blob: b6cb06451f4be9295608a4156d3c32809773919a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * POSIX message queues filesystem for Linux.
3 *
4 * Copyright (C) 2003,2004 Krzysztof Benedyczak (golbi@mat.uni.torun.pl)
Michal Wronskif66e9282006-10-03 23:23:27 +02005 * Michal Wronski (michal.wronski@gmail.com)
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
7 * Spinlocks: Mohamed Abbas (abbas.mohamed@intel.com)
8 * Lockless receive & send, fd based notify:
9 * Manfred Spraul (manfred@colorfullife.com)
10 *
George C. Wilson20ca73b2006-05-24 16:09:55 -050011 * Audit: George Wilson (ltcgcw@us.ibm.com)
12 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * This file is released under the GPL.
14 */
15
Randy.Dunlapc59ede72006-01-11 12:17:46 -080016#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/init.h>
18#include <linux/pagemap.h>
19#include <linux/file.h>
20#include <linux/mount.h>
21#include <linux/namei.h>
22#include <linux/sysctl.h>
23#include <linux/poll.h>
24#include <linux/mqueue.h>
25#include <linux/msg.h>
26#include <linux/skbuff.h>
27#include <linux/netlink.h>
28#include <linux/syscalls.h>
George C. Wilson20ca73b2006-05-24 16:09:55 -050029#include <linux/audit.h>
Jesper Juhl7ed20e12005-05-01 08:59:14 -070030#include <linux/signal.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080031#include <linux/mutex.h>
Pavel Emelyanovb4888932007-10-18 23:40:14 -070032#include <linux/nsproxy.h>
33#include <linux/pid.h>
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070034#include <linux/ipc_namespace.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080035
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <net/sock.h>
37#include "util.h"
38
39#define MQUEUE_MAGIC 0x19800202
40#define DIRENT_SIZE 20
41#define FILENT_SIZE 80
42
43#define SEND 0
44#define RECV 1
45
46#define STATE_NONE 0
47#define STATE_PENDING 1
48#define STATE_READY 2
49
Linus Torvalds1da177e2005-04-16 15:20:36 -070050struct ext_wait_queue { /* queue of sleeping tasks */
51 struct task_struct *task;
52 struct list_head list;
53 struct msg_msg *msg; /* ptr of loaded message */
54 int state; /* one of STATE_* values */
55};
56
57struct mqueue_inode_info {
58 spinlock_t lock;
59 struct inode vfs_inode;
60 wait_queue_head_t wait_q;
61
62 struct msg_msg **messages;
63 struct mq_attr attr;
64
65 struct sigevent notify;
Cedric Le Goatera03fcb72006-10-02 02:17:26 -070066 struct pid* notify_owner;
Adrian Bunk338cec32005-09-10 00:26:54 -070067 struct user_struct *user; /* user who created, for accounting */
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 struct sock *notify_sock;
69 struct sk_buff *notify_cookie;
70
71 /* for tasks waiting for free space and messages, respectively */
72 struct ext_wait_queue e_wait_q[2];
73
74 unsigned long qsize; /* size of queue in memory (sum of all msgs) */
75};
76
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -080077static const struct inode_operations mqueue_dir_inode_operations;
Arjan van de Ven9a321442007-02-12 00:55:35 -080078static const struct file_operations mqueue_file_operations;
Alexey Dobriyanb87221d2009-09-21 17:01:09 -070079static const struct super_operations mqueue_super_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080static void remove_notification(struct mqueue_inode_info *info);
81
Christoph Lametere18b8902006-12-06 20:33:20 -080082static struct kmem_cache *mqueue_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
84static struct ctl_table_header * mq_sysctl_table;
85
86static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
87{
88 return container_of(inode, struct mqueue_inode_info, vfs_inode);
89}
90
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070091/*
92 * This routine should be called with the mq_lock held.
93 */
94static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode)
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070095{
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070096 return get_ipc_ns(inode->i_sb->s_fs_info);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070097}
98
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070099static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700100{
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700101 struct ipc_namespace *ns;
102
103 spin_lock(&mq_lock);
104 ns = __get_ns_from_inode(inode);
105 spin_unlock(&mq_lock);
106 return ns;
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700107}
108
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700109static struct inode *mqueue_get_inode(struct super_block *sb,
110 struct ipc_namespace *ipc_ns, int mode,
111 struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112{
David Howells86a264a2008-11-14 10:39:18 +1100113 struct user_struct *u = current_user();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 struct inode *inode;
115
116 inode = new_inode(sb);
117 if (inode) {
118 inode->i_mode = mode;
David Howells414c0702008-11-14 10:39:06 +1100119 inode->i_uid = current_fsuid();
120 inode->i_gid = current_fsgid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 inode->i_mtime = inode->i_ctime = inode->i_atime =
122 CURRENT_TIME;
123
124 if (S_ISREG(mode)) {
125 struct mqueue_inode_info *info;
126 struct task_struct *p = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 unsigned long mq_bytes, mq_msg_tblsz;
128
129 inode->i_fop = &mqueue_file_operations;
130 inode->i_size = FILENT_SIZE;
131 /* mqueue specific info */
132 info = MQUEUE_I(inode);
133 spin_lock_init(&info->lock);
134 init_waitqueue_head(&info->wait_q);
135 INIT_LIST_HEAD(&info->e_wait_q[0].list);
136 INIT_LIST_HEAD(&info->e_wait_q[1].list);
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700137 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 info->qsize = 0;
139 info->user = NULL; /* set when all is ok */
140 memset(&info->attr, 0, sizeof(info->attr));
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700141 info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
142 info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 if (attr) {
144 info->attr.mq_maxmsg = attr->mq_maxmsg;
145 info->attr.mq_msgsize = attr->mq_msgsize;
146 }
147 mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
André Goddard Rosac8308b12010-02-23 04:04:23 -0300148 info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
149 if (!info->messages)
150 goto out_inode;
151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 mq_bytes = (mq_msg_tblsz +
153 (info->attr.mq_maxmsg * info->attr.mq_msgsize));
154
155 spin_lock(&mq_lock);
156 if (u->mq_bytes + mq_bytes < u->mq_bytes ||
157 u->mq_bytes + mq_bytes >
158 p->signal->rlim[RLIMIT_MSGQUEUE].rlim_cur) {
159 spin_unlock(&mq_lock);
André Goddard Rosac8308b12010-02-23 04:04:23 -0300160 kfree(info->messages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 goto out_inode;
162 }
163 u->mq_bytes += mq_bytes;
164 spin_unlock(&mq_lock);
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 /* all is ok */
167 info->user = get_uid(u);
168 } else if (S_ISDIR(mode)) {
Dave Hansend8c76e62006-09-30 23:29:04 -0700169 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 /* Some things misbehave if size == 0 on a directory */
171 inode->i_size = 2 * DIRENT_SIZE;
172 inode->i_op = &mqueue_dir_inode_operations;
173 inode->i_fop = &simple_dir_operations;
174 }
175 }
176 return inode;
177out_inode:
178 make_bad_inode(inode);
179 iput(inode);
180 return NULL;
181}
182
183static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
184{
185 struct inode *inode;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700186 struct ipc_namespace *ns = data;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300187 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
189 sb->s_blocksize = PAGE_CACHE_SIZE;
190 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
191 sb->s_magic = MQUEUE_MAGIC;
192 sb->s_op = &mqueue_super_ops;
193
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700194 inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO,
195 NULL);
196 if (!inode) {
197 error = -ENOMEM;
198 goto out;
199 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
201 sb->s_root = d_alloc_root(inode);
202 if (!sb->s_root) {
203 iput(inode);
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700204 error = -ENOMEM;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300205 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 }
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300207 error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700209out:
210 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211}
212
David Howells454e2392006-06-23 02:02:57 -0700213static int mqueue_get_sb(struct file_system_type *fs_type,
214 int flags, const char *dev_name,
215 void *data, struct vfsmount *mnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216{
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700217 if (!(flags & MS_KERNMOUNT))
218 data = current->nsproxy->ipc_ns;
219 return get_sb_ns(fs_type, flags, data, mqueue_fill_super, mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220}
221
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700222static void init_once(void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223{
224 struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
225
Christoph Lametera35afb82007-05-16 22:10:57 -0700226 inode_init_once(&p->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227}
228
229static struct inode *mqueue_alloc_inode(struct super_block *sb)
230{
231 struct mqueue_inode_info *ei;
232
Christoph Lametere94b1762006-12-06 20:33:17 -0800233 ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 if (!ei)
235 return NULL;
236 return &ei->vfs_inode;
237}
238
239static void mqueue_destroy_inode(struct inode *inode)
240{
241 kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
242}
243
244static void mqueue_delete_inode(struct inode *inode)
245{
246 struct mqueue_inode_info *info;
247 struct user_struct *user;
248 unsigned long mq_bytes;
249 int i;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700250 struct ipc_namespace *ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 if (S_ISDIR(inode->i_mode)) {
253 clear_inode(inode);
254 return;
255 }
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700256 ipc_ns = get_ns_from_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 info = MQUEUE_I(inode);
258 spin_lock(&info->lock);
259 for (i = 0; i < info->attr.mq_curmsgs; i++)
260 free_msg(info->messages[i]);
261 kfree(info->messages);
262 spin_unlock(&info->lock);
263
264 clear_inode(inode);
265
André Goddard Rosa8834cf72010-02-23 04:04:24 -0300266 /* Total amount of bytes accounted for the mqueue */
267 mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *)
268 + info->attr.mq_msgsize);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 user = info->user;
270 if (user) {
271 spin_lock(&mq_lock);
272 user->mq_bytes -= mq_bytes;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700273 /*
274 * get_ns_from_inode() ensures that the
275 * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
276 * to which we now hold a reference, or it is NULL.
277 * We can't put it here under mq_lock, though.
278 */
279 if (ipc_ns)
280 ipc_ns->mq_queues_count--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 spin_unlock(&mq_lock);
282 free_uid(user);
283 }
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700284 if (ipc_ns)
285 put_ipc_ns(ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286}
287
288static int mqueue_create(struct inode *dir, struct dentry *dentry,
289 int mode, struct nameidata *nd)
290{
291 struct inode *inode;
292 struct mq_attr *attr = dentry->d_fsdata;
293 int error;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700294 struct ipc_namespace *ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
296 spin_lock(&mq_lock);
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700297 ipc_ns = __get_ns_from_inode(dir);
298 if (!ipc_ns) {
299 error = -EACCES;
300 goto out_unlock;
301 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700302 if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
303 !capable(CAP_SYS_RESOURCE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 error = -ENOSPC;
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700305 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700307 ipc_ns->mq_queues_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 spin_unlock(&mq_lock);
309
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700310 inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 if (!inode) {
312 error = -ENOMEM;
313 spin_lock(&mq_lock);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700314 ipc_ns->mq_queues_count--;
315 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 }
317
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700318 put_ipc_ns(ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 dir->i_size += DIRENT_SIZE;
320 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
321
322 d_instantiate(dentry, inode);
323 dget(dentry);
324 return 0;
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700325out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 spin_unlock(&mq_lock);
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700327 if (ipc_ns)
328 put_ipc_ns(ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 return error;
330}
331
332static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
333{
334 struct inode *inode = dentry->d_inode;
335
336 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
337 dir->i_size -= DIRENT_SIZE;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700338 drop_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 dput(dentry);
340 return 0;
341}
342
343/*
344* This is routine for system read from queue file.
345* To avoid mess with doing here some sort of mq_receive we allow
346* to read only queue size & notification info (the only values
347* that are interesting from user point of view and aren't accessible
348* through std routines)
349*/
350static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700351 size_t count, loff_t *off)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352{
Josef Sipek6d630792006-12-08 02:37:11 -0800353 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 char buffer[FILENT_SIZE];
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700355 ssize_t ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
357 spin_lock(&info->lock);
358 snprintf(buffer, sizeof(buffer),
359 "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
360 info->qsize,
361 info->notify_owner ? info->notify.sigev_notify : 0,
362 (info->notify_owner &&
363 info->notify.sigev_notify == SIGEV_SIGNAL) ?
364 info->notify.sigev_signo : 0,
Pavel Emelyanov6c5f3e72008-02-08 04:19:20 -0800365 pid_vnr(info->notify_owner));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 spin_unlock(&info->lock);
367 buffer[sizeof(buffer)-1] = '\0';
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700369 ret = simple_read_from_buffer(u_data, count, off, buffer,
370 strlen(buffer));
371 if (ret <= 0)
372 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373
Josef Sipek6d630792006-12-08 02:37:11 -0800374 filp->f_path.dentry->d_inode->i_atime = filp->f_path.dentry->d_inode->i_ctime = CURRENT_TIME;
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700375 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376}
377
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -0700378static int mqueue_flush_file(struct file *filp, fl_owner_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379{
Josef Sipek6d630792006-12-08 02:37:11 -0800380 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381
382 spin_lock(&info->lock);
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700383 if (task_tgid(current) == info->notify_owner)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 remove_notification(info);
385
386 spin_unlock(&info->lock);
387 return 0;
388}
389
390static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
391{
Josef Sipek6d630792006-12-08 02:37:11 -0800392 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 int retval = 0;
394
395 poll_wait(filp, &info->wait_q, poll_tab);
396
397 spin_lock(&info->lock);
398 if (info->attr.mq_curmsgs)
399 retval = POLLIN | POLLRDNORM;
400
401 if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
402 retval |= POLLOUT | POLLWRNORM;
403 spin_unlock(&info->lock);
404
405 return retval;
406}
407
408/* Adds current to info->e_wait_q[sr] before element with smaller prio */
409static void wq_add(struct mqueue_inode_info *info, int sr,
410 struct ext_wait_queue *ewp)
411{
412 struct ext_wait_queue *walk;
413
414 ewp->task = current;
415
416 list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
417 if (walk->task->static_prio <= current->static_prio) {
418 list_add_tail(&ewp->list, &walk->list);
419 return;
420 }
421 }
422 list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
423}
424
425/*
426 * Puts current task to sleep. Caller must hold queue lock. After return
427 * lock isn't held.
428 * sr: SEND or RECV
429 */
430static int wq_sleep(struct mqueue_inode_info *info, int sr,
431 long timeout, struct ext_wait_queue *ewp)
432{
433 int retval;
434 signed long time;
435
436 wq_add(info, sr, ewp);
437
438 for (;;) {
439 set_current_state(TASK_INTERRUPTIBLE);
440
441 spin_unlock(&info->lock);
442 time = schedule_timeout(timeout);
443
444 while (ewp->state == STATE_PENDING)
445 cpu_relax();
446
447 if (ewp->state == STATE_READY) {
448 retval = 0;
449 goto out;
450 }
451 spin_lock(&info->lock);
452 if (ewp->state == STATE_READY) {
453 retval = 0;
454 goto out_unlock;
455 }
456 if (signal_pending(current)) {
457 retval = -ERESTARTSYS;
458 break;
459 }
460 if (time == 0) {
461 retval = -ETIMEDOUT;
462 break;
463 }
464 }
465 list_del(&ewp->list);
466out_unlock:
467 spin_unlock(&info->lock);
468out:
469 return retval;
470}
471
472/*
473 * Returns waiting task that should be serviced first or NULL if none exists
474 */
475static struct ext_wait_queue *wq_get_first_waiter(
476 struct mqueue_inode_info *info, int sr)
477{
478 struct list_head *ptr;
479
480 ptr = info->e_wait_q[sr].list.prev;
481 if (ptr == &info->e_wait_q[sr].list)
482 return NULL;
483 return list_entry(ptr, struct ext_wait_queue, list);
484}
485
486/* Auxiliary functions to manipulate messages' list */
487static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
488{
489 int k;
490
491 k = info->attr.mq_curmsgs - 1;
492 while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
493 info->messages[k + 1] = info->messages[k];
494 k--;
495 }
496 info->attr.mq_curmsgs++;
497 info->qsize += ptr->m_ts;
498 info->messages[k + 1] = ptr;
499}
500
501static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
502{
503 info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
504 return info->messages[info->attr.mq_curmsgs];
505}
506
507static inline void set_cookie(struct sk_buff *skb, char code)
508{
509 ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
510}
511
512/*
513 * The next function is only to split too long sys_mq_timedsend
514 */
515static void __do_notify(struct mqueue_inode_info *info)
516{
517 /* notification
518 * invoked when there is registered process and there isn't process
519 * waiting synchronously for message AND state of queue changed from
520 * empty to not empty. Here we are sure that no one is waiting
521 * synchronously. */
522 if (info->notify_owner &&
523 info->attr.mq_curmsgs == 1) {
524 struct siginfo sig_i;
525 switch (info->notify.sigev_notify) {
526 case SIGEV_NONE:
527 break;
528 case SIGEV_SIGNAL:
529 /* sends signal */
530
531 sig_i.si_signo = info->notify.sigev_signo;
532 sig_i.si_errno = 0;
533 sig_i.si_code = SI_MESGQ;
534 sig_i.si_value = info->notify.sigev_value;
Sukadev Bhattiprolua6684992009-01-07 18:08:50 -0800535 sig_i.si_pid = task_tgid_nr_ns(current,
536 ns_of_pid(info->notify_owner));
David Howells414c0702008-11-14 10:39:06 +1100537 sig_i.si_uid = current_uid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700539 kill_pid_info(info->notify.sigev_signo,
540 &sig_i, info->notify_owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 break;
542 case SIGEV_THREAD:
543 set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700544 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 break;
546 }
547 /* after notification unregisters process */
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700548 put_pid(info->notify_owner);
549 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 }
551 wake_up(&info->wait_q);
552}
553
Al Viroc32c8af2008-12-14 03:46:48 -0500554static long prepare_timeout(struct timespec *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555{
Al Viroc32c8af2008-12-14 03:46:48 -0500556 struct timespec nowts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 long timeout;
558
Al Viroc32c8af2008-12-14 03:46:48 -0500559 if (p) {
560 if (unlikely(p->tv_nsec < 0 || p->tv_sec < 0
561 || p->tv_nsec >= NSEC_PER_SEC))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562 return -EINVAL;
563 nowts = CURRENT_TIME;
564 /* first subtract as jiffies can't be too big */
Al Viroc32c8af2008-12-14 03:46:48 -0500565 p->tv_sec -= nowts.tv_sec;
566 if (p->tv_nsec < nowts.tv_nsec) {
567 p->tv_nsec += NSEC_PER_SEC;
568 p->tv_sec--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 }
Al Viroc32c8af2008-12-14 03:46:48 -0500570 p->tv_nsec -= nowts.tv_nsec;
571 if (p->tv_sec < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 return 0;
573
Al Viroc32c8af2008-12-14 03:46:48 -0500574 timeout = timespec_to_jiffies(p) + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 } else
576 return MAX_SCHEDULE_TIMEOUT;
577
578 return timeout;
579}
580
581static void remove_notification(struct mqueue_inode_info *info)
582{
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700583 if (info->notify_owner != NULL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 info->notify.sigev_notify == SIGEV_THREAD) {
585 set_cookie(info->notify_cookie, NOTIFY_REMOVED);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700586 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700588 put_pid(info->notify_owner);
589 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590}
591
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700592static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593{
594 if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
595 return 0;
596 if (capable(CAP_SYS_RESOURCE)) {
597 if (attr->mq_maxmsg > HARD_MSGMAX)
598 return 0;
599 } else {
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700600 if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
601 attr->mq_msgsize > ipc_ns->mq_msgsize_max)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 return 0;
603 }
604 /* check for overflow */
605 if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
606 return 0;
André Goddard Rosa8834cf72010-02-23 04:04:24 -0300607 if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize
608 + sizeof (struct msg_msg *))) <
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
610 return 0;
611 return 1;
612}
613
614/*
615 * Invoked when creating a new queue via sys_mq_open
616 */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700617static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
618 struct dentry *dentry, int oflag, mode_t mode,
619 struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620{
David Howells745ca242008-11-14 10:39:22 +1100621 const struct cred *cred = current_cred();
Dave Hansen4a3fd212008-02-15 14:37:48 -0800622 struct file *result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 int ret;
624
Al Viro564f6992008-12-14 04:02:26 -0500625 if (attr) {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300626 if (!mq_attr_ok(ipc_ns, attr)) {
627 ret = -EINVAL;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500628 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300629 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 /* store for use during create */
Al Viro564f6992008-12-14 04:02:26 -0500631 dentry->d_fsdata = attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 }
633
Al Viroce3b0f82009-03-29 19:08:22 -0400634 mode &= ~current_umask();
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700635 ret = mnt_want_write(ipc_ns->mq_mnt);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800636 if (ret)
637 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 ret = vfs_create(dir->d_inode, dentry, mode, NULL);
639 dentry->d_fsdata = NULL;
640 if (ret)
Dave Hansen4a3fd212008-02-15 14:37:48 -0800641 goto out_drop_write;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700643 result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800644 /*
645 * dentry_open() took a persistent mnt_want_write(),
646 * so we can now drop this one.
647 */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700648 mnt_drop_write(ipc_ns->mq_mnt);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800649 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650
Dave Hansen4a3fd212008-02-15 14:37:48 -0800651out_drop_write:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700652 mnt_drop_write(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500653out:
654 dput(dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700655 mntput(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500656 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657}
658
659/* Opens existing queue */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700660static struct file *do_open(struct ipc_namespace *ipc_ns,
661 struct dentry *dentry, int oflag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662{
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300663 int ret;
David Howells745ca242008-11-14 10:39:22 +1100664 const struct cred *cred = current_cred();
665
666 static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
667 MAY_READ | MAY_WRITE };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
Alexander Viro7c7dce92006-01-14 15:29:55 -0500669 if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300670 ret = -EINVAL;
671 goto err;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500672 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673
Al Virof419a2e2008-07-22 00:07:17 -0400674 if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) {
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300675 ret = -EACCES;
676 goto err;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500677 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700679 return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300680
681err:
682 dput(dentry);
683 mntput(ipc_ns->mq_mnt);
684 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685}
686
Heiko Carstensd5460c92009-01-14 14:14:27 +0100687SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
688 struct mq_attr __user *, u_attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689{
690 struct dentry *dentry;
691 struct file *filp;
692 char *name;
Al Viro564f6992008-12-14 04:02:26 -0500693 struct mq_attr attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 int fd, error;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700695 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696
Al Viro564f6992008-12-14 04:02:26 -0500697 if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
698 return -EFAULT;
699
700 audit_mq_open(oflag, mode, u_attr ? &attr : NULL);
George C. Wilson20ca73b2006-05-24 16:09:55 -0500701
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 if (IS_ERR(name = getname(u_name)))
703 return PTR_ERR(name);
704
Ulrich Drepper269f2132008-05-03 15:28:45 -0400705 fd = get_unused_fd_flags(O_CLOEXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 if (fd < 0)
707 goto out_putname;
708
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700709 mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
710 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 if (IS_ERR(dentry)) {
712 error = PTR_ERR(dentry);
André Goddard Rosa4294a8e2010-02-23 04:04:28 -0300713 goto out_putfd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700715 mntget(ipc_ns->mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716
717 if (oflag & O_CREAT) {
718 if (dentry->d_inode) { /* entry already exists */
Al Viro5a190ae2007-06-07 12:19:32 -0400719 audit_inode(name, dentry);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300720 if (oflag & O_EXCL) {
721 error = -EEXIST;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500722 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300723 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700724 filp = do_open(ipc_ns, dentry, oflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 } else {
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700726 filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
727 dentry, oflag, mode,
Al Viro564f6992008-12-14 04:02:26 -0500728 u_attr ? &attr : NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 }
Alexander Viro7c7dce92006-01-14 15:29:55 -0500730 } else {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300731 if (!dentry->d_inode) {
732 error = -ENOENT;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500733 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300734 }
Al Viro5a190ae2007-06-07 12:19:32 -0400735 audit_inode(name, dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700736 filp = do_open(ipc_ns, dentry, oflag);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500737 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
739 if (IS_ERR(filp)) {
740 error = PTR_ERR(filp);
741 goto out_putfd;
742 }
743
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 fd_install(fd, filp);
745 goto out_upsem;
746
Alexander Viro7c7dce92006-01-14 15:29:55 -0500747out:
748 dput(dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700749 mntput(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500750out_putfd:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 put_unused_fd(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 fd = error;
753out_upsem:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700754 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755out_putname:
756 putname(name);
757 return fd;
758}
759
Heiko Carstensd5460c92009-01-14 14:14:27 +0100760SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761{
762 int err;
763 char *name;
764 struct dentry *dentry;
765 struct inode *inode = NULL;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700766 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767
768 name = getname(u_name);
769 if (IS_ERR(name))
770 return PTR_ERR(name);
771
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700772 mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex,
Peter Zijlstra7a434812007-03-06 01:42:09 -0800773 I_MUTEX_PARENT);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700774 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 if (IS_ERR(dentry)) {
776 err = PTR_ERR(dentry);
777 goto out_unlock;
778 }
779
780 if (!dentry->d_inode) {
781 err = -ENOENT;
782 goto out_err;
783 }
784
785 inode = dentry->d_inode;
786 if (inode)
787 atomic_inc(&inode->i_count);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700788 err = mnt_want_write(ipc_ns->mq_mnt);
Dave Hansen06227532008-02-15 14:37:34 -0800789 if (err)
790 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 err = vfs_unlink(dentry->d_parent->d_inode, dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700792 mnt_drop_write(ipc_ns->mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793out_err:
794 dput(dentry);
795
796out_unlock:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700797 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 putname(name);
799 if (inode)
800 iput(inode);
801
802 return err;
803}
804
805/* Pipelined send and receive functions.
806 *
807 * If a receiver finds no waiting message, then it registers itself in the
808 * list of waiting receivers. A sender checks that list before adding the new
809 * message into the message array. If there is a waiting receiver, then it
810 * bypasses the message array and directly hands the message over to the
811 * receiver.
812 * The receiver accepts the message and returns without grabbing the queue
813 * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
814 * are necessary. The same algorithm is used for sysv semaphores, see
Serge E. Hallyn7b7a3172006-03-28 01:56:23 -0800815 * ipc/sem.c for more details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 *
817 * The same algorithm is used for senders.
818 */
819
820/* pipelined_send() - send a message directly to the task waiting in
821 * sys_mq_timedreceive() (without inserting message into a queue).
822 */
823static inline void pipelined_send(struct mqueue_inode_info *info,
824 struct msg_msg *message,
825 struct ext_wait_queue *receiver)
826{
827 receiver->msg = message;
828 list_del(&receiver->list);
829 receiver->state = STATE_PENDING;
830 wake_up_process(receiver->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700831 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 receiver->state = STATE_READY;
833}
834
835/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
836 * gets its message and put to the queue (we have one free place for sure). */
837static inline void pipelined_receive(struct mqueue_inode_info *info)
838{
839 struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
840
841 if (!sender) {
842 /* for poll */
843 wake_up_interruptible(&info->wait_q);
844 return;
845 }
846 msg_insert(sender->msg, info);
847 list_del(&sender->list);
848 sender->state = STATE_PENDING;
849 wake_up_process(sender->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700850 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 sender->state = STATE_READY;
852}
853
Heiko Carstensc4ea37c2009-01-14 14:14:28 +0100854SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
855 size_t, msg_len, unsigned int, msg_prio,
856 const struct timespec __user *, u_abs_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857{
858 struct file *filp;
859 struct inode *inode;
860 struct ext_wait_queue wait;
861 struct ext_wait_queue *receiver;
862 struct msg_msg *msg_ptr;
863 struct mqueue_inode_info *info;
Al Viroc32c8af2008-12-14 03:46:48 -0500864 struct timespec ts, *p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 long timeout;
866 int ret;
867
Al Viroc32c8af2008-12-14 03:46:48 -0500868 if (u_abs_timeout) {
869 if (copy_from_user(&ts, u_abs_timeout,
870 sizeof(struct timespec)))
871 return -EFAULT;
872 p = &ts;
873 }
George C. Wilson20ca73b2006-05-24 16:09:55 -0500874
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
876 return -EINVAL;
877
Al Viroc32c8af2008-12-14 03:46:48 -0500878 audit_mq_sendrecv(mqdes, msg_len, msg_prio, p);
879 timeout = prepare_timeout(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300882 if (unlikely(!filp)) {
883 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300885 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886
Josef Sipek6d630792006-12-08 02:37:11 -0800887 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300888 if (unlikely(filp->f_op != &mqueue_file_operations)) {
889 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300891 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400893 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300895 if (unlikely(!(filp->f_mode & FMODE_WRITE))) {
896 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300898 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899
900 if (unlikely(msg_len > info->attr.mq_msgsize)) {
901 ret = -EMSGSIZE;
902 goto out_fput;
903 }
904
905 /* First try to allocate memory, before doing anything with
906 * existing queues. */
907 msg_ptr = load_msg(u_msg_ptr, msg_len);
908 if (IS_ERR(msg_ptr)) {
909 ret = PTR_ERR(msg_ptr);
910 goto out_fput;
911 }
912 msg_ptr->m_ts = msg_len;
913 msg_ptr->m_type = msg_prio;
914
915 spin_lock(&info->lock);
916
917 if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
918 if (filp->f_flags & O_NONBLOCK) {
919 spin_unlock(&info->lock);
920 ret = -EAGAIN;
921 } else if (unlikely(timeout < 0)) {
922 spin_unlock(&info->lock);
923 ret = timeout;
924 } else {
925 wait.task = current;
926 wait.msg = (void *) msg_ptr;
927 wait.state = STATE_NONE;
928 ret = wq_sleep(info, SEND, timeout, &wait);
929 }
930 if (ret < 0)
931 free_msg(msg_ptr);
932 } else {
933 receiver = wq_get_first_waiter(info, RECV);
934 if (receiver) {
935 pipelined_send(info, msg_ptr, receiver);
936 } else {
937 /* adds message to the queue */
938 msg_insert(msg_ptr, info);
939 __do_notify(info);
940 }
941 inode->i_atime = inode->i_mtime = inode->i_ctime =
942 CURRENT_TIME;
943 spin_unlock(&info->lock);
944 ret = 0;
945 }
946out_fput:
947 fput(filp);
948out:
949 return ret;
950}
951
Heiko Carstensc4ea37c2009-01-14 14:14:28 +0100952SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
953 size_t, msg_len, unsigned int __user *, u_msg_prio,
954 const struct timespec __user *, u_abs_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955{
956 long timeout;
957 ssize_t ret;
958 struct msg_msg *msg_ptr;
959 struct file *filp;
960 struct inode *inode;
961 struct mqueue_inode_info *info;
962 struct ext_wait_queue wait;
Al Viroc32c8af2008-12-14 03:46:48 -0500963 struct timespec ts, *p = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964
Al Viroc32c8af2008-12-14 03:46:48 -0500965 if (u_abs_timeout) {
966 if (copy_from_user(&ts, u_abs_timeout,
967 sizeof(struct timespec)))
968 return -EFAULT;
969 p = &ts;
970 }
George C. Wilson20ca73b2006-05-24 16:09:55 -0500971
Al Viroc32c8af2008-12-14 03:46:48 -0500972 audit_mq_sendrecv(mqdes, msg_len, 0, p);
973 timeout = prepare_timeout(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300976 if (unlikely(!filp)) {
977 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300979 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980
Josef Sipek6d630792006-12-08 02:37:11 -0800981 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300982 if (unlikely(filp->f_op != &mqueue_file_operations)) {
983 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300985 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400987 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300989 if (unlikely(!(filp->f_mode & FMODE_READ))) {
990 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300992 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993
994 /* checks if buffer is big enough */
995 if (unlikely(msg_len < info->attr.mq_msgsize)) {
996 ret = -EMSGSIZE;
997 goto out_fput;
998 }
999
1000 spin_lock(&info->lock);
1001 if (info->attr.mq_curmsgs == 0) {
1002 if (filp->f_flags & O_NONBLOCK) {
1003 spin_unlock(&info->lock);
1004 ret = -EAGAIN;
1005 msg_ptr = NULL;
1006 } else if (unlikely(timeout < 0)) {
1007 spin_unlock(&info->lock);
1008 ret = timeout;
1009 msg_ptr = NULL;
1010 } else {
1011 wait.task = current;
1012 wait.state = STATE_NONE;
1013 ret = wq_sleep(info, RECV, timeout, &wait);
1014 msg_ptr = wait.msg;
1015 }
1016 } else {
1017 msg_ptr = msg_get(info);
1018
1019 inode->i_atime = inode->i_mtime = inode->i_ctime =
1020 CURRENT_TIME;
1021
1022 /* There is now free space in queue. */
1023 pipelined_receive(info);
1024 spin_unlock(&info->lock);
1025 ret = 0;
1026 }
1027 if (ret == 0) {
1028 ret = msg_ptr->m_ts;
1029
1030 if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
1031 store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
1032 ret = -EFAULT;
1033 }
1034 free_msg(msg_ptr);
1035 }
1036out_fput:
1037 fput(filp);
1038out:
1039 return ret;
1040}
1041
1042/*
1043 * Notes: the case when user wants us to deregister (with NULL as pointer)
1044 * and he isn't currently owner of notification, will be silently discarded.
1045 * It isn't explicitly defined in the POSIX.
1046 */
Heiko Carstensc4ea37c2009-01-14 14:14:28 +01001047SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
1048 const struct sigevent __user *, u_notification)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049{
1050 int ret;
1051 struct file *filp;
1052 struct sock *sock;
1053 struct inode *inode;
1054 struct sigevent notification;
1055 struct mqueue_inode_info *info;
1056 struct sk_buff *nc;
1057
Al Viro20114f72008-12-10 07:16:12 -05001058 if (u_notification) {
1059 if (copy_from_user(&notification, u_notification,
1060 sizeof(struct sigevent)))
1061 return -EFAULT;
1062 }
1063
1064 audit_mq_notify(mqdes, u_notification ? &notification : NULL);
George C. Wilson20ca73b2006-05-24 16:09:55 -05001065
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 nc = NULL;
1067 sock = NULL;
1068 if (u_notification != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069 if (unlikely(notification.sigev_notify != SIGEV_NONE &&
1070 notification.sigev_notify != SIGEV_SIGNAL &&
1071 notification.sigev_notify != SIGEV_THREAD))
1072 return -EINVAL;
1073 if (notification.sigev_notify == SIGEV_SIGNAL &&
Jesper Juhl7ed20e12005-05-01 08:59:14 -07001074 !valid_signal(notification.sigev_signo)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 return -EINVAL;
1076 }
1077 if (notification.sigev_notify == SIGEV_THREAD) {
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -08001078 long timeo;
1079
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080 /* create the notify skb */
1081 nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001082 if (!nc) {
1083 ret = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001085 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086 if (copy_from_user(nc->data,
1087 notification.sigev_value.sival_ptr,
1088 NOTIFY_COOKIE_LEN)) {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001089 ret = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090 goto out;
1091 }
1092
1093 /* TODO: add a header? */
1094 skb_put(nc, NOTIFY_COOKIE_LEN);
1095 /* and attach it to the socket */
1096retry:
1097 filp = fget(notification.sigev_signo);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001098 if (!filp) {
1099 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001101 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 sock = netlink_getsockbyfilp(filp);
1103 fput(filp);
1104 if (IS_ERR(sock)) {
1105 ret = PTR_ERR(sock);
1106 sock = NULL;
1107 goto out;
1108 }
1109
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -08001110 timeo = MAX_SCHEDULE_TIMEOUT;
Denis V. Lunev9457afe2008-06-05 11:23:39 -07001111 ret = netlink_attachskb(sock, nc, &timeo, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112 if (ret == 1)
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001113 goto retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114 if (ret) {
1115 sock = NULL;
1116 nc = NULL;
1117 goto out;
1118 }
1119 }
1120 }
1121
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001123 if (!filp) {
1124 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001126 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127
Josef Sipek6d630792006-12-08 02:37:11 -08001128 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001129 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1130 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001132 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133 info = MQUEUE_I(inode);
1134
1135 ret = 0;
1136 spin_lock(&info->lock);
1137 if (u_notification == NULL) {
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001138 if (info->notify_owner == task_tgid(current)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 remove_notification(info);
1140 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1141 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001142 } else if (info->notify_owner != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 ret = -EBUSY;
1144 } else {
1145 switch (notification.sigev_notify) {
1146 case SIGEV_NONE:
1147 info->notify.sigev_notify = SIGEV_NONE;
1148 break;
1149 case SIGEV_THREAD:
1150 info->notify_sock = sock;
1151 info->notify_cookie = nc;
1152 sock = NULL;
1153 nc = NULL;
1154 info->notify.sigev_notify = SIGEV_THREAD;
1155 break;
1156 case SIGEV_SIGNAL:
1157 info->notify.sigev_signo = notification.sigev_signo;
1158 info->notify.sigev_value = notification.sigev_value;
1159 info->notify.sigev_notify = SIGEV_SIGNAL;
1160 break;
1161 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001162
1163 info->notify_owner = get_pid(task_tgid(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1165 }
1166 spin_unlock(&info->lock);
1167out_fput:
1168 fput(filp);
1169out:
1170 if (sock) {
1171 netlink_detachskb(sock, nc);
1172 } else if (nc) {
1173 dev_kfree_skb(nc);
1174 }
1175 return ret;
1176}
1177
Heiko Carstensc4ea37c2009-01-14 14:14:28 +01001178SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
1179 const struct mq_attr __user *, u_mqstat,
1180 struct mq_attr __user *, u_omqstat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181{
1182 int ret;
1183 struct mq_attr mqstat, omqstat;
1184 struct file *filp;
1185 struct inode *inode;
1186 struct mqueue_inode_info *info;
1187
1188 if (u_mqstat != NULL) {
1189 if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr)))
1190 return -EFAULT;
1191 if (mqstat.mq_flags & (~O_NONBLOCK))
1192 return -EINVAL;
1193 }
1194
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001196 if (!filp) {
1197 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001199 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200
Josef Sipek6d630792006-12-08 02:37:11 -08001201 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001202 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1203 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001205 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001206 info = MQUEUE_I(inode);
1207
1208 spin_lock(&info->lock);
1209
1210 omqstat = info->attr;
1211 omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
1212 if (u_mqstat) {
Al Viro73929062008-12-10 06:58:59 -05001213 audit_mq_getsetattr(mqdes, &mqstat);
Jonathan Corbetdb1dd4d2009-02-06 15:25:24 -07001214 spin_lock(&filp->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001215 if (mqstat.mq_flags & O_NONBLOCK)
1216 filp->f_flags |= O_NONBLOCK;
1217 else
1218 filp->f_flags &= ~O_NONBLOCK;
Jonathan Corbetdb1dd4d2009-02-06 15:25:24 -07001219 spin_unlock(&filp->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220
1221 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1222 }
1223
1224 spin_unlock(&info->lock);
1225
1226 ret = 0;
1227 if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat,
1228 sizeof(struct mq_attr)))
1229 ret = -EFAULT;
1230
1231out_fput:
1232 fput(filp);
1233out:
1234 return ret;
1235}
1236
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -08001237static const struct inode_operations mqueue_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238 .lookup = simple_lookup,
1239 .create = mqueue_create,
1240 .unlink = mqueue_unlink,
1241};
1242
Arjan van de Ven9a321442007-02-12 00:55:35 -08001243static const struct file_operations mqueue_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 .flush = mqueue_flush_file,
1245 .poll = mqueue_poll_file,
1246 .read = mqueue_read_file,
1247};
1248
Alexey Dobriyanb87221d2009-09-21 17:01:09 -07001249static const struct super_operations mqueue_super_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 .alloc_inode = mqueue_alloc_inode,
1251 .destroy_inode = mqueue_destroy_inode,
1252 .statfs = simple_statfs,
1253 .delete_inode = mqueue_delete_inode,
1254 .drop_inode = generic_delete_inode,
1255};
1256
1257static struct file_system_type mqueue_fs_type = {
1258 .name = "mqueue",
1259 .get_sb = mqueue_get_sb,
1260 .kill_sb = kill_litter_super,
1261};
1262
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -07001263int mq_init_ns(struct ipc_namespace *ns)
1264{
1265 ns->mq_queues_count = 0;
1266 ns->mq_queues_max = DFLT_QUEUESMAX;
1267 ns->mq_msg_max = DFLT_MSGMAX;
1268 ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
1269
1270 ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
1271 if (IS_ERR(ns->mq_mnt)) {
1272 int err = PTR_ERR(ns->mq_mnt);
1273 ns->mq_mnt = NULL;
1274 return err;
1275 }
1276 return 0;
1277}
1278
1279void mq_clear_sbinfo(struct ipc_namespace *ns)
1280{
1281 ns->mq_mnt->mnt_sb->s_fs_info = NULL;
1282}
1283
1284void mq_put_mnt(struct ipc_namespace *ns)
1285{
1286 mntput(ns->mq_mnt);
1287}
1288
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289static int __init init_mqueue_fs(void)
1290{
1291 int error;
1292
1293 mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
1294 sizeof(struct mqueue_inode_info), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001295 SLAB_HWCACHE_ALIGN, init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296 if (mqueue_inode_cachep == NULL)
1297 return -ENOMEM;
1298
André Goddard Rosa2329e392010-02-23 04:04:27 -03001299 /* ignore failures - they are not fatal */
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -07001300 mq_sysctl_table = mq_register_sysctl_table();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301
1302 error = register_filesystem(&mqueue_fs_type);
1303 if (error)
1304 goto out_sysctl;
1305
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -07001306 spin_lock_init(&mq_lock);
1307
1308 init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001309 if (IS_ERR(init_ipc_ns.mq_mnt)) {
1310 error = PTR_ERR(init_ipc_ns.mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 goto out_filesystem;
1312 }
1313
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 return 0;
1315
1316out_filesystem:
1317 unregister_filesystem(&mqueue_fs_type);
1318out_sysctl:
1319 if (mq_sysctl_table)
1320 unregister_sysctl_table(mq_sysctl_table);
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -07001321 kmem_cache_destroy(mqueue_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322 return error;
1323}
1324
1325__initcall(init_mqueue_fs);