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