ipc/msg.c

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