xref: /openbmc/linux/ipc/msg.c (revision 474be445555ba8f2e776b4b6458c310bc215f76b)
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