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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * POSIX message queues filesystem for Linux. | |
3 | * | |
4 | * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl) | |
f66e928b | 5 | * Michal Wronski (michal.wronski@gmail.com) |
1da177e4 LT |
6 | * |
7 | * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com) | |
8 | * Lockless receive & send, fd based notify: | |
239521f3 | 9 | * Manfred Spraul (manfred@colorfullife.com) |
1da177e4 | 10 | * |
20ca73bc GW |
11 | * Audit: George Wilson (ltcgcw@us.ibm.com) |
12 | * | |
1da177e4 LT |
13 | * This file is released under the GPL. |
14 | */ | |
15 | ||
c59ede7b | 16 | #include <linux/capability.h> |
1da177e4 LT |
17 | #include <linux/init.h> |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/file.h> | |
20 | #include <linux/mount.h> | |
935c6912 | 21 | #include <linux/fs_context.h> |
1da177e4 LT |
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> | |
5b5c4d1a | 28 | #include <linux/vmalloc.h> |
1da177e4 LT |
29 | #include <linux/netlink.h> |
30 | #include <linux/syscalls.h> | |
20ca73bc | 31 | #include <linux/audit.h> |
7ed20e1a | 32 | #include <linux/signal.h> |
5f921ae9 | 33 | #include <linux/mutex.h> |
b488893a PE |
34 | #include <linux/nsproxy.h> |
35 | #include <linux/pid.h> | |
614b84cf | 36 | #include <linux/ipc_namespace.h> |
6b550f94 | 37 | #include <linux/user_namespace.h> |
5a0e3ad6 | 38 | #include <linux/slab.h> |
84f001e1 | 39 | #include <linux/sched/wake_q.h> |
3f07c014 | 40 | #include <linux/sched/signal.h> |
8703e8a4 | 41 | #include <linux/sched/user.h> |
5f921ae9 | 42 | |
1da177e4 LT |
43 | #include <net/sock.h> |
44 | #include "util.h" | |
45 | ||
935c6912 DH |
46 | struct mqueue_fs_context { |
47 | struct ipc_namespace *ipc_ns; | |
48 | }; | |
49 | ||
1da177e4 LT |
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 | |
fa6004ad | 58 | #define STATE_READY 1 |
1da177e4 | 59 | |
d6629859 DL |
60 | struct posix_msg_tree_node { |
61 | struct rb_node rb_node; | |
62 | struct list_head msg_list; | |
63 | int priority; | |
64 | }; | |
65 | ||
c5b2cbdb MS |
66 | /* |
67 | * Locking: | |
68 | * | |
69 | * Accesses to a message queue are synchronized by acquiring info->lock. | |
70 | * | |
71 | * There are two notable exceptions: | |
72 | * - The actual wakeup of a sleeping task is performed using the wake_q | |
73 | * framework. info->lock is already released when wake_up_q is called. | |
74 | * - The exit codepaths after sleeping check ext_wait_queue->state without | |
75 | * any locks. If it is STATE_READY, then the syscall is completed without | |
76 | * acquiring info->lock. | |
77 | * | |
78 | * MQ_BARRIER: | |
79 | * To achieve proper release/acquire memory barrier pairing, the state is set to | |
80 | * STATE_READY with smp_store_release(), and it is read with READ_ONCE followed | |
81 | * by smp_acquire__after_ctrl_dep(). In addition, wake_q_add_safe() is used. | |
82 | * | |
83 | * This prevents the following races: | |
84 | * | |
85 | * 1) With the simple wake_q_add(), the task could be gone already before | |
86 | * the increase of the reference happens | |
87 | * Thread A | |
88 | * Thread B | |
89 | * WRITE_ONCE(wait.state, STATE_NONE); | |
90 | * schedule_hrtimeout() | |
91 | * wake_q_add(A) | |
92 | * if (cmpxchg()) // success | |
93 | * ->state = STATE_READY (reordered) | |
94 | * <timeout returns> | |
95 | * if (wait.state == STATE_READY) return; | |
96 | * sysret to user space | |
97 | * sys_exit() | |
98 | * get_task_struct() // UaF | |
99 | * | |
100 | * Solution: Use wake_q_add_safe() and perform the get_task_struct() before | |
101 | * the smp_store_release() that does ->state = STATE_READY. | |
102 | * | |
103 | * 2) Without proper _release/_acquire barriers, the woken up task | |
104 | * could read stale data | |
105 | * | |
106 | * Thread A | |
107 | * Thread B | |
108 | * do_mq_timedreceive | |
109 | * WRITE_ONCE(wait.state, STATE_NONE); | |
110 | * schedule_hrtimeout() | |
111 | * state = STATE_READY; | |
112 | * <timeout returns> | |
113 | * if (wait.state == STATE_READY) return; | |
114 | * msg_ptr = wait.msg; // Access to stale data! | |
115 | * receiver->msg = message; (reordered) | |
116 | * | |
117 | * Solution: use _release and _acquire barriers. | |
118 | * | |
119 | * 3) There is intentionally no barrier when setting current->state | |
120 | * to TASK_INTERRUPTIBLE: spin_unlock(&info->lock) provides the | |
121 | * release memory barrier, and the wakeup is triggered when holding | |
122 | * info->lock, i.e. spin_lock(&info->lock) provided a pairing | |
123 | * acquire memory barrier. | |
124 | */ | |
125 | ||
1da177e4 LT |
126 | struct ext_wait_queue { /* queue of sleeping tasks */ |
127 | struct task_struct *task; | |
128 | struct list_head list; | |
129 | struct msg_msg *msg; /* ptr of loaded message */ | |
130 | int state; /* one of STATE_* values */ | |
131 | }; | |
132 | ||
133 | struct mqueue_inode_info { | |
134 | spinlock_t lock; | |
135 | struct inode vfs_inode; | |
136 | wait_queue_head_t wait_q; | |
137 | ||
d6629859 | 138 | struct rb_root msg_tree; |
a5091fda | 139 | struct rb_node *msg_tree_rightmost; |
ce2d52cc | 140 | struct posix_msg_tree_node *node_cache; |
1da177e4 LT |
141 | struct mq_attr attr; |
142 | ||
143 | struct sigevent notify; | |
239521f3 | 144 | struct pid *notify_owner; |
6f9ac6d9 | 145 | struct user_namespace *notify_user_ns; |
338cec32 | 146 | struct user_struct *user; /* user who created, for accounting */ |
1da177e4 LT |
147 | struct sock *notify_sock; |
148 | struct sk_buff *notify_cookie; | |
149 | ||
150 | /* for tasks waiting for free space and messages, respectively */ | |
151 | struct ext_wait_queue e_wait_q[2]; | |
152 | ||
153 | unsigned long qsize; /* size of queue in memory (sum of all msgs) */ | |
154 | }; | |
155 | ||
935c6912 | 156 | static struct file_system_type mqueue_fs_type; |
92e1d5be | 157 | static const struct inode_operations mqueue_dir_inode_operations; |
9a32144e | 158 | static const struct file_operations mqueue_file_operations; |
b87221de | 159 | static const struct super_operations mqueue_super_ops; |
935c6912 | 160 | static const struct fs_context_operations mqueue_fs_context_ops; |
1da177e4 LT |
161 | static void remove_notification(struct mqueue_inode_info *info); |
162 | ||
e18b890b | 163 | static struct kmem_cache *mqueue_inode_cachep; |
1da177e4 | 164 | |
239521f3 | 165 | static struct ctl_table_header *mq_sysctl_table; |
1da177e4 LT |
166 | |
167 | static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode) | |
168 | { | |
169 | return container_of(inode, struct mqueue_inode_info, vfs_inode); | |
170 | } | |
171 | ||
7eafd7c7 SH |
172 | /* |
173 | * This routine should be called with the mq_lock held. | |
174 | */ | |
175 | static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode) | |
614b84cf | 176 | { |
7eafd7c7 | 177 | return get_ipc_ns(inode->i_sb->s_fs_info); |
614b84cf SH |
178 | } |
179 | ||
7eafd7c7 | 180 | static struct ipc_namespace *get_ns_from_inode(struct inode *inode) |
614b84cf | 181 | { |
7eafd7c7 SH |
182 | struct ipc_namespace *ns; |
183 | ||
184 | spin_lock(&mq_lock); | |
185 | ns = __get_ns_from_inode(inode); | |
186 | spin_unlock(&mq_lock); | |
187 | return ns; | |
614b84cf SH |
188 | } |
189 | ||
d6629859 DL |
190 | /* Auxiliary functions to manipulate messages' list */ |
191 | static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info) | |
192 | { | |
193 | struct rb_node **p, *parent = NULL; | |
194 | struct posix_msg_tree_node *leaf; | |
a5091fda | 195 | bool rightmost = true; |
d6629859 DL |
196 | |
197 | p = &info->msg_tree.rb_node; | |
198 | while (*p) { | |
199 | parent = *p; | |
200 | leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node); | |
201 | ||
202 | if (likely(leaf->priority == msg->m_type)) | |
203 | goto insert_msg; | |
a5091fda | 204 | else if (msg->m_type < leaf->priority) { |
d6629859 | 205 | p = &(*p)->rb_left; |
a5091fda DB |
206 | rightmost = false; |
207 | } else | |
d6629859 DL |
208 | p = &(*p)->rb_right; |
209 | } | |
ce2d52cc DL |
210 | if (info->node_cache) { |
211 | leaf = info->node_cache; | |
212 | info->node_cache = NULL; | |
213 | } else { | |
214 | leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC); | |
215 | if (!leaf) | |
216 | return -ENOMEM; | |
ce2d52cc | 217 | INIT_LIST_HEAD(&leaf->msg_list); |
ce2d52cc | 218 | } |
d6629859 | 219 | leaf->priority = msg->m_type; |
a5091fda DB |
220 | |
221 | if (rightmost) | |
222 | info->msg_tree_rightmost = &leaf->rb_node; | |
223 | ||
d6629859 DL |
224 | rb_link_node(&leaf->rb_node, parent, p); |
225 | rb_insert_color(&leaf->rb_node, &info->msg_tree); | |
d6629859 DL |
226 | insert_msg: |
227 | info->attr.mq_curmsgs++; | |
228 | info->qsize += msg->m_ts; | |
229 | list_add_tail(&msg->m_list, &leaf->msg_list); | |
230 | return 0; | |
231 | } | |
232 | ||
a5091fda DB |
233 | static inline void msg_tree_erase(struct posix_msg_tree_node *leaf, |
234 | struct mqueue_inode_info *info) | |
235 | { | |
236 | struct rb_node *node = &leaf->rb_node; | |
237 | ||
238 | if (info->msg_tree_rightmost == node) | |
239 | info->msg_tree_rightmost = rb_prev(node); | |
240 | ||
241 | rb_erase(node, &info->msg_tree); | |
242 | if (info->node_cache) { | |
243 | kfree(leaf); | |
244 | } else { | |
245 | info->node_cache = leaf; | |
246 | } | |
247 | } | |
248 | ||
d6629859 DL |
249 | static inline struct msg_msg *msg_get(struct mqueue_inode_info *info) |
250 | { | |
a5091fda | 251 | struct rb_node *parent = NULL; |
d6629859 DL |
252 | struct posix_msg_tree_node *leaf; |
253 | struct msg_msg *msg; | |
254 | ||
255 | try_again: | |
a5091fda DB |
256 | /* |
257 | * During insert, low priorities go to the left and high to the | |
258 | * right. On receive, we want the highest priorities first, so | |
259 | * walk all the way to the right. | |
260 | */ | |
261 | parent = info->msg_tree_rightmost; | |
d6629859 DL |
262 | if (!parent) { |
263 | if (info->attr.mq_curmsgs) { | |
264 | pr_warn_once("Inconsistency in POSIX message queue, " | |
265 | "no tree element, but supposedly messages " | |
266 | "should exist!\n"); | |
267 | info->attr.mq_curmsgs = 0; | |
268 | } | |
269 | return NULL; | |
270 | } | |
271 | leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node); | |
ce2d52cc | 272 | if (unlikely(list_empty(&leaf->msg_list))) { |
d6629859 DL |
273 | pr_warn_once("Inconsistency in POSIX message queue, " |
274 | "empty leaf node but we haven't implemented " | |
275 | "lazy leaf delete!\n"); | |
a5091fda | 276 | msg_tree_erase(leaf, info); |
d6629859 DL |
277 | goto try_again; |
278 | } else { | |
279 | msg = list_first_entry(&leaf->msg_list, | |
280 | struct msg_msg, m_list); | |
281 | list_del(&msg->m_list); | |
282 | if (list_empty(&leaf->msg_list)) { | |
a5091fda | 283 | msg_tree_erase(leaf, info); |
d6629859 DL |
284 | } |
285 | } | |
286 | info->attr.mq_curmsgs--; | |
287 | info->qsize -= msg->m_ts; | |
288 | return msg; | |
289 | } | |
290 | ||
7eafd7c7 | 291 | static struct inode *mqueue_get_inode(struct super_block *sb, |
1b9d5ff7 | 292 | struct ipc_namespace *ipc_ns, umode_t mode, |
7eafd7c7 | 293 | struct mq_attr *attr) |
1da177e4 | 294 | { |
86a264ab | 295 | struct user_struct *u = current_user(); |
1da177e4 | 296 | struct inode *inode; |
d40dcdb0 | 297 | int ret = -ENOMEM; |
1da177e4 LT |
298 | |
299 | inode = new_inode(sb); | |
04715206 JS |
300 | if (!inode) |
301 | goto err; | |
302 | ||
303 | inode->i_ino = get_next_ino(); | |
304 | inode->i_mode = mode; | |
305 | inode->i_uid = current_fsuid(); | |
306 | inode->i_gid = current_fsgid(); | |
078cd827 | 307 | inode->i_mtime = inode->i_ctime = inode->i_atime = current_time(inode); |
04715206 JS |
308 | |
309 | if (S_ISREG(mode)) { | |
310 | struct mqueue_inode_info *info; | |
d6629859 | 311 | unsigned long mq_bytes, mq_treesize; |
04715206 JS |
312 | |
313 | inode->i_fop = &mqueue_file_operations; | |
314 | inode->i_size = FILENT_SIZE; | |
315 | /* mqueue specific info */ | |
316 | info = MQUEUE_I(inode); | |
317 | spin_lock_init(&info->lock); | |
318 | init_waitqueue_head(&info->wait_q); | |
319 | INIT_LIST_HEAD(&info->e_wait_q[0].list); | |
320 | INIT_LIST_HEAD(&info->e_wait_q[1].list); | |
321 | info->notify_owner = NULL; | |
6f9ac6d9 | 322 | info->notify_user_ns = NULL; |
04715206 JS |
323 | info->qsize = 0; |
324 | info->user = NULL; /* set when all is ok */ | |
d6629859 | 325 | info->msg_tree = RB_ROOT; |
a5091fda | 326 | info->msg_tree_rightmost = NULL; |
ce2d52cc | 327 | info->node_cache = NULL; |
04715206 | 328 | memset(&info->attr, 0, sizeof(info->attr)); |
cef0184c KM |
329 | info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max, |
330 | ipc_ns->mq_msg_default); | |
331 | info->attr.mq_msgsize = min(ipc_ns->mq_msgsize_max, | |
332 | ipc_ns->mq_msgsize_default); | |
04715206 JS |
333 | if (attr) { |
334 | info->attr.mq_maxmsg = attr->mq_maxmsg; | |
335 | info->attr.mq_msgsize = attr->mq_msgsize; | |
336 | } | |
d6629859 DL |
337 | /* |
338 | * We used to allocate a static array of pointers and account | |
339 | * the size of that array as well as one msg_msg struct per | |
340 | * possible message into the queue size. That's no longer | |
341 | * accurate as the queue is now an rbtree and will grow and | |
342 | * shrink depending on usage patterns. We can, however, still | |
343 | * account one msg_msg struct per message, but the nodes are | |
344 | * allocated depending on priority usage, and most programs | |
345 | * only use one, or a handful, of priorities. However, since | |
346 | * this is pinned memory, we need to assume worst case, so | |
347 | * that means the min(mq_maxmsg, max_priorities) * struct | |
348 | * posix_msg_tree_node. | |
349 | */ | |
05c1b290 AV |
350 | |
351 | ret = -EINVAL; | |
352 | if (info->attr.mq_maxmsg <= 0 || info->attr.mq_msgsize <= 0) | |
353 | goto out_inode; | |
354 | if (capable(CAP_SYS_RESOURCE)) { | |
355 | if (info->attr.mq_maxmsg > HARD_MSGMAX || | |
356 | info->attr.mq_msgsize > HARD_MSGSIZEMAX) | |
357 | goto out_inode; | |
358 | } else { | |
359 | if (info->attr.mq_maxmsg > ipc_ns->mq_msg_max || | |
360 | info->attr.mq_msgsize > ipc_ns->mq_msgsize_max) | |
361 | goto out_inode; | |
362 | } | |
363 | ret = -EOVERFLOW; | |
364 | /* check for overflow */ | |
365 | if (info->attr.mq_msgsize > ULONG_MAX/info->attr.mq_maxmsg) | |
366 | goto out_inode; | |
d6629859 DL |
367 | mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) + |
368 | min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) * | |
369 | sizeof(struct posix_msg_tree_node); | |
05c1b290 AV |
370 | mq_bytes = info->attr.mq_maxmsg * info->attr.mq_msgsize; |
371 | if (mq_bytes + mq_treesize < mq_bytes) | |
372 | goto out_inode; | |
373 | mq_bytes += mq_treesize; | |
04715206 JS |
374 | spin_lock(&mq_lock); |
375 | if (u->mq_bytes + mq_bytes < u->mq_bytes || | |
2a4e64b8 | 376 | u->mq_bytes + mq_bytes > rlimit(RLIMIT_MSGQUEUE)) { |
04715206 JS |
377 | spin_unlock(&mq_lock); |
378 | /* mqueue_evict_inode() releases info->messages */ | |
d40dcdb0 | 379 | ret = -EMFILE; |
04715206 | 380 | goto out_inode; |
1da177e4 | 381 | } |
04715206 JS |
382 | u->mq_bytes += mq_bytes; |
383 | spin_unlock(&mq_lock); | |
384 | ||
385 | /* all is ok */ | |
386 | info->user = get_uid(u); | |
387 | } else if (S_ISDIR(mode)) { | |
388 | inc_nlink(inode); | |
389 | /* Some things misbehave if size == 0 on a directory */ | |
390 | inode->i_size = 2 * DIRENT_SIZE; | |
391 | inode->i_op = &mqueue_dir_inode_operations; | |
392 | inode->i_fop = &simple_dir_operations; | |
1da177e4 | 393 | } |
04715206 | 394 | |
1da177e4 LT |
395 | return inode; |
396 | out_inode: | |
1da177e4 | 397 | iput(inode); |
04715206 | 398 | err: |
d40dcdb0 | 399 | return ERR_PTR(ret); |
1da177e4 LT |
400 | } |
401 | ||
935c6912 | 402 | static int mqueue_fill_super(struct super_block *sb, struct fs_context *fc) |
1da177e4 LT |
403 | { |
404 | struct inode *inode; | |
cfb2f6f6 | 405 | struct ipc_namespace *ns = sb->s_fs_info; |
1da177e4 | 406 | |
a2982cc9 | 407 | sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV; |
09cbfeaf KS |
408 | sb->s_blocksize = PAGE_SIZE; |
409 | sb->s_blocksize_bits = PAGE_SHIFT; | |
1da177e4 LT |
410 | sb->s_magic = MQUEUE_MAGIC; |
411 | sb->s_op = &mqueue_super_ops; | |
412 | ||
48fde701 AV |
413 | inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO, NULL); |
414 | if (IS_ERR(inode)) | |
415 | return PTR_ERR(inode); | |
1da177e4 | 416 | |
48fde701 AV |
417 | sb->s_root = d_make_root(inode); |
418 | if (!sb->s_root) | |
419 | return -ENOMEM; | |
420 | return 0; | |
1da177e4 LT |
421 | } |
422 | ||
935c6912 | 423 | static int mqueue_get_tree(struct fs_context *fc) |
1da177e4 | 424 | { |
935c6912 DH |
425 | struct mqueue_fs_context *ctx = fc->fs_private; |
426 | ||
533770cc | 427 | return get_tree_keyed(fc, mqueue_fill_super, ctx->ipc_ns); |
935c6912 DH |
428 | } |
429 | ||
430 | static void mqueue_fs_context_free(struct fs_context *fc) | |
431 | { | |
432 | struct mqueue_fs_context *ctx = fc->fs_private; | |
433 | ||
709a643d | 434 | put_ipc_ns(ctx->ipc_ns); |
935c6912 DH |
435 | kfree(ctx); |
436 | } | |
437 | ||
438 | static int mqueue_init_fs_context(struct fs_context *fc) | |
439 | { | |
440 | struct mqueue_fs_context *ctx; | |
441 | ||
442 | ctx = kzalloc(sizeof(struct mqueue_fs_context), GFP_KERNEL); | |
443 | if (!ctx) | |
444 | return -ENOMEM; | |
445 | ||
446 | ctx->ipc_ns = get_ipc_ns(current->nsproxy->ipc_ns); | |
709a643d AV |
447 | put_user_ns(fc->user_ns); |
448 | fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns); | |
935c6912 DH |
449 | fc->fs_private = ctx; |
450 | fc->ops = &mqueue_fs_context_ops; | |
451 | return 0; | |
452 | } | |
453 | ||
454 | static struct vfsmount *mq_create_mount(struct ipc_namespace *ns) | |
455 | { | |
456 | struct mqueue_fs_context *ctx; | |
457 | struct fs_context *fc; | |
458 | struct vfsmount *mnt; | |
459 | ||
460 | fc = fs_context_for_mount(&mqueue_fs_type, SB_KERNMOUNT); | |
461 | if (IS_ERR(fc)) | |
462 | return ERR_CAST(fc); | |
463 | ||
464 | ctx = fc->fs_private; | |
465 | put_ipc_ns(ctx->ipc_ns); | |
466 | ctx->ipc_ns = get_ipc_ns(ns); | |
709a643d AV |
467 | put_user_ns(fc->user_ns); |
468 | fc->user_ns = get_user_ns(ctx->ipc_ns->user_ns); | |
935c6912 DH |
469 | |
470 | mnt = fc_mount(fc); | |
471 | put_fs_context(fc); | |
472 | return mnt; | |
1da177e4 LT |
473 | } |
474 | ||
51cc5068 | 475 | static void init_once(void *foo) |
1da177e4 LT |
476 | { |
477 | struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo; | |
478 | ||
a35afb83 | 479 | inode_init_once(&p->vfs_inode); |
1da177e4 LT |
480 | } |
481 | ||
482 | static struct inode *mqueue_alloc_inode(struct super_block *sb) | |
483 | { | |
484 | struct mqueue_inode_info *ei; | |
485 | ||
e94b1766 | 486 | ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL); |
1da177e4 LT |
487 | if (!ei) |
488 | return NULL; | |
489 | return &ei->vfs_inode; | |
490 | } | |
491 | ||
015d7956 | 492 | static void mqueue_free_inode(struct inode *inode) |
1da177e4 LT |
493 | { |
494 | kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode)); | |
495 | } | |
496 | ||
6d8af64c | 497 | static void mqueue_evict_inode(struct inode *inode) |
1da177e4 LT |
498 | { |
499 | struct mqueue_inode_info *info; | |
500 | struct user_struct *user; | |
7eafd7c7 | 501 | struct ipc_namespace *ipc_ns; |
d6a2946a LR |
502 | struct msg_msg *msg, *nmsg; |
503 | LIST_HEAD(tmp_msg); | |
1da177e4 | 504 | |
dbd5768f | 505 | clear_inode(inode); |
6d8af64c AV |
506 | |
507 | if (S_ISDIR(inode->i_mode)) | |
1da177e4 | 508 | return; |
6d8af64c | 509 | |
7eafd7c7 | 510 | ipc_ns = get_ns_from_inode(inode); |
1da177e4 LT |
511 | info = MQUEUE_I(inode); |
512 | spin_lock(&info->lock); | |
d6629859 | 513 | while ((msg = msg_get(info)) != NULL) |
d6a2946a | 514 | list_add_tail(&msg->m_list, &tmp_msg); |
ce2d52cc | 515 | kfree(info->node_cache); |
1da177e4 LT |
516 | spin_unlock(&info->lock); |
517 | ||
d6a2946a LR |
518 | list_for_each_entry_safe(msg, nmsg, &tmp_msg, m_list) { |
519 | list_del(&msg->m_list); | |
520 | free_msg(msg); | |
521 | } | |
522 | ||
1da177e4 LT |
523 | user = info->user; |
524 | if (user) { | |
a318f12e KC |
525 | unsigned long mq_bytes, mq_treesize; |
526 | ||
527 | /* Total amount of bytes accounted for the mqueue */ | |
528 | mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) + | |
529 | min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) * | |
530 | sizeof(struct posix_msg_tree_node); | |
531 | ||
532 | mq_bytes = mq_treesize + (info->attr.mq_maxmsg * | |
533 | info->attr.mq_msgsize); | |
534 | ||
1da177e4 LT |
535 | spin_lock(&mq_lock); |
536 | user->mq_bytes -= mq_bytes; | |
7eafd7c7 SH |
537 | /* |
538 | * get_ns_from_inode() ensures that the | |
539 | * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns | |
540 | * to which we now hold a reference, or it is NULL. | |
541 | * We can't put it here under mq_lock, though. | |
542 | */ | |
543 | if (ipc_ns) | |
544 | ipc_ns->mq_queues_count--; | |
1da177e4 LT |
545 | spin_unlock(&mq_lock); |
546 | free_uid(user); | |
547 | } | |
7eafd7c7 SH |
548 | if (ipc_ns) |
549 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
550 | } |
551 | ||
eecec19d | 552 | static int mqueue_create_attr(struct dentry *dentry, umode_t mode, void *arg) |
1da177e4 | 553 | { |
eecec19d | 554 | struct inode *dir = dentry->d_parent->d_inode; |
1da177e4 | 555 | struct inode *inode; |
eecec19d | 556 | struct mq_attr *attr = arg; |
1da177e4 | 557 | int error; |
7eafd7c7 | 558 | struct ipc_namespace *ipc_ns; |
1da177e4 LT |
559 | |
560 | spin_lock(&mq_lock); | |
7eafd7c7 SH |
561 | ipc_ns = __get_ns_from_inode(dir); |
562 | if (!ipc_ns) { | |
563 | error = -EACCES; | |
564 | goto out_unlock; | |
565 | } | |
f3713fd9 DB |
566 | |
567 | if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max && | |
568 | !capable(CAP_SYS_RESOURCE)) { | |
1da177e4 | 569 | error = -ENOSPC; |
614b84cf | 570 | goto out_unlock; |
1da177e4 | 571 | } |
614b84cf | 572 | ipc_ns->mq_queues_count++; |
1da177e4 LT |
573 | spin_unlock(&mq_lock); |
574 | ||
7eafd7c7 | 575 | inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr); |
d40dcdb0 JS |
576 | if (IS_ERR(inode)) { |
577 | error = PTR_ERR(inode); | |
1da177e4 | 578 | spin_lock(&mq_lock); |
614b84cf SH |
579 | ipc_ns->mq_queues_count--; |
580 | goto out_unlock; | |
1da177e4 LT |
581 | } |
582 | ||
7eafd7c7 | 583 | put_ipc_ns(ipc_ns); |
1da177e4 | 584 | dir->i_size += DIRENT_SIZE; |
078cd827 | 585 | dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir); |
1da177e4 LT |
586 | |
587 | d_instantiate(dentry, inode); | |
588 | dget(dentry); | |
589 | return 0; | |
614b84cf | 590 | out_unlock: |
1da177e4 | 591 | spin_unlock(&mq_lock); |
7eafd7c7 SH |
592 | if (ipc_ns) |
593 | put_ipc_ns(ipc_ns); | |
1da177e4 LT |
594 | return error; |
595 | } | |
596 | ||
eecec19d AV |
597 | static int mqueue_create(struct inode *dir, struct dentry *dentry, |
598 | umode_t mode, bool excl) | |
599 | { | |
600 | return mqueue_create_attr(dentry, mode, NULL); | |
601 | } | |
602 | ||
1da177e4 LT |
603 | static int mqueue_unlink(struct inode *dir, struct dentry *dentry) |
604 | { | |
75c3cfa8 | 605 | struct inode *inode = d_inode(dentry); |
1da177e4 | 606 | |
078cd827 | 607 | dir->i_ctime = dir->i_mtime = dir->i_atime = current_time(dir); |
1da177e4 | 608 | dir->i_size -= DIRENT_SIZE; |
239521f3 MS |
609 | drop_nlink(inode); |
610 | dput(dentry); | |
611 | return 0; | |
1da177e4 LT |
612 | } |
613 | ||
614 | /* | |
615 | * This is routine for system read from queue file. | |
616 | * To avoid mess with doing here some sort of mq_receive we allow | |
617 | * to read only queue size & notification info (the only values | |
618 | * that are interesting from user point of view and aren't accessible | |
619 | * through std routines) | |
620 | */ | |
621 | static ssize_t mqueue_read_file(struct file *filp, char __user *u_data, | |
f1a43f93 | 622 | size_t count, loff_t *off) |
1da177e4 | 623 | { |
496ad9aa | 624 | struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp)); |
1da177e4 | 625 | char buffer[FILENT_SIZE]; |
f1a43f93 | 626 | ssize_t ret; |
1da177e4 LT |
627 | |
628 | spin_lock(&info->lock); | |
629 | snprintf(buffer, sizeof(buffer), | |
630 | "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n", | |
631 | info->qsize, | |
632 | info->notify_owner ? info->notify.sigev_notify : 0, | |
633 | (info->notify_owner && | |
634 | info->notify.sigev_notify == SIGEV_SIGNAL) ? | |
635 | info->notify.sigev_signo : 0, | |
6c5f3e7b | 636 | pid_vnr(info->notify_owner)); |
1da177e4 LT |
637 | spin_unlock(&info->lock); |
638 | buffer[sizeof(buffer)-1] = '\0'; | |
1da177e4 | 639 | |
f1a43f93 AM |
640 | ret = simple_read_from_buffer(u_data, count, off, buffer, |
641 | strlen(buffer)); | |
642 | if (ret <= 0) | |
643 | return ret; | |
1da177e4 | 644 | |
078cd827 | 645 | file_inode(filp)->i_atime = file_inode(filp)->i_ctime = current_time(file_inode(filp)); |
f1a43f93 | 646 | return ret; |
1da177e4 LT |
647 | } |
648 | ||
75e1fcc0 | 649 | static int mqueue_flush_file(struct file *filp, fl_owner_t id) |
1da177e4 | 650 | { |
496ad9aa | 651 | struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp)); |
1da177e4 LT |
652 | |
653 | spin_lock(&info->lock); | |
a03fcb73 | 654 | if (task_tgid(current) == info->notify_owner) |
1da177e4 LT |
655 | remove_notification(info); |
656 | ||
657 | spin_unlock(&info->lock); | |
658 | return 0; | |
659 | } | |
660 | ||
9dd95748 | 661 | static __poll_t mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab) |
1da177e4 | 662 | { |
496ad9aa | 663 | struct mqueue_inode_info *info = MQUEUE_I(file_inode(filp)); |
9dd95748 | 664 | __poll_t retval = 0; |
1da177e4 LT |
665 | |
666 | poll_wait(filp, &info->wait_q, poll_tab); | |
667 | ||
668 | spin_lock(&info->lock); | |
669 | if (info->attr.mq_curmsgs) | |
a9a08845 | 670 | retval = EPOLLIN | EPOLLRDNORM; |
1da177e4 LT |
671 | |
672 | if (info->attr.mq_curmsgs < info->attr.mq_maxmsg) | |
a9a08845 | 673 | retval |= EPOLLOUT | EPOLLWRNORM; |
1da177e4 LT |
674 | spin_unlock(&info->lock); |
675 | ||
676 | return retval; | |
677 | } | |
678 | ||
679 | /* Adds current to info->e_wait_q[sr] before element with smaller prio */ | |
680 | static void wq_add(struct mqueue_inode_info *info, int sr, | |
681 | struct ext_wait_queue *ewp) | |
682 | { | |
683 | struct ext_wait_queue *walk; | |
684 | ||
1da177e4 | 685 | list_for_each_entry(walk, &info->e_wait_q[sr].list, list) { |
68e34f4e | 686 | if (walk->task->prio <= current->prio) { |
1da177e4 LT |
687 | list_add_tail(&ewp->list, &walk->list); |
688 | return; | |
689 | } | |
690 | } | |
691 | list_add_tail(&ewp->list, &info->e_wait_q[sr].list); | |
692 | } | |
693 | ||
694 | /* | |
695 | * Puts current task to sleep. Caller must hold queue lock. After return | |
696 | * lock isn't held. | |
697 | * sr: SEND or RECV | |
698 | */ | |
699 | static int wq_sleep(struct mqueue_inode_info *info, int sr, | |
9ca7d8e6 | 700 | ktime_t *timeout, struct ext_wait_queue *ewp) |
eac0b1c3 | 701 | __releases(&info->lock) |
1da177e4 LT |
702 | { |
703 | int retval; | |
704 | signed long time; | |
705 | ||
706 | wq_add(info, sr, ewp); | |
707 | ||
708 | for (;;) { | |
c5b2cbdb | 709 | /* memory barrier not required, we hold info->lock */ |
fa6004ad | 710 | __set_current_state(TASK_INTERRUPTIBLE); |
1da177e4 LT |
711 | |
712 | spin_unlock(&info->lock); | |
32ea845d WG |
713 | time = schedule_hrtimeout_range_clock(timeout, 0, |
714 | HRTIMER_MODE_ABS, CLOCK_REALTIME); | |
1da177e4 | 715 | |
c5b2cbdb MS |
716 | if (READ_ONCE(ewp->state) == STATE_READY) { |
717 | /* see MQ_BARRIER for purpose/pairing */ | |
718 | smp_acquire__after_ctrl_dep(); | |
1da177e4 LT |
719 | retval = 0; |
720 | goto out; | |
721 | } | |
722 | spin_lock(&info->lock); | |
c5b2cbdb MS |
723 | |
724 | /* we hold info->lock, so no memory barrier required */ | |
725 | if (READ_ONCE(ewp->state) == STATE_READY) { | |
1da177e4 LT |
726 | retval = 0; |
727 | goto out_unlock; | |
728 | } | |
729 | if (signal_pending(current)) { | |
730 | retval = -ERESTARTSYS; | |
731 | break; | |
732 | } | |
733 | if (time == 0) { | |
734 | retval = -ETIMEDOUT; | |
735 | break; | |
736 | } | |
737 | } | |
738 | list_del(&ewp->list); | |
739 | out_unlock: | |
740 | spin_unlock(&info->lock); | |
741 | out: | |
742 | return retval; | |
743 | } | |
744 | ||
745 | /* | |
746 | * Returns waiting task that should be serviced first or NULL if none exists | |
747 | */ | |
748 | static struct ext_wait_queue *wq_get_first_waiter( | |
749 | struct mqueue_inode_info *info, int sr) | |
750 | { | |
751 | struct list_head *ptr; | |
752 | ||
753 | ptr = info->e_wait_q[sr].list.prev; | |
754 | if (ptr == &info->e_wait_q[sr].list) | |
755 | return NULL; | |
756 | return list_entry(ptr, struct ext_wait_queue, list); | |
757 | } | |
758 | ||
1da177e4 LT |
759 | |
760 | static inline void set_cookie(struct sk_buff *skb, char code) | |
761 | { | |
239521f3 | 762 | ((char *)skb->data)[NOTIFY_COOKIE_LEN-1] = code; |
1da177e4 LT |
763 | } |
764 | ||
765 | /* | |
766 | * The next function is only to split too long sys_mq_timedsend | |
767 | */ | |
768 | static void __do_notify(struct mqueue_inode_info *info) | |
769 | { | |
770 | /* notification | |
771 | * invoked when there is registered process and there isn't process | |
772 | * waiting synchronously for message AND state of queue changed from | |
773 | * empty to not empty. Here we are sure that no one is waiting | |
774 | * synchronously. */ | |
775 | if (info->notify_owner && | |
776 | info->attr.mq_curmsgs == 1) { | |
ae7795bc | 777 | struct kernel_siginfo sig_i; |
1da177e4 LT |
778 | switch (info->notify.sigev_notify) { |
779 | case SIGEV_NONE: | |
780 | break; | |
781 | case SIGEV_SIGNAL: | |
782 | /* sends signal */ | |
783 | ||
faf1f22b | 784 | clear_siginfo(&sig_i); |
1da177e4 LT |
785 | sig_i.si_signo = info->notify.sigev_signo; |
786 | sig_i.si_errno = 0; | |
787 | sig_i.si_code = SI_MESGQ; | |
788 | sig_i.si_value = info->notify.sigev_value; | |
6b550f94 SH |
789 | /* map current pid/uid into info->owner's namespaces */ |
790 | rcu_read_lock(); | |
a6684999 SB |
791 | sig_i.si_pid = task_tgid_nr_ns(current, |
792 | ns_of_pid(info->notify_owner)); | |
76b6db01 | 793 | sig_i.si_uid = from_kuid_munged(info->notify_user_ns, current_uid()); |
6b550f94 | 794 | rcu_read_unlock(); |
1da177e4 | 795 | |
a03fcb73 CLG |
796 | kill_pid_info(info->notify.sigev_signo, |
797 | &sig_i, info->notify_owner); | |
1da177e4 LT |
798 | break; |
799 | case SIGEV_THREAD: | |
800 | set_cookie(info->notify_cookie, NOTIFY_WOKENUP); | |
7ee015e0 | 801 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 LT |
802 | break; |
803 | } | |
804 | /* after notification unregisters process */ | |
a03fcb73 | 805 | put_pid(info->notify_owner); |
6f9ac6d9 | 806 | put_user_ns(info->notify_user_ns); |
a03fcb73 | 807 | info->notify_owner = NULL; |
6f9ac6d9 | 808 | info->notify_user_ns = NULL; |
1da177e4 LT |
809 | } |
810 | wake_up(&info->wait_q); | |
811 | } | |
812 | ||
21fc538d | 813 | static int prepare_timeout(const struct __kernel_timespec __user *u_abs_timeout, |
b9047726 | 814 | struct timespec64 *ts) |
1da177e4 | 815 | { |
b9047726 | 816 | if (get_timespec64(ts, u_abs_timeout)) |
9ca7d8e6 | 817 | return -EFAULT; |
b9047726 | 818 | if (!timespec64_valid(ts)) |
9ca7d8e6 | 819 | return -EINVAL; |
9ca7d8e6 | 820 | return 0; |
1da177e4 LT |
821 | } |
822 | ||
823 | static void remove_notification(struct mqueue_inode_info *info) | |
824 | { | |
a03fcb73 | 825 | if (info->notify_owner != NULL && |
1da177e4 LT |
826 | info->notify.sigev_notify == SIGEV_THREAD) { |
827 | set_cookie(info->notify_cookie, NOTIFY_REMOVED); | |
7ee015e0 | 828 | netlink_sendskb(info->notify_sock, info->notify_cookie); |
1da177e4 | 829 | } |
a03fcb73 | 830 | put_pid(info->notify_owner); |
6f9ac6d9 | 831 | put_user_ns(info->notify_user_ns); |
a03fcb73 | 832 | info->notify_owner = NULL; |
6f9ac6d9 | 833 | info->notify_user_ns = NULL; |
1da177e4 LT |
834 | } |
835 | ||
066cc813 AV |
836 | static int prepare_open(struct dentry *dentry, int oflag, int ro, |
837 | umode_t mode, struct filename *name, | |
614b84cf | 838 | struct mq_attr *attr) |
1da177e4 | 839 | { |
745ca247 DH |
840 | static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, |
841 | MAY_READ | MAY_WRITE }; | |
765927b2 | 842 | int acc; |
066cc813 | 843 | |
9b20d7fc AV |
844 | if (d_really_is_negative(dentry)) { |
845 | if (!(oflag & O_CREAT)) | |
066cc813 | 846 | return -ENOENT; |
9b20d7fc AV |
847 | if (ro) |
848 | return ro; | |
849 | audit_inode_parent_hidden(name, dentry->d_parent); | |
850 | return vfs_mkobj(dentry, mode & ~current_umask(), | |
851 | mqueue_create_attr, attr); | |
066cc813 | 852 | } |
9b20d7fc AV |
853 | /* it already existed */ |
854 | audit_inode(name, dentry, 0); | |
855 | if ((oflag & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) | |
856 | return -EEXIST; | |
765927b2 | 857 | if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) |
af4a5372 | 858 | return -EINVAL; |
765927b2 | 859 | acc = oflag2acc[oflag & O_ACCMODE]; |
066cc813 | 860 | return inode_permission(d_inode(dentry), acc); |
1da177e4 LT |
861 | } |
862 | ||
0d060606 AV |
863 | static int do_mq_open(const char __user *u_name, int oflag, umode_t mode, |
864 | struct mq_attr *attr) | |
1da177e4 | 865 | { |
cfb2f6f6 EB |
866 | struct vfsmount *mnt = current->nsproxy->ipc_ns->mq_mnt; |
867 | struct dentry *root = mnt->mnt_root; | |
91a27b2a | 868 | struct filename *name; |
a713fd7f | 869 | struct path path; |
1da177e4 | 870 | int fd, error; |
312b90fb | 871 | int ro; |
1da177e4 | 872 | |
0d060606 | 873 | audit_mq_open(oflag, mode, attr); |
20ca73bc | 874 | |
1da177e4 LT |
875 | if (IS_ERR(name = getname(u_name))) |
876 | return PTR_ERR(name); | |
877 | ||
269f2134 | 878 | fd = get_unused_fd_flags(O_CLOEXEC); |
1da177e4 LT |
879 | if (fd < 0) |
880 | goto out_putname; | |
881 | ||
312b90fb | 882 | ro = mnt_want_write(mnt); /* we'll drop it in any case */ |
5955102c | 883 | inode_lock(d_inode(root)); |
91a27b2a | 884 | path.dentry = lookup_one_len(name->name, root, strlen(name->name)); |
765927b2 AV |
885 | if (IS_ERR(path.dentry)) { |
886 | error = PTR_ERR(path.dentry); | |
4294a8ee | 887 | goto out_putfd; |
1da177e4 | 888 | } |
312b90fb | 889 | path.mnt = mntget(mnt); |
066cc813 AV |
890 | error = prepare_open(path.dentry, oflag, ro, mode, name, attr); |
891 | if (!error) { | |
892 | struct file *file = dentry_open(&path, oflag, current_cred()); | |
893 | if (!IS_ERR(file)) | |
894 | fd_install(fd, file); | |
895 | else | |
896 | error = PTR_ERR(file); | |
7c7dce92 | 897 | } |
765927b2 | 898 | path_put(&path); |
7c7dce92 | 899 | out_putfd: |
765927b2 AV |
900 | if (error) { |
901 | put_unused_fd(fd); | |
902 | fd = error; | |
903 | } | |
5955102c | 904 | inode_unlock(d_inode(root)); |
38d78e58 VD |
905 | if (!ro) |
906 | mnt_drop_write(mnt); | |
1da177e4 LT |
907 | out_putname: |
908 | putname(name); | |
909 | return fd; | |
910 | } | |
911 | ||
0d060606 AV |
912 | SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, |
913 | struct mq_attr __user *, u_attr) | |
914 | { | |
915 | struct mq_attr attr; | |
916 | if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr))) | |
917 | return -EFAULT; | |
918 | ||
919 | return do_mq_open(u_name, oflag, mode, u_attr ? &attr : NULL); | |
920 | } | |
921 | ||
d5460c99 | 922 | SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name) |
1da177e4 LT |
923 | { |
924 | int err; | |
91a27b2a | 925 | struct filename *name; |
1da177e4 LT |
926 | struct dentry *dentry; |
927 | struct inode *inode = NULL; | |
7eafd7c7 | 928 | struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns; |
312b90fb | 929 | struct vfsmount *mnt = ipc_ns->mq_mnt; |
1da177e4 LT |
930 | |
931 | name = getname(u_name); | |
932 | if (IS_ERR(name)) | |
933 | return PTR_ERR(name); | |
934 | ||
79f6530c | 935 | audit_inode_parent_hidden(name, mnt->mnt_root); |
312b90fb AV |
936 | err = mnt_want_write(mnt); |
937 | if (err) | |
938 | goto out_name; | |
5955102c | 939 | inode_lock_nested(d_inode(mnt->mnt_root), I_MUTEX_PARENT); |
91a27b2a JL |
940 | dentry = lookup_one_len(name->name, mnt->mnt_root, |
941 | strlen(name->name)); | |
1da177e4 LT |
942 | if (IS_ERR(dentry)) { |
943 | err = PTR_ERR(dentry); | |
944 | goto out_unlock; | |
945 | } | |
946 | ||
75c3cfa8 | 947 | inode = d_inode(dentry); |
312b90fb AV |
948 | if (!inode) { |
949 | err = -ENOENT; | |
950 | } else { | |
7de9c6ee | 951 | ihold(inode); |
75c3cfa8 | 952 | err = vfs_unlink(d_inode(dentry->d_parent), dentry, NULL); |
312b90fb | 953 | } |
1da177e4 LT |
954 | dput(dentry); |
955 | ||
956 | out_unlock: | |
5955102c | 957 | inode_unlock(d_inode(mnt->mnt_root)); |
1da177e4 LT |
958 | if (inode) |
959 | iput(inode); | |
312b90fb AV |
960 | mnt_drop_write(mnt); |
961 | out_name: | |
962 | putname(name); | |
1da177e4 LT |
963 | |
964 | return err; | |
965 | } | |
966 | ||
967 | /* Pipelined send and receive functions. | |
968 | * | |
969 | * If a receiver finds no waiting message, then it registers itself in the | |
970 | * list of waiting receivers. A sender checks that list before adding the new | |
971 | * message into the message array. If there is a waiting receiver, then it | |
972 | * bypasses the message array and directly hands the message over to the | |
fa6004ad DB |
973 | * receiver. The receiver accepts the message and returns without grabbing the |
974 | * queue spinlock: | |
975 | * | |
976 | * - Set pointer to message. | |
977 | * - Queue the receiver task for later wakeup (without the info->lock). | |
978 | * - Update its state to STATE_READY. Now the receiver can continue. | |
979 | * - Wake up the process after the lock is dropped. Should the process wake up | |
980 | * before this wakeup (due to a timeout or a signal) it will either see | |
981 | * STATE_READY and continue or acquire the lock to check the state again. | |
1da177e4 LT |
982 | * |
983 | * The same algorithm is used for senders. | |
984 | */ | |
985 | ||
ed29f171 | 986 | static inline void __pipelined_op(struct wake_q_head *wake_q, |
fa6004ad | 987 | struct mqueue_inode_info *info, |
ed29f171 | 988 | struct ext_wait_queue *this) |
1da177e4 | 989 | { |
ed29f171 | 990 | list_del(&this->list); |
c5b2cbdb MS |
991 | get_task_struct(this->task); |
992 | ||
993 | /* see MQ_BARRIER for purpose/pairing */ | |
994 | smp_store_release(&this->state, STATE_READY); | |
995 | wake_q_add_safe(wake_q, this->task); | |
ed29f171 DB |
996 | } |
997 | ||
998 | /* pipelined_send() - send a message directly to the task waiting in | |
999 | * sys_mq_timedreceive() (without inserting message into a queue). | |
1000 | */ | |
1001 | static inline void pipelined_send(struct wake_q_head *wake_q, | |
1002 | struct mqueue_inode_info *info, | |
1003 | struct msg_msg *message, | |
1004 | struct ext_wait_queue *receiver) | |
1005 | { | |
1006 | receiver->msg = message; | |
1007 | __pipelined_op(wake_q, info, receiver); | |
1da177e4 LT |
1008 | } |
1009 | ||
1010 | /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() | |
1011 | * gets its message and put to the queue (we have one free place for sure). */ | |
fa6004ad DB |
1012 | static inline void pipelined_receive(struct wake_q_head *wake_q, |
1013 | struct mqueue_inode_info *info) | |
1da177e4 LT |
1014 | { |
1015 | struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND); | |
1016 | ||
1017 | if (!sender) { | |
1018 | /* for poll */ | |
1019 | wake_up_interruptible(&info->wait_q); | |
1020 | return; | |
1021 | } | |
d6629859 DL |
1022 | if (msg_insert(sender->msg, info)) |
1023 | return; | |
fa6004ad | 1024 | |
ed29f171 | 1025 | __pipelined_op(wake_q, info, sender); |
1da177e4 LT |
1026 | } |
1027 | ||
0d060606 AV |
1028 | static int do_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr, |
1029 | size_t msg_len, unsigned int msg_prio, | |
b9047726 | 1030 | struct timespec64 *ts) |
1da177e4 | 1031 | { |
2903ff01 | 1032 | struct fd f; |
1da177e4 LT |
1033 | struct inode *inode; |
1034 | struct ext_wait_queue wait; | |
1035 | struct ext_wait_queue *receiver; | |
1036 | struct msg_msg *msg_ptr; | |
1037 | struct mqueue_inode_info *info; | |
9ca7d8e6 | 1038 | ktime_t expires, *timeout = NULL; |
ce2d52cc | 1039 | struct posix_msg_tree_node *new_leaf = NULL; |
2903ff01 | 1040 | int ret = 0; |
194a6b5b | 1041 | DEFINE_WAKE_Q(wake_q); |
1da177e4 LT |
1042 | |
1043 | if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX)) | |
1044 | return -EINVAL; | |
1045 | ||
0d060606 | 1046 | if (ts) { |
b9047726 | 1047 | expires = timespec64_to_ktime(*ts); |
0d060606 AV |
1048 | timeout = &expires; |
1049 | } | |
1050 | ||
1051 | audit_mq_sendrecv(mqdes, msg_len, msg_prio, ts); | |
1da177e4 | 1052 | |
2903ff01 AV |
1053 | f = fdget(mqdes); |
1054 | if (unlikely(!f.file)) { | |
8d8ffefa | 1055 | ret = -EBADF; |
1da177e4 | 1056 | goto out; |
8d8ffefa | 1057 | } |
1da177e4 | 1058 | |
496ad9aa | 1059 | inode = file_inode(f.file); |
2903ff01 | 1060 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
8d8ffefa | 1061 | ret = -EBADF; |
1da177e4 | 1062 | goto out_fput; |
8d8ffefa | 1063 | } |
1da177e4 | 1064 | info = MQUEUE_I(inode); |
9f45f5bf | 1065 | audit_file(f.file); |
1da177e4 | 1066 | |
2903ff01 | 1067 | if (unlikely(!(f.file->f_mode & FMODE_WRITE))) { |
8d8ffefa | 1068 | ret = -EBADF; |
1da177e4 | 1069 | goto out_fput; |
8d8ffefa | 1070 | } |
1da177e4 LT |
1071 | |
1072 | if (unlikely(msg_len > info->attr.mq_msgsize)) { | |
1073 | ret = -EMSGSIZE; | |
1074 | goto out_fput; | |
1075 | } | |
1076 | ||
1077 | /* First try to allocate memory, before doing anything with | |
1078 | * existing queues. */ | |
1079 | msg_ptr = load_msg(u_msg_ptr, msg_len); | |
1080 | if (IS_ERR(msg_ptr)) { | |
1081 | ret = PTR_ERR(msg_ptr); | |
1082 | goto out_fput; | |
1083 | } | |
1084 | msg_ptr->m_ts = msg_len; | |
1085 | msg_ptr->m_type = msg_prio; | |
1086 | ||
ce2d52cc DL |
1087 | /* |
1088 | * msg_insert really wants us to have a valid, spare node struct so | |
1089 | * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will | |
1090 | * fall back to that if necessary. | |
1091 | */ | |
1092 | if (!info->node_cache) | |
1093 | new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL); | |
1094 | ||
1da177e4 LT |
1095 | spin_lock(&info->lock); |
1096 | ||
ce2d52cc DL |
1097 | if (!info->node_cache && new_leaf) { |
1098 | /* Save our speculative allocation into the cache */ | |
ce2d52cc DL |
1099 | INIT_LIST_HEAD(&new_leaf->msg_list); |
1100 | info->node_cache = new_leaf; | |
ce2d52cc DL |
1101 | new_leaf = NULL; |
1102 | } else { | |
1103 | kfree(new_leaf); | |
1104 | } | |
1105 | ||
1da177e4 | 1106 | if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) { |
2903ff01 | 1107 | if (f.file->f_flags & O_NONBLOCK) { |
1da177e4 | 1108 | ret = -EAGAIN; |
1da177e4 LT |
1109 | } else { |
1110 | wait.task = current; | |
1111 | wait.msg = (void *) msg_ptr; | |
c5b2cbdb MS |
1112 | |
1113 | /* memory barrier not required, we hold info->lock */ | |
1114 | WRITE_ONCE(wait.state, STATE_NONE); | |
1da177e4 | 1115 | ret = wq_sleep(info, SEND, timeout, &wait); |
ce2d52cc DL |
1116 | /* |
1117 | * wq_sleep must be called with info->lock held, and | |
1118 | * returns with the lock released | |
1119 | */ | |
1120 | goto out_free; | |
1da177e4 | 1121 | } |
1da177e4 LT |
1122 | } else { |
1123 | receiver = wq_get_first_waiter(info, RECV); | |
1124 | if (receiver) { | |
fa6004ad | 1125 | pipelined_send(&wake_q, info, msg_ptr, receiver); |
1da177e4 LT |
1126 | } else { |
1127 | /* adds message to the queue */ | |
ce2d52cc DL |
1128 | ret = msg_insert(msg_ptr, info); |
1129 | if (ret) | |
1130 | goto out_unlock; | |
1da177e4 LT |
1131 | __do_notify(info); |
1132 | } | |
1133 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
078cd827 | 1134 | current_time(inode); |
1da177e4 | 1135 | } |
ce2d52cc DL |
1136 | out_unlock: |
1137 | spin_unlock(&info->lock); | |
fa6004ad | 1138 | wake_up_q(&wake_q); |
ce2d52cc DL |
1139 | out_free: |
1140 | if (ret) | |
1141 | free_msg(msg_ptr); | |
1da177e4 | 1142 | out_fput: |
2903ff01 | 1143 | fdput(f); |
1da177e4 LT |
1144 | out: |
1145 | return ret; | |
1146 | } | |
1147 | ||
0d060606 AV |
1148 | static int do_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr, |
1149 | size_t msg_len, unsigned int __user *u_msg_prio, | |
b9047726 | 1150 | struct timespec64 *ts) |
1da177e4 | 1151 | { |
1da177e4 LT |
1152 | ssize_t ret; |
1153 | struct msg_msg *msg_ptr; | |
2903ff01 | 1154 | struct fd f; |
1da177e4 LT |
1155 | struct inode *inode; |
1156 | struct mqueue_inode_info *info; | |
1157 | struct ext_wait_queue wait; | |
9ca7d8e6 | 1158 | ktime_t expires, *timeout = NULL; |
ce2d52cc | 1159 | struct posix_msg_tree_node *new_leaf = NULL; |
1da177e4 | 1160 | |
0d060606 | 1161 | if (ts) { |
b9047726 | 1162 | expires = timespec64_to_ktime(*ts); |
9ca7d8e6 | 1163 | timeout = &expires; |
c32c8af4 | 1164 | } |
20ca73bc | 1165 | |
0d060606 | 1166 | audit_mq_sendrecv(mqdes, msg_len, 0, ts); |
1da177e4 | 1167 | |
2903ff01 AV |
1168 | f = fdget(mqdes); |
1169 | if (unlikely(!f.file)) { | |
8d8ffefa | 1170 | ret = -EBADF; |
1da177e4 | 1171 | goto out; |
8d8ffefa | 1172 | } |
1da177e4 | 1173 | |
496ad9aa | 1174 | inode = file_inode(f.file); |
2903ff01 | 1175 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
8d8ffefa | 1176 | ret = -EBADF; |
1da177e4 | 1177 | goto out_fput; |
8d8ffefa | 1178 | } |
1da177e4 | 1179 | info = MQUEUE_I(inode); |
9f45f5bf | 1180 | audit_file(f.file); |
1da177e4 | 1181 | |
2903ff01 | 1182 | if (unlikely(!(f.file->f_mode & FMODE_READ))) { |
8d8ffefa | 1183 | ret = -EBADF; |
1da177e4 | 1184 | goto out_fput; |
8d8ffefa | 1185 | } |
1da177e4 LT |
1186 | |
1187 | /* checks if buffer is big enough */ | |
1188 | if (unlikely(msg_len < info->attr.mq_msgsize)) { | |
1189 | ret = -EMSGSIZE; | |
1190 | goto out_fput; | |
1191 | } | |
1192 | ||
ce2d52cc DL |
1193 | /* |
1194 | * msg_insert really wants us to have a valid, spare node struct so | |
1195 | * it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will | |
1196 | * fall back to that if necessary. | |
1197 | */ | |
1198 | if (!info->node_cache) | |
1199 | new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL); | |
1200 | ||
1da177e4 | 1201 | spin_lock(&info->lock); |
ce2d52cc DL |
1202 | |
1203 | if (!info->node_cache && new_leaf) { | |
1204 | /* Save our speculative allocation into the cache */ | |
ce2d52cc DL |
1205 | INIT_LIST_HEAD(&new_leaf->msg_list); |
1206 | info->node_cache = new_leaf; | |
ce2d52cc DL |
1207 | } else { |
1208 | kfree(new_leaf); | |
1209 | } | |
1210 | ||
1da177e4 | 1211 | if (info->attr.mq_curmsgs == 0) { |
2903ff01 | 1212 | if (f.file->f_flags & O_NONBLOCK) { |
1da177e4 LT |
1213 | spin_unlock(&info->lock); |
1214 | ret = -EAGAIN; | |
1da177e4 LT |
1215 | } else { |
1216 | wait.task = current; | |
c5b2cbdb MS |
1217 | |
1218 | /* memory barrier not required, we hold info->lock */ | |
1219 | WRITE_ONCE(wait.state, STATE_NONE); | |
1da177e4 LT |
1220 | ret = wq_sleep(info, RECV, timeout, &wait); |
1221 | msg_ptr = wait.msg; | |
1222 | } | |
1223 | } else { | |
194a6b5b | 1224 | DEFINE_WAKE_Q(wake_q); |
fa6004ad | 1225 | |
1da177e4 LT |
1226 | msg_ptr = msg_get(info); |
1227 | ||
1228 | inode->i_atime = inode->i_mtime = inode->i_ctime = | |
078cd827 | 1229 | current_time(inode); |
1da177e4 LT |
1230 | |
1231 | /* There is now free space in queue. */ | |
fa6004ad | 1232 | pipelined_receive(&wake_q, info); |
1da177e4 | 1233 | spin_unlock(&info->lock); |
fa6004ad | 1234 | wake_up_q(&wake_q); |
1da177e4 LT |
1235 | ret = 0; |
1236 | } | |
1237 | if (ret == 0) { | |
1238 | ret = msg_ptr->m_ts; | |
1239 | ||
1240 | if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) || | |
1241 | store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) { | |
1242 | ret = -EFAULT; | |
1243 | } | |
1244 | free_msg(msg_ptr); | |
1245 | } | |
1246 | out_fput: | |
2903ff01 | 1247 | fdput(f); |
1da177e4 LT |
1248 | out: |
1249 | return ret; | |
1250 | } | |
1251 | ||
0d060606 AV |
1252 | SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, |
1253 | size_t, msg_len, unsigned int, msg_prio, | |
21fc538d | 1254 | const struct __kernel_timespec __user *, u_abs_timeout) |
0d060606 | 1255 | { |
b9047726 | 1256 | struct timespec64 ts, *p = NULL; |
0d060606 AV |
1257 | if (u_abs_timeout) { |
1258 | int res = prepare_timeout(u_abs_timeout, &ts); | |
1259 | if (res) | |
1260 | return res; | |
1261 | p = &ts; | |
1262 | } | |
1263 | return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p); | |
1264 | } | |
1265 | ||
1266 | SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, | |
1267 | size_t, msg_len, unsigned int __user *, u_msg_prio, | |
21fc538d | 1268 | const struct __kernel_timespec __user *, u_abs_timeout) |
0d060606 | 1269 | { |
b9047726 | 1270 | struct timespec64 ts, *p = NULL; |
0d060606 AV |
1271 | if (u_abs_timeout) { |
1272 | int res = prepare_timeout(u_abs_timeout, &ts); | |
1273 | if (res) | |
1274 | return res; | |
1275 | p = &ts; | |
1276 | } | |
1277 | return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p); | |
1278 | } | |
1279 | ||
1da177e4 LT |
1280 | /* |
1281 | * Notes: the case when user wants us to deregister (with NULL as pointer) | |
1282 | * and he isn't currently owner of notification, will be silently discarded. | |
1283 | * It isn't explicitly defined in the POSIX. | |
1284 | */ | |
0d060606 | 1285 | static int do_mq_notify(mqd_t mqdes, const struct sigevent *notification) |
1da177e4 | 1286 | { |
2903ff01 AV |
1287 | int ret; |
1288 | struct fd f; | |
1da177e4 LT |
1289 | struct sock *sock; |
1290 | struct inode *inode; | |
1da177e4 LT |
1291 | struct mqueue_inode_info *info; |
1292 | struct sk_buff *nc; | |
1293 | ||
0d060606 | 1294 | audit_mq_notify(mqdes, notification); |
1da177e4 | 1295 | |
20114f71 AV |
1296 | nc = NULL; |
1297 | sock = NULL; | |
0d060606 AV |
1298 | if (notification != NULL) { |
1299 | if (unlikely(notification->sigev_notify != SIGEV_NONE && | |
1300 | notification->sigev_notify != SIGEV_SIGNAL && | |
1301 | notification->sigev_notify != SIGEV_THREAD)) | |
1da177e4 | 1302 | return -EINVAL; |
0d060606 AV |
1303 | if (notification->sigev_notify == SIGEV_SIGNAL && |
1304 | !valid_signal(notification->sigev_signo)) { | |
1da177e4 LT |
1305 | return -EINVAL; |
1306 | } | |
0d060606 | 1307 | if (notification->sigev_notify == SIGEV_THREAD) { |
c3d8d1e3 PM |
1308 | long timeo; |
1309 | ||
1da177e4 LT |
1310 | /* create the notify skb */ |
1311 | nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL); | |
c231740d ME |
1312 | if (!nc) |
1313 | return -ENOMEM; | |
1314 | ||
1da177e4 | 1315 | if (copy_from_user(nc->data, |
0d060606 | 1316 | notification->sigev_value.sival_ptr, |
1da177e4 | 1317 | NOTIFY_COOKIE_LEN)) { |
8d8ffefa | 1318 | ret = -EFAULT; |
c231740d | 1319 | goto free_skb; |
1da177e4 LT |
1320 | } |
1321 | ||
1322 | /* TODO: add a header? */ | |
1323 | skb_put(nc, NOTIFY_COOKIE_LEN); | |
1324 | /* and attach it to the socket */ | |
1325 | retry: | |
0d060606 | 1326 | f = fdget(notification->sigev_signo); |
2903ff01 | 1327 | if (!f.file) { |
8d8ffefa | 1328 | ret = -EBADF; |
1da177e4 | 1329 | goto out; |
8d8ffefa | 1330 | } |
2903ff01 AV |
1331 | sock = netlink_getsockbyfilp(f.file); |
1332 | fdput(f); | |
1da177e4 LT |
1333 | if (IS_ERR(sock)) { |
1334 | ret = PTR_ERR(sock); | |
c231740d | 1335 | goto free_skb; |
1da177e4 LT |
1336 | } |
1337 | ||
c3d8d1e3 | 1338 | timeo = MAX_SCHEDULE_TIMEOUT; |
9457afee | 1339 | ret = netlink_attachskb(sock, nc, &timeo, NULL); |
f991af3d CW |
1340 | if (ret == 1) { |
1341 | sock = NULL; | |
8d8ffefa | 1342 | goto retry; |
f991af3d | 1343 | } |
c231740d ME |
1344 | if (ret) |
1345 | return ret; | |
1da177e4 LT |
1346 | } |
1347 | } | |
1348 | ||
2903ff01 AV |
1349 | f = fdget(mqdes); |
1350 | if (!f.file) { | |
8d8ffefa | 1351 | ret = -EBADF; |
1da177e4 | 1352 | goto out; |
8d8ffefa | 1353 | } |
1da177e4 | 1354 | |
496ad9aa | 1355 | inode = file_inode(f.file); |
2903ff01 | 1356 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
8d8ffefa | 1357 | ret = -EBADF; |
1da177e4 | 1358 | goto out_fput; |
8d8ffefa | 1359 | } |
1da177e4 LT |
1360 | info = MQUEUE_I(inode); |
1361 | ||
1362 | ret = 0; | |
1363 | spin_lock(&info->lock); | |
0d060606 | 1364 | if (notification == NULL) { |
a03fcb73 | 1365 | if (info->notify_owner == task_tgid(current)) { |
1da177e4 | 1366 | remove_notification(info); |
078cd827 | 1367 | inode->i_atime = inode->i_ctime = current_time(inode); |
1da177e4 | 1368 | } |
a03fcb73 | 1369 | } else if (info->notify_owner != NULL) { |
1da177e4 LT |
1370 | ret = -EBUSY; |
1371 | } else { | |
0d060606 | 1372 | switch (notification->sigev_notify) { |
1da177e4 LT |
1373 | case SIGEV_NONE: |
1374 | info->notify.sigev_notify = SIGEV_NONE; | |
1375 | break; | |
1376 | case SIGEV_THREAD: | |
1377 | info->notify_sock = sock; | |
1378 | info->notify_cookie = nc; | |
1379 | sock = NULL; | |
1380 | nc = NULL; | |
1381 | info->notify.sigev_notify = SIGEV_THREAD; | |
1382 | break; | |
1383 | case SIGEV_SIGNAL: | |
0d060606 AV |
1384 | info->notify.sigev_signo = notification->sigev_signo; |
1385 | info->notify.sigev_value = notification->sigev_value; | |
1da177e4 LT |
1386 | info->notify.sigev_notify = SIGEV_SIGNAL; |
1387 | break; | |
1388 | } | |
a03fcb73 CLG |
1389 | |
1390 | info->notify_owner = get_pid(task_tgid(current)); | |
6f9ac6d9 | 1391 | info->notify_user_ns = get_user_ns(current_user_ns()); |
078cd827 | 1392 | inode->i_atime = inode->i_ctime = current_time(inode); |
1da177e4 LT |
1393 | } |
1394 | spin_unlock(&info->lock); | |
1395 | out_fput: | |
2903ff01 | 1396 | fdput(f); |
1da177e4 | 1397 | out: |
3ab08fe2 | 1398 | if (sock) |
1da177e4 | 1399 | netlink_detachskb(sock, nc); |
97b0b1ad | 1400 | else |
c231740d | 1401 | free_skb: |
1da177e4 | 1402 | dev_kfree_skb(nc); |
3ab08fe2 | 1403 | |
1da177e4 LT |
1404 | return ret; |
1405 | } | |
1406 | ||
0d060606 AV |
1407 | SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
1408 | const struct sigevent __user *, u_notification) | |
1409 | { | |
1410 | struct sigevent n, *p = NULL; | |
1411 | if (u_notification) { | |
1412 | if (copy_from_user(&n, u_notification, sizeof(struct sigevent))) | |
1413 | return -EFAULT; | |
1414 | p = &n; | |
1415 | } | |
1416 | return do_mq_notify(mqdes, p); | |
1417 | } | |
1418 | ||
1419 | static int do_mq_getsetattr(int mqdes, struct mq_attr *new, struct mq_attr *old) | |
1da177e4 | 1420 | { |
2903ff01 | 1421 | struct fd f; |
1da177e4 LT |
1422 | struct inode *inode; |
1423 | struct mqueue_inode_info *info; | |
1424 | ||
0d060606 AV |
1425 | if (new && (new->mq_flags & (~O_NONBLOCK))) |
1426 | return -EINVAL; | |
1da177e4 | 1427 | |
2903ff01 | 1428 | f = fdget(mqdes); |
0d060606 AV |
1429 | if (!f.file) |
1430 | return -EBADF; | |
1da177e4 | 1431 | |
2903ff01 | 1432 | if (unlikely(f.file->f_op != &mqueue_file_operations)) { |
0d060606 AV |
1433 | fdput(f); |
1434 | return -EBADF; | |
8d8ffefa | 1435 | } |
0d060606 AV |
1436 | |
1437 | inode = file_inode(f.file); | |
1da177e4 LT |
1438 | info = MQUEUE_I(inode); |
1439 | ||
1440 | spin_lock(&info->lock); | |
1441 | ||
0d060606 AV |
1442 | if (old) { |
1443 | *old = info->attr; | |
1444 | old->mq_flags = f.file->f_flags & O_NONBLOCK; | |
1445 | } | |
1446 | if (new) { | |
1447 | audit_mq_getsetattr(mqdes, new); | |
2903ff01 | 1448 | spin_lock(&f.file->f_lock); |
0d060606 | 1449 | if (new->mq_flags & O_NONBLOCK) |
2903ff01 | 1450 | f.file->f_flags |= O_NONBLOCK; |
1da177e4 | 1451 | else |
2903ff01 AV |
1452 | f.file->f_flags &= ~O_NONBLOCK; |
1453 | spin_unlock(&f.file->f_lock); | |
1da177e4 | 1454 | |
078cd827 | 1455 | inode->i_atime = inode->i_ctime = current_time(inode); |
1da177e4 LT |
1456 | } |
1457 | ||
1458 | spin_unlock(&info->lock); | |
0d060606 AV |
1459 | fdput(f); |
1460 | return 0; | |
1461 | } | |
1da177e4 | 1462 | |
0d060606 AV |
1463 | SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, |
1464 | const struct mq_attr __user *, u_mqstat, | |
1465 | struct mq_attr __user *, u_omqstat) | |
1466 | { | |
1467 | int ret; | |
1468 | struct mq_attr mqstat, omqstat; | |
1469 | struct mq_attr *new = NULL, *old = NULL; | |
1da177e4 | 1470 | |
0d060606 AV |
1471 | if (u_mqstat) { |
1472 | new = &mqstat; | |
1473 | if (copy_from_user(new, u_mqstat, sizeof(struct mq_attr))) | |
1474 | return -EFAULT; | |
1475 | } | |
1476 | if (u_omqstat) | |
1477 | old = &omqstat; | |
1478 | ||
1479 | ret = do_mq_getsetattr(mqdes, new, old); | |
1480 | if (ret || !old) | |
1481 | return ret; | |
1482 | ||
1483 | if (copy_to_user(u_omqstat, old, sizeof(struct mq_attr))) | |
1484 | return -EFAULT; | |
1485 | return 0; | |
1486 | } | |
1487 | ||
1488 | #ifdef CONFIG_COMPAT | |
1489 | ||
1490 | struct compat_mq_attr { | |
1491 | compat_long_t mq_flags; /* message queue flags */ | |
1492 | compat_long_t mq_maxmsg; /* maximum number of messages */ | |
1493 | compat_long_t mq_msgsize; /* maximum message size */ | |
1494 | compat_long_t mq_curmsgs; /* number of messages currently queued */ | |
1495 | compat_long_t __reserved[4]; /* ignored for input, zeroed for output */ | |
1496 | }; | |
1497 | ||
1498 | static inline int get_compat_mq_attr(struct mq_attr *attr, | |
1499 | const struct compat_mq_attr __user *uattr) | |
1500 | { | |
1501 | struct compat_mq_attr v; | |
1502 | ||
1503 | if (copy_from_user(&v, uattr, sizeof(*uattr))) | |
1504 | return -EFAULT; | |
1505 | ||
1506 | memset(attr, 0, sizeof(*attr)); | |
1507 | attr->mq_flags = v.mq_flags; | |
1508 | attr->mq_maxmsg = v.mq_maxmsg; | |
1509 | attr->mq_msgsize = v.mq_msgsize; | |
1510 | attr->mq_curmsgs = v.mq_curmsgs; | |
1511 | return 0; | |
1512 | } | |
1513 | ||
1514 | static inline int put_compat_mq_attr(const struct mq_attr *attr, | |
1515 | struct compat_mq_attr __user *uattr) | |
1516 | { | |
1517 | struct compat_mq_attr v; | |
1518 | ||
1519 | memset(&v, 0, sizeof(v)); | |
1520 | v.mq_flags = attr->mq_flags; | |
1521 | v.mq_maxmsg = attr->mq_maxmsg; | |
1522 | v.mq_msgsize = attr->mq_msgsize; | |
1523 | v.mq_curmsgs = attr->mq_curmsgs; | |
1524 | if (copy_to_user(uattr, &v, sizeof(*uattr))) | |
1525 | return -EFAULT; | |
1526 | return 0; | |
1527 | } | |
1528 | ||
1529 | COMPAT_SYSCALL_DEFINE4(mq_open, const char __user *, u_name, | |
1530 | int, oflag, compat_mode_t, mode, | |
1531 | struct compat_mq_attr __user *, u_attr) | |
1532 | { | |
1533 | struct mq_attr attr, *p = NULL; | |
1534 | if (u_attr && oflag & O_CREAT) { | |
1535 | p = &attr; | |
1536 | if (get_compat_mq_attr(&attr, u_attr)) | |
1537 | return -EFAULT; | |
1538 | } | |
1539 | return do_mq_open(u_name, oflag, mode, p); | |
1540 | } | |
1541 | ||
b0d17578 AB |
1542 | COMPAT_SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes, |
1543 | const struct compat_sigevent __user *, u_notification) | |
1544 | { | |
1545 | struct sigevent n, *p = NULL; | |
1546 | if (u_notification) { | |
1547 | if (get_compat_sigevent(&n, u_notification)) | |
1548 | return -EFAULT; | |
1549 | if (n.sigev_notify == SIGEV_THREAD) | |
1550 | n.sigev_value.sival_ptr = compat_ptr(n.sigev_value.sival_int); | |
1551 | p = &n; | |
1552 | } | |
1553 | return do_mq_notify(mqdes, p); | |
1554 | } | |
1555 | ||
1556 | COMPAT_SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes, | |
1557 | const struct compat_mq_attr __user *, u_mqstat, | |
1558 | struct compat_mq_attr __user *, u_omqstat) | |
1559 | { | |
1560 | int ret; | |
1561 | struct mq_attr mqstat, omqstat; | |
1562 | struct mq_attr *new = NULL, *old = NULL; | |
1563 | ||
1564 | if (u_mqstat) { | |
1565 | new = &mqstat; | |
1566 | if (get_compat_mq_attr(new, u_mqstat)) | |
1567 | return -EFAULT; | |
1568 | } | |
1569 | if (u_omqstat) | |
1570 | old = &omqstat; | |
1571 | ||
1572 | ret = do_mq_getsetattr(mqdes, new, old); | |
1573 | if (ret || !old) | |
1574 | return ret; | |
1575 | ||
1576 | if (put_compat_mq_attr(old, u_omqstat)) | |
1577 | return -EFAULT; | |
1578 | return 0; | |
1579 | } | |
1580 | #endif | |
1581 | ||
1582 | #ifdef CONFIG_COMPAT_32BIT_TIME | |
9afc5eee | 1583 | static int compat_prepare_timeout(const struct old_timespec32 __user *p, |
b9047726 | 1584 | struct timespec64 *ts) |
0d060606 | 1585 | { |
9afc5eee | 1586 | if (get_old_timespec32(ts, p)) |
0d060606 | 1587 | return -EFAULT; |
b9047726 | 1588 | if (!timespec64_valid(ts)) |
0d060606 AV |
1589 | return -EINVAL; |
1590 | return 0; | |
1591 | } | |
1592 | ||
8dabe724 AB |
1593 | SYSCALL_DEFINE5(mq_timedsend_time32, mqd_t, mqdes, |
1594 | const char __user *, u_msg_ptr, | |
1595 | unsigned int, msg_len, unsigned int, msg_prio, | |
1596 | const struct old_timespec32 __user *, u_abs_timeout) | |
0d060606 | 1597 | { |
b9047726 | 1598 | struct timespec64 ts, *p = NULL; |
0d060606 AV |
1599 | if (u_abs_timeout) { |
1600 | int res = compat_prepare_timeout(u_abs_timeout, &ts); | |
1601 | if (res) | |
1602 | return res; | |
1603 | p = &ts; | |
1604 | } | |
1605 | return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, p); | |
1606 | } | |
1607 | ||
8dabe724 AB |
1608 | SYSCALL_DEFINE5(mq_timedreceive_time32, mqd_t, mqdes, |
1609 | char __user *, u_msg_ptr, | |
1610 | unsigned int, msg_len, unsigned int __user *, u_msg_prio, | |
1611 | const struct old_timespec32 __user *, u_abs_timeout) | |
0d060606 | 1612 | { |
b9047726 | 1613 | struct timespec64 ts, *p = NULL; |
0d060606 AV |
1614 | if (u_abs_timeout) { |
1615 | int res = compat_prepare_timeout(u_abs_timeout, &ts); | |
1616 | if (res) | |
1617 | return res; | |
1618 | p = &ts; | |
1619 | } | |
1620 | return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, p); | |
1621 | } | |
0d060606 | 1622 | #endif |
1da177e4 | 1623 | |
92e1d5be | 1624 | static const struct inode_operations mqueue_dir_inode_operations = { |
1da177e4 LT |
1625 | .lookup = simple_lookup, |
1626 | .create = mqueue_create, | |
1627 | .unlink = mqueue_unlink, | |
1628 | }; | |
1629 | ||
9a32144e | 1630 | static const struct file_operations mqueue_file_operations = { |
1da177e4 LT |
1631 | .flush = mqueue_flush_file, |
1632 | .poll = mqueue_poll_file, | |
1633 | .read = mqueue_read_file, | |
6038f373 | 1634 | .llseek = default_llseek, |
1da177e4 LT |
1635 | }; |
1636 | ||
b87221de | 1637 | static const struct super_operations mqueue_super_ops = { |
1da177e4 | 1638 | .alloc_inode = mqueue_alloc_inode, |
015d7956 | 1639 | .free_inode = mqueue_free_inode, |
6d8af64c | 1640 | .evict_inode = mqueue_evict_inode, |
1da177e4 | 1641 | .statfs = simple_statfs, |
1da177e4 LT |
1642 | }; |
1643 | ||
935c6912 DH |
1644 | static const struct fs_context_operations mqueue_fs_context_ops = { |
1645 | .free = mqueue_fs_context_free, | |
1646 | .get_tree = mqueue_get_tree, | |
1647 | }; | |
1648 | ||
1da177e4 | 1649 | static struct file_system_type mqueue_fs_type = { |
935c6912 DH |
1650 | .name = "mqueue", |
1651 | .init_fs_context = mqueue_init_fs_context, | |
1652 | .kill_sb = kill_litter_super, | |
1653 | .fs_flags = FS_USERNS_MOUNT, | |
1da177e4 LT |
1654 | }; |
1655 | ||
7eafd7c7 SH |
1656 | int mq_init_ns(struct ipc_namespace *ns) |
1657 | { | |
935c6912 DH |
1658 | struct vfsmount *m; |
1659 | ||
7eafd7c7 SH |
1660 | ns->mq_queues_count = 0; |
1661 | ns->mq_queues_max = DFLT_QUEUESMAX; | |
1662 | ns->mq_msg_max = DFLT_MSGMAX; | |
1663 | ns->mq_msgsize_max = DFLT_MSGSIZEMAX; | |
cef0184c KM |
1664 | ns->mq_msg_default = DFLT_MSG; |
1665 | ns->mq_msgsize_default = DFLT_MSGSIZE; | |
7eafd7c7 | 1666 | |
935c6912 DH |
1667 | m = mq_create_mount(ns); |
1668 | if (IS_ERR(m)) | |
1669 | return PTR_ERR(m); | |
1670 | ns->mq_mnt = m; | |
7eafd7c7 SH |
1671 | return 0; |
1672 | } | |
1673 | ||
1674 | void mq_clear_sbinfo(struct ipc_namespace *ns) | |
1675 | { | |
cfb2f6f6 | 1676 | ns->mq_mnt->mnt_sb->s_fs_info = NULL; |
7eafd7c7 SH |
1677 | } |
1678 | ||
1679 | void mq_put_mnt(struct ipc_namespace *ns) | |
1680 | { | |
cfb2f6f6 | 1681 | kern_unmount(ns->mq_mnt); |
7eafd7c7 SH |
1682 | } |
1683 | ||
1da177e4 LT |
1684 | static int __init init_mqueue_fs(void) |
1685 | { | |
1686 | int error; | |
1687 | ||
1688 | mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache", | |
1689 | sizeof(struct mqueue_inode_info), 0, | |
5d097056 | 1690 | SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, init_once); |
1da177e4 LT |
1691 | if (mqueue_inode_cachep == NULL) |
1692 | return -ENOMEM; | |
1693 | ||
2329e392 | 1694 | /* ignore failures - they are not fatal */ |
bdc8e5f8 | 1695 | mq_sysctl_table = mq_register_sysctl_table(); |
1da177e4 LT |
1696 | |
1697 | error = register_filesystem(&mqueue_fs_type); | |
1698 | if (error) | |
1699 | goto out_sysctl; | |
1700 | ||
7eafd7c7 SH |
1701 | spin_lock_init(&mq_lock); |
1702 | ||
6f686574 AV |
1703 | error = mq_init_ns(&init_ipc_ns); |
1704 | if (error) | |
1da177e4 | 1705 | goto out_filesystem; |
1da177e4 | 1706 | |
1da177e4 LT |
1707 | return 0; |
1708 | ||
1709 | out_filesystem: | |
1710 | unregister_filesystem(&mqueue_fs_type); | |
1711 | out_sysctl: | |
1712 | if (mq_sysctl_table) | |
1713 | unregister_sysctl_table(mq_sysctl_table); | |
1a1d92c1 | 1714 | kmem_cache_destroy(mqueue_inode_cachep); |
1da177e4 LT |
1715 | return error; |
1716 | } | |
1717 | ||
6d08a256 | 1718 | device_initcall(init_mqueue_fs); |