1196 		ipc_unlock_object(&msq->q_perm);
1197 		rcu_read_unlock();
1198 		schedule();
1199 
1200 		/*
1201 		 * Lockless receive, part 1:
1202 		 * We don't hold a reference to the queue and getting a
1203 		 * reference would defeat the idea of a lockless operation,
1204 		 * thus the code relies on rcu to guarantee the existence of
1205 		 * msq:
1206 		 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
1207 		 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
1208 		 */
1209 		rcu_read_lock();
1210 
1211 		/*
1212 		 * Lockless receive, part 2:
1213 		 * The work in pipelined_send() and expunge_all():
1214 		 * - Set pointer to message
1215 		 * - Queue the receiver task for later wakeup
1216 		 * - Wake up the process after the lock is dropped.
1217 		 *
1218 		 * Should the process wake up before this wakeup (due to a
1219 		 * signal) it will either see the message and continue ...
1220 		 */
1221 		msg = READ_ONCE(msr_d.r_msg);
1222 		if (msg != ERR_PTR(-EAGAIN)) {
1223 			/* see MSG_BARRIER for purpose/pairing */
1224 			smp_acquire__after_ctrl_dep();
1225 
1226 			goto out_unlock1;
1227 		}
1228 
1229 		 /*
1230 		  * ... or see -EAGAIN, acquire the lock to check the message
1231 		  * again.
1232 		  */
1233 		ipc_lock_object(&msq->q_perm);
1234 
1235 		msg = READ_ONCE(msr_d.r_msg);
1236 		if (msg != ERR_PTR(-EAGAIN))
1237 			goto out_unlock0;
1238 
1239 		list_del(&msr_d.r_list);
1240 		if (signal_pending(current)) {
1241 			msg = ERR_PTR(-ERESTARTNOHAND);
1242 			goto out_unlock0;
1243 		}
1244 
1245 		ipc_unlock_object(&msq->q_perm);
1246 	}
1247 
1248 out_unlock0:
1249 	ipc_unlock_object(&msq->q_perm);
1250 	wake_up_q(&wake_q);
1251 out_unlock1:
1252 	rcu_read_unlock();
1253 	if (IS_ERR(msg)) {
1254 		free_copy(copy);
1255 		return PTR_ERR(msg);
1256 	}
1257 
1258 	bufsz = msg_handler(buf, msg, bufsz);
1259 	free_msg(msg);
1260 
1261 	return bufsz;
1262 }
1263 
1264 long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
1265 		 long msgtyp, int msgflg)
1266 {
1267 	return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
1268 }
1269 
1270 SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
1271 		long, msgtyp, int, msgflg)
1272 {
1273 	return ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg);
1274 }
1275 
1276 #ifdef CONFIG_COMPAT
1277 static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
1278 {
1279 	struct compat_msgbuf __user *msgp = dest;
1280 	size_t msgsz;
1281 
1282 	if (put_user(msg->m_type, &msgp->mtype))
1283 		return -EFAULT;
1284 
1285 	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
1286 	if (store_msg(msgp->mtext, msg, msgsz))
1287 		return -EFAULT;
1288 	return msgsz;
1289 }
1290 
1291 long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
1292 			compat_long_t msgtyp, int msgflg)
1293 {
1294 	return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp,
1295 			 msgflg, compat_do_msg_fill);
1296 }
1297 
1298 COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp,
1299 		       compat_ssize_t, msgsz, compat_long_t, msgtyp,
1300 		       int, msgflg)
1301 {
1302 	return compat_ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg);
1303 }
1304 #endif
1305 
1306 int msg_init_ns(struct ipc_namespace *ns)
1307 {
1308 	int ret;
1309 
1310 	ns->msg_ctlmax = MSGMAX;
1311 	ns->msg_ctlmnb = MSGMNB;
1312 	ns->msg_ctlmni = MSGMNI;
1313 
1314 	ret = percpu_counter_init(&ns->percpu_msg_bytes, 0, GFP_KERNEL);
1315 	if (ret)
1316 		goto fail_msg_bytes;
1317 	ret = percpu_counter_init(&ns->percpu_msg_hdrs, 0, GFP_KERNEL);
1318 	if (ret)
1319 		goto fail_msg_hdrs;
1320 	ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
1321 	return 0;
1322 
1323 fail_msg_hdrs:
1324 	percpu_counter_destroy(&ns->percpu_msg_bytes);
1325 fail_msg_bytes:
1326 	return ret;
1327 }
1328 
1329 #ifdef CONFIG_IPC_NS
1330 void msg_exit_ns(struct ipc_namespace *ns)
1331 {
1332 	free_ipcs(ns, &msg_ids(ns), freeque);
1333 	idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
1334 	rhashtable_destroy(&ns->ids[IPC_MSG_IDS].key_ht);
1335 	percpu_counter_destroy(&ns->percpu_msg_bytes);
1336 	percpu_counter_destroy(&ns->percpu_msg_hdrs);
1337 }
1338 #endif
1339 
1340 #ifdef CONFIG_PROC_FS
1341 static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
1342 {
1343 	struct pid_namespace *pid_ns = ipc_seq_pid_ns(s);
1344 	struct user_namespace *user_ns = seq_user_ns(s);
1345 	struct kern_ipc_perm *ipcp = it;
1346 	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
1347 
1348 	seq_printf(s,
1349 		   "%10d %10d  %4o  %10lu %10lu %5u %5u %5u %5u %5u %5u %10llu %10llu %10llu\n",
1350 		   msq->q_perm.key,
1351 		   msq->q_perm.id,
1352 		   msq->q_perm.mode,
1353 		   msq->q_cbytes,
1354 		   msq->q_qnum,
1355 		   pid_nr_ns(msq->q_lspid, pid_ns),
1356 		   pid_nr_ns(msq->q_lrpid, pid_ns),
1357 		   from_kuid_munged(user_ns, msq->q_perm.uid),
1358 		   from_kgid_munged(user_ns, msq->q_perm.gid),
1359 		   from_kuid_munged(user_ns, msq->q_perm.cuid),
1360 		   from_kgid_munged(user_ns, msq->q_perm.cgid),
1361 		   msq->q_stime,
1362 		   msq->q_rtime,
1363 		   msq->q_ctime);
1364 
1365 	return 0;
1366 }
1367 #endif
1368 
1369 void __init msg_init(void)
1370 {
1371 	msg_init_ns(&init_ipc_ns);
1372 
1373 	ipc_init_proc_interface("sysvipc/msg",
1374 				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
1375 				IPC_MSG_IDS, sysvipc_msg_proc_show);
1376 }
1377