| 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/fs_context.h> |
| 22 | #include <linux/namei.h> |
| 23 | #include <linux/sysctl.h> |
| 24 | #include <linux/poll.h> |
| 25 | #include <linux/mqueue.h> |
| 26 | #include <linux/msg.h> |
| 27 | #include <linux/skbuff.h> |
| 28 | #include <linux/vmalloc.h> |
| 29 | #include <linux/netlink.h> |
| 30 | #include <linux/syscalls.h> |
| 31 | #include <linux/audit.h> |
| 32 | #include <linux/signal.h> |
| 33 | #include <linux/mutex.h> |
| 34 | #include <linux/nsproxy.h> |
| 35 | #include <linux/pid.h> |
| 36 | #include <linux/ipc_namespace.h> |
| 37 | #include <linux/user_namespace.h> |
| 38 | #include <linux/slab.h> |
| 39 | #include <linux/sched/wake_q.h> |
| 40 | #include <linux/sched/signal.h> |
| 41 | #include <linux/sched/user.h> |
| 42 | |
| 43 | #include <net/sock.h> |
| 44 | #include "util.h" |
| 45 | |
| 46 | struct mqueue_fs_context { |
| 47 | struct ipc_namespace *ipc_ns; |
| 48 | }; |
| 49 | |
| 50 | #define MQUEUE_MAGIC 0x19800202 |
| 51 | #define DIRENT_SIZE 20 |
| 52 | #define FILENT_SIZE 80 |
| 53 | |
| 54 | #define SEND 0 |
| 55 | #define RECV 1 |
| 56 | |
| 57 | #define STATE_NONE 0 |
| 58 | #define STATE_READY 1 |
| 59 | |
| 60 | struct posix_msg_tree_node { |
| 61 | struct rb_node rb_node; |
| 62 | struct list_head msg_list; |
| 63 | int priority; |
| 64 | }; |
| 65 | |
| 66 | /* |
| 67 | * Locking: |
| 68 | * |
| 69 | * Accesses to a message queue are synchronized by acquiring info->lock. |
| 70 | * |
| 71 | * There are two notable exceptions: |
| 72 | * - The actual wakeup of a sleeping task is performed using the wake_q |
| 73 | * framework. info->lock is already released when wake_up_q is called. |
| 74 | * - The exit codepaths after sleeping check ext_wait_queue->state without |
| 75 | * any locks. If it is STATE_READY, then the syscall is completed without |
| 76 | * acquiring info->lock. |
| 77 | * |
| 78 | * MQ_BARRIER: |
| 79 | * To achieve proper release/acquire memory barrier pairing, the state is set to |
| 80 | * STATE_READY with smp_store_release(), and it is read with READ_ONCE followed |
| 81 | * by smp_acquire__after_ctrl_dep(). In addition, wake_q_add_safe() is used. |
| 82 | * |
| 83 | * This prevents the following races: |
| 84 | * |
| 85 | * 1) With the simple wake_q_add(), the task could be gone already before |
| 86 | * the increase of the reference happens |
| 87 | * Thread A |
| 88 | * Thread B |
| 89 | * WRITE_ONCE(wait.state, STATE_NONE); |
| 90 | * schedule_hrtimeout() |
| 91 | * wake_q_add(A) |
| 92 | * if (cmpxchg()) // success |
| 93 | * ->state = STATE_READY (reordered) |
| 94 | * <timeout returns> |
| 95 | * if (wait.state == STATE_READY) return; |
| 96 | * sysret to user space |
| 97 | * sys_exit() |
| 98 | * get_task_struct() // UaF |
| 99 | * |
| 100 | * Solution: Use wake_q_add_safe() and perform the get_task_struct() before |
| 101 | * the smp_store_release() that does ->state = STATE_READY. |
| 102 | * |
| 103 | * 2) Without proper _release/_acquire barriers, the woken up task |
| 104 | * could read stale data |
| 105 | * |
| 106 | * Thread A |
| 107 | * Thread B |
| 108 | * do_mq_timedreceive |
| 109 | * WRITE_ONCE(wait.state, STATE_NONE); |
| 110 | * schedule_hrtimeout() |
| 111 | * state = STATE_READY; |
| 112 | * <timeout returns> |
| 113 | * if (wait.state == STATE_READY) return; |
| 114 | * msg_ptr = wait.msg; // Access to stale data! |
| 115 | * receiver->msg = message; (reordered) |
| 116 | * |
| 117 | * Solution: use _release and _acquire barriers. |
| 118 | * |
| 119 | * 3) There is intentionally no barrier when setting current->state |
| 120 | * to TASK_INTERRUPTIBLE: spin_unlock(&info->lock) provides the |
| 121 | * release memory barrier, and the wakeup is triggered when holding |
| 122 | * info->lock, i.e. spin_lock(&info->lock) provided a pairing |
| 123 | * acquire memory barrier. |
| 124 | */ |
| 125 | |
| 126 | struct ext_wait_queue { /* queue of sleeping tasks */ |
| 127 | struct task_struct *task; |
| 128 | struct list_head list; |
| 129 | struct msg_msg *msg; /* ptr of loaded message */ |
| 130 | int state; /* one of STATE_* values */ |
| 131 | }; |
| 132 | |
| 133 | struct mqueue_inode_info { |
| 134 | spinlock_t lock; |
| 135 | struct inode vfs_inode; |
| 136 | wait_queue_head_t wait_q; |
| 137 | |
| 138 | struct rb_root msg_tree; |
| 139 | struct rb_node *msg_tree_rightmost; |
| 140 | struct posix_msg_tree_node *node_cache; |
| 141 | struct mq_attr attr; |
| 142 | |
| 143 | struct sigevent notify; |
| 144 | struct pid *notify_owner; |
| 145 | struct user_namespace *notify_user_ns; |
| 146 | struct user_struct *user; /* user who created, for accounting */ |
| 147 | struct sock *notify_sock; |
| 148 | struct sk_buff *notify_cookie; |
| 149 | |
| 150 | /* for tasks waiting for free space and messages, respectively */ |
| 151 | struct ext_wait_queue e_wait_q[2]; |
| 152 | |
| 153 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ |
| 154 | }; |
| 155 | |
| 156 | static struct file_system_type mqueue_fs_type; |
| 157 | static const struct inode_operations mqueue_dir_inode_operations; |
| 158 | static const struct file_operations mqueue_file_operations; |
| 159 | static const struct super_operations mqueue_super_ops; |
| 160 | static const struct fs_context_operations mqueue_fs_context_ops; |
| 161 | static void remove_notification(struct mqueue_inode_info *info); |
| 162 | |
| 163 | static struct kmem_cache *mqueue_inode_cachep; |
| 164 | |
| 165 | static struct ctl_table_header *mq_sysctl_table; |
| 166 | |
| 167 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) |
| 168 | { |
| 169 | return container_of(inode, struct mqueue_inode_info, vfs_inode); |
| 170 | } |
| 171 | |
| 172 | /* |
| 173 | * This routine should be called with the mq_lock held. |
| 174 | */ |
| 175 | static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) |
| 176 | { |
| 177 | return get_ipc_ns(inode->i_sb->s_fs_info); |
| 178 | } |
| 179 | |
| 180 | static struct ipc_namespace *get_ns_from_inode(struct inode *inode) |
| 181 | { |
| 182 | struct ipc_namespace *ns; |
| 183 | |
| 184 | spin_lock(&mq_lock); |
| 185 | ns = __get_ns_from_inode(inode); |
| 186 | spin_unlock(&mq_lock); |
| 187 | return ns; |
| 188 | } |
| 189 | |
| 190 | /* Auxiliary functions to manipulate messages' list */ |
| 191 | static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info) |
| 192 | { |
| 193 | struct rb_node **p, *parent = NULL; |
| 194 | struct posix_msg_tree_node *leaf; |
| 195 | bool rightmost = true; |
| 196 | |
| 197 | p = &info->msg_tree.rb_node; |
| 198 | while (*p) { |
| 199 | parent = *p; |
| 200 | leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node); |
| 201 | |
| 202 | if (likely(leaf->priority == msg->m_type)) |
| 203 | goto insert_msg; |
| 204 | else if (msg->m_type < leaf->priority) { |
| 205 | p = &(*p)->rb_left; |
| 206 | rightmost = false; |
| 207 | } else |
| 208 | p = &(*p)->rb_right; |
| 209 | } |
| 210 | if (info->node_cache) { |
| 211 | leaf = info->node_cache; |
| 212 | info->node_cache = NULL; |
| 213 | } else { |
| 214 | leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC); |
| 215 | if (!leaf) |
| 216 | return -ENOMEM; |
| 217 | INIT_LIST_HEAD(&leaf->msg_list); |
| 218 | } |
| 219 | leaf->priority = msg->m_type; |
| 220 | |
| 221 | if (rightmost) |
| 222 | info->msg_tree_rightmost = &leaf->rb_node; |
| 223 | |
| 224 | rb_link_node(&leaf->rb_node, parent, p); |
| 225 | rb_insert_color(&leaf->rb_node, &info->msg_tree); |
| 226 | insert_msg: |
| 227 | info->attr.mq_curmsgs++; |
| 228 | info->qsize += msg->m_ts; |
| 229 | list_add_tail(&msg->m_list, &leaf->msg_list); |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | static inline void msg_tree_erase(struct posix_msg_tree_node *leaf, |
| 234 | struct mqueue_inode_info *info) |
| 235 | { |
| 236 | struct rb_node *node = &leaf->rb_node; |
| 237 | |
| 238 | if (info->msg_tree_rightmost == node) |
| 239 | info->msg_tree_rightmost = rb_prev(node); |
| 240 | |
| 241 | rb_erase(node, &info->msg_tree); |
| 242 | if (info->node_cache) |
| 243 | kfree(leaf); |
| 244 | else |
| 245 | info->node_cache = leaf; |
| 246 | } |
| 247 | |
| 248 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) |
| 249 | { |
| 250 | struct rb_node *parent = NULL; |
| 251 | struct posix_msg_tree_node *leaf; |
| 252 | struct msg_msg *msg; |
| 253 | |
| 254 | try_again: |
| 255 | /* |
| 256 | * During insert, low priorities go to the left and high to the |
| 257 | * right. On receive, we want the highest priorities first, so |
| 258 | * walk all the way to the right. |
| 259 | */ |
| 260 | parent = info->msg_tree_rightmost; |
| 261 | if (!parent) { |
| 262 | if (info->attr.mq_curmsgs) { |
| 263 | pr_warn_once("Inconsistency in POSIX message queue, " |
| 264 | "no tree element, but supposedly messages " |
| 265 | "should exist!\n"); |
| 266 | info->attr.mq_curmsgs = 0; |
| 267 | } |
| 268 | return NULL; |
| 269 | } |
| 270 | leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node); |
| 271 | if (unlikely(list_empty(&leaf->msg_list))) { |
| 272 | pr_warn_once("Inconsistency in POSIX message queue, " |
| 273 | "empty leaf node but we haven't implemented " |
| 274 | "lazy leaf delete!\n"); |
| 275 | msg_tree_erase(leaf, info); |
| 276 | goto try_again; |
| 277 | } else { |
| 278 | msg = list_first_entry(&leaf->msg_list, |
| 279 | struct msg_msg, m_list); |
| 280 | list_del(&msg->m_list); |
| 281 | if (list_empty(&leaf->msg_list)) { |
| 282 | msg_tree_erase(leaf, info); |
| 283 | } |
| 284 | } |
| 285 | info->attr.mq_curmsgs--; |
| 286 | info->qsize -= msg->m_ts; |
| 287 | return msg; |
| 288 | } |
| 289 | |
| 290 | static struct inode *mqueue_get_inode(struct super_block *sb, |
| 291 | struct ipc_namespace *ipc_ns, umode_t mode, |
| 292 | struct mq_attr *attr) |
| 293 | { |
| 294 | struct user_struct *u = current_user(); |
| 295 | struct inode *inode; |
| 296 | int ret = -ENOMEM; |
| 297 | |
| 298 | inode = new_inode(sb); |
| 299 | if (!inode) |
| 300 | goto err; |
| 301 | |
| 302 | inode->i_ino = get_next_ino(); |
| 303 | inode->i_mode = mode; |
| 304 | inode->i_uid = current_fsuid(); |
| 305 | inode->i_gid = current_fsgid(); |
| 306 | inode->i_mtime = inode->i_ctime = inode->i_atime = current_time(inode); |
| 307 | |
| 308 | if (S_ISREG(mode)) { |
| 309 | struct mqueue_inode_info *info; |
| 310 | unsigned long mq_bytes, mq_treesize; |
| 311 | |
| 312 | inode->i_fop = &mqueue_file_operations; |
| 313 | inode->i_size = FILENT_SIZE; |
| 314 | /* mqueue specific info */ |
| 315 | info = MQUEUE_I(inode); |
| 316 | spin_lock_init(&info->lock); |
| 317 | init_waitqueue_head(&info->wait_q); |
| 318 | INIT_LIST_HEAD(&info->e_wait_q[0].list); |
| 319 | INIT_LIST_HEAD(&info->e_wait_q[1].list); |
| 320 | info->notify_owner = NULL; |
| 321 | info->notify_user_ns = NULL; |
| 322 | info->qsize = 0; |
| 323 | info->user = NULL; /* set when all is ok */ |
| 324 | info->msg_tree = RB_ROOT; |
| 325 | info->msg_tree_rightmost = NULL; |
| 326 | info->node_cache = NULL; |
| 327 | memset(&info->attr, 0, sizeof(info->attr)); |
| 328 | info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max, |
| 329 | ipc_ns->mq_msg_default); |
| 330 | info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max, |
| 331 | ipc_ns->mq_msgsize_default); |
| 332 | if (attr) { |
| 333 | info->attr.mq_maxmsg = attr->mq_maxmsg; |
| 334 | info->attr.mq_msgsize = attr->mq_msgsize; |
| 335 | } |
| 336 | /* |
| 337 | * We used to allocate a static array of pointers and account |
| 338 | * the size of that array as well as one msg_msg struct per |
| 339 | * possible message into the queue size. That's no longer |
| 340 | * accurate as the queue is now an rbtree and will grow and |
| 341 | * shrink depending on usage patterns. We can, however, still |
| 342 | * account one msg_msg struct per message, but the nodes are |
| 343 | * allocated depending on priority usage, and most programs |
| 344 | * only use one, or a handful, of priorities. However, since |
| 345 | * this is pinned memory, we need to assume worst case, so |
| 346 | * that means the min(mq_maxmsg, max_priorities) * struct |
| 347 | * posix_msg_tree_node. |
| 348 | */ |
| 349 | |
| 350 | ret = -EINVAL; |
| 351 | if (info->attr.mq_maxmsg <= 0 || info->attr.mq_msgsize <= 0) |
| 352 | goto out_inode; |
| 353 | if (capable(CAP_SYS_RESOURCE)) { |
| 354 | if (info->attr.mq_maxmsg > HARD_MSGMAX || |
| 355 | info->attr.mq_msgsize > HARD_MSGSIZEMAX) |
| 356 | goto out_inode; |
| 357 | } else { |
| 358 | if (info->attr.mq_maxmsg > ipc_ns->mq_msg_max || |
| 359 | info->attr.mq_msgsize > ipc_ns->mq_msgsize_max) |
| 360 | goto out_inode; |
| 361 | } |
| 362 | ret = -EOVERFLOW; |
| 363 | /* check for overflow */ |
| 364 | if (info->attr.mq_msgsize > ULONG_MAX/info->attr.mq_maxmsg) |
| 365 | goto out_inode; |
| 366 | mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) + |
| 367 | min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) * |
| 368 | sizeof(struct posix_msg_tree_node); |
| 369 | mq_bytes = info->attr.mq_maxmsg * info->attr.mq_msgsize; |
| 370 | if (mq_bytes + mq_treesize < mq_bytes) |
| 371 | goto out_inode; |
| 372 | mq_bytes += mq_treesize; |
| 373 | spin_lock(&mq_lock); |
| 374 | if (u->mq_bytes + mq_bytes < u->mq_bytes || |
| 375 | u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) { |
| 376 | spin_unlock(&mq_lock); |
| 377 | /* mqueue_evict_inode() releases info->messages */ |
| 378 | ret = -EMFILE; |
| 379 | goto out_inode; |
| 380 | } |
| 381 | u->mq_bytes += mq_bytes; |
| 382 | spin_unlock(&mq_lock); |
| 383 | |
| 384 | /* all is ok */ |
| 385 | info->user = get_uid(u); |
| 386 | } else if (S_ISDIR(mode)) { |
| 387 | inc_nlink(inode); |
| 388 | /* Some things misbehave if size == 0 on a directory */ |
| 389 | inode->i_size = 2 * DIRENT_SIZE; |
| 390 | inode->i_op = &mqueue_dir_inode_operations; |
| 391 | inode->i_fop = &simple_dir_operations; |
| 392 | } |
| 393 | |
| 394 | return inode; |
| 395 | out_inode: |
| 396 | iput(inode); |
| 397 | err: |
| 398 | return ERR_PTR(ret); |
| 399 | } |
| 400 | |
| 401 | static int mqueue_fill_super(struct super_block *sb, struct fs_context *fc) |
| 402 | { |
| 403 | struct inode *inode; |
| 404 | struct ipc_namespace *ns = sb->s_fs_info; |
| 405 | |
| 406 | sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV; |
| 407 | sb->s_blocksize = PAGE_SIZE; |
| 408 | sb->s_blocksize_bits = PAGE_SHIFT; |
| 409 | sb->s_magic = MQUEUE_MAGIC; |
| 410 | sb->s_op = &mqueue_super_ops; |
| 411 | |
| 412 | inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); |
| 413 | if (IS_ERR(inode)) |
| 414 | return PTR_ERR(inode); |
| 415 | |
| 416 | sb->s_root = d_make_root(inode); |
| 417 | if (!sb->s_root) |
| 418 | return -ENOMEM; |
| 419 | return 0; |
| 420 | } |
| 421 | |
| 422 | static int mqueue_get_tree(struct fs_context *fc) |
| 423 | { |
| 424 | struct mqueue_fs_context *ctx = fc->fs_private; |
| 425 | |
| 426 | return get_tree_keyed(fc, mqueue_fill_super, ctx->ipc_ns); |
| 427 | } |
| 428 | |
| 429 | static void mqueue_fs_context_free(struct fs_context *fc) |
| 430 | { |
| 431 | struct mqueue_fs_context *ctx = fc->fs_private; |
| 432 | |
| 433 | put_ipc_ns(ctx->ipc_ns); |
| 434 | kfree(ctx); |
| 435 | } |
| 436 | |
| 437 | static int mqueue_init_fs_context(struct fs_context *fc) |
| 438 | { |
| 439 | struct mqueue_fs_context *ctx; |
| 440 | |
| 441 | ctx = kzalloc(sizeof(struct mqueue_fs_context), GFP_KERNEL); |
| 442 | if (!ctx) |
| 443 | return -ENOMEM; |
| 444 | |
| 445 | ctx->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns); |
| 446 | put_user_ns(fc->user_ns); |
| 447 | fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns); |
| 448 | fc->fs_private = ctx; |
| 449 | fc->ops = &mqueue_fs_context_ops; |
| 450 | return 0; |
| 451 | } |
| 452 | |
| 453 | static struct vfsmount *mq_create_mount(struct ipc_namespace *ns) |
| 454 | { |
| 455 | struct mqueue_fs_context *ctx; |
| 456 | struct fs_context *fc; |
| 457 | struct vfsmount *mnt; |
| 458 | |
| 459 | fc = fs_context_for_mount(&mqueue_fs_type, SB_KERNMOUNT); |
| 460 | if (IS_ERR(fc)) |
| 461 | return ERR_CAST(fc); |
| 462 | |
| 463 | ctx = fc->fs_private; |
| 464 | put_ipc_ns(ctx->ipc_ns); |
| 465 | ctx->ipc_ns = get_ipc_ns(ns); |
| 466 | put_user_ns(fc->user_ns); |
| 467 | fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns); |
| 468 | |
| 469 | mnt = fc_mount(fc); |
| 470 | put_fs_context(fc); |
| 471 | return mnt; |
| 472 | } |
| 473 | |
| 474 | static void init_once(void *foo) |
| 475 | { |
| 476 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; |
| 477 | |
| 478 | inode_init_once(&p->vfs_inode); |
| 479 | } |
| 480 | |
| 481 | static struct inode *mqueue_alloc_inode(struct super_block *sb) |
| 482 | { |
| 483 | struct mqueue_inode_info *ei; |
| 484 | |
| 485 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); |
| 486 | if (!ei) |
| 487 | return NULL; |
| 488 | return &ei->vfs_inode; |
| 489 | } |
| 490 | |
| 491 | static void mqueue_free_inode(struct inode *inode) |
| 492 | { |
| 493 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); |
| 494 | } |
| 495 | |
| 496 | static void mqueue_evict_inode(struct inode *inode) |
| 497 | { |
| 498 | struct mqueue_inode_info *info; |
| 499 | struct user_struct *user; |
| 500 | struct ipc_namespace *ipc_ns; |
| 501 | struct msg_msg *msg, *nmsg; |
| 502 | LIST_HEAD(tmp_msg); |
| 503 | |
| 504 | clear_inode(inode); |
| 505 | |
| 506 | if (S_ISDIR(inode->i_mode)) |
| 507 | return; |
| 508 | |
| 509 | ipc_ns = get_ns_from_inode(inode); |
| 510 | info = MQUEUE_I(inode); |
| 511 | spin_lock(&info->lock); |
| 512 | while ((msg = msg_get(info)) != NULL) |
| 513 | list_add_tail(&msg->m_list, &tmp_msg); |
| 514 | kfree(info->node_cache); |
| 515 | spin_unlock(&info->lock); |
| 516 | |
| 517 | list_for_each_entry_safe(msg, nmsg, &tmp_msg, m_list) { |
| 518 | list_del(&msg->m_list); |
| 519 | free_msg(msg); |
| 520 | } |
| 521 | |
| 522 | user = info->user; |
| 523 | if (user) { |
| 524 | unsigned long mq_bytes, mq_treesize; |
| 525 | |
| 526 | /* Total amount of bytes accounted for the mqueue */ |
| 527 | mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) + |
| 528 | min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) * |
| 529 | sizeof(struct posix_msg_tree_node); |
| 530 | |
| 531 | mq_bytes = mq_treesize + (info->attr.mq_maxmsg * |
| 532 | info->attr.mq_msgsize); |
| 533 | |
| 534 | spin_lock(&mq_lock); |
| 535 | user->mq_bytes -= mq_bytes; |
| 536 | /* |
| 537 | * get_ns_from_inode() ensures that the |
| 538 | * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns |
| 539 | * to which we now hold a reference, or it is NULL. |
| 540 | * We can't put it here under mq_lock, though. |
| 541 | */ |
| 542 | if (ipc_ns) |
| 543 | ipc_ns->mq_queues_count--; |
| 544 | spin_unlock(&mq_lock); |
| 545 | free_uid(user); |
| 546 | } |
| 547 | if (ipc_ns) |
| 548 | put_ipc_ns(ipc_ns); |
| 549 | } |
| 550 | |
| 551 | static int mqueue_create_attr(struct dentry *dentry, umode_t mode, void *arg) |
| 552 | { |
| 553 | struct inode *dir = dentry->d_parent->d_inode; |
| 554 | struct inode *inode; |
| 555 | struct mq_attr *attr = arg; |
| 556 | int error; |
| 557 | struct ipc_namespace *ipc_ns; |
| 558 | |
| 559 | spin_lock(&mq_lock); |
| 560 | ipc_ns = __get_ns_from_inode(dir); |
| 561 | if (!ipc_ns) { |
| 562 | error = -EACCES; |
| 563 | goto out_unlock; |
| 564 | } |
| 565 | |
| 566 | if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && |
| 567 | !capable(CAP_SYS_RESOURCE)) { |
| 568 | error = -ENOSPC; |
| 569 | goto out_unlock; |
| 570 | } |
| 571 | ipc_ns->mq_queues_count++; |
| 572 | spin_unlock(&mq_lock); |
| 573 | |
| 574 | inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); |
| 575 | if (IS_ERR(inode)) { |
| 576 | error = PTR_ERR(inode); |
| 577 | spin_lock(&mq_lock); |
| 578 | ipc_ns->mq_queues_count--; |
| 579 | goto out_unlock; |
| 580 | } |
| 581 | |
| 582 | put_ipc_ns(ipc_ns); |
| 583 | dir->i_size += DIRENT_SIZE; |
| 584 | dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir); |
| 585 | |
| 586 | d_instantiate(dentry, inode); |
| 587 | dget(dentry); |
| 588 | return 0; |
| 589 | out_unlock: |
| 590 | spin_unlock(&mq_lock); |
| 591 | if (ipc_ns) |
| 592 | put_ipc_ns(ipc_ns); |
| 593 | return error; |
| 594 | } |
| 595 | |
| 596 | static int mqueue_create(struct inode *dir, struct dentry *dentry, |
| 597 | umode_t mode, bool excl) |
| 598 | { |
| 599 | return mqueue_create_attr(dentry, mode, NULL); |
| 600 | } |
| 601 | |
| 602 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) |
| 603 | { |
| 604 | struct inode *inode = d_inode(dentry); |
| 605 | |
| 606 | dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir); |
| 607 | dir->i_size -= DIRENT_SIZE; |
| 608 | drop_nlink(inode); |
| 609 | dput(dentry); |
| 610 | return 0; |
| 611 | } |
| 612 | |
| 613 | /* |
| 614 | * This is routine for system read from queue file. |
| 615 | * To avoid mess with doing here some sort of mq_receive we allow |
| 616 | * to read only queue size & notification info (the only values |
| 617 | * that are interesting from user point of view and aren't accessible |
| 618 | * through std routines) |
| 619 | */ |
| 620 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, |
| 621 | size_t count, loff_t *off) |
| 622 | { |
| 623 | struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp)); |
| 624 | char buffer[FILENT_SIZE]; |
| 625 | ssize_t ret; |
| 626 | |
| 627 | spin_lock(&info->lock); |
| 628 | snprintf(buffer, sizeof(buffer), |
| 629 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", |
| 630 | info->qsize, |
| 631 | info->notify_owner ? info->notify.sigev_notify : 0, |
| 632 | (info->notify_owner && |
| 633 | info->notify.sigev_notify == SIGEV_SIGNAL) ? |
| 634 | info->notify.sigev_signo : 0, |
| 635 | pid_vnr(info->notify_owner)); |
| 636 | spin_unlock(&info->lock); |
| 637 | buffer[sizeof(buffer)-1] = '\0'; |
| 638 | |
| 639 | ret = simple_read_from_buffer(u_data, count, off, buffer, |
| 640 | strlen(buffer)); |
| 641 | if (ret <= 0) |
| 642 | return ret; |
| 643 | |
| 644 | file_inode(filp)->i_atime = file_inode(filp)->i_ctime = current_time(file_inode(filp)); |
| 645 | return ret; |
| 646 | } |
| 647 | |
| 648 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
| 649 | { |
| 650 | struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp)); |
| 651 | |
| 652 | spin_lock(&info->lock); |
| 653 | if (task_tgid(current) == info->notify_owner) |
| 654 | remove_notification(info); |
| 655 | |
| 656 | spin_unlock(&info->lock); |
| 657 | return 0; |
| 658 | } |
| 659 | |
| 660 | static __poll_t mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) |
| 661 | { |
| 662 | struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp)); |
| 663 | __poll_t retval = 0; |
| 664 | |
| 665 | poll_wait(filp, &info->wait_q, poll_tab); |
| 666 | |
| 667 | spin_lock(&info->lock); |
| 668 | if (info->attr.mq_curmsgs) |
| 669 | retval = EPOLLIN | EPOLLRDNORM; |
| 670 | |
| 671 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) |
| 672 | retval |= EPOLLOUT | EPOLLWRNORM; |
| 673 | spin_unlock(&info->lock); |
| 674 | |
| 675 | return retval; |
| 676 | } |
| 677 | |
| 678 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ |
| 679 | static void wq_add(struct mqueue_inode_info *info, int sr, |
| 680 | struct ext_wait_queue *ewp) |
| 681 | { |
| 682 | struct ext_wait_queue *walk; |
| 683 | |
| 684 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { |
| 685 | if (walk->task->prio <= current->prio) { |
| 686 | list_add_tail(&ewp->list, &walk->list); |
| 687 | return; |
| 688 | } |
| 689 | } |
| 690 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); |
| 691 | } |
| 692 | |
| 693 | /* |
| 694 | * Puts current task to sleep. Caller must hold queue lock. After return |
| 695 | * lock isn't held. |
| 696 | * sr: SEND or RECV |
| 697 | */ |
| 698 | static int wq_sleep(struct mqueue_inode_info *info, int sr, |
| 699 | ktime_t *timeout, struct ext_wait_queue *ewp) |
| 700 | __releases(&info->lock) |
| 701 | { |
| 702 | int retval; |
| 703 | signed long time; |
| 704 | |
| 705 | wq_add(info, sr, ewp); |
| 706 | |
| 707 | for (;;) { |
| 708 | /* memory barrier not required, we hold info->lock */ |
| 709 | __set_current_state(TASK_INTERRUPTIBLE); |
| 710 | |
| 711 | spin_unlock(&info->lock); |
| 712 | time = schedule_hrtimeout_range_clock(timeout, 0, |
| 713 | HRTIMER_MODE_ABS, CLOCK_REALTIME); |
| 714 | |
| 715 | if (READ_ONCE(ewp->state) == STATE_READY) { |
| 716 | /* see MQ_BARRIER for purpose/pairing */ |
| 717 | smp_acquire__after_ctrl_dep(); |
| 718 | retval = 0; |
| 719 | goto out; |
| 720 | } |
| 721 | spin_lock(&info->lock); |
| 722 | |
| 723 | /* we hold info->lock, so no memory barrier required */ |
| 724 | if (READ_ONCE(ewp->state) == STATE_READY) { |
| 725 | retval = 0; |
| 726 | goto out_unlock; |
| 727 | } |
| 728 | if (signal_pending(current)) { |
| 729 | retval = -ERESTARTSYS; |
| 730 | break; |
| 731 | } |
| 732 | if (time == 0) { |
| 733 | retval = -ETIMEDOUT; |
| 734 | break; |
| 735 | } |
| 736 | } |
| 737 | list_del(&ewp->list); |
| 738 | out_unlock: |
| 739 | spin_unlock(&info->lock); |
| 740 | out: |
| 741 | return retval; |
| 742 | } |
| 743 | |
| 744 | /* |
| 745 | * Returns waiting task that should be serviced first or NULL if none exists |
| 746 | */ |
| 747 | static struct ext_wait_queue *wq_get_first_waiter( |
| 748 | struct mqueue_inode_info *info, int sr) |
| 749 | { |
| 750 | struct list_head *ptr; |
| 751 | |
| 752 | ptr = info->e_wait_q[sr].list.prev; |
| 753 | if (ptr == &info->e_wait_q[sr].list) |
| 754 | return NULL; |
| 755 | return list_entry(ptr, struct ext_wait_queue, list); |
| 756 | } |
| 757 | |
| 758 | |
| 759 | static inline void set_cookie(struct sk_buff *skb, char code) |
| 760 | { |
| 761 | ((char *)skb->data)[NOTIFY_COOKIE_LEN-1] = code; |
| 762 | } |
| 763 | |
| 764 | /* |
| 765 | * The next function is only to split too long sys_mq_timedsend |
| 766 | */ |
| 767 | static void __do_notify(struct mqueue_inode_info *info) |
| 768 | { |
| 769 | /* notification |
| 770 | * invoked when there is registered process and there isn't process |
| 771 | * waiting synchronously for message AND state of queue changed from |
| 772 | * empty to not empty. Here we are sure that no one is waiting |
| 773 | * synchronously. */ |
| 774 | if (info->notify_owner && |
| 775 | info->attr.mq_curmsgs == 1) { |
| 776 | struct kernel_siginfo sig_i; |
| 777 | switch (info->notify.sigev_notify) { |
| 778 | case SIGEV_NONE: |
| 779 | break; |
| 780 | case SIGEV_SIGNAL: |
| 781 | /* sends signal */ |
| 782 | |
| 783 | clear_siginfo(&sig_i); |
| 784 | sig_i.si_signo = info->notify.sigev_signo; |
| 785 | sig_i.si_errno = 0; |
| 786 | sig_i.si_code = SI_MESGQ; |
| 787 | sig_i.si_value = info->notify.sigev_value; |
| 788 | /* map current pid/uid into info->owner's namespaces */ |
| 789 | rcu_read_lock(); |
| 790 | sig_i.si_pid = task_tgid_nr_ns(current, |
| 791 | ns_of_pid(info->notify_owner)); |
| 792 | sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid()); |
| 793 | rcu_read_unlock(); |
| 794 | |
| 795 | kill_pid_info(info->notify.sigev_signo, |
| 796 | &sig_i, info->notify_owner); |
| 797 | break; |
| 798 | case SIGEV_THREAD: |
| 799 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); |
| 800 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
| 801 | break; |
| 802 | } |
| 803 | /* after notification unregisters process */ |
| 804 | put_pid(info->notify_owner); |
| 805 | put_user_ns(info->notify_user_ns); |
| 806 | info->notify_owner = NULL; |
| 807 | info->notify_user_ns = NULL; |
| 808 | } |
| 809 | wake_up(&info->wait_q); |
| 810 | } |
| 811 | |
| 812 | static int prepare_timeout(const struct __kernel_timespec __user *u_abs_timeout, |
| 813 | struct timespec64 *ts) |
| 814 | { |
| 815 | if (get_timespec64(ts, u_abs_timeout)) |
| 816 | return -EFAULT; |
| 817 | if (!timespec64_valid(ts)) |
| 818 | return -EINVAL; |
| 819 | return 0; |
| 820 | } |
| 821 | |
| 822 | static void remove_notification(struct mqueue_inode_info *info) |
| 823 | { |
| 824 | if (info->notify_owner != NULL && |
| 825 | info->notify.sigev_notify == SIGEV_THREAD) { |
| 826 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); |
| 827 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
| 828 | } |
| 829 | put_pid(info->notify_owner); |
| 830 | put_user_ns(info->notify_user_ns); |
| 831 | info->notify_owner = NULL; |
| 832 | info->notify_user_ns = NULL; |
| 833 | } |
| 834 | |
| 835 | static int prepare_open(struct dentry *dentry, int oflag, int ro, |
| 836 | umode_t mode, struct filename *name, |
| 837 | struct mq_attr *attr) |
| 838 | { |
| 839 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, |
| 840 | MAY_READ | MAY_WRITE }; |
| 841 | int acc; |
| 842 | |
| 843 | if (d_really_is_negative(dentry)) { |
| 844 | if (!(oflag & O_CREAT)) |
| 845 | return -ENOENT; |
| 846 | if (ro) |
| 847 | return ro; |
| 848 | audit_inode_parent_hidden(name, dentry->d_parent); |
| 849 | return vfs_mkobj(dentry, mode & ~current_umask(), |
| 850 | mqueue_create_attr, attr); |
| 851 | } |
| 852 | /* it already existed */ |
| 853 | audit_inode(name, dentry, 0); |
| 854 | if ((oflag & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) |
| 855 | return -EEXIST; |
| 856 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) |
| 857 | return -EINVAL; |
| 858 | acc = oflag2acc[oflag & O_ACCMODE]; |
| 859 | return inode_permission(d_inode(dentry), acc); |
| 860 | } |
| 861 | |
| 862 | static int do_mq_open(const char __user *u_name, int oflag, umode_t mode, |
| 863 | struct mq_attr *attr) |
| 864 | { |
| 865 | struct vfsmount *mnt = current->nsproxy->ipc_ns->mq_mnt; |
| 866 | struct dentry *root = mnt->mnt_root; |
| 867 | struct filename *name; |
| 868 | struct path path; |
| 869 | int fd, error; |
| 870 | int ro; |
| 871 | |
| 872 | audit_mq_open(oflag, mode, attr); |
| 873 | |
| 874 | if (IS_ERR(name = getname(u_name))) |
| 875 | return PTR_ERR(name); |
| 876 | |
| 877 | fd = get_unused_fd_flags(O_CLOEXEC); |
| 878 | if (fd < 0) |
| 879 | goto out_putname; |
| 880 | |
| 881 | ro = mnt_want_write(mnt); /* we'll drop it in any case */ |
| 882 | inode_lock(d_inode(root)); |
| 883 | path.dentry = lookup_one_len(name->name, root, strlen(name->name)); |
| 884 | if (IS_ERR(path.dentry)) { |
| 885 | error = PTR_ERR(path.dentry); |
| 886 | goto out_putfd; |
| 887 | } |
| 888 | path.mnt = mntget(mnt); |
| 889 | error = prepare_open(path.dentry, oflag, ro, mode, name, attr); |
| 890 | if (!error) { |
| 891 | struct file *file = dentry_open(&path, oflag, current_cred()); |
| 892 | if (!IS_ERR(file)) |
| 893 | fd_install(fd, file); |
| 894 | else |
| 895 | error = PTR_ERR(file); |
| 896 | } |
| 897 | path_put(&path); |
| 898 | out_putfd: |
| 899 | if (error) { |
| 900 | put_unused_fd(fd); |
| 901 | fd = error; |
| 902 | } |
| 903 | inode_unlock(d_inode(root)); |
| 904 | if (!ro) |
| 905 | mnt_drop_write(mnt); |
| 906 | out_putname: |
| 907 | putname(name); |
| 908 | return fd; |
| 909 | } |
| 910 | |
| 911 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, |
| 912 | struct mq_attr __user *, u_attr) |
| 913 | { |
| 914 | struct mq_attr attr; |
| 915 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) |
| 916 | return -EFAULT; |
| 917 | |
| 918 | return do_mq_open(u_name, oflag, mode, u_attr ? &attr : NULL); |
| 919 | } |
| 920 | |
| 921 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) |
| 922 | { |
| 923 | int err; |
| 924 | struct filename *name; |
| 925 | struct dentry *dentry; |
| 926 | struct inode *inode = NULL; |
| 927 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
| 928 | struct vfsmount *mnt = ipc_ns->mq_mnt; |
| 929 | |
| 930 | name = getname(u_name); |
| 931 | if (IS_ERR(name)) |
| 932 | return PTR_ERR(name); |
| 933 | |
| 934 | audit_inode_parent_hidden(name, mnt->mnt_root); |
| 935 | err = mnt_want_write(mnt); |
| 936 | if (err) |
| 937 | goto out_name; |
| 938 | inode_lock_nested(d_inode(mnt->mnt_root), I_MUTEX_PARENT); |
| 939 | dentry = lookup_one_len(name->name, mnt->mnt_root, |
| 940 | strlen(name->name)); |
| 941 | if (IS_ERR(dentry)) { |
| 942 | err = PTR_ERR(dentry); |
| 943 | goto out_unlock; |
| 944 | } |
| 945 | |
| 946 | inode = d_inode(dentry); |
| 947 | if (!inode) { |
| 948 | err = -ENOENT; |
| 949 | } else { |
| 950 | ihold(inode); |
| 951 | err = vfs_unlink(d_inode(dentry->d_parent), dentry, NULL); |
| 952 | } |
| 953 | dput(dentry); |
| 954 | |
| 955 | out_unlock: |
| 956 | inode_unlock(d_inode(mnt->mnt_root)); |
| 957 | if (inode) |
| 958 | iput(inode); |
| 959 | mnt_drop_write(mnt); |
| 960 | out_name: |
| 961 | putname(name); |
| 962 | |
| 963 | return err; |
| 964 | } |
| 965 | |
| 966 | /* Pipelined send and receive functions. |
| 967 | * |
| 968 | * If a receiver finds no waiting message, then it registers itself in the |
| 969 | * list of waiting receivers. A sender checks that list before adding the new |
| 970 | * message into the message array. If there is a waiting receiver, then it |
| 971 | * bypasses the message array and directly hands the message over to the |
| 972 | * receiver. The receiver accepts the message and returns without grabbing the |
| 973 | * queue spinlock: |
| 974 | * |
| 975 | * - Set pointer to message. |
| 976 | * - Queue the receiver task for later wakeup (without the info->lock). |
| 977 | * - Update its state to STATE_READY. Now the receiver can continue. |
| 978 | * - Wake up the process after the lock is dropped. Should the process wake up |
| 979 | * before this wakeup (due to a timeout or a signal) it will either see |
| 980 | * STATE_READY and continue or acquire the lock to check the state again. |
| 981 | * |
| 982 | * The same algorithm is used for senders. |
| 983 | */ |
| 984 | |
| 985 | static inline void __pipelined_op(struct wake_q_head *wake_q, |
| 986 | struct mqueue_inode_info *info, |
| 987 | struct ext_wait_queue *this) |
| 988 | { |
| 989 | list_del(&this->list); |
| 990 | get_task_struct(this->task); |
| 991 | |
| 992 | /* see MQ_BARRIER for purpose/pairing */ |
| 993 | smp_store_release(&this->state, STATE_READY); |
| 994 | wake_q_add_safe(wake_q, this->task); |
| 995 | } |
| 996 | |
| 997 | /* pipelined_send() - send a message directly to the task waiting in |
| 998 | * sys_mq_timedreceive() (without inserting message into a queue). |
| 999 | */ |
| 1000 | static inline void pipelined_send(struct wake_q_head *wake_q, |
| 1001 | struct mqueue_inode_info *info, |
| 1002 | struct msg_msg *message, |
| 1003 | struct ext_wait_queue *receiver) |
| 1004 | { |
| 1005 | receiver->msg = message; |
| 1006 | __pipelined_op(wake_q, info, receiver); |
| 1007 | } |
| 1008 | |
| 1009 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() |
| 1010 | * gets its message and put to the queue (we have one free place for sure). */ |
| 1011 | static inline void pipelined_receive(struct wake_q_head *wake_q, |
| 1012 | struct mqueue_inode_info *info) |
| 1013 | { |
| 1014 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); |
| 1015 | |
| 1016 | if (!sender) { |
| 1017 | /* for poll */ |
| 1018 | wake_up_interruptible(&info->wait_q); |
| 1019 | return; |
| 1020 | } |
| 1021 | if (msg_insert(sender->msg, info)) |
| 1022 | return; |
| 1023 | |
| 1024 | __pipelined_op(wake_q, info, sender); |
| 1025 | } |
| 1026 | |
| 1027 | static int do_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr, |
| 1028 | size_t msg_len, unsigned int msg_prio, |
| 1029 | struct timespec64 *ts) |
| 1030 | { |
| 1031 | struct fd f; |
| 1032 | struct inode *inode; |
| 1033 | struct ext_wait_queue wait; |
| 1034 | struct ext_wait_queue *receiver; |
| 1035 | struct msg_msg *msg_ptr; |
| 1036 | struct mqueue_inode_info *info; |
| 1037 | ktime_t expires, *timeout = NULL; |
| 1038 | struct posix_msg_tree_node *new_leaf = NULL; |
| 1039 | int ret = 0; |
| 1040 | DEFINE_WAKE_Q(wake_q); |
| 1041 | |
| 1042 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) |
| 1043 | return -EINVAL; |
| 1044 | |
| 1045 | if (ts) { |
| 1046 | expires = timespec64_to_ktime(*ts); |
| 1047 | timeout = &expires; |
| 1048 | } |
| 1049 | |
| 1050 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, ts); |
| 1051 | |
| 1052 | f = fdget(mqdes); |
| 1053 | if (unlikely(!f.file)) { |
| 1054 | ret = -EBADF; |
| 1055 | goto out; |
| 1056 | } |
| 1057 | |
| 1058 | inode = file_inode(f.file); |
| 1059 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
| 1060 | ret = -EBADF; |
| 1061 | goto out_fput; |
| 1062 | } |
| 1063 | info = MQUEUE_I(inode); |
| 1064 | audit_file(f.file); |
| 1065 | |
| 1066 | if (unlikely(!(f.file->f_mode & FMODE_WRITE))) { |
| 1067 | ret = -EBADF; |
| 1068 | goto out_fput; |
| 1069 | } |
| 1070 | |
| 1071 | if (unlikely(msg_len > info->attr.mq_msgsize)) { |
| 1072 | ret = -EMSGSIZE; |
| 1073 | goto out_fput; |
| 1074 | } |
| 1075 | |
| 1076 | /* First try to allocate memory, before doing anything with |
| 1077 | * existing queues. */ |
| 1078 | msg_ptr = load_msg(u_msg_ptr, msg_len); |
| 1079 | if (IS_ERR(msg_ptr)) { |
| 1080 | ret = PTR_ERR(msg_ptr); |
| 1081 | goto out_fput; |
| 1082 | } |
| 1083 | msg_ptr->m_ts = msg_len; |
| 1084 | msg_ptr->m_type = msg_prio; |
| 1085 | |
| 1086 | /* |
| 1087 | * msg_insert really wants us to have a valid, spare node struct so |
| 1088 | * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will |
| 1089 | * fall back to that if necessary. |
| 1090 | */ |
| 1091 | if (!info->node_cache) |
| 1092 | new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL); |
| 1093 | |
| 1094 | spin_lock(&info->lock); |
| 1095 | |
| 1096 | if (!info->node_cache && new_leaf) { |
| 1097 | /* Save our speculative allocation into the cache */ |
| 1098 | INIT_LIST_HEAD(&new_leaf->msg_list); |
| 1099 | info->node_cache = new_leaf; |
| 1100 | new_leaf = NULL; |
| 1101 | } else { |
| 1102 | kfree(new_leaf); |
| 1103 | } |
| 1104 | |
| 1105 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { |
| 1106 | if (f.file->f_flags & O_NONBLOCK) { |
| 1107 | ret = -EAGAIN; |
| 1108 | } else { |
| 1109 | wait.task = current; |
| 1110 | wait.msg = (void *) msg_ptr; |
| 1111 | |
| 1112 | /* memory barrier not required, we hold info->lock */ |
| 1113 | WRITE_ONCE(wait.state, STATE_NONE); |
| 1114 | ret = wq_sleep(info, SEND, timeout, &wait); |
| 1115 | /* |
| 1116 | * wq_sleep must be called with info->lock held, and |
| 1117 | * returns with the lock released |
| 1118 | */ |
| 1119 | goto out_free; |
| 1120 | } |
| 1121 | } else { |
| 1122 | receiver = wq_get_first_waiter(info, RECV); |
| 1123 | if (receiver) { |
| 1124 | pipelined_send(&wake_q, info, msg_ptr, receiver); |
| 1125 | } else { |
| 1126 | /* adds message to the queue */ |
| 1127 | ret = msg_insert(msg_ptr, info); |
| 1128 | if (ret) |
| 1129 | goto out_unlock; |
| 1130 | __do_notify(info); |
| 1131 | } |
| 1132 | inode->i_atime = inode->i_mtime = inode->i_ctime = |
| 1133 | current_time(inode); |
| 1134 | } |
| 1135 | out_unlock: |
| 1136 | spin_unlock(&info->lock); |
| 1137 | wake_up_q(&wake_q); |
| 1138 | out_free: |
| 1139 | if (ret) |
| 1140 | free_msg(msg_ptr); |
| 1141 | out_fput: |
| 1142 | fdput(f); |
| 1143 | out: |
| 1144 | return ret; |
| 1145 | } |
| 1146 | |
| 1147 | static int do_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr, |
| 1148 | size_t msg_len, unsigned int __user *u_msg_prio, |
| 1149 | struct timespec64 *ts) |
| 1150 | { |
| 1151 | ssize_t ret; |
| 1152 | struct msg_msg *msg_ptr; |
| 1153 | struct fd f; |
| 1154 | struct inode *inode; |
| 1155 | struct mqueue_inode_info *info; |
| 1156 | struct ext_wait_queue wait; |
| 1157 | ktime_t expires, *timeout = NULL; |
| 1158 | struct posix_msg_tree_node *new_leaf = NULL; |
| 1159 | |
| 1160 | if (ts) { |
| 1161 | expires = timespec64_to_ktime(*ts); |
| 1162 | timeout = &expires; |
| 1163 | } |
| 1164 | |
| 1165 | audit_mq_sendrecv(mqdes, msg_len, 0, ts); |
| 1166 | |
| 1167 | f = fdget(mqdes); |
| 1168 | if (unlikely(!f.file)) { |
| 1169 | ret = -EBADF; |
| 1170 | goto out; |
| 1171 | } |
| 1172 | |
| 1173 | inode = file_inode(f.file); |
| 1174 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
| 1175 | ret = -EBADF; |
| 1176 | goto out_fput; |
| 1177 | } |
| 1178 | info = MQUEUE_I(inode); |
| 1179 | audit_file(f.file); |
| 1180 | |
| 1181 | if (unlikely(!(f.file->f_mode & FMODE_READ))) { |
| 1182 | ret = -EBADF; |
| 1183 | goto out_fput; |
| 1184 | } |
| 1185 | |
| 1186 | /* checks if buffer is big enough */ |
| 1187 | if (unlikely(msg_len < info->attr.mq_msgsize)) { |
| 1188 | ret = -EMSGSIZE; |
| 1189 | goto out_fput; |
| 1190 | } |
| 1191 | |
| 1192 | /* |
| 1193 | * msg_insert really wants us to have a valid, spare node struct so |
| 1194 | * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will |
| 1195 | * fall back to that if necessary. |
| 1196 | */ |
| 1197 | if (!info->node_cache) |
| 1198 | new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL); |
| 1199 | |
| 1200 | spin_lock(&info->lock); |
| 1201 | |
| 1202 | if (!info->node_cache && new_leaf) { |
| 1203 | /* Save our speculative allocation into the cache */ |
| 1204 | INIT_LIST_HEAD(&new_leaf->msg_list); |
| 1205 | info->node_cache = new_leaf; |
| 1206 | } else { |
| 1207 | kfree(new_leaf); |
| 1208 | } |
| 1209 | |
| 1210 | if (info->attr.mq_curmsgs == 0) { |
| 1211 | if (f.file->f_flags & O_NONBLOCK) { |
| 1212 | spin_unlock(&info->lock); |
| 1213 | ret = -EAGAIN; |
| 1214 | } else { |
| 1215 | wait.task = current; |
| 1216 | |
| 1217 | /* memory barrier not required, we hold info->lock */ |
| 1218 | WRITE_ONCE(wait.state, STATE_NONE); |
| 1219 | ret = wq_sleep(info, RECV, timeout, &wait); |
| 1220 | msg_ptr = wait.msg; |
| 1221 | } |
| 1222 | } else { |
| 1223 | DEFINE_WAKE_Q(wake_q); |
| 1224 | |
| 1225 | msg_ptr = msg_get(info); |
| 1226 | |
| 1227 | inode->i_atime = inode->i_mtime = inode->i_ctime = |
| 1228 | current_time(inode); |
| 1229 | |
| 1230 | /* There is now free space in queue. */ |
| 1231 | pipelined_receive(&wake_q, info); |
| 1232 | spin_unlock(&info->lock); |
| 1233 | wake_up_q(&wake_q); |
| 1234 | ret = 0; |
| 1235 | } |
| 1236 | if (ret == 0) { |
| 1237 | ret = msg_ptr->m_ts; |
| 1238 | |
| 1239 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || |
| 1240 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { |
| 1241 | ret = -EFAULT; |
| 1242 | } |
| 1243 | free_msg(msg_ptr); |
| 1244 | } |
| 1245 | out_fput: |
| 1246 | fdput(f); |
| 1247 | out: |
| 1248 | return ret; |
| 1249 | } |
| 1250 | |
| 1251 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, |
| 1252 | size_t, msg_len, unsigned int, msg_prio, |
| 1253 | const struct __kernel_timespec __user *, u_abs_timeout) |
| 1254 | { |
| 1255 | struct timespec64 ts, *p = NULL; |
| 1256 | if (u_abs_timeout) { |
| 1257 | int res = prepare_timeout(u_abs_timeout, &ts); |
| 1258 | if (res) |
| 1259 | return res; |
| 1260 | p = &ts; |
| 1261 | } |
| 1262 | return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p); |
| 1263 | } |
| 1264 | |
| 1265 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, |
| 1266 | size_t, msg_len, unsigned int __user *, u_msg_prio, |
| 1267 | const struct __kernel_timespec __user *, u_abs_timeout) |
| 1268 | { |
| 1269 | struct timespec64 ts, *p = NULL; |
| 1270 | if (u_abs_timeout) { |
| 1271 | int res = prepare_timeout(u_abs_timeout, &ts); |
| 1272 | if (res) |
| 1273 | return res; |
| 1274 | p = &ts; |
| 1275 | } |
| 1276 | return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p); |
| 1277 | } |
| 1278 | |
| 1279 | /* |
| 1280 | * Notes: the case when user wants us to deregister (with NULL as pointer) |
| 1281 | * and he isn't currently owner of notification, will be silently discarded. |
| 1282 | * It isn't explicitly defined in the POSIX. |
| 1283 | */ |
| 1284 | static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification) |
| 1285 | { |
| 1286 | int ret; |
| 1287 | struct fd f; |
| 1288 | struct sock *sock; |
| 1289 | struct inode *inode; |
| 1290 | struct mqueue_inode_info *info; |
| 1291 | struct sk_buff *nc; |
| 1292 | |
| 1293 | audit_mq_notify(mqdes, notification); |
| 1294 | |
| 1295 | nc = NULL; |
| 1296 | sock = NULL; |
| 1297 | if (notification != NULL) { |
| 1298 | if (unlikely(notification->sigev_notify != SIGEV_NONE && |
| 1299 | notification->sigev_notify != SIGEV_SIGNAL && |
| 1300 | notification->sigev_notify != SIGEV_THREAD)) |
| 1301 | return -EINVAL; |
| 1302 | if (notification->sigev_notify == SIGEV_SIGNAL && |
| 1303 | !valid_signal(notification->sigev_signo)) { |
| 1304 | return -EINVAL; |
| 1305 | } |
| 1306 | if (notification->sigev_notify == SIGEV_THREAD) { |
| 1307 | long timeo; |
| 1308 | |
| 1309 | /* create the notify skb */ |
| 1310 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); |
| 1311 | if (!nc) |
| 1312 | return -ENOMEM; |
| 1313 | |
| 1314 | if (copy_from_user(nc->data, |
| 1315 | notification->sigev_value.sival_ptr, |
| 1316 | NOTIFY_COOKIE_LEN)) { |
| 1317 | ret = -EFAULT; |
| 1318 | goto free_skb; |
| 1319 | } |
| 1320 | |
| 1321 | /* TODO: add a header? */ |
| 1322 | skb_put(nc, NOTIFY_COOKIE_LEN); |
| 1323 | /* and attach it to the socket */ |
| 1324 | retry: |
| 1325 | f = fdget(notification->sigev_signo); |
| 1326 | if (!f.file) { |
| 1327 | ret = -EBADF; |
| 1328 | goto out; |
| 1329 | } |
| 1330 | sock = netlink_getsockbyfilp(f.file); |
| 1331 | fdput(f); |
| 1332 | if (IS_ERR(sock)) { |
| 1333 | ret = PTR_ERR(sock); |
| 1334 | goto free_skb; |
| 1335 | } |
| 1336 | |
| 1337 | timeo = MAX_SCHEDULE_TIMEOUT; |
| 1338 | ret = netlink_attachskb(sock, nc, &timeo, NULL); |
| 1339 | if (ret == 1) { |
| 1340 | sock = NULL; |
| 1341 | goto retry; |
| 1342 | } |
| 1343 | if (ret) |
| 1344 | return ret; |
| 1345 | } |
| 1346 | } |
| 1347 | |
| 1348 | f = fdget(mqdes); |
| 1349 | if (!f.file) { |
| 1350 | ret = -EBADF; |
| 1351 | goto out; |
| 1352 | } |
| 1353 | |
| 1354 | inode = file_inode(f.file); |
| 1355 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
| 1356 | ret = -EBADF; |
| 1357 | goto out_fput; |
| 1358 | } |
| 1359 | info = MQUEUE_I(inode); |
| 1360 | |
| 1361 | ret = 0; |
| 1362 | spin_lock(&info->lock); |
| 1363 | if (notification == NULL) { |
| 1364 | if (info->notify_owner == task_tgid(current)) { |
| 1365 | remove_notification(info); |
| 1366 | inode->i_atime = inode->i_ctime = current_time(inode); |
| 1367 | } |
| 1368 | } else if (info->notify_owner != NULL) { |
| 1369 | ret = -EBUSY; |
| 1370 | } else { |
| 1371 | switch (notification->sigev_notify) { |
| 1372 | case SIGEV_NONE: |
| 1373 | info->notify.sigev_notify = SIGEV_NONE; |
| 1374 | break; |
| 1375 | case SIGEV_THREAD: |
| 1376 | info->notify_sock = sock; |
| 1377 | info->notify_cookie = nc; |
| 1378 | sock = NULL; |
| 1379 | nc = NULL; |
| 1380 | info->notify.sigev_notify = SIGEV_THREAD; |
| 1381 | break; |
| 1382 | case SIGEV_SIGNAL: |
| 1383 | info->notify.sigev_signo = notification->sigev_signo; |
| 1384 | info->notify.sigev_value = notification->sigev_value; |
| 1385 | info->notify.sigev_notify = SIGEV_SIGNAL; |
| 1386 | break; |
| 1387 | } |
| 1388 | |
| 1389 | info->notify_owner = get_pid(task_tgid(current)); |
| 1390 | info->notify_user_ns = get_user_ns(current_user_ns()); |
| 1391 | inode->i_atime = inode->i_ctime = current_time(inode); |
| 1392 | } |
| 1393 | spin_unlock(&info->lock); |
| 1394 | out_fput: |
| 1395 | fdput(f); |
| 1396 | out: |
| 1397 | if (sock) |
| 1398 | netlink_detachskb(sock, nc); |
| 1399 | else |
| 1400 | free_skb: |
| 1401 | dev_kfree_skb(nc); |
| 1402 | |
| 1403 | return ret; |
| 1404 | } |
| 1405 | |
| 1406 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
| 1407 | const struct sigevent __user *, u_notification) |
| 1408 | { |
| 1409 | struct sigevent n, *p = NULL; |
| 1410 | if (u_notification) { |
| 1411 | if (copy_from_user(&n, u_notification, sizeof(struct sigevent))) |
| 1412 | return -EFAULT; |
| 1413 | p = &n; |
| 1414 | } |
| 1415 | return do_mq_notify(mqdes, p); |
| 1416 | } |
| 1417 | |
| 1418 | static int do_mq_getsetattr(int mqdes, struct mq_attr *new, struct mq_attr *old) |
| 1419 | { |
| 1420 | struct fd f; |
| 1421 | struct inode *inode; |
| 1422 | struct mqueue_inode_info *info; |
| 1423 | |
| 1424 | if (new && (new->mq_flags & (~O_NONBLOCK))) |
| 1425 | return -EINVAL; |
| 1426 | |
| 1427 | f = fdget(mqdes); |
| 1428 | if (!f.file) |
| 1429 | return -EBADF; |
| 1430 | |
| 1431 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
| 1432 | fdput(f); |
| 1433 | return -EBADF; |
| 1434 | } |
| 1435 | |
| 1436 | inode = file_inode(f.file); |
| 1437 | info = MQUEUE_I(inode); |
| 1438 | |
| 1439 | spin_lock(&info->lock); |
| 1440 | |
| 1441 | if (old) { |
| 1442 | *old = info->attr; |
| 1443 | old->mq_flags = f.file->f_flags & O_NONBLOCK; |
| 1444 | } |
| 1445 | if (new) { |
| 1446 | audit_mq_getsetattr(mqdes, new); |
| 1447 | spin_lock(&f.file->f_lock); |
| 1448 | if (new->mq_flags & O_NONBLOCK) |
| 1449 | f.file->f_flags |= O_NONBLOCK; |
| 1450 | else |
| 1451 | f.file->f_flags &= ~O_NONBLOCK; |
| 1452 | spin_unlock(&f.file->f_lock); |
| 1453 | |
| 1454 | inode->i_atime = inode->i_ctime = current_time(inode); |
| 1455 | } |
| 1456 | |
| 1457 | spin_unlock(&info->lock); |
| 1458 | fdput(f); |
| 1459 | return 0; |
| 1460 | } |
| 1461 | |
| 1462 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, |
| 1463 | const struct mq_attr __user *, u_mqstat, |
| 1464 | struct mq_attr __user *, u_omqstat) |
| 1465 | { |
| 1466 | int ret; |
| 1467 | struct mq_attr mqstat, omqstat; |
| 1468 | struct mq_attr *new = NULL, *old = NULL; |
| 1469 | |
| 1470 | if (u_mqstat) { |
| 1471 | new = &mqstat; |
| 1472 | if (copy_from_user(new, u_mqstat, sizeof(struct mq_attr))) |
| 1473 | return -EFAULT; |
| 1474 | } |
| 1475 | if (u_omqstat) |
| 1476 | old = &omqstat; |
| 1477 | |
| 1478 | ret = do_mq_getsetattr(mqdes, new, old); |
| 1479 | if (ret || !old) |
| 1480 | return ret; |
| 1481 | |
| 1482 | if (copy_to_user(u_omqstat, old, sizeof(struct mq_attr))) |
| 1483 | return -EFAULT; |
| 1484 | return 0; |
| 1485 | } |
| 1486 | |
| 1487 | #ifdef CONFIG_COMPAT |
| 1488 | |
| 1489 | struct compat_mq_attr { |
| 1490 | compat_long_t mq_flags; /* message queue flags */ |
| 1491 | compat_long_t mq_maxmsg; /* maximum number of messages */ |
| 1492 | compat_long_t mq_msgsize; /* maximum message size */ |
| 1493 | compat_long_t mq_curmsgs; /* number of messages currently queued */ |
| 1494 | compat_long_t __reserved[4]; /* ignored for input, zeroed for output */ |
| 1495 | }; |
| 1496 | |
| 1497 | static inline int get_compat_mq_attr(struct mq_attr *attr, |
| 1498 | const struct compat_mq_attr __user *uattr) |
| 1499 | { |
| 1500 | struct compat_mq_attr v; |
| 1501 | |
| 1502 | if (copy_from_user(&v, uattr, sizeof(*uattr))) |
| 1503 | return -EFAULT; |
| 1504 | |
| 1505 | memset(attr, 0, sizeof(*attr)); |
| 1506 | attr->mq_flags = v.mq_flags; |
| 1507 | attr->mq_maxmsg = v.mq_maxmsg; |
| 1508 | attr->mq_msgsize = v.mq_msgsize; |
| 1509 | attr->mq_curmsgs = v.mq_curmsgs; |
| 1510 | return 0; |
| 1511 | } |
| 1512 | |
| 1513 | static inline int put_compat_mq_attr(const struct mq_attr *attr, |
| 1514 | struct compat_mq_attr __user *uattr) |
| 1515 | { |
| 1516 | struct compat_mq_attr v; |
| 1517 | |
| 1518 | memset(&v, 0, sizeof(v)); |
| 1519 | v.mq_flags = attr->mq_flags; |
| 1520 | v.mq_maxmsg = attr->mq_maxmsg; |
| 1521 | v.mq_msgsize = attr->mq_msgsize; |
| 1522 | v.mq_curmsgs = attr->mq_curmsgs; |
| 1523 | if (copy_to_user(uattr, &v, sizeof(*uattr))) |
| 1524 | return -EFAULT; |
| 1525 | return 0; |
| 1526 | } |
| 1527 | |
| 1528 | COMPAT_SYSCALL_DEFINE4(mq_open, const char __user *, u_name, |
| 1529 | int, oflag, compat_mode_t, mode, |
| 1530 | struct compat_mq_attr __user *, u_attr) |
| 1531 | { |
| 1532 | struct mq_attr attr, *p = NULL; |
| 1533 | if (u_attr && oflag & O_CREAT) { |
| 1534 | p = &attr; |
| 1535 | if (get_compat_mq_attr(&attr, u_attr)) |
| 1536 | return -EFAULT; |
| 1537 | } |
| 1538 | return do_mq_open(u_name, oflag, mode, p); |
| 1539 | } |
| 1540 | |
| 1541 | COMPAT_SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
| 1542 | const struct compat_sigevent __user *, u_notification) |
| 1543 | { |
| 1544 | struct sigevent n, *p = NULL; |
| 1545 | if (u_notification) { |
| 1546 | if (get_compat_sigevent(&n, u_notification)) |
| 1547 | return -EFAULT; |
| 1548 | if (n.sigev_notify == SIGEV_THREAD) |
| 1549 | n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int); |
| 1550 | p = &n; |
| 1551 | } |
| 1552 | return do_mq_notify(mqdes, p); |
| 1553 | } |
| 1554 | |
| 1555 | COMPAT_SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, |
| 1556 | const struct compat_mq_attr __user *, u_mqstat, |
| 1557 | struct compat_mq_attr __user *, u_omqstat) |
| 1558 | { |
| 1559 | int ret; |
| 1560 | struct mq_attr mqstat, omqstat; |
| 1561 | struct mq_attr *new = NULL, *old = NULL; |
| 1562 | |
| 1563 | if (u_mqstat) { |
| 1564 | new = &mqstat; |
| 1565 | if (get_compat_mq_attr(new, u_mqstat)) |
| 1566 | return -EFAULT; |
| 1567 | } |
| 1568 | if (u_omqstat) |
| 1569 | old = &omqstat; |
| 1570 | |
| 1571 | ret = do_mq_getsetattr(mqdes, new, old); |
| 1572 | if (ret || !old) |
| 1573 | return ret; |
| 1574 | |
| 1575 | if (put_compat_mq_attr(old, u_omqstat)) |
| 1576 | return -EFAULT; |
| 1577 | return 0; |
| 1578 | } |
| 1579 | #endif |
| 1580 | |
| 1581 | #ifdef CONFIG_COMPAT_32BIT_TIME |
| 1582 | static int compat_prepare_timeout(const struct old_timespec32 __user *p, |
| 1583 | struct timespec64 *ts) |
| 1584 | { |
| 1585 | if (get_old_timespec32(ts, p)) |
| 1586 | return -EFAULT; |
| 1587 | if (!timespec64_valid(ts)) |
| 1588 | return -EINVAL; |
| 1589 | return 0; |
| 1590 | } |
| 1591 | |
| 1592 | SYSCALL_DEFINE5(mq_timedsend_time32, mqd_t, mqdes, |
| 1593 | const char __user *, u_msg_ptr, |
| 1594 | unsigned int, msg_len, unsigned int, msg_prio, |
| 1595 | const struct old_timespec32 __user *, u_abs_timeout) |
| 1596 | { |
| 1597 | struct timespec64 ts, *p = NULL; |
| 1598 | if (u_abs_timeout) { |
| 1599 | int res = compat_prepare_timeout(u_abs_timeout, &ts); |
| 1600 | if (res) |
| 1601 | return res; |
| 1602 | p = &ts; |
| 1603 | } |
| 1604 | return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p); |
| 1605 | } |
| 1606 | |
| 1607 | SYSCALL_DEFINE5(mq_timedreceive_time32, mqd_t, mqdes, |
| 1608 | char __user *, u_msg_ptr, |
| 1609 | unsigned int, msg_len, unsigned int __user *, u_msg_prio, |
| 1610 | const struct old_timespec32 __user *, u_abs_timeout) |
| 1611 | { |
| 1612 | struct timespec64 ts, *p = NULL; |
| 1613 | if (u_abs_timeout) { |
| 1614 | int res = compat_prepare_timeout(u_abs_timeout, &ts); |
| 1615 | if (res) |
| 1616 | return res; |
| 1617 | p = &ts; |
| 1618 | } |
| 1619 | return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p); |
| 1620 | } |
| 1621 | #endif |
| 1622 | |
| 1623 | static const struct inode_operations mqueue_dir_inode_operations = { |
| 1624 | .lookup = simple_lookup, |
| 1625 | .create = mqueue_create, |
| 1626 | .unlink = mqueue_unlink, |
| 1627 | }; |
| 1628 | |
| 1629 | static const struct file_operations mqueue_file_operations = { |
| 1630 | .flush = mqueue_flush_file, |
| 1631 | .poll = mqueue_poll_file, |
| 1632 | .read = mqueue_read_file, |
| 1633 | .llseek = default_llseek, |
| 1634 | }; |
| 1635 | |
| 1636 | static const struct super_operations mqueue_super_ops = { |
| 1637 | .alloc_inode = mqueue_alloc_inode, |
| 1638 | .free_inode = mqueue_free_inode, |
| 1639 | .evict_inode = mqueue_evict_inode, |
| 1640 | .statfs = simple_statfs, |
| 1641 | }; |
| 1642 | |
| 1643 | static const struct fs_context_operations mqueue_fs_context_ops = { |
| 1644 | .free = mqueue_fs_context_free, |
| 1645 | .get_tree = mqueue_get_tree, |
| 1646 | }; |
| 1647 | |
| 1648 | static struct file_system_type mqueue_fs_type = { |
| 1649 | .name = "mqueue", |
| 1650 | .init_fs_context = mqueue_init_fs_context, |
| 1651 | .kill_sb = kill_litter_super, |
| 1652 | .fs_flags = FS_USERNS_MOUNT, |
| 1653 | }; |
| 1654 | |
| 1655 | int mq_init_ns(struct ipc_namespace *ns) |
| 1656 | { |
| 1657 | struct vfsmount *m; |
| 1658 | |
| 1659 | ns->mq_queues_count = 0; |
| 1660 | ns->mq_queues_max = DFLT_QUEUESMAX; |
| 1661 | ns->mq_msg_max = DFLT_MSGMAX; |
| 1662 | ns->mq_msgsize_max = DFLT_MSGSIZEMAX; |
| 1663 | ns->mq_msg_default = DFLT_MSG; |
| 1664 | ns->mq_msgsize_default = DFLT_MSGSIZE; |
| 1665 | |
| 1666 | m = mq_create_mount(ns); |
| 1667 | if (IS_ERR(m)) |
| 1668 | return PTR_ERR(m); |
| 1669 | ns->mq_mnt = m; |
| 1670 | return 0; |
| 1671 | } |
| 1672 | |
| 1673 | void mq_clear_sbinfo(struct ipc_namespace *ns) |
| 1674 | { |
| 1675 | ns->mq_mnt->mnt_sb->s_fs_info = NULL; |
| 1676 | } |
| 1677 | |
| 1678 | void mq_put_mnt(struct ipc_namespace *ns) |
| 1679 | { |
| 1680 | kern_unmount(ns->mq_mnt); |
| 1681 | } |
| 1682 | |
| 1683 | static int __init init_mqueue_fs(void) |
| 1684 | { |
| 1685 | int error; |
| 1686 | |
| 1687 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", |
| 1688 | sizeof(struct mqueue_inode_info), 0, |
| 1689 | SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, init_once); |
| 1690 | if (mqueue_inode_cachep == NULL) |
| 1691 | return -ENOMEM; |
| 1692 | |
| 1693 | /* ignore failures - they are not fatal */ |
| 1694 | mq_sysctl_table = mq_register_sysctl_table(); |
| 1695 | |
| 1696 | error = register_filesystem(&mqueue_fs_type); |
| 1697 | if (error) |
| 1698 | goto out_sysctl; |
| 1699 | |
| 1700 | spin_lock_init(&mq_lock); |
| 1701 | |
| 1702 | error = mq_init_ns(&init_ipc_ns); |
| 1703 | if (error) |
| 1704 | goto out_filesystem; |
| 1705 | |
| 1706 | return 0; |
| 1707 | |
| 1708 | out_filesystem: |
| 1709 | unregister_filesystem(&mqueue_fs_type); |
| 1710 | out_sysctl: |
| 1711 | if (mq_sysctl_table) |
| 1712 | unregister_sysctl_table(mq_sysctl_table); |
| 1713 | kmem_cache_destroy(mqueue_inode_cachep); |
| 1714 | return error; |
| 1715 | } |
| 1716 | |
| 1717 | device_initcall(init_mqueue_fs); |