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