1 /* 2 * POSIX message queues filesystem for Linux. 3 * 4 * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl) 5 * Michal Wronski (michal.wronski@gmail.com) 6 * 7 * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com) 8 * Lockless receive & send, fd based notify: 9 * Manfred Spraul (manfred@colorfullife.com) 10 * 11 * Audit: George Wilson (ltcgcw@us.ibm.com) 12 * 13 * This file is released under the GPL. 14 */ 15 16 #include <linux/capability.h> 17 #include <linux/init.h> 18 #include <linux/pagemap.h> 19 #include <linux/file.h> 20 #include <linux/mount.h> 21 #include <linux/namei.h> 22 #include <linux/sysctl.h> 23 #include <linux/poll.h> 24 #include <linux/mqueue.h> 25 #include <linux/msg.h> 26 #include <linux/skbuff.h> 27 #include <linux/vmalloc.h> 28 #include <linux/netlink.h> 29 #include <linux/syscalls.h> 30 #include <linux/audit.h> 31 #include <linux/signal.h> 32 #include <linux/mutex.h> 33 #include <linux/nsproxy.h> 34 #include <linux/pid.h> 35 #include <linux/ipc_namespace.h> 36 #include <linux/user_namespace.h> 37 #include <linux/slab.h> 38 39 #include <net/sock.h> 40 #include "util.h" 41 42 #define MQUEUE_MAGIC 0x19800202 43 #define DIRENT_SIZE 20 44 #define FILENT_SIZE 80 45 46 #define SEND 0 47 #define RECV 1 48 49 #define STATE_NONE 0 50 #define STATE_PENDING 1 51 #define STATE_READY 2 52 53 struct posix_msg_tree_node { 54 struct rb_node rb_node; 55 struct list_head msg_list; 56 int priority; 57 }; 58 59 struct ext_wait_queue { /* queue of sleeping tasks */ 60 struct task_struct *task; 61 struct list_head list; 62 struct msg_msg *msg; /* ptr of loaded message */ 63 int state; /* one of STATE_* values */ 64 }; 65 66 struct mqueue_inode_info { 67 spinlock_t lock; 68 struct inode vfs_inode; 69 wait_queue_head_t wait_q; 70 71 struct rb_root msg_tree; 72 struct mq_attr attr; 73 74 struct sigevent notify; 75 struct pid* notify_owner; 76 struct user_namespace *notify_user_ns; 77 struct user_struct *user; /* user who created, for accounting */ 78 struct sock *notify_sock; 79 struct sk_buff *notify_cookie; 80 81 /* for tasks waiting for free space and messages, respectively */ 82 struct ext_wait_queue e_wait_q[2]; 83 84 unsigned long qsize; /* size of queue in memory (sum of all msgs) */ 85 }; 86 87 static const struct inode_operations mqueue_dir_inode_operations; 88 static const struct file_operations mqueue_file_operations; 89 static const struct super_operations mqueue_super_ops; 90 static void remove_notification(struct mqueue_inode_info *info); 91 92 static struct kmem_cache *mqueue_inode_cachep; 93 94 static struct ctl_table_header * mq_sysctl_table; 95 96 static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) 97 { 98 return container_of(inode, struct mqueue_inode_info, vfs_inode); 99 } 100 101 /* 102 * This routine should be called with the mq_lock held. 103 */ 104 static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) 105 { 106 return get_ipc_ns(inode->i_sb->s_fs_info); 107 } 108 109 static struct ipc_namespace *get_ns_from_inode(struct inode *inode) 110 { 111 struct ipc_namespace *ns; 112 113 spin_lock(&mq_lock); 114 ns = __get_ns_from_inode(inode); 115 spin_unlock(&mq_lock); 116 return ns; 117 } 118 119 /* Auxiliary functions to manipulate messages' list */ 120 static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info) 121 { 122 struct rb_node **p, *parent = NULL; 123 struct posix_msg_tree_node *leaf; 124 125 p = &info->msg_tree.rb_node; 126 while (*p) { 127 parent = *p; 128 leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node); 129 130 if (likely(leaf->priority == msg->m_type)) 131 goto insert_msg; 132 else if (msg->m_type < leaf->priority) 133 p = &(*p)->rb_left; 134 else 135 p = &(*p)->rb_right; 136 } 137 leaf = kzalloc(sizeof(*leaf), GFP_ATOMIC); 138 if (!leaf) 139 return -ENOMEM; 140 rb_init_node(&leaf->rb_node); 141 INIT_LIST_HEAD(&leaf->msg_list); 142 leaf->priority = msg->m_type; 143 rb_link_node(&leaf->rb_node, parent, p); 144 rb_insert_color(&leaf->rb_node, &info->msg_tree); 145 info->qsize += sizeof(struct posix_msg_tree_node); 146 insert_msg: 147 info->attr.mq_curmsgs++; 148 info->qsize += msg->m_ts; 149 list_add_tail(&msg->m_list, &leaf->msg_list); 150 return 0; 151 } 152 153 static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) 154 { 155 struct rb_node **p, *parent = NULL; 156 struct posix_msg_tree_node *leaf; 157 struct msg_msg *msg; 158 159 try_again: 160 p = &info->msg_tree.rb_node; 161 while (*p) { 162 parent = *p; 163 /* 164 * During insert, low priorities go to the left and high to the 165 * right. On receive, we want the highest priorities first, so 166 * walk all the way to the right. 167 */ 168 p = &(*p)->rb_right; 169 } 170 if (!parent) { 171 if (info->attr.mq_curmsgs) { 172 pr_warn_once("Inconsistency in POSIX message queue, " 173 "no tree element, but supposedly messages " 174 "should exist!\n"); 175 info->attr.mq_curmsgs = 0; 176 } 177 return NULL; 178 } 179 leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node); 180 if (list_empty(&leaf->msg_list)) { 181 pr_warn_once("Inconsistency in POSIX message queue, " 182 "empty leaf node but we haven't implemented " 183 "lazy leaf delete!\n"); 184 rb_erase(&leaf->rb_node, &info->msg_tree); 185 info->qsize -= sizeof(struct posix_msg_tree_node); 186 kfree(leaf); 187 goto try_again; 188 } else { 189 msg = list_first_entry(&leaf->msg_list, 190 struct msg_msg, m_list); 191 list_del(&msg->m_list); 192 if (list_empty(&leaf->msg_list)) { 193 rb_erase(&leaf->rb_node, &info->msg_tree); 194 info->qsize -= sizeof(struct posix_msg_tree_node); 195 kfree(leaf); 196 } 197 } 198 info->attr.mq_curmsgs--; 199 info->qsize -= msg->m_ts; 200 return msg; 201 } 202 203 static struct inode *mqueue_get_inode(struct super_block *sb, 204 struct ipc_namespace *ipc_ns, umode_t mode, 205 struct mq_attr *attr) 206 { 207 struct user_struct *u = current_user(); 208 struct inode *inode; 209 int ret = -ENOMEM; 210 211 inode = new_inode(sb); 212 if (!inode) 213 goto err; 214 215 inode->i_ino = get_next_ino(); 216 inode->i_mode = mode; 217 inode->i_uid = current_fsuid(); 218 inode->i_gid = current_fsgid(); 219 inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME; 220 221 if (S_ISREG(mode)) { 222 struct mqueue_inode_info *info; 223 unsigned long mq_bytes, mq_treesize; 224 225 inode->i_fop = &mqueue_file_operations; 226 inode->i_size = FILENT_SIZE; 227 /* mqueue specific info */ 228 info = MQUEUE_I(inode); 229 spin_lock_init(&info->lock); 230 init_waitqueue_head(&info->wait_q); 231 INIT_LIST_HEAD(&info->e_wait_q[0].list); 232 INIT_LIST_HEAD(&info->e_wait_q[1].list); 233 info->notify_owner = NULL; 234 info->notify_user_ns = NULL; 235 info->qsize = 0; 236 info->user = NULL; /* set when all is ok */ 237 info->msg_tree = RB_ROOT; 238 memset(&info->attr, 0, sizeof(info->attr)); 239 info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max, 240 ipc_ns->mq_msg_default); 241 info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max, 242 ipc_ns->mq_msgsize_default); 243 if (attr) { 244 info->attr.mq_maxmsg = attr->mq_maxmsg; 245 info->attr.mq_msgsize = attr->mq_msgsize; 246 } 247 /* 248 * We used to allocate a static array of pointers and account 249 * the size of that array as well as one msg_msg struct per 250 * possible message into the queue size. That's no longer 251 * accurate as the queue is now an rbtree and will grow and 252 * shrink depending on usage patterns. We can, however, still 253 * account one msg_msg struct per message, but the nodes are 254 * allocated depending on priority usage, and most programs 255 * only use one, or a handful, of priorities. However, since 256 * this is pinned memory, we need to assume worst case, so 257 * that means the min(mq_maxmsg, max_priorities) * struct 258 * posix_msg_tree_node. 259 */ 260 mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) + 261 min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) * 262 sizeof(struct posix_msg_tree_node); 263 264 mq_bytes = mq_treesize + (info->attr.mq_maxmsg * 265 info->attr.mq_msgsize); 266 267 spin_lock(&mq_lock); 268 if (u->mq_bytes + mq_bytes < u->mq_bytes || 269 u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) { 270 spin_unlock(&mq_lock); 271 /* mqueue_evict_inode() releases info->messages */ 272 ret = -EMFILE; 273 goto out_inode; 274 } 275 u->mq_bytes += mq_bytes; 276 spin_unlock(&mq_lock); 277 278 /* all is ok */ 279 info->user = get_uid(u); 280 } else if (S_ISDIR(mode)) { 281 inc_nlink(inode); 282 /* Some things misbehave if size == 0 on a directory */ 283 inode->i_size = 2 * DIRENT_SIZE; 284 inode->i_op = &mqueue_dir_inode_operations; 285 inode->i_fop = &simple_dir_operations; 286 } 287 288 return inode; 289 out_inode: 290 iput(inode); 291 err: 292 return ERR_PTR(ret); 293 } 294 295 static int mqueue_fill_super(struct super_block *sb, void *data, int silent) 296 { 297 struct inode *inode; 298 struct ipc_namespace *ns = data; 299 300 sb->s_blocksize = PAGE_CACHE_SIZE; 301 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 302 sb->s_magic = MQUEUE_MAGIC; 303 sb->s_op = &mqueue_super_ops; 304 305 inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); 306 if (IS_ERR(inode)) 307 return PTR_ERR(inode); 308 309 sb->s_root = d_make_root(inode); 310 if (!sb->s_root) 311 return -ENOMEM; 312 return 0; 313 } 314 315 static struct dentry *mqueue_mount(struct file_system_type *fs_type, 316 int flags, const char *dev_name, 317 void *data) 318 { 319 if (!(flags & MS_KERNMOUNT)) 320 data = current->nsproxy->ipc_ns; 321 return mount_ns(fs_type, flags, data, mqueue_fill_super); 322 } 323 324 static void init_once(void *foo) 325 { 326 struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; 327 328 inode_init_once(&p->vfs_inode); 329 } 330 331 static struct inode *mqueue_alloc_inode(struct super_block *sb) 332 { 333 struct mqueue_inode_info *ei; 334 335 ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); 336 if (!ei) 337 return NULL; 338 return &ei->vfs_inode; 339 } 340 341 static void mqueue_i_callback(struct rcu_head *head) 342 { 343 struct inode *inode = container_of(head, struct inode, i_rcu); 344 kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); 345 } 346 347 static void mqueue_destroy_inode(struct inode *inode) 348 { 349 call_rcu(&inode->i_rcu, mqueue_i_callback); 350 } 351 352 static void mqueue_evict_inode(struct inode *inode) 353 { 354 struct mqueue_inode_info *info; 355 struct user_struct *user; 356 unsigned long mq_bytes, mq_treesize; 357 struct ipc_namespace *ipc_ns; 358 struct msg_msg *msg; 359 360 clear_inode(inode); 361 362 if (S_ISDIR(inode->i_mode)) 363 return; 364 365 ipc_ns = get_ns_from_inode(inode); 366 info = MQUEUE_I(inode); 367 spin_lock(&info->lock); 368 while ((msg = msg_get(info)) != NULL) 369 free_msg(msg); 370 spin_unlock(&info->lock); 371 372 /* Total amount of bytes accounted for the mqueue */ 373 mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) + 374 min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) * 375 sizeof(struct posix_msg_tree_node); 376 377 mq_bytes = mq_treesize + (info->attr.mq_maxmsg * 378 info->attr.mq_msgsize); 379 380 user = info->user; 381 if (user) { 382 spin_lock(&mq_lock); 383 user->mq_bytes -= mq_bytes; 384 /* 385 * get_ns_from_inode() ensures that the 386 * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns 387 * to which we now hold a reference, or it is NULL. 388 * We can't put it here under mq_lock, though. 389 */ 390 if (ipc_ns) 391 ipc_ns->mq_queues_count--; 392 spin_unlock(&mq_lock); 393 free_uid(user); 394 } 395 if (ipc_ns) 396 put_ipc_ns(ipc_ns); 397 } 398 399 static int mqueue_create(struct inode *dir, struct dentry *dentry, 400 umode_t mode, struct nameidata *nd) 401 { 402 struct inode *inode; 403 struct mq_attr *attr = dentry->d_fsdata; 404 int error; 405 struct ipc_namespace *ipc_ns; 406 407 spin_lock(&mq_lock); 408 ipc_ns = __get_ns_from_inode(dir); 409 if (!ipc_ns) { 410 error = -EACCES; 411 goto out_unlock; 412 } 413 if (ipc_ns->mq_queues_count >= HARD_QUEUESMAX || 414 (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && 415 !capable(CAP_SYS_RESOURCE))) { 416 error = -ENOSPC; 417 goto out_unlock; 418 } 419 ipc_ns->mq_queues_count++; 420 spin_unlock(&mq_lock); 421 422 inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); 423 if (IS_ERR(inode)) { 424 error = PTR_ERR(inode); 425 spin_lock(&mq_lock); 426 ipc_ns->mq_queues_count--; 427 goto out_unlock; 428 } 429 430 put_ipc_ns(ipc_ns); 431 dir->i_size += DIRENT_SIZE; 432 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; 433 434 d_instantiate(dentry, inode); 435 dget(dentry); 436 return 0; 437 out_unlock: 438 spin_unlock(&mq_lock); 439 if (ipc_ns) 440 put_ipc_ns(ipc_ns); 441 return error; 442 } 443 444 static int mqueue_unlink(struct inode *dir, struct dentry *dentry) 445 { 446 struct inode *inode = dentry->d_inode; 447 448 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; 449 dir->i_size -= DIRENT_SIZE; 450 drop_nlink(inode); 451 dput(dentry); 452 return 0; 453 } 454 455 /* 456 * This is routine for system read from queue file. 457 * To avoid mess with doing here some sort of mq_receive we allow 458 * to read only queue size & notification info (the only values 459 * that are interesting from user point of view and aren't accessible 460 * through std routines) 461 */ 462 static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, 463 size_t count, loff_t *off) 464 { 465 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); 466 char buffer[FILENT_SIZE]; 467 ssize_t ret; 468 469 spin_lock(&info->lock); 470 snprintf(buffer, sizeof(buffer), 471 "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", 472 info->qsize, 473 info->notify_owner ? info->notify.sigev_notify : 0, 474 (info->notify_owner && 475 info->notify.sigev_notify == SIGEV_SIGNAL) ? 476 info->notify.sigev_signo : 0, 477 pid_vnr(info->notify_owner)); 478 spin_unlock(&info->lock); 479 buffer[sizeof(buffer)-1] = '\0'; 480 481 ret = simple_read_from_buffer(u_data, count, off, buffer, 482 strlen(buffer)); 483 if (ret <= 0) 484 return ret; 485 486 filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME; 487 return ret; 488 } 489 490 static int mqueue_flush_file(struct file *filp, fl_owner_t id) 491 { 492 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); 493 494 spin_lock(&info->lock); 495 if (task_tgid(current) == info->notify_owner) 496 remove_notification(info); 497 498 spin_unlock(&info->lock); 499 return 0; 500 } 501 502 static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) 503 { 504 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode); 505 int retval = 0; 506 507 poll_wait(filp, &info->wait_q, poll_tab); 508 509 spin_lock(&info->lock); 510 if (info->attr.mq_curmsgs) 511 retval = POLLIN | POLLRDNORM; 512 513 if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) 514 retval |= POLLOUT | POLLWRNORM; 515 spin_unlock(&info->lock); 516 517 return retval; 518 } 519 520 /* Adds current to info->e_wait_q[sr] before element with smaller prio */ 521 static void wq_add(struct mqueue_inode_info *info, int sr, 522 struct ext_wait_queue *ewp) 523 { 524 struct ext_wait_queue *walk; 525 526 ewp->task = current; 527 528 list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { 529 if (walk->task->static_prio <= current->static_prio) { 530 list_add_tail(&ewp->list, &walk->list); 531 return; 532 } 533 } 534 list_add_tail(&ewp->list, &info->e_wait_q[sr].list); 535 } 536 537 /* 538 * Puts current task to sleep. Caller must hold queue lock. After return 539 * lock isn't held. 540 * sr: SEND or RECV 541 */ 542 static int wq_sleep(struct mqueue_inode_info *info, int sr, 543 ktime_t *timeout, struct ext_wait_queue *ewp) 544 { 545 int retval; 546 signed long time; 547 548 wq_add(info, sr, ewp); 549 550 for (;;) { 551 set_current_state(TASK_INTERRUPTIBLE); 552 553 spin_unlock(&info->lock); 554 time = schedule_hrtimeout_range_clock(timeout, 0, 555 HRTIMER_MODE_ABS, CLOCK_REALTIME); 556 557 while (ewp->state == STATE_PENDING) 558 cpu_relax(); 559 560 if (ewp->state == STATE_READY) { 561 retval = 0; 562 goto out; 563 } 564 spin_lock(&info->lock); 565 if (ewp->state == STATE_READY) { 566 retval = 0; 567 goto out_unlock; 568 } 569 if (signal_pending(current)) { 570 retval = -ERESTARTSYS; 571 break; 572 } 573 if (time == 0) { 574 retval = -ETIMEDOUT; 575 break; 576 } 577 } 578 list_del(&ewp->list); 579 out_unlock: 580 spin_unlock(&info->lock); 581 out: 582 return retval; 583 } 584 585 /* 586 * Returns waiting task that should be serviced first or NULL if none exists 587 */ 588 static struct ext_wait_queue *wq_get_first_waiter( 589 struct mqueue_inode_info *info, int sr) 590 { 591 struct list_head *ptr; 592 593 ptr = info->e_wait_q[sr].list.prev; 594 if (ptr == &info->e_wait_q[sr].list) 595 return NULL; 596 return list_entry(ptr, struct ext_wait_queue, list); 597 } 598 599 600 static inline void set_cookie(struct sk_buff *skb, char code) 601 { 602 ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; 603 } 604 605 /* 606 * The next function is only to split too long sys_mq_timedsend 607 */ 608 static void __do_notify(struct mqueue_inode_info *info) 609 { 610 /* notification 611 * invoked when there is registered process and there isn't process 612 * waiting synchronously for message AND state of queue changed from 613 * empty to not empty. Here we are sure that no one is waiting 614 * synchronously. */ 615 if (info->notify_owner && 616 info->attr.mq_curmsgs == 1) { 617 struct siginfo sig_i; 618 switch (info->notify.sigev_notify) { 619 case SIGEV_NONE: 620 break; 621 case SIGEV_SIGNAL: 622 /* sends signal */ 623 624 sig_i.si_signo = info->notify.sigev_signo; 625 sig_i.si_errno = 0; 626 sig_i.si_code = SI_MESGQ; 627 sig_i.si_value = info->notify.sigev_value; 628 /* map current pid/uid into info->owner's namespaces */ 629 rcu_read_lock(); 630 sig_i.si_pid = task_tgid_nr_ns(current, 631 ns_of_pid(info->notify_owner)); 632 sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid()); 633 rcu_read_unlock(); 634 635 kill_pid_info(info->notify.sigev_signo, 636 &sig_i, info->notify_owner); 637 break; 638 case SIGEV_THREAD: 639 set_cookie(info->notify_cookie, NOTIFY_WOKENUP); 640 netlink_sendskb(info->notify_sock, info->notify_cookie); 641 break; 642 } 643 /* after notification unregisters process */ 644 put_pid(info->notify_owner); 645 put_user_ns(info->notify_user_ns); 646 info->notify_owner = NULL; 647 info->notify_user_ns = NULL; 648 } 649 wake_up(&info->wait_q); 650 } 651 652 static int prepare_timeout(const struct timespec __user *u_abs_timeout, 653 ktime_t *expires, struct timespec *ts) 654 { 655 if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec))) 656 return -EFAULT; 657 if (!timespec_valid(ts)) 658 return -EINVAL; 659 660 *expires = timespec_to_ktime(*ts); 661 return 0; 662 } 663 664 static void remove_notification(struct mqueue_inode_info *info) 665 { 666 if (info->notify_owner != NULL && 667 info->notify.sigev_notify == SIGEV_THREAD) { 668 set_cookie(info->notify_cookie, NOTIFY_REMOVED); 669 netlink_sendskb(info->notify_sock, info->notify_cookie); 670 } 671 put_pid(info->notify_owner); 672 put_user_ns(info->notify_user_ns); 673 info->notify_owner = NULL; 674 info->notify_user_ns = NULL; 675 } 676 677 static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr) 678 { 679 int mq_treesize; 680 unsigned long total_size; 681 682 if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) 683 return -EINVAL; 684 if (capable(CAP_SYS_RESOURCE)) { 685 if (attr->mq_maxmsg > HARD_MSGMAX || 686 attr->mq_msgsize > HARD_MSGSIZEMAX) 687 return -EINVAL; 688 } else { 689 if (attr->mq_maxmsg > ipc_ns->mq_msg_max || 690 attr->mq_msgsize > ipc_ns->mq_msgsize_max) 691 return -EINVAL; 692 } 693 /* check for overflow */ 694 if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) 695 return -EOVERFLOW; 696 mq_treesize = attr->mq_maxmsg * sizeof(struct msg_msg) + 697 min_t(unsigned int, attr->mq_maxmsg, MQ_PRIO_MAX) * 698 sizeof(struct posix_msg_tree_node); 699 total_size = attr->mq_maxmsg * attr->mq_msgsize; 700 if (total_size + mq_treesize < total_size) 701 return -EOVERFLOW; 702 return 0; 703 } 704 705 /* 706 * Invoked when creating a new queue via sys_mq_open 707 */ 708 static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir, 709 struct dentry *dentry, int oflag, umode_t mode, 710 struct mq_attr *attr) 711 { 712 const struct cred *cred = current_cred(); 713 struct file *result; 714 int ret; 715 716 if (attr) { 717 ret = mq_attr_ok(ipc_ns, attr); 718 if (ret) 719 goto out; 720 /* store for use during create */ 721 dentry->d_fsdata = attr; 722 } else { 723 struct mq_attr def_attr; 724 725 def_attr.mq_maxmsg = min(ipc_ns->mq_msg_max, 726 ipc_ns->mq_msg_default); 727 def_attr.mq_msgsize = min(ipc_ns->mq_msgsize_max, 728 ipc_ns->mq_msgsize_default); 729 ret = mq_attr_ok(ipc_ns, &def_attr); 730 if (ret) 731 goto out; 732 } 733 734 mode &= ~current_umask(); 735 ret = mnt_want_write(ipc_ns->mq_mnt); 736 if (ret) 737 goto out; 738 ret = vfs_create(dir->d_inode, dentry, mode, NULL); 739 dentry->d_fsdata = NULL; 740 if (ret) 741 goto out_drop_write; 742 743 result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); 744 /* 745 * dentry_open() took a persistent mnt_want_write(), 746 * so we can now drop this one. 747 */ 748 mnt_drop_write(ipc_ns->mq_mnt); 749 return result; 750 751 out_drop_write: 752 mnt_drop_write(ipc_ns->mq_mnt); 753 out: 754 dput(dentry); 755 mntput(ipc_ns->mq_mnt); 756 return ERR_PTR(ret); 757 } 758 759 /* Opens existing queue */ 760 static struct file *do_open(struct ipc_namespace *ipc_ns, 761 struct dentry *dentry, int oflag) 762 { 763 int ret; 764 const struct cred *cred = current_cred(); 765 766 static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, 767 MAY_READ | MAY_WRITE }; 768 769 if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) { 770 ret = -EINVAL; 771 goto err; 772 } 773 774 if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) { 775 ret = -EACCES; 776 goto err; 777 } 778 779 return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred); 780 781 err: 782 dput(dentry); 783 mntput(ipc_ns->mq_mnt); 784 return ERR_PTR(ret); 785 } 786 787 SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, 788 struct mq_attr __user *, u_attr) 789 { 790 struct dentry *dentry; 791 struct file *filp; 792 char *name; 793 struct mq_attr attr; 794 int fd, error; 795 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; 796 797 if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) 798 return -EFAULT; 799 800 audit_mq_open(oflag, mode, u_attr ? &attr : NULL); 801 802 if (IS_ERR(name = getname(u_name))) 803 return PTR_ERR(name); 804 805 fd = get_unused_fd_flags(O_CLOEXEC); 806 if (fd < 0) 807 goto out_putname; 808 809 mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); 810 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); 811 if (IS_ERR(dentry)) { 812 error = PTR_ERR(dentry); 813 goto out_putfd; 814 } 815 mntget(ipc_ns->mq_mnt); 816 817 if (oflag & O_CREAT) { 818 if (dentry->d_inode) { /* entry already exists */ 819 audit_inode(name, dentry); 820 if (oflag & O_EXCL) { 821 error = -EEXIST; 822 goto out; 823 } 824 filp = do_open(ipc_ns, dentry, oflag); 825 } else { 826 filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root, 827 dentry, oflag, mode, 828 u_attr ? &attr : NULL); 829 } 830 } else { 831 if (!dentry->d_inode) { 832 error = -ENOENT; 833 goto out; 834 } 835 audit_inode(name, dentry); 836 filp = do_open(ipc_ns, dentry, oflag); 837 } 838 839 if (IS_ERR(filp)) { 840 error = PTR_ERR(filp); 841 goto out_putfd; 842 } 843 844 fd_install(fd, filp); 845 goto out_upsem; 846 847 out: 848 dput(dentry); 849 mntput(ipc_ns->mq_mnt); 850 out_putfd: 851 put_unused_fd(fd); 852 fd = error; 853 out_upsem: 854 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); 855 out_putname: 856 putname(name); 857 return fd; 858 } 859 860 SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) 861 { 862 int err; 863 char *name; 864 struct dentry *dentry; 865 struct inode *inode = NULL; 866 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; 867 868 name = getname(u_name); 869 if (IS_ERR(name)) 870 return PTR_ERR(name); 871 872 mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex, 873 I_MUTEX_PARENT); 874 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name)); 875 if (IS_ERR(dentry)) { 876 err = PTR_ERR(dentry); 877 goto out_unlock; 878 } 879 880 if (!dentry->d_inode) { 881 err = -ENOENT; 882 goto out_err; 883 } 884 885 inode = dentry->d_inode; 886 if (inode) 887 ihold(inode); 888 err = mnt_want_write(ipc_ns->mq_mnt); 889 if (err) 890 goto out_err; 891 err = vfs_unlink(dentry->d_parent->d_inode, dentry); 892 mnt_drop_write(ipc_ns->mq_mnt); 893 out_err: 894 dput(dentry); 895 896 out_unlock: 897 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex); 898 putname(name); 899 if (inode) 900 iput(inode); 901 902 return err; 903 } 904 905 /* Pipelined send and receive functions. 906 * 907 * If a receiver finds no waiting message, then it registers itself in the 908 * list of waiting receivers. A sender checks that list before adding the new 909 * message into the message array. If there is a waiting receiver, then it 910 * bypasses the message array and directly hands the message over to the 911 * receiver. 912 * The receiver accepts the message and returns without grabbing the queue 913 * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers 914 * are necessary. The same algorithm is used for sysv semaphores, see 915 * ipc/sem.c for more details. 916 * 917 * The same algorithm is used for senders. 918 */ 919 920 /* pipelined_send() - send a message directly to the task waiting in 921 * sys_mq_timedreceive() (without inserting message into a queue). 922 */ 923 static inline void pipelined_send(struct mqueue_inode_info *info, 924 struct msg_msg *message, 925 struct ext_wait_queue *receiver) 926 { 927 receiver->msg = message; 928 list_del(&receiver->list); 929 receiver->state = STATE_PENDING; 930 wake_up_process(receiver->task); 931 smp_wmb(); 932 receiver->state = STATE_READY; 933 } 934 935 /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() 936 * gets its message and put to the queue (we have one free place for sure). */ 937 static inline void pipelined_receive(struct mqueue_inode_info *info) 938 { 939 struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); 940 941 if (!sender) { 942 /* for poll */ 943 wake_up_interruptible(&info->wait_q); 944 return; 945 } 946 if (msg_insert(sender->msg, info)) 947 return; 948 list_del(&sender->list); 949 sender->state = STATE_PENDING; 950 wake_up_process(sender->task); 951 smp_wmb(); 952 sender->state = STATE_READY; 953 } 954 955 SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, 956 size_t, msg_len, unsigned int, msg_prio, 957 const struct timespec __user *, u_abs_timeout) 958 { 959 struct file *filp; 960 struct inode *inode; 961 struct ext_wait_queue wait; 962 struct ext_wait_queue *receiver; 963 struct msg_msg *msg_ptr; 964 struct mqueue_inode_info *info; 965 ktime_t expires, *timeout = NULL; 966 struct timespec ts; 967 int ret; 968 969 if (u_abs_timeout) { 970 int res = prepare_timeout(u_abs_timeout, &expires, &ts); 971 if (res) 972 return res; 973 timeout = &expires; 974 } 975 976 if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) 977 return -EINVAL; 978 979 audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL); 980 981 filp = fget(mqdes); 982 if (unlikely(!filp)) { 983 ret = -EBADF; 984 goto out; 985 } 986 987 inode = filp->f_path.dentry->d_inode; 988 if (unlikely(filp->f_op != &mqueue_file_operations)) { 989 ret = -EBADF; 990 goto out_fput; 991 } 992 info = MQUEUE_I(inode); 993 audit_inode(NULL, filp->f_path.dentry); 994 995 if (unlikely(!(filp->f_mode & FMODE_WRITE))) { 996 ret = -EBADF; 997 goto out_fput; 998 } 999 1000 if (unlikely(msg_len > info->attr.mq_msgsize)) { 1001 ret = -EMSGSIZE; 1002 goto out_fput; 1003 } 1004 1005 /* First try to allocate memory, before doing anything with 1006 * existing queues. */ 1007 msg_ptr = load_msg(u_msg_ptr, msg_len); 1008 if (IS_ERR(msg_ptr)) { 1009 ret = PTR_ERR(msg_ptr); 1010 goto out_fput; 1011 } 1012 msg_ptr->m_ts = msg_len; 1013 msg_ptr->m_type = msg_prio; 1014 1015 spin_lock(&info->lock); 1016 1017 if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { 1018 if (filp->f_flags & O_NONBLOCK) { 1019 spin_unlock(&info->lock); 1020 ret = -EAGAIN; 1021 } else { 1022 wait.task = current; 1023 wait.msg = (void *) msg_ptr; 1024 wait.state = STATE_NONE; 1025 ret = wq_sleep(info, SEND, timeout, &wait); 1026 } 1027 if (ret < 0) 1028 free_msg(msg_ptr); 1029 } else { 1030 receiver = wq_get_first_waiter(info, RECV); 1031 if (receiver) { 1032 pipelined_send(info, msg_ptr, receiver); 1033 } else { 1034 /* adds message to the queue */ 1035 if (msg_insert(msg_ptr, info)) { 1036 free_msg(msg_ptr); 1037 ret = -ENOMEM; 1038 spin_unlock(&info->lock); 1039 goto out_fput; 1040 } 1041 __do_notify(info); 1042 } 1043 inode->i_atime = inode->i_mtime = inode->i_ctime = 1044 CURRENT_TIME; 1045 spin_unlock(&info->lock); 1046 ret = 0; 1047 } 1048 out_fput: 1049 fput(filp); 1050 out: 1051 return ret; 1052 } 1053 1054 SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, 1055 size_t, msg_len, unsigned int __user *, u_msg_prio, 1056 const struct timespec __user *, u_abs_timeout) 1057 { 1058 ssize_t ret; 1059 struct msg_msg *msg_ptr; 1060 struct file *filp; 1061 struct inode *inode; 1062 struct mqueue_inode_info *info; 1063 struct ext_wait_queue wait; 1064 ktime_t expires, *timeout = NULL; 1065 struct timespec ts; 1066 1067 if (u_abs_timeout) { 1068 int res = prepare_timeout(u_abs_timeout, &expires, &ts); 1069 if (res) 1070 return res; 1071 timeout = &expires; 1072 } 1073 1074 audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL); 1075 1076 filp = fget(mqdes); 1077 if (unlikely(!filp)) { 1078 ret = -EBADF; 1079 goto out; 1080 } 1081 1082 inode = filp->f_path.dentry->d_inode; 1083 if (unlikely(filp->f_op != &mqueue_file_operations)) { 1084 ret = -EBADF; 1085 goto out_fput; 1086 } 1087 info = MQUEUE_I(inode); 1088 audit_inode(NULL, filp->f_path.dentry); 1089 1090 if (unlikely(!(filp->f_mode & FMODE_READ))) { 1091 ret = -EBADF; 1092 goto out_fput; 1093 } 1094 1095 /* checks if buffer is big enough */ 1096 if (unlikely(msg_len < info->attr.mq_msgsize)) { 1097 ret = -EMSGSIZE; 1098 goto out_fput; 1099 } 1100 1101 spin_lock(&info->lock); 1102 if (info->attr.mq_curmsgs == 0) { 1103 if (filp->f_flags & O_NONBLOCK) { 1104 spin_unlock(&info->lock); 1105 ret = -EAGAIN; 1106 } else { 1107 wait.task = current; 1108 wait.state = STATE_NONE; 1109 ret = wq_sleep(info, RECV, timeout, &wait); 1110 msg_ptr = wait.msg; 1111 } 1112 } else { 1113 msg_ptr = msg_get(info); 1114 1115 inode->i_atime = inode->i_mtime = inode->i_ctime = 1116 CURRENT_TIME; 1117 1118 /* There is now free space in queue. */ 1119 pipelined_receive(info); 1120 spin_unlock(&info->lock); 1121 ret = 0; 1122 } 1123 if (ret == 0) { 1124 ret = msg_ptr->m_ts; 1125 1126 if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || 1127 store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { 1128 ret = -EFAULT; 1129 } 1130 free_msg(msg_ptr); 1131 } 1132 out_fput: 1133 fput(filp); 1134 out: 1135 return ret; 1136 } 1137 1138 /* 1139 * Notes: the case when user wants us to deregister (with NULL as pointer) 1140 * and he isn't currently owner of notification, will be silently discarded. 1141 * It isn't explicitly defined in the POSIX. 1142 */ 1143 SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, 1144 const struct sigevent __user *, u_notification) 1145 { 1146 int ret; 1147 struct file *filp; 1148 struct sock *sock; 1149 struct inode *inode; 1150 struct sigevent notification; 1151 struct mqueue_inode_info *info; 1152 struct sk_buff *nc; 1153 1154 if (u_notification) { 1155 if (copy_from_user(¬ification, u_notification, 1156 sizeof(struct sigevent))) 1157 return -EFAULT; 1158 } 1159 1160 audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); 1161 1162 nc = NULL; 1163 sock = NULL; 1164 if (u_notification != NULL) { 1165 if (unlikely(notification.sigev_notify != SIGEV_NONE && 1166 notification.sigev_notify != SIGEV_SIGNAL && 1167 notification.sigev_notify != SIGEV_THREAD)) 1168 return -EINVAL; 1169 if (notification.sigev_notify == SIGEV_SIGNAL && 1170 !valid_signal(notification.sigev_signo)) { 1171 return -EINVAL; 1172 } 1173 if (notification.sigev_notify == SIGEV_THREAD) { 1174 long timeo; 1175 1176 /* create the notify skb */ 1177 nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); 1178 if (!nc) { 1179 ret = -ENOMEM; 1180 goto out; 1181 } 1182 if (copy_from_user(nc->data, 1183 notification.sigev_value.sival_ptr, 1184 NOTIFY_COOKIE_LEN)) { 1185 ret = -EFAULT; 1186 goto out; 1187 } 1188 1189 /* TODO: add a header? */ 1190 skb_put(nc, NOTIFY_COOKIE_LEN); 1191 /* and attach it to the socket */ 1192 retry: 1193 filp = fget(notification.sigev_signo); 1194 if (!filp) { 1195 ret = -EBADF; 1196 goto out; 1197 } 1198 sock = netlink_getsockbyfilp(filp); 1199 fput(filp); 1200 if (IS_ERR(sock)) { 1201 ret = PTR_ERR(sock); 1202 sock = NULL; 1203 goto out; 1204 } 1205 1206 timeo = MAX_SCHEDULE_TIMEOUT; 1207 ret = netlink_attachskb(sock, nc, &timeo, NULL); 1208 if (ret == 1) 1209 goto retry; 1210 if (ret) { 1211 sock = NULL; 1212 nc = NULL; 1213 goto out; 1214 } 1215 } 1216 } 1217 1218 filp = fget(mqdes); 1219 if (!filp) { 1220 ret = -EBADF; 1221 goto out; 1222 } 1223 1224 inode = filp->f_path.dentry->d_inode; 1225 if (unlikely(filp->f_op != &mqueue_file_operations)) { 1226 ret = -EBADF; 1227 goto out_fput; 1228 } 1229 info = MQUEUE_I(inode); 1230 1231 ret = 0; 1232 spin_lock(&info->lock); 1233 if (u_notification == NULL) { 1234 if (info->notify_owner == task_tgid(current)) { 1235 remove_notification(info); 1236 inode->i_atime = inode->i_ctime = CURRENT_TIME; 1237 } 1238 } else if (info->notify_owner != NULL) { 1239 ret = -EBUSY; 1240 } else { 1241 switch (notification.sigev_notify) { 1242 case SIGEV_NONE: 1243 info->notify.sigev_notify = SIGEV_NONE; 1244 break; 1245 case SIGEV_THREAD: 1246 info->notify_sock = sock; 1247 info->notify_cookie = nc; 1248 sock = NULL; 1249 nc = NULL; 1250 info->notify.sigev_notify = SIGEV_THREAD; 1251 break; 1252 case SIGEV_SIGNAL: 1253 info->notify.sigev_signo = notification.sigev_signo; 1254 info->notify.sigev_value = notification.sigev_value; 1255 info->notify.sigev_notify = SIGEV_SIGNAL; 1256 break; 1257 } 1258 1259 info->notify_owner = get_pid(task_tgid(current)); 1260 info->notify_user_ns = get_user_ns(current_user_ns()); 1261 inode->i_atime = inode->i_ctime = CURRENT_TIME; 1262 } 1263 spin_unlock(&info->lock); 1264 out_fput: 1265 fput(filp); 1266 out: 1267 if (sock) { 1268 netlink_detachskb(sock, nc); 1269 } else if (nc) { 1270 dev_kfree_skb(nc); 1271 } 1272 return ret; 1273 } 1274 1275 SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, 1276 const struct mq_attr __user *, u_mqstat, 1277 struct mq_attr __user *, u_omqstat) 1278 { 1279 int ret; 1280 struct mq_attr mqstat, omqstat; 1281 struct file *filp; 1282 struct inode *inode; 1283 struct mqueue_inode_info *info; 1284 1285 if (u_mqstat != NULL) { 1286 if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) 1287 return -EFAULT; 1288 if (mqstat.mq_flags & (~O_NONBLOCK)) 1289 return -EINVAL; 1290 } 1291 1292 filp = fget(mqdes); 1293 if (!filp) { 1294 ret = -EBADF; 1295 goto out; 1296 } 1297 1298 inode = filp->f_path.dentry->d_inode; 1299 if (unlikely(filp->f_op != &mqueue_file_operations)) { 1300 ret = -EBADF; 1301 goto out_fput; 1302 } 1303 info = MQUEUE_I(inode); 1304 1305 spin_lock(&info->lock); 1306 1307 omqstat = info->attr; 1308 omqstat.mq_flags = filp->f_flags & O_NONBLOCK; 1309 if (u_mqstat) { 1310 audit_mq_getsetattr(mqdes, &mqstat); 1311 spin_lock(&filp->f_lock); 1312 if (mqstat.mq_flags & O_NONBLOCK) 1313 filp->f_flags |= O_NONBLOCK; 1314 else 1315 filp->f_flags &= ~O_NONBLOCK; 1316 spin_unlock(&filp->f_lock); 1317 1318 inode->i_atime = inode->i_ctime = CURRENT_TIME; 1319 } 1320 1321 spin_unlock(&info->lock); 1322 1323 ret = 0; 1324 if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, 1325 sizeof(struct mq_attr))) 1326 ret = -EFAULT; 1327 1328 out_fput: 1329 fput(filp); 1330 out: 1331 return ret; 1332 } 1333 1334 static const struct inode_operations mqueue_dir_inode_operations = { 1335 .lookup = simple_lookup, 1336 .create = mqueue_create, 1337 .unlink = mqueue_unlink, 1338 }; 1339 1340 static const struct file_operations mqueue_file_operations = { 1341 .flush = mqueue_flush_file, 1342 .poll = mqueue_poll_file, 1343 .read = mqueue_read_file, 1344 .llseek = default_llseek, 1345 }; 1346 1347 static const struct super_operations mqueue_super_ops = { 1348 .alloc_inode = mqueue_alloc_inode, 1349 .destroy_inode = mqueue_destroy_inode, 1350 .evict_inode = mqueue_evict_inode, 1351 .statfs = simple_statfs, 1352 }; 1353 1354 static struct file_system_type mqueue_fs_type = { 1355 .name = "mqueue", 1356 .mount = mqueue_mount, 1357 .kill_sb = kill_litter_super, 1358 }; 1359 1360 int mq_init_ns(struct ipc_namespace *ns) 1361 { 1362 ns->mq_queues_count = 0; 1363 ns->mq_queues_max = DFLT_QUEUESMAX; 1364 ns->mq_msg_max = DFLT_MSGMAX; 1365 ns->mq_msgsize_max = DFLT_MSGSIZEMAX; 1366 ns->mq_msg_default = DFLT_MSG; 1367 ns->mq_msgsize_default = DFLT_MSGSIZE; 1368 1369 ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns); 1370 if (IS_ERR(ns->mq_mnt)) { 1371 int err = PTR_ERR(ns->mq_mnt); 1372 ns->mq_mnt = NULL; 1373 return err; 1374 } 1375 return 0; 1376 } 1377 1378 void mq_clear_sbinfo(struct ipc_namespace *ns) 1379 { 1380 ns->mq_mnt->mnt_sb->s_fs_info = NULL; 1381 } 1382 1383 void mq_put_mnt(struct ipc_namespace *ns) 1384 { 1385 kern_unmount(ns->mq_mnt); 1386 } 1387 1388 static int __init init_mqueue_fs(void) 1389 { 1390 int error; 1391 1392 mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", 1393 sizeof(struct mqueue_inode_info), 0, 1394 SLAB_HWCACHE_ALIGN, init_once); 1395 if (mqueue_inode_cachep == NULL) 1396 return -ENOMEM; 1397 1398 /* ignore failures - they are not fatal */ 1399 mq_sysctl_table = mq_register_sysctl_table(); 1400 1401 error = register_filesystem(&mqueue_fs_type); 1402 if (error) 1403 goto out_sysctl; 1404 1405 spin_lock_init(&mq_lock); 1406 1407 error = mq_init_ns(&init_ipc_ns); 1408 if (error) 1409 goto out_filesystem; 1410 1411 return 0; 1412 1413 out_filesystem: 1414 unregister_filesystem(&mqueue_fs_type); 1415 out_sysctl: 1416 if (mq_sysctl_table) 1417 unregister_sysctl_table(mq_sysctl_table); 1418 kmem_cache_destroy(mqueue_inode_cachep); 1419 return error; 1420 } 1421 1422 __initcall(init_mqueue_fs); 1423