?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
net: phy: Avoid NPD upon phy_detach() when driver is unbound
[linux/fpc-iii.git] / ipc / mqueue.c
blob2ea0c08188e674f972ae821759ef4e67e4c9a675
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 struct ext_wait_queue { /* queue of sleeping tasks */
67 struct task_struct *task;
68 struct list_head list;
69 struct msg_msg *msg; /* ptr of loaded message */
70 int state; /* one of STATE_* values */
71 };
72
73 struct mqueue_inode_info {
74 spinlock_t lock;
75 struct inode vfs_inode;
76 wait_queue_head_t wait_q;
77
78 struct rb_root msg_tree;
79 struct rb_node *msg_tree_rightmost;
80 struct posix_msg_tree_node *node_cache;
81 struct mq_attr attr;
82
83 struct sigevent notify;
84 struct pid *notify_owner;
85 u32 notify_self_exec_id;
86 struct user_namespace *notify_user_ns;
87 struct user_struct *user; /* user who created, for accounting */
88 struct sock *notify_sock;
89 struct sk_buff *notify_cookie;
90
91 /* for tasks waiting for free space and messages, respectively */
92 struct ext_wait_queue e_wait_q[2];
93
94 unsigned long qsize; /* size of queue in memory (sum of all msgs) */
95 };
96
97 static struct file_system_type mqueue_fs_type;
98 static const struct inode_operations mqueue_dir_inode_operations;
99 static const struct file_operations mqueue_file_operations;
100 static const struct super_operations mqueue_super_ops;
101 static const struct fs_context_operations mqueue_fs_context_ops;
102 static void remove_notification(struct mqueue_inode_info *info);
103
104 static struct kmem_cache *mqueue_inode_cachep;
105
106 static struct ctl_table_header *mq_sysctl_table;
107
108 static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
109 {
110 return container_of(inode, struct mqueue_inode_info, vfs_inode);
111 }
112
113 /*
114 * This routine should be called with the mq_lock held.
115 */
116 static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode)
117 {
118 return get_ipc_ns(inode->i_sb->s_fs_info);
119 }
120
121 static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
122 {
123 struct ipc_namespace *ns;
124
125 spin_lock(&mq_lock);
126 ns = __get_ns_from_inode(inode);
127 spin_unlock(&mq_lock);
128 return ns;
129 }
130
131 /* Auxiliary functions to manipulate messages' list */
132 static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info)
133 {
134 struct rb_node **p, *parent = NULL;
135 struct posix_msg_tree_node *leaf;
136 bool rightmost = true;
137
138 p = &info->msg_tree.rb_node;
139 while (*p) {
140 parent = *p;
141 leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
142
143 if (likely(leaf->priority == msg->m_type))
144 goto insert_msg;
145 else if (msg->m_type < leaf->priority) {
146 p = &(*p)->rb_left;
147 rightmost = false;
148 } else
149 p = &(*p)->rb_right;
150 }
151 if (info->node_cache) {
152 leaf = info->node_cache;
153 info->node_cache = NULL;
154 } else {
155 leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC);
156 if (!leaf)
157 return -ENOMEM;
158 INIT_LIST_HEAD(&leaf->msg_list);
159 }
160 leaf->priority = msg->m_type;
161
162 if (rightmost)
163 info->msg_tree_rightmost = &leaf->rb_node;
164
165 rb_link_node(&leaf->rb_node, parent, p);
166 rb_insert_color(&leaf->rb_node, &info->msg_tree);
167 insert_msg:
168 info->attr.mq_curmsgs++;
169 info->qsize += msg->m_ts;
170 list_add_tail(&msg->m_list, &leaf->msg_list);
171 return 0;
172 }
173
174 static inline void msg_tree_erase(struct posix_msg_tree_node *leaf,
175 struct mqueue_inode_info *info)
176 {
177 struct rb_node *node = &leaf->rb_node;
178
179 if (info->msg_tree_rightmost == node)
180 info->msg_tree_rightmost = rb_prev(node);
181
182 rb_erase(node, &info->msg_tree);
183 if (info->node_cache) {
184 kfree(leaf);
185 } else {
186 info->node_cache = leaf;
187 }
188 }
189
190 static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
191 {
192 struct rb_node *parent = NULL;
193 struct posix_msg_tree_node *leaf;
194 struct msg_msg *msg;
195
196 try_again:
197 /*
198 * During insert, low priorities go to the left and high to the
199 * right. On receive, we want the highest priorities first, so
200 * walk all the way to the right.
201 */
202 parent = info->msg_tree_rightmost;
203 if (!parent) {
204 if (info->attr.mq_curmsgs) {
205 pr_warn_once("Inconsistency in POSIX message queue, "
206 "no tree element, but supposedly messages "
207 "should exist!\n");
208 info->attr.mq_curmsgs = 0;
209 }
210 return NULL;
211 }
212 leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
213 if (unlikely(list_empty(&leaf->msg_list))) {
214 pr_warn_once("Inconsistency in POSIX message queue, "
215 "empty leaf node but we haven't implemented "
216 "lazy leaf delete!\n");
217 msg_tree_erase(leaf, info);
218 goto try_again;
219 } else {
220 msg = list_first_entry(&leaf->msg_list,
221 struct msg_msg, m_list);
222 list_del(&msg->m_list);
223 if (list_empty(&leaf->msg_list)) {
224 msg_tree_erase(leaf, info);
225 }
226 }
227 info->attr.mq_curmsgs--;
228 info->qsize -= msg->m_ts;
229 return msg;
230 }
231
232 static struct inode *mqueue_get_inode(struct super_block *sb,
233 struct ipc_namespace *ipc_ns, umode_t mode,
234 struct mq_attr *attr)
235 {
236 struct user_struct *u = current_user();
237 struct inode *inode;
238 int ret = -ENOMEM;
239
240 inode = new_inode(sb);
241 if (!inode)
242 goto err;
243
244 inode->i_ino = get_next_ino();
245 inode->i_mode = mode;
246 inode->i_uid = current_fsuid();
247 inode->i_gid = current_fsgid();
248 inode->i_mtime = inode->i_ctime = inode->i_atime = current_time(inode);
249
250 if (S_ISREG(mode)) {
251 struct mqueue_inode_info *info;
252 unsigned long mq_bytes, mq_treesize;
253
254 inode->i_fop = &mqueue_file_operations;
255 inode->i_size = FILENT_SIZE;
256 /* mqueue specific info */
257 info = MQUEUE_I(inode);
258 spin_lock_init(&info->lock);
259 init_waitqueue_head(&info->wait_q);
260 INIT_LIST_HEAD(&info->e_wait_q[0].list);
261 INIT_LIST_HEAD(&info->e_wait_q[1].list);
262 info->notify_owner = NULL;
263 info->notify_user_ns = NULL;
264 info->qsize = 0;
265 info->user = NULL; /* set when all is ok */
266 info->msg_tree = RB_ROOT;
267 info->msg_tree_rightmost = NULL;
268 info->node_cache = NULL;
269 memset(&info->attr, 0, sizeof(info->attr));
270 info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
271 ipc_ns->mq_msg_default);
272 info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max,
273 ipc_ns->mq_msgsize_default);
274 if (attr) {
275 info->attr.mq_maxmsg = attr->mq_maxmsg;
276 info->attr.mq_msgsize = attr->mq_msgsize;
277 }
278 /*
279 * We used to allocate a static array of pointers and account
280 * the size of that array as well as one msg_msg struct per
281 * possible message into the queue size. That's no longer
282 * accurate as the queue is now an rbtree and will grow and
283 * shrink depending on usage patterns. We can, however, still
284 * account one msg_msg struct per message, but the nodes are
285 * allocated depending on priority usage, and most programs
286 * only use one, or a handful, of priorities. However, since
287 * this is pinned memory, we need to assume worst case, so
288 * that means the min(mq_maxmsg, max_priorities) * struct
289 * posix_msg_tree_node.
290 */
291
292 ret = -EINVAL;
293 if (info->attr.mq_maxmsg <= 0 || info->attr.mq_msgsize <= 0)
294 goto out_inode;
295 if (capable(CAP_SYS_RESOURCE)) {
296 if (info->attr.mq_maxmsg > HARD_MSGMAX ||
297 info->attr.mq_msgsize > HARD_MSGSIZEMAX)
298 goto out_inode;
299 } else {
300 if (info->attr.mq_maxmsg > ipc_ns->mq_msg_max ||
301 info->attr.mq_msgsize > ipc_ns->mq_msgsize_max)
302 goto out_inode;
303 }
304 ret = -EOVERFLOW;
305 /* check for overflow */
306 if (info->attr.mq_msgsize > ULONG_MAX/info->attr.mq_maxmsg)
307 goto out_inode;
308 mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
309 min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
310 sizeof(struct posix_msg_tree_node);
311 mq_bytes = info->attr.mq_maxmsg * info->attr.mq_msgsize;
312 if (mq_bytes + mq_treesize < mq_bytes)
313 goto out_inode;
314 mq_bytes += mq_treesize;
315 spin_lock(&mq_lock);
316 if (u->mq_bytes + mq_bytes < u->mq_bytes ||
317 u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) {
318 spin_unlock(&mq_lock);
319 /* mqueue_evict_inode() releases info->messages */
320 ret = -EMFILE;
321 goto out_inode;
322 }
323 u->mq_bytes += mq_bytes;
324 spin_unlock(&mq_lock);
325
326 /* all is ok */
327 info->user = get_uid(u);
328 } else if (S_ISDIR(mode)) {
329 inc_nlink(inode);
330 /* Some things misbehave if size == 0 on a directory */
331 inode->i_size = 2 * DIRENT_SIZE;
332 inode->i_op = &mqueue_dir_inode_operations;
333 inode->i_fop = &simple_dir_operations;
334 }
335
336 return inode;
337 out_inode:
338 iput(inode);
339 err:
340 return ERR_PTR(ret);
341 }
342
343 static int mqueue_fill_super(struct super_block *sb, struct fs_context *fc)
344 {
345 struct inode *inode;
346 struct ipc_namespace *ns = sb->s_fs_info;
347
348 sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
349 sb->s_blocksize = PAGE_SIZE;
350 sb->s_blocksize_bits = PAGE_SHIFT;
351 sb->s_magic = MQUEUE_MAGIC;
352 sb->s_op = &mqueue_super_ops;
353
354 inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL);
355 if (IS_ERR(inode))
356 return PTR_ERR(inode);
357
358 sb->s_root = d_make_root(inode);
359 if (!sb->s_root)
360 return -ENOMEM;
361 return 0;
362 }
363
364 static int mqueue_get_tree(struct fs_context *fc)
365 {
366 struct mqueue_fs_context *ctx = fc->fs_private;
367
368 return get_tree_keyed(fc, mqueue_fill_super, ctx->ipc_ns);
369 }
370
371 static void mqueue_fs_context_free(struct fs_context *fc)
372 {
373 struct mqueue_fs_context *ctx = fc->fs_private;
374
375 put_ipc_ns(ctx->ipc_ns);
376 kfree(ctx);
377 }
378
379 static int mqueue_init_fs_context(struct fs_context *fc)
380 {
381 struct mqueue_fs_context *ctx;
382
383 ctx = kzalloc(sizeof(struct mqueue_fs_context), GFP_KERNEL);
384 if (!ctx)
385 return -ENOMEM;
386
387 ctx->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns);
388 put_user_ns(fc->user_ns);
389 fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns);
390 fc->fs_private = ctx;
391 fc->ops = &mqueue_fs_context_ops;
392 return 0;
393 }
394
395 static struct vfsmount *mq_create_mount(struct ipc_namespace *ns)
396 {
397 struct mqueue_fs_context *ctx;
398 struct fs_context *fc;
399 struct vfsmount *mnt;
400
401 fc = fs_context_for_mount(&mqueue_fs_type, SB_KERNMOUNT);
402 if (IS_ERR(fc))
403 return ERR_CAST(fc);
404
405 ctx = fc->fs_private;
406 put_ipc_ns(ctx->ipc_ns);
407 ctx->ipc_ns = get_ipc_ns(ns);
408 put_user_ns(fc->user_ns);
409 fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns);
410
411 mnt = fc_mount(fc);
412 put_fs_context(fc);
413 return mnt;
414 }
415
416 static void init_once(void *foo)
417 {
418 struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
419
420 inode_init_once(&p->vfs_inode);
421 }
422
423 static struct inode *mqueue_alloc_inode(struct super_block *sb)
424 {
425 struct mqueue_inode_info *ei;
426
427 ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
428 if (!ei)
429 return NULL;
430 return &ei->vfs_inode;
431 }
432
433 static void mqueue_free_inode(struct inode *inode)
434 {
435 kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
436 }
437
438 static void mqueue_evict_inode(struct inode *inode)
439 {
440 struct mqueue_inode_info *info;
441 struct user_struct *user;
442 struct ipc_namespace *ipc_ns;
443 struct msg_msg *msg, *nmsg;
444 LIST_HEAD(tmp_msg);
445
446 clear_inode(inode);
447
448 if (S_ISDIR(inode->i_mode))
449 return;
450
451 ipc_ns = get_ns_from_inode(inode);
452 info = MQUEUE_I(inode);
453 spin_lock(&info->lock);
454 while ((msg = msg_get(info)) != NULL)
455 list_add_tail(&msg->m_list, &tmp_msg);
456 kfree(info->node_cache);
457 spin_unlock(&info->lock);
458
459 list_for_each_entry_safe(msg, nmsg, &tmp_msg, m_list) {
460 list_del(&msg->m_list);
461 free_msg(msg);
462 }
463
464 user = info->user;
465 if (user) {
466 unsigned long mq_bytes, mq_treesize;
467
468 /* Total amount of bytes accounted for the mqueue */
469 mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) +
470 min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) *
471 sizeof(struct posix_msg_tree_node);
472
473 mq_bytes = mq_treesize + (info->attr.mq_maxmsg *
474 info->attr.mq_msgsize);
475
476 spin_lock(&mq_lock);
477 user->mq_bytes -= mq_bytes;
478 /*
479 * get_ns_from_inode() ensures that the
480 * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
481 * to which we now hold a reference, or it is NULL.
482 * We can't put it here under mq_lock, though.
483 */
484 if (ipc_ns)
485 ipc_ns->mq_queues_count--;
486 spin_unlock(&mq_lock);
487 free_uid(user);
488 }
489 if (ipc_ns)
490 put_ipc_ns(ipc_ns);
491 }
492
493 static int mqueue_create_attr(struct dentry *dentry, umode_t mode, void *arg)
494 {
495 struct inode *dir = dentry->d_parent->d_inode;
496 struct inode *inode;
497 struct mq_attr *attr = arg;
498 int error;
499 struct ipc_namespace *ipc_ns;
500
501 spin_lock(&mq_lock);
502 ipc_ns = __get_ns_from_inode(dir);
503 if (!ipc_ns) {
504 error = -EACCES;
505 goto out_unlock;
506 }
507
508 if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
509 !capable(CAP_SYS_RESOURCE)) {
510 error = -ENOSPC;
511 goto out_unlock;
512 }
513 ipc_ns->mq_queues_count++;
514 spin_unlock(&mq_lock);
515
516 inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
517 if (IS_ERR(inode)) {
518 error = PTR_ERR(inode);
519 spin_lock(&mq_lock);
520 ipc_ns->mq_queues_count--;
521 goto out_unlock;
522 }
523
524 put_ipc_ns(ipc_ns);
525 dir->i_size += DIRENT_SIZE;
526 dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir);
527
528 d_instantiate(dentry, inode);
529 dget(dentry);
530 return 0;
531 out_unlock:
532 spin_unlock(&mq_lock);
533 if (ipc_ns)
534 put_ipc_ns(ipc_ns);
535 return error;
536 }
537
538 static int mqueue_create(struct inode *dir, struct dentry *dentry,
539 umode_t mode, bool excl)
540 {
541 return mqueue_create_attr(dentry, mode, NULL);
542 }
543
544 static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
545 {
546 struct inode *inode = d_inode(dentry);
547
548 dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir);
549 dir->i_size -= DIRENT_SIZE;
550 drop_nlink(inode);
551 dput(dentry);
552 return 0;
553 }
554
555 /*
556 * This is routine for system read from queue file.
557 * To avoid mess with doing here some sort of mq_receive we allow
558 * to read only queue size & notification info (the only values
559 * that are interesting from user point of view and aren't accessible
560 * through std routines)
561 */
562 static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
563 size_t count, loff_t *off)
564 {
565 struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
566 char buffer[FILENT_SIZE];
567 ssize_t ret;
568
569 spin_lock(&info->lock);
570 snprintf(buffer, sizeof(buffer),
571 "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
572 info->qsize,
573 info->notify_owner ? info->notify.sigev_notify : 0,
574 (info->notify_owner &&
575 info->notify.sigev_notify == SIGEV_SIGNAL) ?
576 info->notify.sigev_signo : 0,
577 pid_vnr(info->notify_owner));
578 spin_unlock(&info->lock);
579 buffer[sizeof(buffer)-1] = '\0';
580
581 ret = simple_read_from_buffer(u_data, count, off, buffer,
582 strlen(buffer));
583 if (ret <= 0)
584 return ret;
585
586 file_inode(filp)->i_atime = file_inode(filp)->i_ctime = current_time(file_inode(filp));
587 return ret;
588 }
589
590 static int mqueue_flush_file(struct file *filp, fl_owner_t id)
591 {
592 struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
593
594 spin_lock(&info->lock);
595 if (task_tgid(current) == info->notify_owner)
596 remove_notification(info);
597
598 spin_unlock(&info->lock);
599 return 0;
600 }
601
602 static __poll_t mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
603 {
604 struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp));
605 __poll_t retval = 0;
606
607 poll_wait(filp, &info->wait_q, poll_tab);
608
609 spin_lock(&info->lock);
610 if (info->attr.mq_curmsgs)
611 retval = EPOLLIN | EPOLLRDNORM;
612
613 if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
614 retval |= EPOLLOUT | EPOLLWRNORM;
615 spin_unlock(&info->lock);
616
617 return retval;
618 }
619
620 /* Adds current to info->e_wait_q[sr] before element with smaller prio */
621 static void wq_add(struct mqueue_inode_info *info, int sr,
622 struct ext_wait_queue *ewp)
623 {
624 struct ext_wait_queue *walk;
625
626 list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
627 if (walk->task->prio <= current->prio) {
628 list_add_tail(&ewp->list, &walk->list);
629 return;
630 }
631 }
632 list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
633 }
634
635 /*
636 * Puts current task to sleep. Caller must hold queue lock. After return
637 * lock isn't held.
638 * sr: SEND or RECV
639 */
640 static int wq_sleep(struct mqueue_inode_info *info, int sr,
641 ktime_t *timeout, struct ext_wait_queue *ewp)
642 __releases(&info->lock)
643 {
644 int retval;
645 signed long time;
646
647 wq_add(info, sr, ewp);
648
649 for (;;) {
650 __set_current_state(TASK_INTERRUPTIBLE);
651
652 spin_unlock(&info->lock);
653 time = schedule_hrtimeout_range_clock(timeout, 0,
654 HRTIMER_MODE_ABS, CLOCK_REALTIME);
655
656 if (ewp->state == STATE_READY) {
657 retval = 0;
658 goto out;
659 }
660 spin_lock(&info->lock);
661 if (ewp->state == STATE_READY) {
662 retval = 0;
663 goto out_unlock;
664 }
665 if (signal_pending(current)) {
666 retval = -ERESTARTSYS;
667 break;
668 }
669 if (time == 0) {
670 retval = -ETIMEDOUT;
671 break;
672 }
673 }
674 list_del(&ewp->list);
675 out_unlock:
676 spin_unlock(&info->lock);
677 out:
678 return retval;
679 }
680
681 /*
682 * Returns waiting task that should be serviced first or NULL if none exists
683 */
684 static struct ext_wait_queue *wq_get_first_waiter(
685 struct mqueue_inode_info *info, int sr)
686 {
687 struct list_head *ptr;
688
689 ptr = info->e_wait_q[sr].list.prev;
690 if (ptr == &info->e_wait_q[sr].list)
691 return NULL;
692 return list_entry(ptr, struct ext_wait_queue, list);
693 }
694
695
696 static inline void set_cookie(struct sk_buff *skb, char code)
697 {
698 ((char *)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
699 }
700
701 /*
702 * The next function is only to split too long sys_mq_timedsend
703 */
704 static void __do_notify(struct mqueue_inode_info *info)
705 {
706 /* notification
707 * invoked when there is registered process and there isn't process
708 * waiting synchronously for message AND state of queue changed from
709 * empty to not empty. Here we are sure that no one is waiting
710 * synchronously. */
711 if (info->notify_owner &&
712 info->attr.mq_curmsgs == 1) {
713 switch (info->notify.sigev_notify) {
714 case SIGEV_NONE:
715 break;
716 case SIGEV_SIGNAL: {
717 struct kernel_siginfo sig_i;
718 struct task_struct *task;
719
720 /* do_mq_notify() accepts sigev_signo == 0, why?? */
721 if (!info->notify.sigev_signo)
722 break;
723
724 clear_siginfo(&sig_i);
725 sig_i.si_signo = info->notify.sigev_signo;
726 sig_i.si_errno = 0;
727 sig_i.si_code = SI_MESGQ;
728 sig_i.si_value = info->notify.sigev_value;
729 rcu_read_lock();
730 /* map current pid/uid into info->owner's namespaces */
731 sig_i.si_pid = task_tgid_nr_ns(current,
732 ns_of_pid(info->notify_owner));
733 sig_i.si_uid = from_kuid_munged(info->notify_user_ns,
734 current_uid());
735 /*
736 * We can't use kill_pid_info(), this signal should
737 * bypass check_kill_permission(). It is from kernel
738 * but si_fromuser() can't know this.
739 * We do check the self_exec_id, to avoid sending
740 * signals to programs that don't expect them.
741 */
742 task = pid_task(info->notify_owner, PIDTYPE_TGID);
743 if (task && task->self_exec_id ==
744 info->notify_self_exec_id) {
745 do_send_sig_info(info->notify.sigev_signo,
746 &sig_i, task, PIDTYPE_TGID);
747 }
748 rcu_read_unlock();
749 break;
750 }
751 case SIGEV_THREAD:
752 set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
753 netlink_sendskb(info->notify_sock, info->notify_cookie);
754 break;
755 }
756 /* after notification unregisters process */
757 put_pid(info->notify_owner);
758 put_user_ns(info->notify_user_ns);
759 info->notify_owner = NULL;
760 info->notify_user_ns = NULL;
761 }
762 wake_up(&info->wait_q);
763 }
764
765 static int prepare_timeout(const struct __kernel_timespec __user *u_abs_timeout,
766 struct timespec64 *ts)
767 {
768 if (get_timespec64(ts, u_abs_timeout))
769 return -EFAULT;
770 if (!timespec64_valid(ts))
771 return -EINVAL;
772 return 0;
773 }
774
775 static void remove_notification(struct mqueue_inode_info *info)
776 {
777 if (info->notify_owner != NULL &&
778 info->notify.sigev_notify == SIGEV_THREAD) {
779 set_cookie(info->notify_cookie, NOTIFY_REMOVED);
780 netlink_sendskb(info->notify_sock, info->notify_cookie);
781 }
782 put_pid(info->notify_owner);
783 put_user_ns(info->notify_user_ns);
784 info->notify_owner = NULL;
785 info->notify_user_ns = NULL;
786 }
787
788 static int prepare_open(struct dentry *dentry, int oflag, int ro,
789 umode_t mode, struct filename *name,
790 struct mq_attr *attr)
791 {
792 static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
793 MAY_READ | MAY_WRITE };
794 int acc;
795
796 if (d_really_is_negative(dentry)) {
797 if (!(oflag & O_CREAT))
798 return -ENOENT;
799 if (ro)
800 return ro;
801 audit_inode_parent_hidden(name, dentry->d_parent);
802 return vfs_mkobj(dentry, mode & ~current_umask(),
803 mqueue_create_attr, attr);
804 }
805 /* it already existed */
806 audit_inode(name, dentry, 0);
807 if ((oflag & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
808 return -EEXIST;
809 if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
810 return -EINVAL;
811 acc = oflag2acc[oflag & O_ACCMODE];
812 return inode_permission(d_inode(dentry), acc);
813 }
814
815 static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
816 struct mq_attr *attr)
817 {
818 struct vfsmount *mnt = current->nsproxy->ipc_ns->mq_mnt;
819 struct dentry *root = mnt->mnt_root;
820 struct filename *name;
821 struct path path;
822 int fd, error;
823 int ro;
824
825 audit_mq_open(oflag, mode, attr);
826
827 if (IS_ERR(name = getname(u_name)))
828 return PTR_ERR(name);
829
830 fd = get_unused_fd_flags(O_CLOEXEC);
831 if (fd < 0)
832 goto out_putname;
833
834 ro = mnt_want_write(mnt); /* we'll drop it in any case */
835 inode_lock(d_inode(root));
836 path.dentry = lookup_one_len(name->name, root, strlen(name->name));
837 if (IS_ERR(path.dentry)) {
838 error = PTR_ERR(path.dentry);
839 goto out_putfd;
840 }
841 path.mnt = mntget(mnt);
842 error = prepare_open(path.dentry, oflag, ro, mode, name, attr);
843 if (!error) {
844 struct file *file = dentry_open(&path, oflag, current_cred());
845 if (!IS_ERR(file))
846 fd_install(fd, file);
847 else
848 error = PTR_ERR(file);
849 }
850 path_put(&path);
851 out_putfd:
852 if (error) {
853 put_unused_fd(fd);
854 fd = error;
855 }
856 inode_unlock(d_inode(root));
857 if (!ro)
858 mnt_drop_write(mnt);
859 out_putname:
860 putname(name);
861 return fd;
862 }
863
864 SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode,
865 struct mq_attr __user *, u_attr)
866 {
867 struct mq_attr attr;
868 if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
869 return -EFAULT;
870
871 return do_mq_open(u_name, oflag, mode, u_attr ? &attr : NULL);
872 }
873
874 SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
875 {
876 int err;
877 struct filename *name;
878 struct dentry *dentry;
879 struct inode *inode = NULL;
880 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
881 struct vfsmount *mnt = ipc_ns->mq_mnt;
882
883 name = getname(u_name);
884 if (IS_ERR(name))
885 return PTR_ERR(name);
886
887 audit_inode_parent_hidden(name, mnt->mnt_root);
888 err = mnt_want_write(mnt);
889 if (err)
890 goto out_name;
891 inode_lock_nested(d_inode(mnt->mnt_root), I_MUTEX_PARENT);
892 dentry = lookup_one_len(name->name, mnt->mnt_root,
893 strlen(name->name));
894 if (IS_ERR(dentry)) {
895 err = PTR_ERR(dentry);
896 goto out_unlock;
897 }
898
899 inode = d_inode(dentry);
900 if (!inode) {
901 err = -ENOENT;
902 } else {
903 ihold(inode);
904 err = vfs_unlink(d_inode(dentry->d_parent), dentry, NULL);
905 }
906 dput(dentry);
907
908 out_unlock:
909 inode_unlock(d_inode(mnt->mnt_root));
910 if (inode)
911 iput(inode);
912 mnt_drop_write(mnt);
913 out_name:
914 putname(name);
915
916 return err;
917 }
918
919 /* Pipelined send and receive functions.
920 *
921 * If a receiver finds no waiting message, then it registers itself in the
922 * list of waiting receivers. A sender checks that list before adding the new
923 * message into the message array. If there is a waiting receiver, then it
924 * bypasses the message array and directly hands the message over to the
925 * receiver. The receiver accepts the message and returns without grabbing the
926 * queue spinlock:
927 *
928 * - Set pointer to message.
929 * - Queue the receiver task for later wakeup (without the info->lock).
930 * - Update its state to STATE_READY. Now the receiver can continue.
931 * - Wake up the process after the lock is dropped. Should the process wake up
932 * before this wakeup (due to a timeout or a signal) it will either see
933 * STATE_READY and continue or acquire the lock to check the state again.
934 *
935 * The same algorithm is used for senders.
936 */
937
938 /* pipelined_send() - send a message directly to the task waiting in
939 * sys_mq_timedreceive() (without inserting message into a queue).
940 */
941 static inline void pipelined_send(struct wake_q_head *wake_q,
942 struct mqueue_inode_info *info,
943 struct msg_msg *message,
944 struct ext_wait_queue *receiver)
945 {
946 receiver->msg = message;
947 list_del(&receiver->list);
948 wake_q_add(wake_q, receiver->task);
949 /*
950 * Rely on the implicit cmpxchg barrier from wake_q_add such
951 * that we can ensure that updating receiver->state is the last
952 * write operation: As once set, the receiver can continue,
953 * and if we don't have the reference count from the wake_q,
954 * yet, at that point we can later have a use-after-free
955 * condition and bogus wakeup.
956 */
957 receiver->state = STATE_READY;
958 }
959
960 /* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
961 * gets its message and put to the queue (we have one free place for sure). */
962 static inline void pipelined_receive(struct wake_q_head *wake_q,
963 struct mqueue_inode_info *info)
964 {
965 struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
966
967 if (!sender) {
968 /* for poll */
969 wake_up_interruptible(&info->wait_q);
970 return;
971 }
972 if (msg_insert(sender->msg, info))
973 return;
974
975 list_del(&sender->list);
976 wake_q_add(wake_q, sender->task);
977 sender->state = STATE_READY;
978 }
979
980 static int do_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
981 size_t msg_len, unsigned int msg_prio,
982 struct timespec64 *ts)
983 {
984 struct fd f;
985 struct inode *inode;
986 struct ext_wait_queue wait;
987 struct ext_wait_queue *receiver;
988 struct msg_msg *msg_ptr;
989 struct mqueue_inode_info *info;
990 ktime_t expires, *timeout = NULL;
991 struct posix_msg_tree_node *new_leaf = NULL;
992 int ret = 0;
993 DEFINE_WAKE_Q(wake_q);
994
995 if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
996 return -EINVAL;
997
998 if (ts) {
999 expires = timespec64_to_ktime(*ts);
1000 timeout = &expires;
1001 }
1002
1003 audit_mq_sendrecv(mqdes, msg_len, msg_prio, ts);
1004
1005 f = fdget(mqdes);
1006 if (unlikely(!f.file)) {
1007 ret = -EBADF;
1008 goto out;
1009 }
1010
1011 inode = file_inode(f.file);
1012 if (unlikely(f.file->f_op != &mqueue_file_operations)) {
1013 ret = -EBADF;
1014 goto out_fput;
1015 }
1016 info = MQUEUE_I(inode);
1017 audit_file(f.file);
1018
1019 if (unlikely(!(f.file->f_mode & FMODE_WRITE))) {
1020 ret = -EBADF;
1021 goto out_fput;
1022 }
1023
1024 if (unlikely(msg_len > info->attr.mq_msgsize)) {
1025 ret = -EMSGSIZE;
1026 goto out_fput;
1027 }
1028
1029 /* First try to allocate memory, before doing anything with
1030 * existing queues. */
1031 msg_ptr = load_msg(u_msg_ptr, msg_len);
1032 if (IS_ERR(msg_ptr)) {
1033 ret = PTR_ERR(msg_ptr);
1034 goto out_fput;
1035 }
1036 msg_ptr->m_ts = msg_len;
1037 msg_ptr->m_type = msg_prio;
1038
1039 /*
1040 * msg_insert really wants us to have a valid, spare node struct so
1041 * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
1042 * fall back to that if necessary.
1043 */
1044 if (!info->node_cache)
1045 new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);
1046
1047 spin_lock(&info->lock);
1048
1049 if (!info->node_cache && new_leaf) {
1050 /* Save our speculative allocation into the cache */
1051 INIT_LIST_HEAD(&new_leaf->msg_list);
1052 info->node_cache = new_leaf;
1053 new_leaf = NULL;
1054 } else {
1055 kfree(new_leaf);
1056 }
1057
1058 if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
1059 if (f.file->f_flags & O_NONBLOCK) {
1060 ret = -EAGAIN;
1061 } else {
1062 wait.task = current;
1063 wait.msg = (void *) msg_ptr;
1064 wait.state = STATE_NONE;
1065 ret = wq_sleep(info, SEND, timeout, &wait);
1066 /*
1067 * wq_sleep must be called with info->lock held, and
1068 * returns with the lock released
1069 */
1070 goto out_free;
1071 }
1072 } else {
1073 receiver = wq_get_first_waiter(info, RECV);
1074 if (receiver) {
1075 pipelined_send(&wake_q, info, msg_ptr, receiver);
1076 } else {
1077 /* adds message to the queue */
1078 ret = msg_insert(msg_ptr, info);
1079 if (ret)
1080 goto out_unlock;
1081 __do_notify(info);
1082 }
1083 inode->i_atime = inode->i_mtime = inode->i_ctime =
1084 current_time(inode);
1085 }
1086 out_unlock:
1087 spin_unlock(&info->lock);
1088 wake_up_q(&wake_q);
1089 out_free:
1090 if (ret)
1091 free_msg(msg_ptr);
1092 out_fput:
1093 fdput(f);
1094 out:
1095 return ret;
1096 }
1097
1098 static int do_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
1099 size_t msg_len, unsigned int __user *u_msg_prio,
1100 struct timespec64 *ts)
1101 {
1102 ssize_t ret;
1103 struct msg_msg *msg_ptr;
1104 struct fd f;
1105 struct inode *inode;
1106 struct mqueue_inode_info *info;
1107 struct ext_wait_queue wait;
1108 ktime_t expires, *timeout = NULL;
1109 struct posix_msg_tree_node *new_leaf = NULL;
1110
1111 if (ts) {
1112 expires = timespec64_to_ktime(*ts);
1113 timeout = &expires;
1114 }
1115
1116 audit_mq_sendrecv(mqdes, msg_len, 0, ts);
1117
1118 f = fdget(mqdes);
1119 if (unlikely(!f.file)) {
1120 ret = -EBADF;
1121 goto out;
1122 }
1123
1124 inode = file_inode(f.file);
1125 if (unlikely(f.file->f_op != &mqueue_file_operations)) {
1126 ret = -EBADF;
1127 goto out_fput;
1128 }
1129 info = MQUEUE_I(inode);
1130 audit_file(f.file);
1131
1132 if (unlikely(!(f.file->f_mode & FMODE_READ))) {
1133 ret = -EBADF;
1134 goto out_fput;
1135 }
1136
1137 /* checks if buffer is big enough */
1138 if (unlikely(msg_len < info->attr.mq_msgsize)) {
1139 ret = -EMSGSIZE;
1140 goto out_fput;
1141 }
1142
1143 /*
1144 * msg_insert really wants us to have a valid, spare node struct so
1145 * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
1146 * fall back to that if necessary.
1147 */
1148 if (!info->node_cache)
1149 new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);
1150
1151 spin_lock(&info->lock);
1152
1153 if (!info->node_cache && new_leaf) {
1154 /* Save our speculative allocation into the cache */
1155 INIT_LIST_HEAD(&new_leaf->msg_list);
1156 info->node_cache = new_leaf;
1157 } else {
1158 kfree(new_leaf);
1159 }
1160
1161 if (info->attr.mq_curmsgs == 0) {
1162 if (f.file->f_flags & O_NONBLOCK) {
1163 spin_unlock(&info->lock);
1164 ret = -EAGAIN;
1165 } else {
1166 wait.task = current;
1167 wait.state = STATE_NONE;
1168 ret = wq_sleep(info, RECV, timeout, &wait);
1169 msg_ptr = wait.msg;
1170 }
1171 } else {
1172 DEFINE_WAKE_Q(wake_q);
1173
1174 msg_ptr = msg_get(info);
1175
1176 inode->i_atime = inode->i_mtime = inode->i_ctime =
1177 current_time(inode);
1178
1179 /* There is now free space in queue. */
1180 pipelined_receive(&wake_q, info);
1181 spin_unlock(&info->lock);
1182 wake_up_q(&wake_q);
1183 ret = 0;
1184 }
1185 if (ret == 0) {
1186 ret = msg_ptr->m_ts;
1187
1188 if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
1189 store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
1190 ret = -EFAULT;
1191 }
1192 free_msg(msg_ptr);
1193 }
1194 out_fput:
1195 fdput(f);
1196 out:
1197 return ret;
1198 }
1199
1200 SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
1201 size_t, msg_len, unsigned int, msg_prio,
1202 const struct __kernel_timespec __user *, u_abs_timeout)
1203 {
1204 struct timespec64 ts, *p = NULL;
1205 if (u_abs_timeout) {
1206 int res = prepare_timeout(u_abs_timeout, &ts);
1207 if (res)
1208 return res;
1209 p = &ts;
1210 }
1211 return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p);
1212 }
1213
1214 SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
1215 size_t, msg_len, unsigned int __user *, u_msg_prio,
1216 const struct __kernel_timespec __user *, u_abs_timeout)
1217 {
1218 struct timespec64 ts, *p = NULL;
1219 if (u_abs_timeout) {
1220 int res = prepare_timeout(u_abs_timeout, &ts);
1221 if (res)
1222 return res;
1223 p = &ts;
1224 }
1225 return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p);
1226 }
1227
1228 /*
1229 * Notes: the case when user wants us to deregister (with NULL as pointer)
1230 * and he isn't currently owner of notification, will be silently discarded.
1231 * It isn't explicitly defined in the POSIX.
1232 */
1233 static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification)
1234 {
1235 int ret;
1236 struct fd f;
1237 struct sock *sock;
1238 struct inode *inode;
1239 struct mqueue_inode_info *info;
1240 struct sk_buff *nc;
1241
1242 audit_mq_notify(mqdes, notification);
1243
1244 nc = NULL;
1245 sock = NULL;
1246 if (notification != NULL) {
1247 if (unlikely(notification->sigev_notify != SIGEV_NONE &&
1248 notification->sigev_notify != SIGEV_SIGNAL &&
1249 notification->sigev_notify != SIGEV_THREAD))
1250 return -EINVAL;
1251 if (notification->sigev_notify == SIGEV_SIGNAL &&
1252 !valid_signal(notification->sigev_signo)) {
1253 return -EINVAL;
1254 }
1255 if (notification->sigev_notify == SIGEV_THREAD) {
1256 long timeo;
1257
1258 /* create the notify skb */
1259 nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
1260 if (!nc)
1261 return -ENOMEM;
1262
1263 if (copy_from_user(nc->data,
1264 notification->sigev_value.sival_ptr,
1265 NOTIFY_COOKIE_LEN)) {
1266 ret = -EFAULT;
1267 goto free_skb;
1268 }
1269
1270 /* TODO: add a header? */
1271 skb_put(nc, NOTIFY_COOKIE_LEN);
1272 /* and attach it to the socket */
1273 retry:
1274 f = fdget(notification->sigev_signo);
1275 if (!f.file) {
1276 ret = -EBADF;
1277 goto out;
1278 }
1279 sock = netlink_getsockbyfilp(f.file);
1280 fdput(f);
1281 if (IS_ERR(sock)) {
1282 ret = PTR_ERR(sock);
1283 goto free_skb;
1284 }
1285
1286 timeo = MAX_SCHEDULE_TIMEOUT;
1287 ret = netlink_attachskb(sock, nc, &timeo, NULL);
1288 if (ret == 1) {
1289 sock = NULL;
1290 goto retry;
1291 }
1292 if (ret)
1293 return ret;
1294 }
1295 }
1296
1297 f = fdget(mqdes);
1298 if (!f.file) {
1299 ret = -EBADF;
1300 goto out;
1301 }
1302
1303 inode = file_inode(f.file);
1304 if (unlikely(f.file->f_op != &mqueue_file_operations)) {
1305 ret = -EBADF;
1306 goto out_fput;
1307 }
1308 info = MQUEUE_I(inode);
1309
1310 ret = 0;
1311 spin_lock(&info->lock);
1312 if (notification == NULL) {
1313 if (info->notify_owner == task_tgid(current)) {
1314 remove_notification(info);
1315 inode->i_atime = inode->i_ctime = current_time(inode);
1316 }
1317 } else if (info->notify_owner != NULL) {
1318 ret = -EBUSY;
1319 } else {
1320 switch (notification->sigev_notify) {
1321 case SIGEV_NONE:
1322 info->notify.sigev_notify = SIGEV_NONE;
1323 break;
1324 case SIGEV_THREAD:
1325 info->notify_sock = sock;
1326 info->notify_cookie = nc;
1327 sock = NULL;
1328 nc = NULL;
1329 info->notify.sigev_notify = SIGEV_THREAD;
1330 break;
1331 case SIGEV_SIGNAL:
1332 info->notify.sigev_signo = notification->sigev_signo;
1333 info->notify.sigev_value = notification->sigev_value;
1334 info->notify.sigev_notify = SIGEV_SIGNAL;
1335 info->notify_self_exec_id = current->self_exec_id;
1336 break;
1337 }
1338
1339 info->notify_owner = get_pid(task_tgid(current));
1340 info->notify_user_ns = get_user_ns(current_user_ns());
1341 inode->i_atime = inode->i_ctime = current_time(inode);
1342 }
1343 spin_unlock(&info->lock);
1344 out_fput:
1345 fdput(f);
1346 out:
1347 if (sock)
1348 netlink_detachskb(sock, nc);
1349 else
1350 free_skb:
1351 dev_kfree_skb(nc);
1352
1353 return ret;
1354 }
1355
1356 SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
1357 const struct sigevent __user *, u_notification)
1358 {
1359 struct sigevent n, *p = NULL;
1360 if (u_notification) {
1361 if (copy_from_user(&n, u_notification, sizeof(struct sigevent)))
1362 return -EFAULT;
1363 p = &n;
1364 }
1365 return do_mq_notify(mqdes, p);
1366 }
1367
1368 static int do_mq_getsetattr(int mqdes, struct mq_attr *new, struct mq_attr *old)
1369 {
1370 struct fd f;
1371 struct inode *inode;
1372 struct mqueue_inode_info *info;
1373
1374 if (new && (new->mq_flags & (~O_NONBLOCK)))
1375 return -EINVAL;
1376
1377 f = fdget(mqdes);
1378 if (!f.file)
1379 return -EBADF;
1380
1381 if (unlikely(f.file->f_op != &mqueue_file_operations)) {
1382 fdput(f);
1383 return -EBADF;
1384 }
1385
1386 inode = file_inode(f.file);
1387 info = MQUEUE_I(inode);
1388
1389 spin_lock(&info->lock);
1390
1391 if (old) {
1392 *old = info->attr;
1393 old->mq_flags = f.file->f_flags & O_NONBLOCK;
1394 }
1395 if (new) {
1396 audit_mq_getsetattr(mqdes, new);
1397 spin_lock(&f.file->f_lock);
1398 if (new->mq_flags & O_NONBLOCK)
1399 f.file->f_flags |= O_NONBLOCK;
1400 else
1401 f.file->f_flags &= ~O_NONBLOCK;
1402 spin_unlock(&f.file->f_lock);
1403
1404 inode->i_atime = inode->i_ctime = current_time(inode);
1405 }
1406
1407 spin_unlock(&info->lock);
1408 fdput(f);
1409 return 0;
1410 }
1411
1412 SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
1413 const struct mq_attr __user *, u_mqstat,
1414 struct mq_attr __user *, u_omqstat)
1415 {
1416 int ret;
1417 struct mq_attr mqstat, omqstat;
1418 struct mq_attr *new = NULL, *old = NULL;
1419
1420 if (u_mqstat) {
1421 new = &mqstat;
1422 if (copy_from_user(new, u_mqstat, sizeof(struct mq_attr)))
1423 return -EFAULT;
1424 }
1425 if (u_omqstat)
1426 old = &omqstat;
1427
1428 ret = do_mq_getsetattr(mqdes, new, old);
1429 if (ret || !old)
1430 return ret;
1431
1432 if (copy_to_user(u_omqstat, old, sizeof(struct mq_attr)))
1433 return -EFAULT;
1434 return 0;
1435 }
1436
1437 #ifdef CONFIG_COMPAT
1438
1439 struct compat_mq_attr {
1440 compat_long_t mq_flags; /* message queue flags */
1441 compat_long_t mq_maxmsg; /* maximum number of messages */
1442 compat_long_t mq_msgsize; /* maximum message size */
1443 compat_long_t mq_curmsgs; /* number of messages currently queued */
1444 compat_long_t __reserved[4]; /* ignored for input, zeroed for output */
1445 };
1446
1447 static inline int get_compat_mq_attr(struct mq_attr *attr,
1448 const struct compat_mq_attr __user *uattr)
1449 {
1450 struct compat_mq_attr v;
1451
1452 if (copy_from_user(&v, uattr, sizeof(*uattr)))
1453 return -EFAULT;
1454
1455 memset(attr, 0, sizeof(*attr));
1456 attr->mq_flags = v.mq_flags;
1457 attr->mq_maxmsg = v.mq_maxmsg;
1458 attr->mq_msgsize = v.mq_msgsize;
1459 attr->mq_curmsgs = v.mq_curmsgs;
1460 return 0;
1461 }
1462
1463 static inline int put_compat_mq_attr(const struct mq_attr *attr,
1464 struct compat_mq_attr __user *uattr)
1465 {
1466 struct compat_mq_attr v;
1467
1468 memset(&v, 0, sizeof(v));
1469 v.mq_flags = attr->mq_flags;
1470 v.mq_maxmsg = attr->mq_maxmsg;
1471 v.mq_msgsize = attr->mq_msgsize;
1472 v.mq_curmsgs = attr->mq_curmsgs;
1473 if (copy_to_user(uattr, &v, sizeof(*uattr)))
1474 return -EFAULT;
1475 return 0;
1476 }
1477
1478 COMPAT_SYSCALL_DEFINE4(mq_open, const char __user *, u_name,
1479 int, oflag, compat_mode_t, mode,
1480 struct compat_mq_attr __user *, u_attr)
1481 {
1482 struct mq_attr attr, *p = NULL;
1483 if (u_attr && oflag & O_CREAT) {
1484 p = &attr;
1485 if (get_compat_mq_attr(&attr, u_attr))
1486 return -EFAULT;
1487 }
1488 return do_mq_open(u_name, oflag, mode, p);
1489 }
1490
1491 COMPAT_SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
1492 const struct compat_sigevent __user *, u_notification)
1493 {
1494 struct sigevent n, *p = NULL;
1495 if (u_notification) {
1496 if (get_compat_sigevent(&n, u_notification))
1497 return -EFAULT;
1498 if (n.sigev_notify == SIGEV_THREAD)
1499 n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int);
1500 p = &n;
1501 }
1502 return do_mq_notify(mqdes, p);
1503 }
1504
1505 COMPAT_SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
1506 const struct compat_mq_attr __user *, u_mqstat,
1507 struct compat_mq_attr __user *, u_omqstat)
1508 {
1509 int ret;
1510 struct mq_attr mqstat, omqstat;
1511 struct mq_attr *new = NULL, *old = NULL;
1512
1513 if (u_mqstat) {
1514 new = &mqstat;
1515 if (get_compat_mq_attr(new, u_mqstat))
1516 return -EFAULT;
1517 }
1518 if (u_omqstat)
1519 old = &omqstat;
1520
1521 ret = do_mq_getsetattr(mqdes, new, old);
1522 if (ret || !old)
1523 return ret;
1524
1525 if (put_compat_mq_attr(old, u_omqstat))
1526 return -EFAULT;
1527 return 0;
1528 }
1529 #endif
1530
1531 #ifdef CONFIG_COMPAT_32BIT_TIME
1532 static int compat_prepare_timeout(const struct old_timespec32 __user *p,
1533 struct timespec64 *ts)
1534 {
1535 if (get_old_timespec32(ts, p))
1536 return -EFAULT;
1537 if (!timespec64_valid(ts))
1538 return -EINVAL;
1539 return 0;
1540 }
1541
1542 SYSCALL_DEFINE5(mq_timedsend_time32, mqd_t, mqdes,
1543 const char __user *, u_msg_ptr,
1544 unsigned int, msg_len, unsigned int, msg_prio,
1545 const struct old_timespec32 __user *, u_abs_timeout)
1546 {
1547 struct timespec64 ts, *p = NULL;
1548 if (u_abs_timeout) {
1549 int res = compat_prepare_timeout(u_abs_timeout, &ts);
1550 if (res)
1551 return res;
1552 p = &ts;
1553 }
1554 return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p);
1555 }
1556
1557 SYSCALL_DEFINE5(mq_timedreceive_time32, mqd_t, mqdes,
1558 char __user *, u_msg_ptr,
1559 unsigned int, msg_len, unsigned int __user *, u_msg_prio,
1560 const struct old_timespec32 __user *, u_abs_timeout)
1561 {
1562 struct timespec64 ts, *p = NULL;
1563 if (u_abs_timeout) {
1564 int res = compat_prepare_timeout(u_abs_timeout, &ts);
1565 if (res)
1566 return res;
1567 p = &ts;
1568 }
1569 return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p);
1570 }
1571 #endif
1572
1573 static const struct inode_operations mqueue_dir_inode_operations = {
1574 .lookup = simple_lookup,
1575 .create = mqueue_create,
1576 .unlink = mqueue_unlink,
1577 };
1578
1579 static const struct file_operations mqueue_file_operations = {
1580 .flush = mqueue_flush_file,
1581 .poll = mqueue_poll_file,
1582 .read = mqueue_read_file,
1583 .llseek = default_llseek,
1584 };
1585
1586 static const struct super_operations mqueue_super_ops = {
1587 .alloc_inode = mqueue_alloc_inode,
1588 .free_inode = mqueue_free_inode,
1589 .evict_inode = mqueue_evict_inode,
1590 .statfs = simple_statfs,
1591 };
1592
1593 static const struct fs_context_operations mqueue_fs_context_ops = {
1594 .free = mqueue_fs_context_free,
1595 .get_tree = mqueue_get_tree,
1596 };
1597
1598 static struct file_system_type mqueue_fs_type = {
1599 .name = "mqueue",
1600 .init_fs_context = mqueue_init_fs_context,
1601 .kill_sb = kill_litter_super,
1602 .fs_flags = FS_USERNS_MOUNT,
1603 };
1604
1605 int mq_init_ns(struct ipc_namespace *ns)
1606 {
1607 struct vfsmount *m;
1608
1609 ns->mq_queues_count = 0;
1610 ns->mq_queues_max = DFLT_QUEUESMAX;
1611 ns->mq_msg_max = DFLT_MSGMAX;
1612 ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
1613 ns->mq_msg_default = DFLT_MSG;
1614 ns->mq_msgsize_default = DFLT_MSGSIZE;
1615
1616 m = mq_create_mount(ns);
1617 if (IS_ERR(m))
1618 return PTR_ERR(m);
1619 ns->mq_mnt = m;
1620 return 0;
1621 }
1622
1623 void mq_clear_sbinfo(struct ipc_namespace *ns)
1624 {
1625 ns->mq_mnt->mnt_sb->s_fs_info = NULL;
1626 }
1627
1628 void mq_put_mnt(struct ipc_namespace *ns)
1629 {
1630 kern_unmount(ns->mq_mnt);
1631 }
1632
1633 static int __init init_mqueue_fs(void)
1634 {
1635 int error;
1636
1637 mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
1638 sizeof(struct mqueue_inode_info), 0,
1639 SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, init_once);
1640 if (mqueue_inode_cachep == NULL)
1641 return -ENOMEM;
1642
1643 /* ignore failures - they are not fatal */
1644 mq_sysctl_table = mq_register_sysctl_table();
1645
1646 error = register_filesystem(&mqueue_fs_type);
1647 if (error)
1648 goto out_sysctl;
1649
1650 spin_lock_init(&mq_lock);
1651
1652 error = mq_init_ns(&init_ipc_ns);
1653 if (error)
1654 goto out_filesystem;
1655
1656 return 0;
1657
1658 out_filesystem:
1659 unregister_filesystem(&mqueue_fs_type);
1660 out_sysctl:
1661 if (mq_sysctl_table)
1662 unregister_sysctl_table(mq_sysctl_table);
1663 kmem_cache_destroy(mqueue_inode_cachep);
1664 return error;
1665 }
1666
1667 device_initcall(init_mqueue_fs);
Linux with added FPC-III support