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