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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 posix_msg_tree_node *node_cache; |
73 | struct mq_attr attr; |
74 | |
75 | struct sigevent notify; |
76 | struct pid* notify_owner; |
77 | struct user_namespace *notify_user_ns; |
78 | struct user_struct *user; /* user who created, for accounting */ |
79 | struct sock *notify_sock; |
80 | struct sk_buff *notify_cookie; |
81 | |
82 | /* for tasks waiting for free space and messages, respectively */ |
83 | struct ext_wait_queue e_wait_q[2]; |
84 | |
85 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ |
86 | }; |
87 | |
88 | static const struct inode_operations mqueue_dir_inode_operations; |
89 | static const struct file_operations mqueue_file_operations; |
90 | static const struct super_operations mqueue_super_ops; |
91 | static void remove_notification(struct mqueue_inode_info *info); |
92 | |
93 | static struct kmem_cache *mqueue_inode_cachep; |
94 | |
95 | static struct ctl_table_header * mq_sysctl_table; |
96 | |
97 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) |
98 | { |
99 | return container_of(inode, struct mqueue_inode_info, vfs_inode); |
100 | } |
101 | |
102 | /* |
103 | * This routine should be called with the mq_lock held. |
104 | */ |
105 | static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) |
106 | { |
107 | return get_ipc_ns(inode->i_sb->s_fs_info); |
108 | } |
109 | |
110 | static struct ipc_namespace *get_ns_from_inode(struct inode *inode) |
111 | { |
112 | struct ipc_namespace *ns; |
113 | |
114 | spin_lock(&mq_lock); |
115 | ns = __get_ns_from_inode(inode); |
116 | spin_unlock(&mq_lock); |
117 | return ns; |
118 | } |
119 | |
120 | /* Auxiliary functions to manipulate messages' list */ |
121 | static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info) |
122 | { |
123 | struct rb_node **p, *parent = NULL; |
124 | struct posix_msg_tree_node *leaf; |
125 | |
126 | p = &info->msg_tree.rb_node; |
127 | while (*p) { |
128 | parent = *p; |
129 | leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node); |
130 | |
131 | if (likely(leaf->priority == msg->m_type)) |
132 | goto insert_msg; |
133 | else if (msg->m_type < leaf->priority) |
134 | p = &(*p)->rb_left; |
135 | else |
136 | p = &(*p)->rb_right; |
137 | } |
138 | if (info->node_cache) { |
139 | leaf = info->node_cache; |
140 | info->node_cache = NULL; |
141 | } else { |
142 | leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC); |
143 | if (!leaf) |
144 | return -ENOMEM; |
145 | INIT_LIST_HEAD(&leaf->msg_list); |
146 | info->qsize += sizeof(*leaf); |
147 | } |
148 | leaf->priority = msg->m_type; |
149 | rb_link_node(&leaf->rb_node, parent, p); |
150 | rb_insert_color(&leaf->rb_node, &info->msg_tree); |
151 | insert_msg: |
152 | info->attr.mq_curmsgs++; |
153 | info->qsize += msg->m_ts; |
154 | list_add_tail(&msg->m_list, &leaf->msg_list); |
155 | return 0; |
156 | } |
157 | |
158 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) |
159 | { |
160 | struct rb_node **p, *parent = NULL; |
161 | struct posix_msg_tree_node *leaf; |
162 | struct msg_msg *msg; |
163 | |
164 | try_again: |
165 | p = &info->msg_tree.rb_node; |
166 | while (*p) { |
167 | parent = *p; |
168 | /* |
169 | * During insert, low priorities go to the left and high to the |
170 | * right. On receive, we want the highest priorities first, so |
171 | * walk all the way to the right. |
172 | */ |
173 | p = &(*p)->rb_right; |
174 | } |
175 | if (!parent) { |
176 | if (info->attr.mq_curmsgs) { |
177 | pr_warn_once("Inconsistency in POSIX message queue, " |
178 | "no tree element, but supposedly messages " |
179 | "should exist!\n"); |
180 | info->attr.mq_curmsgs = 0; |
181 | } |
182 | return NULL; |
183 | } |
184 | leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node); |
185 | if (unlikely(list_empty(&leaf->msg_list))) { |
186 | pr_warn_once("Inconsistency in POSIX message queue, " |
187 | "empty leaf node but we haven't implemented " |
188 | "lazy leaf delete!\n"); |
189 | rb_erase(&leaf->rb_node, &info->msg_tree); |
190 | if (info->node_cache) { |
191 | info->qsize -= sizeof(*leaf); |
192 | kfree(leaf); |
193 | } else { |
194 | info->node_cache = leaf; |
195 | } |
196 | goto try_again; |
197 | } else { |
198 | msg = list_first_entry(&leaf->msg_list, |
199 | struct msg_msg, m_list); |
200 | list_del(&msg->m_list); |
201 | if (list_empty(&leaf->msg_list)) { |
202 | rb_erase(&leaf->rb_node, &info->msg_tree); |
203 | if (info->node_cache) { |
204 | info->qsize -= sizeof(*leaf); |
205 | kfree(leaf); |
206 | } else { |
207 | info->node_cache = leaf; |
208 | } |
209 | } |
210 | } |
211 | info->attr.mq_curmsgs--; |
212 | info->qsize -= msg->m_ts; |
213 | return msg; |
214 | } |
215 | |
216 | static struct inode *mqueue_get_inode(struct super_block *sb, |
217 | struct ipc_namespace *ipc_ns, umode_t mode, |
218 | struct mq_attr *attr) |
219 | { |
220 | struct user_struct *u = current_user(); |
221 | struct inode *inode; |
222 | int ret = -ENOMEM; |
223 | |
224 | inode = new_inode(sb); |
225 | if (!inode) |
226 | goto err; |
227 | |
228 | inode->i_ino = get_next_ino(); |
229 | inode->i_mode = mode; |
230 | inode->i_uid = current_fsuid(); |
231 | inode->i_gid = current_fsgid(); |
232 | inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME; |
233 | |
234 | if (S_ISREG(mode)) { |
235 | struct mqueue_inode_info *info; |
236 | unsigned long mq_bytes, mq_treesize; |
237 | |
238 | inode->i_fop = &mqueue_file_operations; |
239 | inode->i_size = FILENT_SIZE; |
240 | /* mqueue specific info */ |
241 | info = MQUEUE_I(inode); |
242 | spin_lock_init(&info->lock); |
243 | init_waitqueue_head(&info->wait_q); |
244 | INIT_LIST_HEAD(&info->e_wait_q[0].list); |
245 | INIT_LIST_HEAD(&info->e_wait_q[1].list); |
246 | info->notify_owner = NULL; |
247 | info->notify_user_ns = NULL; |
248 | info->qsize = 0; |
249 | info->user = NULL; /* set when all is ok */ |
250 | info->msg_tree = RB_ROOT; |
251 | info->node_cache = NULL; |
252 | memset(&info->attr, 0, sizeof(info->attr)); |
253 | info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max, |
254 | ipc_ns->mq_msg_default); |
255 | info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max, |
256 | ipc_ns->mq_msgsize_default); |
257 | if (attr) { |
258 | info->attr.mq_maxmsg = attr->mq_maxmsg; |
259 | info->attr.mq_msgsize = attr->mq_msgsize; |
260 | } |
261 | /* |
262 | * We used to allocate a static array of pointers and account |
263 | * the size of that array as well as one msg_msg struct per |
264 | * possible message into the queue size. That's no longer |
265 | * accurate as the queue is now an rbtree and will grow and |
266 | * shrink depending on usage patterns. We can, however, still |
267 | * account one msg_msg struct per message, but the nodes are |
268 | * allocated depending on priority usage, and most programs |
269 | * only use one, or a handful, of priorities. However, since |
270 | * this is pinned memory, we need to assume worst case, so |
271 | * that means the min(mq_maxmsg, max_priorities) * struct |
272 | * posix_msg_tree_node. |
273 | */ |
274 | mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) + |
275 | min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) * |
276 | sizeof(struct posix_msg_tree_node); |
277 | |
278 | mq_bytes = mq_treesize + (info->attr.mq_maxmsg * |
279 | info->attr.mq_msgsize); |
280 | |
281 | spin_lock(&mq_lock); |
282 | if (u->mq_bytes + mq_bytes < u->mq_bytes || |
283 | u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) { |
284 | spin_unlock(&mq_lock); |
285 | /* mqueue_evict_inode() releases info->messages */ |
286 | ret = -EMFILE; |
287 | goto out_inode; |
288 | } |
289 | u->mq_bytes += mq_bytes; |
290 | spin_unlock(&mq_lock); |
291 | |
292 | /* all is ok */ |
293 | info->user = get_uid(u); |
294 | } else if (S_ISDIR(mode)) { |
295 | inc_nlink(inode); |
296 | /* Some things misbehave if size == 0 on a directory */ |
297 | inode->i_size = 2 * DIRENT_SIZE; |
298 | inode->i_op = &mqueue_dir_inode_operations; |
299 | inode->i_fop = &simple_dir_operations; |
300 | } |
301 | |
302 | return inode; |
303 | out_inode: |
304 | iput(inode); |
305 | err: |
306 | return ERR_PTR(ret); |
307 | } |
308 | |
309 | static int mqueue_fill_super(struct super_block *sb, void *data, int silent) |
310 | { |
311 | struct inode *inode; |
312 | struct ipc_namespace *ns = data; |
313 | |
314 | sb->s_blocksize = PAGE_CACHE_SIZE; |
315 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
316 | sb->s_magic = MQUEUE_MAGIC; |
317 | sb->s_op = &mqueue_super_ops; |
318 | |
319 | inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); |
320 | if (IS_ERR(inode)) |
321 | return PTR_ERR(inode); |
322 | |
323 | sb->s_root = d_make_root(inode); |
324 | if (!sb->s_root) |
325 | return -ENOMEM; |
326 | return 0; |
327 | } |
328 | |
329 | static struct dentry *mqueue_mount(struct file_system_type *fs_type, |
330 | int flags, const char *dev_name, |
331 | void *data) |
332 | { |
333 | if (!(flags & MS_KERNMOUNT)) { |
334 | struct ipc_namespace *ns = current->nsproxy->ipc_ns; |
335 | /* Don't allow mounting unless the caller has CAP_SYS_ADMIN |
336 | * over the ipc namespace. |
337 | */ |
338 | if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN)) |
339 | return ERR_PTR(-EPERM); |
340 | |
341 | data = ns; |
342 | } |
343 | return mount_ns(fs_type, flags, data, mqueue_fill_super); |
344 | } |
345 | |
346 | static void init_once(void *foo) |
347 | { |
348 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; |
349 | |
350 | inode_init_once(&p->vfs_inode); |
351 | } |
352 | |
353 | static struct inode *mqueue_alloc_inode(struct super_block *sb) |
354 | { |
355 | struct mqueue_inode_info *ei; |
356 | |
357 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); |
358 | if (!ei) |
359 | return NULL; |
360 | return &ei->vfs_inode; |
361 | } |
362 | |
363 | static void mqueue_i_callback(struct rcu_head *head) |
364 | { |
365 | struct inode *inode = container_of(head, struct inode, i_rcu); |
366 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); |
367 | } |
368 | |
369 | static void mqueue_destroy_inode(struct inode *inode) |
370 | { |
371 | call_rcu(&inode->i_rcu, mqueue_i_callback); |
372 | } |
373 | |
374 | static void mqueue_evict_inode(struct inode *inode) |
375 | { |
376 | struct mqueue_inode_info *info; |
377 | struct user_struct *user; |
378 | unsigned long mq_bytes, mq_treesize; |
379 | struct ipc_namespace *ipc_ns; |
380 | struct msg_msg *msg; |
381 | |
382 | clear_inode(inode); |
383 | |
384 | if (S_ISDIR(inode->i_mode)) |
385 | return; |
386 | |
387 | ipc_ns = get_ns_from_inode(inode); |
388 | info = MQUEUE_I(inode); |
389 | spin_lock(&info->lock); |
390 | while ((msg = msg_get(info)) != NULL) |
391 | free_msg(msg); |
392 | kfree(info->node_cache); |
393 | spin_unlock(&info->lock); |
394 | |
395 | /* Total amount of bytes accounted for the mqueue */ |
396 | mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) + |
397 | min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) * |
398 | sizeof(struct posix_msg_tree_node); |
399 | |
400 | mq_bytes = mq_treesize + (info->attr.mq_maxmsg * |
401 | info->attr.mq_msgsize); |
402 | |
403 | user = info->user; |
404 | if (user) { |
405 | spin_lock(&mq_lock); |
406 | user->mq_bytes -= mq_bytes; |
407 | /* |
408 | * get_ns_from_inode() ensures that the |
409 | * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns |
410 | * to which we now hold a reference, or it is NULL. |
411 | * We can't put it here under mq_lock, though. |
412 | */ |
413 | if (ipc_ns) |
414 | ipc_ns->mq_queues_count--; |
415 | spin_unlock(&mq_lock); |
416 | free_uid(user); |
417 | } |
418 | if (ipc_ns) |
419 | put_ipc_ns(ipc_ns); |
420 | } |
421 | |
422 | static int mqueue_create(struct inode *dir, struct dentry *dentry, |
423 | umode_t mode, bool excl) |
424 | { |
425 | struct inode *inode; |
426 | struct mq_attr *attr = dentry->d_fsdata; |
427 | int error; |
428 | struct ipc_namespace *ipc_ns; |
429 | |
430 | spin_lock(&mq_lock); |
431 | ipc_ns = __get_ns_from_inode(dir); |
432 | if (!ipc_ns) { |
433 | error = -EACCES; |
434 | goto out_unlock; |
435 | } |
436 | if (ipc_ns->mq_queues_count >= HARD_QUEUESMAX || |
437 | (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && |
438 | !capable(CAP_SYS_RESOURCE))) { |
439 | error = -ENOSPC; |
440 | goto out_unlock; |
441 | } |
442 | ipc_ns->mq_queues_count++; |
443 | spin_unlock(&mq_lock); |
444 | |
445 | inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); |
446 | if (IS_ERR(inode)) { |
447 | error = PTR_ERR(inode); |
448 | spin_lock(&mq_lock); |
449 | ipc_ns->mq_queues_count--; |
450 | goto out_unlock; |
451 | } |
452 | |
453 | put_ipc_ns(ipc_ns); |
454 | dir->i_size += DIRENT_SIZE; |
455 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; |
456 | |
457 | d_instantiate(dentry, inode); |
458 | dget(dentry); |
459 | return 0; |
460 | out_unlock: |
461 | spin_unlock(&mq_lock); |
462 | if (ipc_ns) |
463 | put_ipc_ns(ipc_ns); |
464 | return error; |
465 | } |
466 | |
467 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) |
468 | { |
469 | struct inode *inode = dentry->d_inode; |
470 | |
471 | dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME; |
472 | dir->i_size -= DIRENT_SIZE; |
473 | drop_nlink(inode); |
474 | dput(dentry); |
475 | return 0; |
476 | } |
477 | |
478 | /* |
479 | * This is routine for system read from queue file. |
480 | * To avoid mess with doing here some sort of mq_receive we allow |
481 | * to read only queue size & notification info (the only values |
482 | * that are interesting from user point of view and aren't accessible |
483 | * through std routines) |
484 | */ |
485 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, |
486 | size_t count, loff_t *off) |
487 | { |
488 | struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp)); |
489 | char buffer[FILENT_SIZE]; |
490 | ssize_t ret; |
491 | |
492 | spin_lock(&info->lock); |
493 | snprintf(buffer, sizeof(buffer), |
494 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", |
495 | info->qsize, |
496 | info->notify_owner ? info->notify.sigev_notify : 0, |
497 | (info->notify_owner && |
498 | info->notify.sigev_notify == SIGEV_SIGNAL) ? |
499 | info->notify.sigev_signo : 0, |
500 | pid_vnr(info->notify_owner)); |
501 | spin_unlock(&info->lock); |
502 | buffer[sizeof(buffer)-1] = '\0'; |
503 | |
504 | ret = simple_read_from_buffer(u_data, count, off, buffer, |
505 | strlen(buffer)); |
506 | if (ret <= 0) |
507 | return ret; |
508 | |
509 | file_inode(filp)->i_atime = file_inode(filp)->i_ctime = CURRENT_TIME; |
510 | return ret; |
511 | } |
512 | |
513 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
514 | { |
515 | struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp)); |
516 | |
517 | spin_lock(&info->lock); |
518 | if (task_tgid(current) == info->notify_owner) |
519 | remove_notification(info); |
520 | |
521 | spin_unlock(&info->lock); |
522 | return 0; |
523 | } |
524 | |
525 | static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) |
526 | { |
527 | struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp)); |
528 | int retval = 0; |
529 | |
530 | poll_wait(filp, &info->wait_q, poll_tab); |
531 | |
532 | spin_lock(&info->lock); |
533 | if (info->attr.mq_curmsgs) |
534 | retval = POLLIN | POLLRDNORM; |
535 | |
536 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) |
537 | retval |= POLLOUT | POLLWRNORM; |
538 | spin_unlock(&info->lock); |
539 | |
540 | return retval; |
541 | } |
542 | |
543 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ |
544 | static void wq_add(struct mqueue_inode_info *info, int sr, |
545 | struct ext_wait_queue *ewp) |
546 | { |
547 | struct ext_wait_queue *walk; |
548 | |
549 | ewp->task = current; |
550 | |
551 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { |
552 | if (walk->task->static_prio <= current->static_prio) { |
553 | list_add_tail(&ewp->list, &walk->list); |
554 | return; |
555 | } |
556 | } |
557 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); |
558 | } |
559 | |
560 | /* |
561 | * Puts current task to sleep. Caller must hold queue lock. After return |
562 | * lock isn't held. |
563 | * sr: SEND or RECV |
564 | */ |
565 | static int wq_sleep(struct mqueue_inode_info *info, int sr, |
566 | ktime_t *timeout, struct ext_wait_queue *ewp) |
567 | { |
568 | int retval; |
569 | signed long time; |
570 | |
571 | wq_add(info, sr, ewp); |
572 | |
573 | for (;;) { |
574 | set_current_state(TASK_INTERRUPTIBLE); |
575 | |
576 | spin_unlock(&info->lock); |
577 | time = schedule_hrtimeout_range_clock(timeout, 0, |
578 | HRTIMER_MODE_ABS, CLOCK_REALTIME); |
579 | |
580 | while (ewp->state == STATE_PENDING) |
581 | cpu_relax(); |
582 | |
583 | if (ewp->state == STATE_READY) { |
584 | retval = 0; |
585 | goto out; |
586 | } |
587 | spin_lock(&info->lock); |
588 | if (ewp->state == STATE_READY) { |
589 | retval = 0; |
590 | goto out_unlock; |
591 | } |
592 | if (signal_pending(current)) { |
593 | retval = -ERESTARTSYS; |
594 | break; |
595 | } |
596 | if (time == 0) { |
597 | retval = -ETIMEDOUT; |
598 | break; |
599 | } |
600 | } |
601 | list_del(&ewp->list); |
602 | out_unlock: |
603 | spin_unlock(&info->lock); |
604 | out: |
605 | return retval; |
606 | } |
607 | |
608 | /* |
609 | * Returns waiting task that should be serviced first or NULL if none exists |
610 | */ |
611 | static struct ext_wait_queue *wq_get_first_waiter( |
612 | struct mqueue_inode_info *info, int sr) |
613 | { |
614 | struct list_head *ptr; |
615 | |
616 | ptr = info->e_wait_q[sr].list.prev; |
617 | if (ptr == &info->e_wait_q[sr].list) |
618 | return NULL; |
619 | return list_entry(ptr, struct ext_wait_queue, list); |
620 | } |
621 | |
622 | |
623 | static inline void set_cookie(struct sk_buff *skb, char code) |
624 | { |
625 | ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code; |
626 | } |
627 | |
628 | /* |
629 | * The next function is only to split too long sys_mq_timedsend |
630 | */ |
631 | static void __do_notify(struct mqueue_inode_info *info) |
632 | { |
633 | /* notification |
634 | * invoked when there is registered process and there isn't process |
635 | * waiting synchronously for message AND state of queue changed from |
636 | * empty to not empty. Here we are sure that no one is waiting |
637 | * synchronously. */ |
638 | if (info->notify_owner && |
639 | info->attr.mq_curmsgs == 1) { |
640 | struct siginfo sig_i; |
641 | switch (info->notify.sigev_notify) { |
642 | case SIGEV_NONE: |
643 | break; |
644 | case SIGEV_SIGNAL: |
645 | /* sends signal */ |
646 | |
647 | sig_i.si_signo = info->notify.sigev_signo; |
648 | sig_i.si_errno = 0; |
649 | sig_i.si_code = SI_MESGQ; |
650 | sig_i.si_value = info->notify.sigev_value; |
651 | /* map current pid/uid into info->owner's namespaces */ |
652 | rcu_read_lock(); |
653 | sig_i.si_pid = task_tgid_nr_ns(current, |
654 | ns_of_pid(info->notify_owner)); |
655 | sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid()); |
656 | rcu_read_unlock(); |
657 | |
658 | kill_pid_info(info->notify.sigev_signo, |
659 | &sig_i, info->notify_owner); |
660 | break; |
661 | case SIGEV_THREAD: |
662 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); |
663 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
664 | break; |
665 | } |
666 | /* after notification unregisters process */ |
667 | put_pid(info->notify_owner); |
668 | put_user_ns(info->notify_user_ns); |
669 | info->notify_owner = NULL; |
670 | info->notify_user_ns = NULL; |
671 | } |
672 | wake_up(&info->wait_q); |
673 | } |
674 | |
675 | static int prepare_timeout(const struct timespec __user *u_abs_timeout, |
676 | ktime_t *expires, struct timespec *ts) |
677 | { |
678 | if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec))) |
679 | return -EFAULT; |
680 | if (!timespec_valid(ts)) |
681 | return -EINVAL; |
682 | |
683 | *expires = timespec_to_ktime(*ts); |
684 | return 0; |
685 | } |
686 | |
687 | static void remove_notification(struct mqueue_inode_info *info) |
688 | { |
689 | if (info->notify_owner != NULL && |
690 | info->notify.sigev_notify == SIGEV_THREAD) { |
691 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); |
692 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
693 | } |
694 | put_pid(info->notify_owner); |
695 | put_user_ns(info->notify_user_ns); |
696 | info->notify_owner = NULL; |
697 | info->notify_user_ns = NULL; |
698 | } |
699 | |
700 | static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr) |
701 | { |
702 | int mq_treesize; |
703 | unsigned long total_size; |
704 | |
705 | if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) |
706 | return -EINVAL; |
707 | if (capable(CAP_SYS_RESOURCE)) { |
708 | if (attr->mq_maxmsg > HARD_MSGMAX || |
709 | attr->mq_msgsize > HARD_MSGSIZEMAX) |
710 | return -EINVAL; |
711 | } else { |
712 | if (attr->mq_maxmsg > ipc_ns->mq_msg_max || |
713 | attr->mq_msgsize > ipc_ns->mq_msgsize_max) |
714 | return -EINVAL; |
715 | } |
716 | /* check for overflow */ |
717 | if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg) |
718 | return -EOVERFLOW; |
719 | mq_treesize = attr->mq_maxmsg * sizeof(struct msg_msg) + |
720 | min_t(unsigned int, attr->mq_maxmsg, MQ_PRIO_MAX) * |
721 | sizeof(struct posix_msg_tree_node); |
722 | total_size = attr->mq_maxmsg * attr->mq_msgsize; |
723 | if (total_size + mq_treesize < total_size) |
724 | return -EOVERFLOW; |
725 | return 0; |
726 | } |
727 | |
728 | /* |
729 | * Invoked when creating a new queue via sys_mq_open |
730 | */ |
731 | static struct file *do_create(struct ipc_namespace *ipc_ns, struct inode *dir, |
732 | struct path *path, int oflag, umode_t mode, |
733 | struct mq_attr *attr) |
734 | { |
735 | const struct cred *cred = current_cred(); |
736 | int ret; |
737 | |
738 | if (attr) { |
739 | ret = mq_attr_ok(ipc_ns, attr); |
740 | if (ret) |
741 | return ERR_PTR(ret); |
742 | /* store for use during create */ |
743 | path->dentry->d_fsdata = attr; |
744 | } else { |
745 | struct mq_attr def_attr; |
746 | |
747 | def_attr.mq_maxmsg = min(ipc_ns->mq_msg_max, |
748 | ipc_ns->mq_msg_default); |
749 | def_attr.mq_msgsize = min(ipc_ns->mq_msgsize_max, |
750 | ipc_ns->mq_msgsize_default); |
751 | ret = mq_attr_ok(ipc_ns, &def_attr); |
752 | if (ret) |
753 | return ERR_PTR(ret); |
754 | } |
755 | |
756 | mode &= ~current_umask(); |
757 | ret = vfs_create(dir, path->dentry, mode, true); |
758 | path->dentry->d_fsdata = NULL; |
759 | if (ret) |
760 | return ERR_PTR(ret); |
761 | return dentry_open(path, oflag, cred); |
762 | } |
763 | |
764 | /* Opens existing queue */ |
765 | static struct file *do_open(struct path *path, int oflag) |
766 | { |
767 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, |
768 | MAY_READ | MAY_WRITE }; |
769 | int acc; |
770 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) |
771 | return ERR_PTR(-EINVAL); |
772 | acc = oflag2acc[oflag & O_ACCMODE]; |
773 | if (inode_permission(path->dentry->d_inode, acc)) |
774 | return ERR_PTR(-EACCES); |
775 | return dentry_open(path, oflag, current_cred()); |
776 | } |
777 | |
778 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, |
779 | struct mq_attr __user *, u_attr) |
780 | { |
781 | struct path path; |
782 | struct file *filp; |
783 | struct filename *name; |
784 | struct mq_attr attr; |
785 | int fd, error; |
786 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
787 | struct vfsmount *mnt = ipc_ns->mq_mnt; |
788 | struct dentry *root = mnt->mnt_root; |
789 | int ro; |
790 | |
791 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) |
792 | return -EFAULT; |
793 | |
794 | audit_mq_open(oflag, mode, u_attr ? &attr : NULL); |
795 | |
796 | if (IS_ERR(name = getname(u_name))) |
797 | return PTR_ERR(name); |
798 | |
799 | fd = get_unused_fd_flags(O_CLOEXEC); |
800 | if (fd < 0) |
801 | goto out_putname; |
802 | |
803 | ro = mnt_want_write(mnt); /* we'll drop it in any case */ |
804 | error = 0; |
805 | mutex_lock(&root->d_inode->i_mutex); |
806 | path.dentry = lookup_one_len(name->name, root, strlen(name->name)); |
807 | if (IS_ERR(path.dentry)) { |
808 | error = PTR_ERR(path.dentry); |
809 | goto out_putfd; |
810 | } |
811 | path.mnt = mntget(mnt); |
812 | |
813 | if (oflag & O_CREAT) { |
814 | if (path.dentry->d_inode) { /* entry already exists */ |
815 | audit_inode(name, path.dentry, 0); |
816 | if (oflag & O_EXCL) { |
817 | error = -EEXIST; |
818 | goto out; |
819 | } |
820 | filp = do_open(&path, oflag); |
821 | } else { |
822 | if (ro) { |
823 | error = ro; |
824 | goto out; |
825 | } |
826 | filp = do_create(ipc_ns, root->d_inode, |
827 | &path, oflag, mode, |
828 | u_attr ? &attr : NULL); |
829 | } |
830 | } else { |
831 | if (!path.dentry->d_inode) { |
832 | error = -ENOENT; |
833 | goto out; |
834 | } |
835 | audit_inode(name, path.dentry, 0); |
836 | filp = do_open(&path, oflag); |
837 | } |
838 | |
839 | if (!IS_ERR(filp)) |
840 | fd_install(fd, filp); |
841 | else |
842 | error = PTR_ERR(filp); |
843 | out: |
844 | path_put(&path); |
845 | out_putfd: |
846 | if (error) { |
847 | put_unused_fd(fd); |
848 | fd = error; |
849 | } |
850 | mutex_unlock(&root->d_inode->i_mutex); |
851 | if (!ro) |
852 | mnt_drop_write(mnt); |
853 | out_putname: |
854 | putname(name); |
855 | return fd; |
856 | } |
857 | |
858 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) |
859 | { |
860 | int err; |
861 | struct filename *name; |
862 | struct dentry *dentry; |
863 | struct inode *inode = NULL; |
864 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
865 | struct vfsmount *mnt = ipc_ns->mq_mnt; |
866 | |
867 | name = getname(u_name); |
868 | if (IS_ERR(name)) |
869 | return PTR_ERR(name); |
870 | |
871 | err = mnt_want_write(mnt); |
872 | if (err) |
873 | goto out_name; |
874 | mutex_lock_nested(&mnt->mnt_root->d_inode->i_mutex, I_MUTEX_PARENT); |
875 | dentry = lookup_one_len(name->name, mnt->mnt_root, |
876 | strlen(name->name)); |
877 | if (IS_ERR(dentry)) { |
878 | err = PTR_ERR(dentry); |
879 | goto out_unlock; |
880 | } |
881 | |
882 | inode = dentry->d_inode; |
883 | if (!inode) { |
884 | err = -ENOENT; |
885 | } else { |
886 | ihold(inode); |
887 | err = vfs_unlink(dentry->d_parent->d_inode, dentry); |
888 | } |
889 | dput(dentry); |
890 | |
891 | out_unlock: |
892 | mutex_unlock(&mnt->mnt_root->d_inode->i_mutex); |
893 | if (inode) |
894 | iput(inode); |
895 | mnt_drop_write(mnt); |
896 | out_name: |
897 | putname(name); |
898 | |
899 | return err; |
900 | } |
901 | |
902 | /* Pipelined send and receive functions. |
903 | * |
904 | * If a receiver finds no waiting message, then it registers itself in the |
905 | * list of waiting receivers. A sender checks that list before adding the new |
906 | * message into the message array. If there is a waiting receiver, then it |
907 | * bypasses the message array and directly hands the message over to the |
908 | * receiver. |
909 | * The receiver accepts the message and returns without grabbing the queue |
910 | * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers |
911 | * are necessary. The same algorithm is used for sysv semaphores, see |
912 | * ipc/sem.c for more details. |
913 | * |
914 | * The same algorithm is used for senders. |
915 | */ |
916 | |
917 | /* pipelined_send() - send a message directly to the task waiting in |
918 | * sys_mq_timedreceive() (without inserting message into a queue). |
919 | */ |
920 | static inline void pipelined_send(struct mqueue_inode_info *info, |
921 | struct msg_msg *message, |
922 | struct ext_wait_queue *receiver) |
923 | { |
924 | receiver->msg = message; |
925 | list_del(&receiver->list); |
926 | receiver->state = STATE_PENDING; |
927 | wake_up_process(receiver->task); |
928 | smp_wmb(); |
929 | receiver->state = STATE_READY; |
930 | } |
931 | |
932 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() |
933 | * gets its message and put to the queue (we have one free place for sure). */ |
934 | static inline void pipelined_receive(struct mqueue_inode_info *info) |
935 | { |
936 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); |
937 | |
938 | if (!sender) { |
939 | /* for poll */ |
940 | wake_up_interruptible(&info->wait_q); |
941 | return; |
942 | } |
943 | if (msg_insert(sender->msg, info)) |
944 | return; |
945 | list_del(&sender->list); |
946 | sender->state = STATE_PENDING; |
947 | wake_up_process(sender->task); |
948 | smp_wmb(); |
949 | sender->state = STATE_READY; |
950 | } |
951 | |
952 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, |
953 | size_t, msg_len, unsigned int, msg_prio, |
954 | const struct timespec __user *, u_abs_timeout) |
955 | { |
956 | struct fd f; |
957 | struct inode *inode; |
958 | struct ext_wait_queue wait; |
959 | struct ext_wait_queue *receiver; |
960 | struct msg_msg *msg_ptr; |
961 | struct mqueue_inode_info *info; |
962 | ktime_t expires, *timeout = NULL; |
963 | struct timespec ts; |
964 | struct posix_msg_tree_node *new_leaf = NULL; |
965 | int ret = 0; |
966 | |
967 | if (u_abs_timeout) { |
968 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); |
969 | if (res) |
970 | return res; |
971 | timeout = &expires; |
972 | } |
973 | |
974 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) |
975 | return -EINVAL; |
976 | |
977 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL); |
978 | |
979 | f = fdget(mqdes); |
980 | if (unlikely(!f.file)) { |
981 | ret = -EBADF; |
982 | goto out; |
983 | } |
984 | |
985 | inode = file_inode(f.file); |
986 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
987 | ret = -EBADF; |
988 | goto out_fput; |
989 | } |
990 | info = MQUEUE_I(inode); |
991 | audit_inode(NULL, f.file->f_path.dentry, 0); |
992 | |
993 | if (unlikely(!(f.file->f_mode & FMODE_WRITE))) { |
994 | ret = -EBADF; |
995 | goto out_fput; |
996 | } |
997 | |
998 | if (unlikely(msg_len > info->attr.mq_msgsize)) { |
999 | ret = -EMSGSIZE; |
1000 | goto out_fput; |
1001 | } |
1002 | |
1003 | /* First try to allocate memory, before doing anything with |
1004 | * existing queues. */ |
1005 | msg_ptr = load_msg(u_msg_ptr, msg_len); |
1006 | if (IS_ERR(msg_ptr)) { |
1007 | ret = PTR_ERR(msg_ptr); |
1008 | goto out_fput; |
1009 | } |
1010 | msg_ptr->m_ts = msg_len; |
1011 | msg_ptr->m_type = msg_prio; |
1012 | |
1013 | /* |
1014 | * msg_insert really wants us to have a valid, spare node struct so |
1015 | * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will |
1016 | * fall back to that if necessary. |
1017 | */ |
1018 | if (!info->node_cache) |
1019 | new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL); |
1020 | |
1021 | spin_lock(&info->lock); |
1022 | |
1023 | if (!info->node_cache && new_leaf) { |
1024 | /* Save our speculative allocation into the cache */ |
1025 | INIT_LIST_HEAD(&new_leaf->msg_list); |
1026 | info->node_cache = new_leaf; |
1027 | info->qsize += sizeof(*new_leaf); |
1028 | new_leaf = NULL; |
1029 | } else { |
1030 | kfree(new_leaf); |
1031 | } |
1032 | |
1033 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { |
1034 | if (f.file->f_flags & O_NONBLOCK) { |
1035 | ret = -EAGAIN; |
1036 | } else { |
1037 | wait.task = current; |
1038 | wait.msg = (void *) msg_ptr; |
1039 | wait.state = STATE_NONE; |
1040 | ret = wq_sleep(info, SEND, timeout, &wait); |
1041 | /* |
1042 | * wq_sleep must be called with info->lock held, and |
1043 | * returns with the lock released |
1044 | */ |
1045 | goto out_free; |
1046 | } |
1047 | } else { |
1048 | receiver = wq_get_first_waiter(info, RECV); |
1049 | if (receiver) { |
1050 | pipelined_send(info, msg_ptr, receiver); |
1051 | } else { |
1052 | /* adds message to the queue */ |
1053 | ret = msg_insert(msg_ptr, info); |
1054 | if (ret) |
1055 | goto out_unlock; |
1056 | __do_notify(info); |
1057 | } |
1058 | inode->i_atime = inode->i_mtime = inode->i_ctime = |
1059 | CURRENT_TIME; |
1060 | } |
1061 | out_unlock: |
1062 | spin_unlock(&info->lock); |
1063 | out_free: |
1064 | if (ret) |
1065 | free_msg(msg_ptr); |
1066 | out_fput: |
1067 | fdput(f); |
1068 | out: |
1069 | return ret; |
1070 | } |
1071 | |
1072 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, |
1073 | size_t, msg_len, unsigned int __user *, u_msg_prio, |
1074 | const struct timespec __user *, u_abs_timeout) |
1075 | { |
1076 | ssize_t ret; |
1077 | struct msg_msg *msg_ptr; |
1078 | struct fd f; |
1079 | struct inode *inode; |
1080 | struct mqueue_inode_info *info; |
1081 | struct ext_wait_queue wait; |
1082 | ktime_t expires, *timeout = NULL; |
1083 | struct timespec ts; |
1084 | struct posix_msg_tree_node *new_leaf = NULL; |
1085 | |
1086 | if (u_abs_timeout) { |
1087 | int res = prepare_timeout(u_abs_timeout, &expires, &ts); |
1088 | if (res) |
1089 | return res; |
1090 | timeout = &expires; |
1091 | } |
1092 | |
1093 | audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL); |
1094 | |
1095 | f = fdget(mqdes); |
1096 | if (unlikely(!f.file)) { |
1097 | ret = -EBADF; |
1098 | goto out; |
1099 | } |
1100 | |
1101 | inode = file_inode(f.file); |
1102 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
1103 | ret = -EBADF; |
1104 | goto out_fput; |
1105 | } |
1106 | info = MQUEUE_I(inode); |
1107 | audit_inode(NULL, f.file->f_path.dentry, 0); |
1108 | |
1109 | if (unlikely(!(f.file->f_mode & FMODE_READ))) { |
1110 | ret = -EBADF; |
1111 | goto out_fput; |
1112 | } |
1113 | |
1114 | /* checks if buffer is big enough */ |
1115 | if (unlikely(msg_len < info->attr.mq_msgsize)) { |
1116 | ret = -EMSGSIZE; |
1117 | goto out_fput; |
1118 | } |
1119 | |
1120 | /* |
1121 | * msg_insert really wants us to have a valid, spare node struct so |
1122 | * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will |
1123 | * fall back to that if necessary. |
1124 | */ |
1125 | if (!info->node_cache) |
1126 | new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL); |
1127 | |
1128 | spin_lock(&info->lock); |
1129 | |
1130 | if (!info->node_cache && new_leaf) { |
1131 | /* Save our speculative allocation into the cache */ |
1132 | INIT_LIST_HEAD(&new_leaf->msg_list); |
1133 | info->node_cache = new_leaf; |
1134 | info->qsize += sizeof(*new_leaf); |
1135 | } else { |
1136 | kfree(new_leaf); |
1137 | } |
1138 | |
1139 | if (info->attr.mq_curmsgs == 0) { |
1140 | if (f.file->f_flags & O_NONBLOCK) { |
1141 | spin_unlock(&info->lock); |
1142 | ret = -EAGAIN; |
1143 | } else { |
1144 | wait.task = current; |
1145 | wait.state = STATE_NONE; |
1146 | ret = wq_sleep(info, RECV, timeout, &wait); |
1147 | msg_ptr = wait.msg; |
1148 | } |
1149 | } else { |
1150 | msg_ptr = msg_get(info); |
1151 | |
1152 | inode->i_atime = inode->i_mtime = inode->i_ctime = |
1153 | CURRENT_TIME; |
1154 | |
1155 | /* There is now free space in queue. */ |
1156 | pipelined_receive(info); |
1157 | spin_unlock(&info->lock); |
1158 | ret = 0; |
1159 | } |
1160 | if (ret == 0) { |
1161 | ret = msg_ptr->m_ts; |
1162 | |
1163 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || |
1164 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { |
1165 | ret = -EFAULT; |
1166 | } |
1167 | free_msg(msg_ptr); |
1168 | } |
1169 | out_fput: |
1170 | fdput(f); |
1171 | out: |
1172 | return ret; |
1173 | } |
1174 | |
1175 | /* |
1176 | * Notes: the case when user wants us to deregister (with NULL as pointer) |
1177 | * and he isn't currently owner of notification, will be silently discarded. |
1178 | * It isn't explicitly defined in the POSIX. |
1179 | */ |
1180 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
1181 | const struct sigevent __user *, u_notification) |
1182 | { |
1183 | int ret; |
1184 | struct fd f; |
1185 | struct sock *sock; |
1186 | struct inode *inode; |
1187 | struct sigevent notification; |
1188 | struct mqueue_inode_info *info; |
1189 | struct sk_buff *nc; |
1190 | |
1191 | if (u_notification) { |
1192 | if (copy_from_user(¬ification, u_notification, |
1193 | sizeof(struct sigevent))) |
1194 | return -EFAULT; |
1195 | } |
1196 | |
1197 | audit_mq_notify(mqdes, u_notification ? ¬ification : NULL); |
1198 | |
1199 | nc = NULL; |
1200 | sock = NULL; |
1201 | if (u_notification != NULL) { |
1202 | if (unlikely(notification.sigev_notify != SIGEV_NONE && |
1203 | notification.sigev_notify != SIGEV_SIGNAL && |
1204 | notification.sigev_notify != SIGEV_THREAD)) |
1205 | return -EINVAL; |
1206 | if (notification.sigev_notify == SIGEV_SIGNAL && |
1207 | !valid_signal(notification.sigev_signo)) { |
1208 | return -EINVAL; |
1209 | } |
1210 | if (notification.sigev_notify == SIGEV_THREAD) { |
1211 | long timeo; |
1212 | |
1213 | /* create the notify skb */ |
1214 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); |
1215 | if (!nc) { |
1216 | ret = -ENOMEM; |
1217 | goto out; |
1218 | } |
1219 | if (copy_from_user(nc->data, |
1220 | notification.sigev_value.sival_ptr, |
1221 | NOTIFY_COOKIE_LEN)) { |
1222 | ret = -EFAULT; |
1223 | goto out; |
1224 | } |
1225 | |
1226 | /* TODO: add a header? */ |
1227 | skb_put(nc, NOTIFY_COOKIE_LEN); |
1228 | /* and attach it to the socket */ |
1229 | retry: |
1230 | f = fdget(notification.sigev_signo); |
1231 | if (!f.file) { |
1232 | ret = -EBADF; |
1233 | goto out; |
1234 | } |
1235 | sock = netlink_getsockbyfilp(f.file); |
1236 | fdput(f); |
1237 | if (IS_ERR(sock)) { |
1238 | ret = PTR_ERR(sock); |
1239 | sock = NULL; |
1240 | goto out; |
1241 | } |
1242 | |
1243 | timeo = MAX_SCHEDULE_TIMEOUT; |
1244 | ret = netlink_attachskb(sock, nc, &timeo, NULL); |
1245 | if (ret == 1) |
1246 | goto retry; |
1247 | if (ret) { |
1248 | sock = NULL; |
1249 | nc = NULL; |
1250 | goto out; |
1251 | } |
1252 | } |
1253 | } |
1254 | |
1255 | f = fdget(mqdes); |
1256 | if (!f.file) { |
1257 | ret = -EBADF; |
1258 | goto out; |
1259 | } |
1260 | |
1261 | inode = file_inode(f.file); |
1262 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
1263 | ret = -EBADF; |
1264 | goto out_fput; |
1265 | } |
1266 | info = MQUEUE_I(inode); |
1267 | |
1268 | ret = 0; |
1269 | spin_lock(&info->lock); |
1270 | if (u_notification == NULL) { |
1271 | if (info->notify_owner == task_tgid(current)) { |
1272 | remove_notification(info); |
1273 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
1274 | } |
1275 | } else if (info->notify_owner != NULL) { |
1276 | ret = -EBUSY; |
1277 | } else { |
1278 | switch (notification.sigev_notify) { |
1279 | case SIGEV_NONE: |
1280 | info->notify.sigev_notify = SIGEV_NONE; |
1281 | break; |
1282 | case SIGEV_THREAD: |
1283 | info->notify_sock = sock; |
1284 | info->notify_cookie = nc; |
1285 | sock = NULL; |
1286 | nc = NULL; |
1287 | info->notify.sigev_notify = SIGEV_THREAD; |
1288 | break; |
1289 | case SIGEV_SIGNAL: |
1290 | info->notify.sigev_signo = notification.sigev_signo; |
1291 | info->notify.sigev_value = notification.sigev_value; |
1292 | info->notify.sigev_notify = SIGEV_SIGNAL; |
1293 | break; |
1294 | } |
1295 | |
1296 | info->notify_owner = get_pid(task_tgid(current)); |
1297 | info->notify_user_ns = get_user_ns(current_user_ns()); |
1298 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
1299 | } |
1300 | spin_unlock(&info->lock); |
1301 | out_fput: |
1302 | fdput(f); |
1303 | out: |
1304 | if (sock) { |
1305 | netlink_detachskb(sock, nc); |
1306 | } else if (nc) { |
1307 | dev_kfree_skb(nc); |
1308 | } |
1309 | return ret; |
1310 | } |
1311 | |
1312 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, |
1313 | const struct mq_attr __user *, u_mqstat, |
1314 | struct mq_attr __user *, u_omqstat) |
1315 | { |
1316 | int ret; |
1317 | struct mq_attr mqstat, omqstat; |
1318 | struct fd f; |
1319 | struct inode *inode; |
1320 | struct mqueue_inode_info *info; |
1321 | |
1322 | if (u_mqstat != NULL) { |
1323 | if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr))) |
1324 | return -EFAULT; |
1325 | if (mqstat.mq_flags & (~O_NONBLOCK)) |
1326 | return -EINVAL; |
1327 | } |
1328 | |
1329 | f = fdget(mqdes); |
1330 | if (!f.file) { |
1331 | ret = -EBADF; |
1332 | goto out; |
1333 | } |
1334 | |
1335 | inode = file_inode(f.file); |
1336 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
1337 | ret = -EBADF; |
1338 | goto out_fput; |
1339 | } |
1340 | info = MQUEUE_I(inode); |
1341 | |
1342 | spin_lock(&info->lock); |
1343 | |
1344 | omqstat = info->attr; |
1345 | omqstat.mq_flags = f.file->f_flags & O_NONBLOCK; |
1346 | if (u_mqstat) { |
1347 | audit_mq_getsetattr(mqdes, &mqstat); |
1348 | spin_lock(&f.file->f_lock); |
1349 | if (mqstat.mq_flags & O_NONBLOCK) |
1350 | f.file->f_flags |= O_NONBLOCK; |
1351 | else |
1352 | f.file->f_flags &= ~O_NONBLOCK; |
1353 | spin_unlock(&f.file->f_lock); |
1354 | |
1355 | inode->i_atime = inode->i_ctime = CURRENT_TIME; |
1356 | } |
1357 | |
1358 | spin_unlock(&info->lock); |
1359 | |
1360 | ret = 0; |
1361 | if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, |
1362 | sizeof(struct mq_attr))) |
1363 | ret = -EFAULT; |
1364 | |
1365 | out_fput: |
1366 | fdput(f); |
1367 | out: |
1368 | return ret; |
1369 | } |
1370 | |
1371 | static const struct inode_operations mqueue_dir_inode_operations = { |
1372 | .lookup = simple_lookup, |
1373 | .create = mqueue_create, |
1374 | .unlink = mqueue_unlink, |
1375 | }; |
1376 | |
1377 | static const struct file_operations mqueue_file_operations = { |
1378 | .flush = mqueue_flush_file, |
1379 | .poll = mqueue_poll_file, |
1380 | .read = mqueue_read_file, |
1381 | .llseek = default_llseek, |
1382 | }; |
1383 | |
1384 | static const struct super_operations mqueue_super_ops = { |
1385 | .alloc_inode = mqueue_alloc_inode, |
1386 | .destroy_inode = mqueue_destroy_inode, |
1387 | .evict_inode = mqueue_evict_inode, |
1388 | .statfs = simple_statfs, |
1389 | }; |
1390 | |
1391 | static struct file_system_type mqueue_fs_type = { |
1392 | .name = "mqueue", |
1393 | .mount = mqueue_mount, |
1394 | .kill_sb = kill_litter_super, |
1395 | .fs_flags = FS_USERNS_MOUNT, |
1396 | }; |
1397 | |
1398 | int mq_init_ns(struct ipc_namespace *ns) |
1399 | { |
1400 | ns->mq_queues_count = 0; |
1401 | ns->mq_queues_max = DFLT_QUEUESMAX; |
1402 | ns->mq_msg_max = DFLT_MSGMAX; |
1403 | ns->mq_msgsize_max = DFLT_MSGSIZEMAX; |
1404 | ns->mq_msg_default = DFLT_MSG; |
1405 | ns->mq_msgsize_default = DFLT_MSGSIZE; |
1406 | |
1407 | ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns); |
1408 | if (IS_ERR(ns->mq_mnt)) { |
1409 | int err = PTR_ERR(ns->mq_mnt); |
1410 | ns->mq_mnt = NULL; |
1411 | return err; |
1412 | } |
1413 | return 0; |
1414 | } |
1415 | |
1416 | void mq_clear_sbinfo(struct ipc_namespace *ns) |
1417 | { |
1418 | ns->mq_mnt->mnt_sb->s_fs_info = NULL; |
1419 | } |
1420 | |
1421 | void mq_put_mnt(struct ipc_namespace *ns) |
1422 | { |
1423 | kern_unmount(ns->mq_mnt); |
1424 | } |
1425 | |
1426 | static int __init init_mqueue_fs(void) |
1427 | { |
1428 | int error; |
1429 | |
1430 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", |
1431 | sizeof(struct mqueue_inode_info), 0, |
1432 | SLAB_HWCACHE_ALIGN, init_once); |
1433 | if (mqueue_inode_cachep == NULL) |
1434 | return -ENOMEM; |
1435 | |
1436 | /* ignore failures - they are not fatal */ |
1437 | mq_sysctl_table = mq_register_sysctl_table(); |
1438 | |
1439 | error = register_filesystem(&mqueue_fs_type); |
1440 | if (error) |
1441 | goto out_sysctl; |
1442 | |
1443 | spin_lock_init(&mq_lock); |
1444 | |
1445 | error = mq_init_ns(&init_ipc_ns); |
1446 | if (error) |
1447 | goto out_filesystem; |
1448 | |
1449 | return 0; |
1450 | |
1451 | out_filesystem: |
1452 | unregister_filesystem(&mqueue_fs_type); |
1453 | out_sysctl: |
1454 | if (mq_sysctl_table) |
1455 | unregister_sysctl_table(mq_sysctl_table); |
1456 | kmem_cache_destroy(mqueue_inode_cachep); |
1457 | return error; |
1458 | } |
1459 | |
1460 | __initcall(init_mqueue_fs); |
1461 |
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9