xref: /openbmc/linux/ipc/msg.c (revision 60630924bb5af8751adcecc896e7763c3783ca89)
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  	kfree(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 = kmalloc(sizeof(*msq), GFP_KERNEL_ACCOUNT);
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  		kfree(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  		struct task_struct *r_tsk;
255  
256  		r_tsk = get_task_struct(msr->r_tsk);
257  
258  		/* see MSG_BARRIER for purpose/pairing */
259  		smp_store_release(&msr->r_msg, ERR_PTR(res));
260  		wake_q_add_safe(wake_q, r_tsk);
261  	}
262  }
263  
264  /*
265   * freeque() wakes up waiters on the sender and receiver waiting queue,
266   * removes the message queue from message queue ID IDR, and cleans up all the
267   * messages associated with this queue.
268   *
269   * msg_ids.rwsem (writer) and the spinlock for this message queue are held
270   * before freeque() is called. msg_ids.rwsem remains locked on exit.
271   */
272  static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
273  	__releases(RCU)
274  	__releases(&msq->q_perm)
275  {
276  	struct msg_msg *msg, *t;
277  	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
278  	DEFINE_WAKE_Q(wake_q);
279  
280  	expunge_all(msq, -EIDRM, &wake_q);
281  	ss_wakeup(msq, &wake_q, true);
282  	msg_rmid(ns, msq);
283  	ipc_unlock_object(&msq->q_perm);
284  	wake_up_q(&wake_q);
285  	rcu_read_unlock();
286  
287  	list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
288  		atomic_dec(&ns->msg_hdrs);
289  		free_msg(msg);
290  	}
291  	atomic_sub(msq->q_cbytes, &ns->msg_bytes);
292  	ipc_update_pid(&msq->q_lspid, NULL);
293  	ipc_update_pid(&msq->q_lrpid, NULL);
294  	ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
295  }
296  
297  long ksys_msgget(key_t key, int msgflg)
298  {
299  	struct ipc_namespace *ns;
300  	static const struct ipc_ops msg_ops = {
301  		.getnew = newque,
302  		.associate = security_msg_queue_associate,
303  	};
304  	struct ipc_params msg_params;
305  
306  	ns = current->nsproxy->ipc_ns;
307  
308  	msg_params.key = key;
309  	msg_params.flg = msgflg;
310  
311  	return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
312  }
313  
314  SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
315  {
316  	return ksys_msgget(key, msgflg);
317  }
318  
319  static inline unsigned long
320  copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
321  {
322  	switch (version) {
323  	case IPC_64:
324  		return copy_to_user(buf, in, sizeof(*in));
325  	case IPC_OLD:
326  	{
327  		struct msqid_ds out;
328  
329  		memset(&out, 0, sizeof(out));
330  
331  		ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
332  
333  		out.msg_stime		= in->msg_stime;
334  		out.msg_rtime		= in->msg_rtime;
335  		out.msg_ctime		= in->msg_ctime;
336  
337  		if (in->msg_cbytes > USHRT_MAX)
338  			out.msg_cbytes	= USHRT_MAX;
339  		else
340  			out.msg_cbytes	= in->msg_cbytes;
341  		out.msg_lcbytes		= in->msg_cbytes;
342  
343  		if (in->msg_qnum > USHRT_MAX)
344  			out.msg_qnum	= USHRT_MAX;
345  		else
346  			out.msg_qnum	= in->msg_qnum;
347  
348  		if (in->msg_qbytes > USHRT_MAX)
349  			out.msg_qbytes	= USHRT_MAX;
350  		else
351  			out.msg_qbytes	= in->msg_qbytes;
352  		out.msg_lqbytes		= in->msg_qbytes;
353  
354  		out.msg_lspid		= in->msg_lspid;
355  		out.msg_lrpid		= in->msg_lrpid;
356  
357  		return copy_to_user(buf, &out, sizeof(out));
358  	}
359  	default:
360  		return -EINVAL;
361  	}
362  }
363  
364  static inline unsigned long
365  copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
366  {
367  	switch (version) {
368  	case IPC_64:
369  		if (copy_from_user(out, buf, sizeof(*out)))
370  			return -EFAULT;
371  		return 0;
372  	case IPC_OLD:
373  	{
374  		struct msqid_ds tbuf_old;
375  
376  		if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
377  			return -EFAULT;
378  
379  		out->msg_perm.uid	= tbuf_old.msg_perm.uid;
380  		out->msg_perm.gid	= tbuf_old.msg_perm.gid;
381  		out->msg_perm.mode	= tbuf_old.msg_perm.mode;
382  
383  		if (tbuf_old.msg_qbytes == 0)
384  			out->msg_qbytes	= tbuf_old.msg_lqbytes;
385  		else
386  			out->msg_qbytes	= tbuf_old.msg_qbytes;
387  
388  		return 0;
389  	}
390  	default:
391  		return -EINVAL;
392  	}
393  }
394  
395  /*
396   * This function handles some msgctl commands which require the rwsem
397   * to be held in write mode.
398   * NOTE: no locks must be held, the rwsem is taken inside this function.
399   */
400  static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
401  			struct ipc64_perm *perm, int msg_qbytes)
402  {
403  	struct kern_ipc_perm *ipcp;
404  	struct msg_queue *msq;
405  	int err;
406  
407  	down_write(&msg_ids(ns).rwsem);
408  	rcu_read_lock();
409  
410  	ipcp = ipcctl_obtain_check(ns, &msg_ids(ns), msqid, cmd,
411  				      perm, msg_qbytes);
412  	if (IS_ERR(ipcp)) {
413  		err = PTR_ERR(ipcp);
414  		goto out_unlock1;
415  	}
416  
417  	msq = container_of(ipcp, struct msg_queue, q_perm);
418  
419  	err = security_msg_queue_msgctl(&msq->q_perm, cmd);
420  	if (err)
421  		goto out_unlock1;
422  
423  	switch (cmd) {
424  	case IPC_RMID:
425  		ipc_lock_object(&msq->q_perm);
426  		/* freeque unlocks the ipc object and rcu */
427  		freeque(ns, ipcp);
428  		goto out_up;
429  	case IPC_SET:
430  	{
431  		DEFINE_WAKE_Q(wake_q);
432  
433  		if (msg_qbytes > ns->msg_ctlmnb &&
434  		    !capable(CAP_SYS_RESOURCE)) {
435  			err = -EPERM;
436  			goto out_unlock1;
437  		}
438  
439  		ipc_lock_object(&msq->q_perm);
440  		err = ipc_update_perm(perm, ipcp);
441  		if (err)
442  			goto out_unlock0;
443  
444  		msq->q_qbytes = msg_qbytes;
445  
446  		msq->q_ctime = ktime_get_real_seconds();
447  		/*
448  		 * Sleeping receivers might be excluded by
449  		 * stricter permissions.
450  		 */
451  		expunge_all(msq, -EAGAIN, &wake_q);
452  		/*
453  		 * Sleeping senders might be able to send
454  		 * due to a larger queue size.
455  		 */
456  		ss_wakeup(msq, &wake_q, false);
457  		ipc_unlock_object(&msq->q_perm);
458  		wake_up_q(&wake_q);
459  
460  		goto out_unlock1;
461  	}
462  	default:
463  		err = -EINVAL;
464  		goto out_unlock1;
465  	}
466  
467  out_unlock0:
468  	ipc_unlock_object(&msq->q_perm);
469  out_unlock1:
470  	rcu_read_unlock();
471  out_up:
472  	up_write(&msg_ids(ns).rwsem);
473  	return err;
474  }
475  
476  static int msgctl_info(struct ipc_namespace *ns, int msqid,
477  			 int cmd, struct msginfo *msginfo)
478  {
479  	int err;
480  	int max_idx;
481  
482  	/*
483  	 * We must not return kernel stack data.
484  	 * due to padding, it's not enough
485  	 * to set all member fields.
486  	 */
487  	err = security_msg_queue_msgctl(NULL, cmd);
488  	if (err)
489  		return err;
490  
491  	memset(msginfo, 0, sizeof(*msginfo));
492  	msginfo->msgmni = ns->msg_ctlmni;
493  	msginfo->msgmax = ns->msg_ctlmax;
494  	msginfo->msgmnb = ns->msg_ctlmnb;
495  	msginfo->msgssz = MSGSSZ;
496  	msginfo->msgseg = MSGSEG;
497  	down_read(&msg_ids(ns).rwsem);
498  	if (cmd == MSG_INFO) {
499  		msginfo->msgpool = msg_ids(ns).in_use;
500  		msginfo->msgmap = atomic_read(&ns->msg_hdrs);
501  		msginfo->msgtql = atomic_read(&ns->msg_bytes);
502  	} else {
503  		msginfo->msgmap = MSGMAP;
504  		msginfo->msgpool = MSGPOOL;
505  		msginfo->msgtql = MSGTQL;
506  	}
507  	max_idx = ipc_get_maxidx(&msg_ids(ns));
508  	up_read(&msg_ids(ns).rwsem);
509  	return (max_idx < 0) ? 0 : max_idx;
510  }
511  
512  static int msgctl_stat(struct ipc_namespace *ns, int msqid,
513  			 int cmd, struct msqid64_ds *p)
514  {
515  	struct msg_queue *msq;
516  	int err;
517  
518  	memset(p, 0, sizeof(*p));
519  
520  	rcu_read_lock();
521  	if (cmd == MSG_STAT || cmd == MSG_STAT_ANY) {
522  		msq = msq_obtain_object(ns, msqid);
523  		if (IS_ERR(msq)) {
524  			err = PTR_ERR(msq);
525  			goto out_unlock;
526  		}
527  	} else { /* IPC_STAT */
528  		msq = msq_obtain_object_check(ns, msqid);
529  		if (IS_ERR(msq)) {
530  			err = PTR_ERR(msq);
531  			goto out_unlock;
532  		}
533  	}
534  
535  	/* see comment for SHM_STAT_ANY */
536  	if (cmd == MSG_STAT_ANY)
537  		audit_ipc_obj(&msq->q_perm);
538  	else {
539  		err = -EACCES;
540  		if (ipcperms(ns, &msq->q_perm, S_IRUGO))
541  			goto out_unlock;
542  	}
543  
544  	err = security_msg_queue_msgctl(&msq->q_perm, cmd);
545  	if (err)
546  		goto out_unlock;
547  
548  	ipc_lock_object(&msq->q_perm);
549  
550  	if (!ipc_valid_object(&msq->q_perm)) {
551  		ipc_unlock_object(&msq->q_perm);
552  		err = -EIDRM;
553  		goto out_unlock;
554  	}
555  
556  	kernel_to_ipc64_perm(&msq->q_perm, &p->msg_perm);
557  	p->msg_stime  = msq->q_stime;
558  	p->msg_rtime  = msq->q_rtime;
559  	p->msg_ctime  = msq->q_ctime;
560  #ifndef CONFIG_64BIT
561  	p->msg_stime_high = msq->q_stime >> 32;
562  	p->msg_rtime_high = msq->q_rtime >> 32;
563  	p->msg_ctime_high = msq->q_ctime >> 32;
564  #endif
565  	p->msg_cbytes = msq->q_cbytes;
566  	p->msg_qnum   = msq->q_qnum;
567  	p->msg_qbytes = msq->q_qbytes;
568  	p->msg_lspid  = pid_vnr(msq->q_lspid);
569  	p->msg_lrpid  = pid_vnr(msq->q_lrpid);
570  
571  	if (cmd == IPC_STAT) {
572  		/*
573  		 * As defined in SUS:
574  		 * Return 0 on success
575  		 */
576  		err = 0;
577  	} else {
578  		/*
579  		 * MSG_STAT and MSG_STAT_ANY (both Linux specific)
580  		 * Return the full id, including the sequence number
581  		 */
582  		err = msq->q_perm.id;
583  	}
584  
585  	ipc_unlock_object(&msq->q_perm);
586  out_unlock:
587  	rcu_read_unlock();
588  	return err;
589  }
590  
591  static long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf, int version)
592  {
593  	struct ipc_namespace *ns;
594  	struct msqid64_ds msqid64;
595  	int err;
596  
597  	if (msqid < 0 || cmd < 0)
598  		return -EINVAL;
599  
600  	ns = current->nsproxy->ipc_ns;
601  
602  	switch (cmd) {
603  	case IPC_INFO:
604  	case MSG_INFO: {
605  		struct msginfo msginfo;
606  		err = msgctl_info(ns, msqid, cmd, &msginfo);
607  		if (err < 0)
608  			return err;
609  		if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
610  			err = -EFAULT;
611  		return err;
612  	}
613  	case MSG_STAT:	/* msqid is an index rather than a msg queue id */
614  	case MSG_STAT_ANY:
615  	case IPC_STAT:
616  		err = msgctl_stat(ns, msqid, cmd, &msqid64);
617  		if (err < 0)
618  			return err;
619  		if (copy_msqid_to_user(buf, &msqid64, version))
620  			err = -EFAULT;
621  		return err;
622  	case IPC_SET:
623  		if (copy_msqid_from_user(&msqid64, buf, version))
624  			return -EFAULT;
625  		return msgctl_down(ns, msqid, cmd, &msqid64.msg_perm,
626  				   msqid64.msg_qbytes);
627  	case IPC_RMID:
628  		return msgctl_down(ns, msqid, cmd, NULL, 0);
629  	default:
630  		return  -EINVAL;
631  	}
632  }
633  
634  SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
635  {
636  	return ksys_msgctl(msqid, cmd, buf, IPC_64);
637  }
638  
639  #ifdef CONFIG_ARCH_WANT_IPC_PARSE_VERSION
640  long ksys_old_msgctl(int msqid, int cmd, struct msqid_ds __user *buf)
641  {
642  	int version = ipc_parse_version(&cmd);
643  
644  	return ksys_msgctl(msqid, cmd, buf, version);
645  }
646  
647  SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
648  {
649  	return ksys_old_msgctl(msqid, cmd, buf);
650  }
651  #endif
652  
653  #ifdef CONFIG_COMPAT
654  
655  struct compat_msqid_ds {
656  	struct compat_ipc_perm msg_perm;
657  	compat_uptr_t msg_first;
658  	compat_uptr_t msg_last;
659  	old_time32_t msg_stime;
660  	old_time32_t msg_rtime;
661  	old_time32_t msg_ctime;
662  	compat_ulong_t msg_lcbytes;
663  	compat_ulong_t msg_lqbytes;
664  	unsigned short msg_cbytes;
665  	unsigned short msg_qnum;
666  	unsigned short msg_qbytes;
667  	compat_ipc_pid_t msg_lspid;
668  	compat_ipc_pid_t msg_lrpid;
669  };
670  
671  static int copy_compat_msqid_from_user(struct msqid64_ds *out, void __user *buf,
672  					int version)
673  {
674  	memset(out, 0, sizeof(*out));
675  	if (version == IPC_64) {
676  		struct compat_msqid64_ds __user *p = buf;
677  		if (get_compat_ipc64_perm(&out->msg_perm, &p->msg_perm))
678  			return -EFAULT;
679  		if (get_user(out->msg_qbytes, &p->msg_qbytes))
680  			return -EFAULT;
681  	} else {
682  		struct compat_msqid_ds __user *p = buf;
683  		if (get_compat_ipc_perm(&out->msg_perm, &p->msg_perm))
684  			return -EFAULT;
685  		if (get_user(out->msg_qbytes, &p->msg_qbytes))
686  			return -EFAULT;
687  	}
688  	return 0;
689  }
690  
691  static int copy_compat_msqid_to_user(void __user *buf, struct msqid64_ds *in,
692  					int version)
693  {
694  	if (version == IPC_64) {
695  		struct compat_msqid64_ds v;
696  		memset(&v, 0, sizeof(v));
697  		to_compat_ipc64_perm(&v.msg_perm, &in->msg_perm);
698  		v.msg_stime	 = lower_32_bits(in->msg_stime);
699  		v.msg_stime_high = upper_32_bits(in->msg_stime);
700  		v.msg_rtime	 = lower_32_bits(in->msg_rtime);
701  		v.msg_rtime_high = upper_32_bits(in->msg_rtime);
702  		v.msg_ctime	 = lower_32_bits(in->msg_ctime);
703  		v.msg_ctime_high = upper_32_bits(in->msg_ctime);
704  		v.msg_cbytes = in->msg_cbytes;
705  		v.msg_qnum = in->msg_qnum;
706  		v.msg_qbytes = in->msg_qbytes;
707  		v.msg_lspid = in->msg_lspid;
708  		v.msg_lrpid = in->msg_lrpid;
709  		return copy_to_user(buf, &v, sizeof(v));
710  	} else {
711  		struct compat_msqid_ds v;
712  		memset(&v, 0, sizeof(v));
713  		to_compat_ipc_perm(&v.msg_perm, &in->msg_perm);
714  		v.msg_stime = in->msg_stime;
715  		v.msg_rtime = in->msg_rtime;
716  		v.msg_ctime = in->msg_ctime;
717  		v.msg_cbytes = in->msg_cbytes;
718  		v.msg_qnum = in->msg_qnum;
719  		v.msg_qbytes = in->msg_qbytes;
720  		v.msg_lspid = in->msg_lspid;
721  		v.msg_lrpid = in->msg_lrpid;
722  		return copy_to_user(buf, &v, sizeof(v));
723  	}
724  }
725  
726  static long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr, int version)
727  {
728  	struct ipc_namespace *ns;
729  	int err;
730  	struct msqid64_ds msqid64;
731  
732  	ns = current->nsproxy->ipc_ns;
733  
734  	if (msqid < 0 || cmd < 0)
735  		return -EINVAL;
736  
737  	switch (cmd & (~IPC_64)) {
738  	case IPC_INFO:
739  	case MSG_INFO: {
740  		struct msginfo msginfo;
741  		err = msgctl_info(ns, msqid, cmd, &msginfo);
742  		if (err < 0)
743  			return err;
744  		if (copy_to_user(uptr, &msginfo, sizeof(struct msginfo)))
745  			err = -EFAULT;
746  		return err;
747  	}
748  	case IPC_STAT:
749  	case MSG_STAT:
750  	case MSG_STAT_ANY:
751  		err = msgctl_stat(ns, msqid, cmd, &msqid64);
752  		if (err < 0)
753  			return err;
754  		if (copy_compat_msqid_to_user(uptr, &msqid64, version))
755  			err = -EFAULT;
756  		return err;
757  	case IPC_SET:
758  		if (copy_compat_msqid_from_user(&msqid64, uptr, version))
759  			return -EFAULT;
760  		return msgctl_down(ns, msqid, cmd, &msqid64.msg_perm, msqid64.msg_qbytes);
761  	case IPC_RMID:
762  		return msgctl_down(ns, msqid, cmd, NULL, 0);
763  	default:
764  		return -EINVAL;
765  	}
766  }
767  
768  COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr)
769  {
770  	return compat_ksys_msgctl(msqid, cmd, uptr, IPC_64);
771  }
772  
773  #ifdef CONFIG_ARCH_WANT_COMPAT_IPC_PARSE_VERSION
774  long compat_ksys_old_msgctl(int msqid, int cmd, void __user *uptr)
775  {
776  	int version = compat_ipc_parse_version(&cmd);
777  
778  	return compat_ksys_msgctl(msqid, cmd, uptr, version);
779  }
780  
781  COMPAT_SYSCALL_DEFINE3(old_msgctl, int, msqid, int, cmd, void __user *, uptr)
782  {
783  	return compat_ksys_old_msgctl(msqid, cmd, uptr);
784  }
785  #endif
786  #endif
787  
788  static int testmsg(struct msg_msg *msg, long type, int mode)
789  {
790  	switch (mode) {
791  	case SEARCH_ANY:
792  	case SEARCH_NUMBER:
793  		return 1;
794  	case SEARCH_LESSEQUAL:
795  		if (msg->m_type <= type)
796  			return 1;
797  		break;
798  	case SEARCH_EQUAL:
799  		if (msg->m_type == type)
800  			return 1;
801  		break;
802  	case SEARCH_NOTEQUAL:
803  		if (msg->m_type != type)
804  			return 1;
805  		break;
806  	}
807  	return 0;
808  }
809  
810  static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg,
811  				 struct wake_q_head *wake_q)
812  {
813  	struct msg_receiver *msr, *t;
814  
815  	list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
816  		if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
817  		    !security_msg_queue_msgrcv(&msq->q_perm, msg, msr->r_tsk,
818  					       msr->r_msgtype, msr->r_mode)) {
819  
820  			list_del(&msr->r_list);
821  			if (msr->r_maxsize < msg->m_ts) {
822  				wake_q_add(wake_q, msr->r_tsk);
823  
824  				/* See expunge_all regarding memory barrier */
825  				smp_store_release(&msr->r_msg, ERR_PTR(-E2BIG));
826  			} else {
827  				ipc_update_pid(&msq->q_lrpid, task_pid(msr->r_tsk));
828  				msq->q_rtime = ktime_get_real_seconds();
829  
830  				wake_q_add(wake_q, msr->r_tsk);
831  
832  				/* See expunge_all regarding memory barrier */
833  				smp_store_release(&msr->r_msg, msg);
834  				return 1;
835  			}
836  		}
837  	}
838  
839  	return 0;
840  }
841  
842  static long do_msgsnd(int msqid, long mtype, void __user *mtext,
843  		size_t msgsz, int msgflg)
844  {
845  	struct msg_queue *msq;
846  	struct msg_msg *msg;
847  	int err;
848  	struct ipc_namespace *ns;
849  	DEFINE_WAKE_Q(wake_q);
850  
851  	ns = current->nsproxy->ipc_ns;
852  
853  	if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
854  		return -EINVAL;
855  	if (mtype < 1)
856  		return -EINVAL;
857  
858  	msg = load_msg(mtext, msgsz);
859  	if (IS_ERR(msg))
860  		return PTR_ERR(msg);
861  
862  	msg->m_type = mtype;
863  	msg->m_ts = msgsz;
864  
865  	rcu_read_lock();
866  	msq = msq_obtain_object_check(ns, msqid);
867  	if (IS_ERR(msq)) {
868  		err = PTR_ERR(msq);
869  		goto out_unlock1;
870  	}
871  
872  	ipc_lock_object(&msq->q_perm);
873  
874  	for (;;) {
875  		struct msg_sender s;
876  
877  		err = -EACCES;
878  		if (ipcperms(ns, &msq->q_perm, S_IWUGO))
879  			goto out_unlock0;
880  
881  		/* raced with RMID? */
882  		if (!ipc_valid_object(&msq->q_perm)) {
883  			err = -EIDRM;
884  			goto out_unlock0;
885  		}
886  
887  		err = security_msg_queue_msgsnd(&msq->q_perm, msg, msgflg);
888  		if (err)
889  			goto out_unlock0;
890  
891  		if (msg_fits_inqueue(msq, msgsz))
892  			break;
893  
894  		/* queue full, wait: */
895  		if (msgflg & IPC_NOWAIT) {
896  			err = -EAGAIN;
897  			goto out_unlock0;
898  		}
899  
900  		/* enqueue the sender and prepare to block */
901  		ss_add(msq, &s, msgsz);
902  
903  		if (!ipc_rcu_getref(&msq->q_perm)) {
904  			err = -EIDRM;
905  			goto out_unlock0;
906  		}
907  
908  		ipc_unlock_object(&msq->q_perm);
909  		rcu_read_unlock();
910  		schedule();
911  
912  		rcu_read_lock();
913  		ipc_lock_object(&msq->q_perm);
914  
915  		ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
916  		/* raced with RMID? */
917  		if (!ipc_valid_object(&msq->q_perm)) {
918  			err = -EIDRM;
919  			goto out_unlock0;
920  		}
921  		ss_del(&s);
922  
923  		if (signal_pending(current)) {
924  			err = -ERESTARTNOHAND;
925  			goto out_unlock0;
926  		}
927  
928  	}
929  
930  	ipc_update_pid(&msq->q_lspid, task_tgid(current));
931  	msq->q_stime = ktime_get_real_seconds();
932  
933  	if (!pipelined_send(msq, msg, &wake_q)) {
934  		/* no one is waiting for this message, enqueue it */
935  		list_add_tail(&msg->m_list, &msq->q_messages);
936  		msq->q_cbytes += msgsz;
937  		msq->q_qnum++;
938  		atomic_add(msgsz, &ns->msg_bytes);
939  		atomic_inc(&ns->msg_hdrs);
940  	}
941  
942  	err = 0;
943  	msg = NULL;
944  
945  out_unlock0:
946  	ipc_unlock_object(&msq->q_perm);
947  	wake_up_q(&wake_q);
948  out_unlock1:
949  	rcu_read_unlock();
950  	if (msg != NULL)
951  		free_msg(msg);
952  	return err;
953  }
954  
955  long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz,
956  		 int msgflg)
957  {
958  	long mtype;
959  
960  	if (get_user(mtype, &msgp->mtype))
961  		return -EFAULT;
962  	return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
963  }
964  
965  SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
966  		int, msgflg)
967  {
968  	return ksys_msgsnd(msqid, msgp, msgsz, msgflg);
969  }
970  
971  #ifdef CONFIG_COMPAT
972  
973  struct compat_msgbuf {
974  	compat_long_t mtype;
975  	char mtext[1];
976  };
977  
978  long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp,
979  		       compat_ssize_t msgsz, int msgflg)
980  {
981  	struct compat_msgbuf __user *up = compat_ptr(msgp);
982  	compat_long_t mtype;
983  
984  	if (get_user(mtype, &up->mtype))
985  		return -EFAULT;
986  	return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg);
987  }
988  
989  COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
990  		       compat_ssize_t, msgsz, int, msgflg)
991  {
992  	return compat_ksys_msgsnd(msqid, msgp, msgsz, msgflg);
993  }
994  #endif
995  
996  static inline int convert_mode(long *msgtyp, int msgflg)
997  {
998  	if (msgflg & MSG_COPY)
999  		return SEARCH_NUMBER;
1000  	/*
1001  	 *  find message of correct type.
1002  	 *  msgtyp = 0 => get first.
1003  	 *  msgtyp > 0 => get first message of matching type.
1004  	 *  msgtyp < 0 => get message with least type must be < abs(msgtype).
1005  	 */
1006  	if (*msgtyp == 0)
1007  		return SEARCH_ANY;
1008  	if (*msgtyp < 0) {
1009  		if (*msgtyp == LONG_MIN) /* -LONG_MIN is undefined */
1010  			*msgtyp = LONG_MAX;
1011  		else
1012  			*msgtyp = -*msgtyp;
1013  		return SEARCH_LESSEQUAL;
1014  	}
1015  	if (msgflg & MSG_EXCEPT)
1016  		return SEARCH_NOTEQUAL;
1017  	return SEARCH_EQUAL;
1018  }
1019  
1020  static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
1021  {
1022  	struct msgbuf __user *msgp = dest;
1023  	size_t msgsz;
1024  
1025  	if (put_user(msg->m_type, &msgp->mtype))
1026  		return -EFAULT;
1027  
1028  	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
1029  	if (store_msg(msgp->mtext, msg, msgsz))
1030  		return -EFAULT;
1031  	return msgsz;
1032  }
1033  
1034  #ifdef CONFIG_CHECKPOINT_RESTORE
1035  /*
1036   * This function creates new kernel message structure, large enough to store
1037   * bufsz message bytes.
1038   */
1039  static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
1040  {
1041  	struct msg_msg *copy;
1042  
1043  	/*
1044  	 * Create dummy message to copy real message to.
1045  	 */
1046  	copy = load_msg(buf, bufsz);
1047  	if (!IS_ERR(copy))
1048  		copy->m_ts = bufsz;
1049  	return copy;
1050  }
1051  
1052  static inline void free_copy(struct msg_msg *copy)
1053  {
1054  	if (copy)
1055  		free_msg(copy);
1056  }
1057  #else
1058  static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
1059  {
1060  	return ERR_PTR(-ENOSYS);
1061  }
1062  
1063  static inline void free_copy(struct msg_msg *copy)
1064  {
1065  }
1066  #endif
1067  
1068  static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
1069  {
1070  	struct msg_msg *msg, *found = NULL;
1071  	long count = 0;
1072  
1073  	list_for_each_entry(msg, &msq->q_messages, m_list) {
1074  		if (testmsg(msg, *msgtyp, mode) &&
1075  		    !security_msg_queue_msgrcv(&msq->q_perm, msg, current,
1076  					       *msgtyp, mode)) {
1077  			if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
1078  				*msgtyp = msg->m_type - 1;
1079  				found = msg;
1080  			} else if (mode == SEARCH_NUMBER) {
1081  				if (*msgtyp == count)
1082  					return msg;
1083  			} else
1084  				return msg;
1085  			count++;
1086  		}
1087  	}
1088  
1089  	return found ?: ERR_PTR(-EAGAIN);
1090  }
1091  
1092  static long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
1093  	       long (*msg_handler)(void __user *, struct msg_msg *, size_t))
1094  {
1095  	int mode;
1096  	struct msg_queue *msq;
1097  	struct ipc_namespace *ns;
1098  	struct msg_msg *msg, *copy = NULL;
1099  	DEFINE_WAKE_Q(wake_q);
1100  
1101  	ns = current->nsproxy->ipc_ns;
1102  
1103  	if (msqid < 0 || (long) bufsz < 0)
1104  		return -EINVAL;
1105  
1106  	if (msgflg & MSG_COPY) {
1107  		if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT))
1108  			return -EINVAL;
1109  		copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
1110  		if (IS_ERR(copy))
1111  			return PTR_ERR(copy);
1112  	}
1113  	mode = convert_mode(&msgtyp, msgflg);
1114  
1115  	rcu_read_lock();
1116  	msq = msq_obtain_object_check(ns, msqid);
1117  	if (IS_ERR(msq)) {
1118  		rcu_read_unlock();
1119  		free_copy(copy);
1120  		return PTR_ERR(msq);
1121  	}
1122  
1123  	for (;;) {
1124  		struct msg_receiver msr_d;
1125  
1126  		msg = ERR_PTR(-EACCES);
1127  		if (ipcperms(ns, &msq->q_perm, S_IRUGO))
1128  			goto out_unlock1;
1129  
1130  		ipc_lock_object(&msq->q_perm);
1131  
1132  		/* raced with RMID? */
1133  		if (!ipc_valid_object(&msq->q_perm)) {
1134  			msg = ERR_PTR(-EIDRM);
1135  			goto out_unlock0;
1136  		}
1137  
1138  		msg = find_msg(msq, &msgtyp, mode);
1139  		if (!IS_ERR(msg)) {
1140  			/*
1141  			 * Found a suitable message.
1142  			 * Unlink it from the queue.
1143  			 */
1144  			if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
1145  				msg = ERR_PTR(-E2BIG);
1146  				goto out_unlock0;
1147  			}
1148  			/*
1149  			 * If we are copying, then do not unlink message and do
1150  			 * not update queue parameters.
1151  			 */
1152  			if (msgflg & MSG_COPY) {
1153  				msg = copy_msg(msg, copy);
1154  				goto out_unlock0;
1155  			}
1156  
1157  			list_del(&msg->m_list);
1158  			msq->q_qnum--;
1159  			msq->q_rtime = ktime_get_real_seconds();
1160  			ipc_update_pid(&msq->q_lrpid, task_tgid(current));
1161  			msq->q_cbytes -= msg->m_ts;
1162  			atomic_sub(msg->m_ts, &ns->msg_bytes);
1163  			atomic_dec(&ns->msg_hdrs);
1164  			ss_wakeup(msq, &wake_q, false);
1165  
1166  			goto out_unlock0;
1167  		}
1168  
1169  		/* No message waiting. Wait for a message */
1170  		if (msgflg & IPC_NOWAIT) {
1171  			msg = ERR_PTR(-ENOMSG);
1172  			goto out_unlock0;
1173  		}
1174  
1175  		list_add_tail(&msr_d.r_list, &msq->q_receivers);
1176  		msr_d.r_tsk = current;
1177  		msr_d.r_msgtype = msgtyp;
1178  		msr_d.r_mode = mode;
1179  		if (msgflg & MSG_NOERROR)
1180  			msr_d.r_maxsize = INT_MAX;
1181  		else
1182  			msr_d.r_maxsize = bufsz;
1183  
1184  		/* memory barrier not require due to ipc_lock_object() */
1185  		WRITE_ONCE(msr_d.r_msg, ERR_PTR(-EAGAIN));
1186  
1187  		/* memory barrier not required, we own ipc_lock_object() */
1188  		__set_current_state(TASK_INTERRUPTIBLE);
1189  
1190  		ipc_unlock_object(&msq->q_perm);
1191  		rcu_read_unlock();
1192  		schedule();
1193  
1194  		/*
1195  		 * Lockless receive, part 1:
1196  		 * We don't hold a reference to the queue and getting a
1197  		 * reference would defeat the idea of a lockless operation,
1198  		 * thus the code relies on rcu to guarantee the existence of
1199  		 * msq:
1200  		 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
1201  		 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
1202  		 */
1203  		rcu_read_lock();
1204  
1205  		/*
1206  		 * Lockless receive, part 2:
1207  		 * The work in pipelined_send() and expunge_all():
1208  		 * - Set pointer to message
1209  		 * - Queue the receiver task for later wakeup
1210  		 * - Wake up the process after the lock is dropped.
1211  		 *
1212  		 * Should the process wake up before this wakeup (due to a
1213  		 * signal) it will either see the message and continue ...
1214  		 */
1215  		msg = READ_ONCE(msr_d.r_msg);
1216  		if (msg != ERR_PTR(-EAGAIN)) {
1217  			/* see MSG_BARRIER for purpose/pairing */
1218  			smp_acquire__after_ctrl_dep();
1219  
1220  			goto out_unlock1;
1221  		}
1222  
1223  		 /*
1224  		  * ... or see -EAGAIN, acquire the lock to check the message
1225  		  * again.
1226  		  */
1227  		ipc_lock_object(&msq->q_perm);
1228  
1229  		msg = READ_ONCE(msr_d.r_msg);
1230  		if (msg != ERR_PTR(-EAGAIN))
1231  			goto out_unlock0;
1232  
1233  		list_del(&msr_d.r_list);
1234  		if (signal_pending(current)) {
1235  			msg = ERR_PTR(-ERESTARTNOHAND);
1236  			goto out_unlock0;
1237  		}
1238  
1239  		ipc_unlock_object(&msq->q_perm);
1240  	}
1241  
1242  out_unlock0:
1243  	ipc_unlock_object(&msq->q_perm);
1244  	wake_up_q(&wake_q);
1245  out_unlock1:
1246  	rcu_read_unlock();
1247  	if (IS_ERR(msg)) {
1248  		free_copy(copy);
1249  		return PTR_ERR(msg);
1250  	}
1251  
1252  	bufsz = msg_handler(buf, msg, bufsz);
1253  	free_msg(msg);
1254  
1255  	return bufsz;
1256  }
1257  
1258  long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz,
1259  		 long msgtyp, int msgflg)
1260  {
1261  	return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
1262  }
1263  
1264  SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
1265  		long, msgtyp, int, msgflg)
1266  {
1267  	return ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg);
1268  }
1269  
1270  #ifdef CONFIG_COMPAT
1271  static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
1272  {
1273  	struct compat_msgbuf __user *msgp = dest;
1274  	size_t msgsz;
1275  
1276  	if (put_user(msg->m_type, &msgp->mtype))
1277  		return -EFAULT;
1278  
1279  	msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
1280  	if (store_msg(msgp->mtext, msg, msgsz))
1281  		return -EFAULT;
1282  	return msgsz;
1283  }
1284  
1285  long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz,
1286  			compat_long_t msgtyp, int msgflg)
1287  {
1288  	return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp,
1289  			 msgflg, compat_do_msg_fill);
1290  }
1291  
1292  COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp,
1293  		       compat_ssize_t, msgsz, compat_long_t, msgtyp,
1294  		       int, msgflg)
1295  {
1296  	return compat_ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg);
1297  }
1298  #endif
1299  
1300  void msg_init_ns(struct ipc_namespace *ns)
1301  {
1302  	ns->msg_ctlmax = MSGMAX;
1303  	ns->msg_ctlmnb = MSGMNB;
1304  	ns->msg_ctlmni = MSGMNI;
1305  
1306  	atomic_set(&ns->msg_bytes, 0);
1307  	atomic_set(&ns->msg_hdrs, 0);
1308  	ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
1309  }
1310  
1311  #ifdef CONFIG_IPC_NS
1312  void msg_exit_ns(struct ipc_namespace *ns)
1313  {
1314  	free_ipcs(ns, &msg_ids(ns), freeque);
1315  	idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
1316  	rhashtable_destroy(&ns->ids[IPC_MSG_IDS].key_ht);
1317  }
1318  #endif
1319  
1320  #ifdef CONFIG_PROC_FS
1321  static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
1322  {
1323  	struct pid_namespace *pid_ns = ipc_seq_pid_ns(s);
1324  	struct user_namespace *user_ns = seq_user_ns(s);
1325  	struct kern_ipc_perm *ipcp = it;
1326  	struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
1327  
1328  	seq_printf(s,
1329  		   "%10d %10d  %4o  %10lu %10lu %5u %5u %5u %5u %5u %5u %10llu %10llu %10llu\n",
1330  		   msq->q_perm.key,
1331  		   msq->q_perm.id,
1332  		   msq->q_perm.mode,
1333  		   msq->q_cbytes,
1334  		   msq->q_qnum,
1335  		   pid_nr_ns(msq->q_lspid, pid_ns),
1336  		   pid_nr_ns(msq->q_lrpid, pid_ns),
1337  		   from_kuid_munged(user_ns, msq->q_perm.uid),
1338  		   from_kgid_munged(user_ns, msq->q_perm.gid),
1339  		   from_kuid_munged(user_ns, msq->q_perm.cuid),
1340  		   from_kgid_munged(user_ns, msq->q_perm.cgid),
1341  		   msq->q_stime,
1342  		   msq->q_rtime,
1343  		   msq->q_ctime);
1344  
1345  	return 0;
1346  }
1347  #endif
1348  
1349  void __init msg_init(void)
1350  {
1351  	msg_init_ns(&init_ipc_ns);
1352  
1353  	ipc_init_proc_interface("sysvipc/msg",
1354  				"       key      msqid perms      cbytes       qnum lspid lrpid   uid   gid  cuid  cgid      stime      rtime      ctime\n",
1355  				IPC_MSG_IDS, sysvipc_msg_proc_show);
1356  }
1357