blob: c93fd3faac2d288e7d87db2642df7b167e15ddc0 [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090035#include <linux/slab.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080036
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <net/sock.h>
38#include "util.h"
39
40#define MQUEUE_MAGIC 0x19800202
41#define DIRENT_SIZE 20
42#define FILENT_SIZE 80
43
44#define SEND 0
45#define RECV 1
46
47#define STATE_NONE 0
48#define STATE_PENDING 1
49#define STATE_READY 2
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051struct ext_wait_queue { /* queue of sleeping tasks */
52 struct task_struct *task;
53 struct list_head list;
54 struct msg_msg *msg; /* ptr of loaded message */
55 int state; /* one of STATE_* values */
56};
57
58struct mqueue_inode_info {
59 spinlock_t lock;
60 struct inode vfs_inode;
61 wait_queue_head_t wait_q;
62
63 struct msg_msg **messages;
64 struct mq_attr attr;
65
66 struct sigevent notify;
Cedric Le Goatera03fcb72006-10-02 02:17:26 -070067 struct pid* notify_owner;
Adrian Bunk338cec32005-09-10 00:26:54 -070068 struct user_struct *user; /* user who created, for accounting */
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 struct sock *notify_sock;
70 struct sk_buff *notify_cookie;
71
72 /* for tasks waiting for free space and messages, respectively */
73 struct ext_wait_queue e_wait_q[2];
74
75 unsigned long qsize; /* size of queue in memory (sum of all msgs) */
76};
77
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -080078static const struct inode_operations mqueue_dir_inode_operations;
Arjan van de Ven9a321442007-02-12 00:55:35 -080079static const struct file_operations mqueue_file_operations;
Alexey Dobriyanb87221d2009-09-21 17:01:09 -070080static const struct super_operations mqueue_super_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081static void remove_notification(struct mqueue_inode_info *info);
82
Christoph Lametere18b8902006-12-06 20:33:20 -080083static struct kmem_cache *mqueue_inode_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85static struct ctl_table_header * mq_sysctl_table;
86
87static inline struct mqueue_inode_info *MQUEUE_I(struct inode *inode)
88{
89 return container_of(inode, struct mqueue_inode_info, vfs_inode);
90}
91
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070092/*
93 * This routine should be called with the mq_lock held.
94 */
95static inline struct ipc_namespace *__get_ns_from_inode(struct inode *inode)
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070096{
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -070097 return get_ipc_ns(inode->i_sb->s_fs_info);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -070098}
99
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700100static struct ipc_namespace *get_ns_from_inode(struct inode *inode)
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700101{
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700102 struct ipc_namespace *ns;
103
104 spin_lock(&mq_lock);
105 ns = __get_ns_from_inode(inode);
106 spin_unlock(&mq_lock);
107 return ns;
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700108}
109
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700110static struct inode *mqueue_get_inode(struct super_block *sb,
111 struct ipc_namespace *ipc_ns, int mode,
112 struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113{
David Howells86a264a2008-11-14 10:39:18 +1100114 struct user_struct *u = current_user();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 struct inode *inode;
116
117 inode = new_inode(sb);
118 if (inode) {
119 inode->i_mode = mode;
David Howells414c0702008-11-14 10:39:06 +1100120 inode->i_uid = current_fsuid();
121 inode->i_gid = current_fsgid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 inode->i_mtime = inode->i_ctime = inode->i_atime =
123 CURRENT_TIME;
124
125 if (S_ISREG(mode)) {
126 struct mqueue_inode_info *info;
127 struct task_struct *p = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 unsigned long mq_bytes, mq_msg_tblsz;
129
130 inode->i_fop = &mqueue_file_operations;
131 inode->i_size = FILENT_SIZE;
132 /* mqueue specific info */
133 info = MQUEUE_I(inode);
134 spin_lock_init(&info->lock);
135 init_waitqueue_head(&info->wait_q);
136 INIT_LIST_HEAD(&info->e_wait_q[0].list);
137 INIT_LIST_HEAD(&info->e_wait_q[1].list);
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700138 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 info->qsize = 0;
140 info->user = NULL; /* set when all is ok */
141 memset(&info->attr, 0, sizeof(info->attr));
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700142 info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
143 info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 if (attr) {
145 info->attr.mq_maxmsg = attr->mq_maxmsg;
146 info->attr.mq_msgsize = attr->mq_msgsize;
147 }
148 mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
André Goddard Rosac8308b12010-02-23 04:04:23 -0300149 info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
150 if (!info->messages)
151 goto out_inode;
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 mq_bytes = (mq_msg_tblsz +
154 (info->attr.mq_maxmsg * info->attr.mq_msgsize));
155
156 spin_lock(&mq_lock);
157 if (u->mq_bytes + mq_bytes < u->mq_bytes ||
158 u->mq_bytes + mq_bytes >
Jiri Slabyf1eb1332010-03-10 15:23:05 -0800159 task_rlimit(p, RLIMIT_MSGQUEUE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 spin_unlock(&mq_lock);
André Goddard Rosaa3ed2a12010-05-11 14:07:03 -0700161 /* mqueue_delete_inode() releases info->messages */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 goto out_inode;
163 }
164 u->mq_bytes += mq_bytes;
165 spin_unlock(&mq_lock);
166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 /* all is ok */
168 info->user = get_uid(u);
169 } else if (S_ISDIR(mode)) {
Dave Hansend8c76e62006-09-30 23:29:04 -0700170 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 /* Some things misbehave if size == 0 on a directory */
172 inode->i_size = 2 * DIRENT_SIZE;
173 inode->i_op = &mqueue_dir_inode_operations;
174 inode->i_fop = &simple_dir_operations;
175 }
176 }
177 return inode;
178out_inode:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 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,
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200431 ktime_t *timeout, struct ext_wait_queue *ewp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432{
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);
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200442 time = schedule_hrtimeout_range_clock(timeout,
443 HRTIMER_MODE_ABS, 0, CLOCK_REALTIME);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
445 while (ewp->state == STATE_PENDING)
446 cpu_relax();
447
448 if (ewp->state == STATE_READY) {
449 retval = 0;
450 goto out;
451 }
452 spin_lock(&info->lock);
453 if (ewp->state == STATE_READY) {
454 retval = 0;
455 goto out_unlock;
456 }
457 if (signal_pending(current)) {
458 retval = -ERESTARTSYS;
459 break;
460 }
461 if (time == 0) {
462 retval = -ETIMEDOUT;
463 break;
464 }
465 }
466 list_del(&ewp->list);
467out_unlock:
468 spin_unlock(&info->lock);
469out:
470 return retval;
471}
472
473/*
474 * Returns waiting task that should be serviced first or NULL if none exists
475 */
476static struct ext_wait_queue *wq_get_first_waiter(
477 struct mqueue_inode_info *info, int sr)
478{
479 struct list_head *ptr;
480
481 ptr = info->e_wait_q[sr].list.prev;
482 if (ptr == &info->e_wait_q[sr].list)
483 return NULL;
484 return list_entry(ptr, struct ext_wait_queue, list);
485}
486
487/* Auxiliary functions to manipulate messages' list */
488static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
489{
490 int k;
491
492 k = info->attr.mq_curmsgs - 1;
493 while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
494 info->messages[k + 1] = info->messages[k];
495 k--;
496 }
497 info->attr.mq_curmsgs++;
498 info->qsize += ptr->m_ts;
499 info->messages[k + 1] = ptr;
500}
501
502static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
503{
504 info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
505 return info->messages[info->attr.mq_curmsgs];
506}
507
508static inline void set_cookie(struct sk_buff *skb, char code)
509{
510 ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
511}
512
513/*
514 * The next function is only to split too long sys_mq_timedsend
515 */
516static void __do_notify(struct mqueue_inode_info *info)
517{
518 /* notification
519 * invoked when there is registered process and there isn't process
520 * waiting synchronously for message AND state of queue changed from
521 * empty to not empty. Here we are sure that no one is waiting
522 * synchronously. */
523 if (info->notify_owner &&
524 info->attr.mq_curmsgs == 1) {
525 struct siginfo sig_i;
526 switch (info->notify.sigev_notify) {
527 case SIGEV_NONE:
528 break;
529 case SIGEV_SIGNAL:
530 /* sends signal */
531
532 sig_i.si_signo = info->notify.sigev_signo;
533 sig_i.si_errno = 0;
534 sig_i.si_code = SI_MESGQ;
535 sig_i.si_value = info->notify.sigev_value;
Sukadev Bhattiprolua6684992009-01-07 18:08:50 -0800536 sig_i.si_pid = task_tgid_nr_ns(current,
537 ns_of_pid(info->notify_owner));
David Howells414c0702008-11-14 10:39:06 +1100538 sig_i.si_uid = current_uid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700540 kill_pid_info(info->notify.sigev_signo,
541 &sig_i, info->notify_owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 break;
543 case SIGEV_THREAD:
544 set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700545 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 break;
547 }
548 /* after notification unregisters process */
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700549 put_pid(info->notify_owner);
550 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 }
552 wake_up(&info->wait_q);
553}
554
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200555static int prepare_timeout(const struct timespec __user *u_abs_timeout,
556 ktime_t *expires, struct timespec *ts)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557{
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200558 if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec)))
559 return -EFAULT;
560 if (!timespec_valid(ts))
561 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200563 *expires = timespec_to_ktime(*ts);
564 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565}
566
567static void remove_notification(struct mqueue_inode_info *info)
568{
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700569 if (info->notify_owner != NULL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 info->notify.sigev_notify == SIGEV_THREAD) {
571 set_cookie(info->notify_cookie, NOTIFY_REMOVED);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700572 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700574 put_pid(info->notify_owner);
575 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576}
577
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700578static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579{
580 if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
581 return 0;
582 if (capable(CAP_SYS_RESOURCE)) {
583 if (attr->mq_maxmsg > HARD_MSGMAX)
584 return 0;
585 } else {
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700586 if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
587 attr->mq_msgsize > ipc_ns->mq_msgsize_max)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 return 0;
589 }
590 /* check for overflow */
591 if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
592 return 0;
André Goddard Rosa8834cf72010-02-23 04:04:24 -0300593 if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize
594 + sizeof (struct msg_msg *))) <
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
596 return 0;
597 return 1;
598}
599
600/*
601 * Invoked when creating a new queue via sys_mq_open
602 */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700603static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
604 struct dentry *dentry, int oflag, mode_t mode,
605 struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606{
David Howells745ca242008-11-14 10:39:22 +1100607 const struct cred *cred = current_cred();
Dave Hansen4a3fd212008-02-15 14:37:48 -0800608 struct file *result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 int ret;
610
Al Viro564f6992008-12-14 04:02:26 -0500611 if (attr) {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300612 if (!mq_attr_ok(ipc_ns, attr)) {
613 ret = -EINVAL;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500614 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300615 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 /* store for use during create */
Al Viro564f6992008-12-14 04:02:26 -0500617 dentry->d_fsdata = attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 }
619
Al Viroce3b0f82009-03-29 19:08:22 -0400620 mode &= ~current_umask();
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700621 ret = mnt_want_write(ipc_ns->mq_mnt);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800622 if (ret)
623 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 ret = vfs_create(dir->d_inode, dentry, mode, NULL);
625 dentry->d_fsdata = NULL;
626 if (ret)
Dave Hansen4a3fd212008-02-15 14:37:48 -0800627 goto out_drop_write;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700629 result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800630 /*
631 * dentry_open() took a persistent mnt_want_write(),
632 * so we can now drop this one.
633 */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700634 mnt_drop_write(ipc_ns->mq_mnt);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800635 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636
Dave Hansen4a3fd212008-02-15 14:37:48 -0800637out_drop_write:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700638 mnt_drop_write(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500639out:
640 dput(dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700641 mntput(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500642 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643}
644
645/* Opens existing queue */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700646static struct file *do_open(struct ipc_namespace *ipc_ns,
647 struct dentry *dentry, int oflag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648{
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300649 int ret;
David Howells745ca242008-11-14 10:39:22 +1100650 const struct cred *cred = current_cred();
651
652 static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
653 MAY_READ | MAY_WRITE };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654
Alexander Viro7c7dce92006-01-14 15:29:55 -0500655 if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300656 ret = -EINVAL;
657 goto err;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500658 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659
Al Virof419a2e2008-07-22 00:07:17 -0400660 if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) {
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300661 ret = -EACCES;
662 goto err;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500663 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700665 return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300666
667err:
668 dput(dentry);
669 mntput(ipc_ns->mq_mnt);
670 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671}
672
Heiko Carstensd5460c92009-01-14 14:14:27 +0100673SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
674 struct mq_attr __user *, u_attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675{
676 struct dentry *dentry;
677 struct file *filp;
678 char *name;
Al Viro564f6992008-12-14 04:02:26 -0500679 struct mq_attr attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 int fd, error;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700681 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682
Al Viro564f6992008-12-14 04:02:26 -0500683 if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
684 return -EFAULT;
685
686 audit_mq_open(oflag, mode, u_attr ? &attr : NULL);
George C. Wilson20ca73b2006-05-24 16:09:55 -0500687
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 if (IS_ERR(name = getname(u_name)))
689 return PTR_ERR(name);
690
Ulrich Drepper269f2132008-05-03 15:28:45 -0400691 fd = get_unused_fd_flags(O_CLOEXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 if (fd < 0)
693 goto out_putname;
694
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700695 mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
696 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 if (IS_ERR(dentry)) {
698 error = PTR_ERR(dentry);
André Goddard Rosa4294a8e2010-02-23 04:04:28 -0300699 goto out_putfd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700701 mntget(ipc_ns->mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702
703 if (oflag & O_CREAT) {
704 if (dentry->d_inode) { /* entry already exists */
Al Viro5a190ae2007-06-07 12:19:32 -0400705 audit_inode(name, dentry);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300706 if (oflag & O_EXCL) {
707 error = -EEXIST;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500708 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300709 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700710 filp = do_open(ipc_ns, dentry, oflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 } else {
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700712 filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
713 dentry, oflag, mode,
Al Viro564f6992008-12-14 04:02:26 -0500714 u_attr ? &attr : NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 }
Alexander Viro7c7dce92006-01-14 15:29:55 -0500716 } else {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300717 if (!dentry->d_inode) {
718 error = -ENOENT;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500719 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300720 }
Al Viro5a190ae2007-06-07 12:19:32 -0400721 audit_inode(name, dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700722 filp = do_open(ipc_ns, dentry, oflag);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500723 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
725 if (IS_ERR(filp)) {
726 error = PTR_ERR(filp);
727 goto out_putfd;
728 }
729
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 fd_install(fd, filp);
731 goto out_upsem;
732
Alexander Viro7c7dce92006-01-14 15:29:55 -0500733out:
734 dput(dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700735 mntput(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500736out_putfd:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 put_unused_fd(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 fd = error;
739out_upsem:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700740 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741out_putname:
742 putname(name);
743 return fd;
744}
745
Heiko Carstensd5460c92009-01-14 14:14:27 +0100746SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747{
748 int err;
749 char *name;
750 struct dentry *dentry;
751 struct inode *inode = NULL;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700752 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753
754 name = getname(u_name);
755 if (IS_ERR(name))
756 return PTR_ERR(name);
757
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700758 mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex,
Peter Zijlstra7a434812007-03-06 01:42:09 -0800759 I_MUTEX_PARENT);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700760 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 if (IS_ERR(dentry)) {
762 err = PTR_ERR(dentry);
763 goto out_unlock;
764 }
765
766 if (!dentry->d_inode) {
767 err = -ENOENT;
768 goto out_err;
769 }
770
771 inode = dentry->d_inode;
772 if (inode)
773 atomic_inc(&inode->i_count);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700774 err = mnt_want_write(ipc_ns->mq_mnt);
Dave Hansen06227532008-02-15 14:37:34 -0800775 if (err)
776 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 err = vfs_unlink(dentry->d_parent->d_inode, dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700778 mnt_drop_write(ipc_ns->mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779out_err:
780 dput(dentry);
781
782out_unlock:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700783 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 putname(name);
785 if (inode)
786 iput(inode);
787
788 return err;
789}
790
791/* Pipelined send and receive functions.
792 *
793 * If a receiver finds no waiting message, then it registers itself in the
794 * list of waiting receivers. A sender checks that list before adding the new
795 * message into the message array. If there is a waiting receiver, then it
796 * bypasses the message array and directly hands the message over to the
797 * receiver.
798 * The receiver accepts the message and returns without grabbing the queue
799 * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
800 * are necessary. The same algorithm is used for sysv semaphores, see
Serge E. Hallyn7b7a3172006-03-28 01:56:23 -0800801 * ipc/sem.c for more details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 *
803 * The same algorithm is used for senders.
804 */
805
806/* pipelined_send() - send a message directly to the task waiting in
807 * sys_mq_timedreceive() (without inserting message into a queue).
808 */
809static inline void pipelined_send(struct mqueue_inode_info *info,
810 struct msg_msg *message,
811 struct ext_wait_queue *receiver)
812{
813 receiver->msg = message;
814 list_del(&receiver->list);
815 receiver->state = STATE_PENDING;
816 wake_up_process(receiver->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700817 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 receiver->state = STATE_READY;
819}
820
821/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
822 * gets its message and put to the queue (we have one free place for sure). */
823static inline void pipelined_receive(struct mqueue_inode_info *info)
824{
825 struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
826
827 if (!sender) {
828 /* for poll */
829 wake_up_interruptible(&info->wait_q);
830 return;
831 }
832 msg_insert(sender->msg, info);
833 list_del(&sender->list);
834 sender->state = STATE_PENDING;
835 wake_up_process(sender->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700836 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 sender->state = STATE_READY;
838}
839
Heiko Carstensc4ea37c2009-01-14 14:14:28 +0100840SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
841 size_t, msg_len, unsigned int, msg_prio,
842 const struct timespec __user *, u_abs_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843{
844 struct file *filp;
845 struct inode *inode;
846 struct ext_wait_queue wait;
847 struct ext_wait_queue *receiver;
848 struct msg_msg *msg_ptr;
849 struct mqueue_inode_info *info;
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200850 ktime_t expires, *timeout = NULL;
851 struct timespec ts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 int ret;
853
Al Viroc32c8af2008-12-14 03:46:48 -0500854 if (u_abs_timeout) {
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200855 int res = prepare_timeout(u_abs_timeout, &expires, &ts);
856 if (res)
857 return res;
858 timeout = &expires;
Al Viroc32c8af2008-12-14 03:46:48 -0500859 }
George C. Wilson20ca73b2006-05-24 16:09:55 -0500860
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
862 return -EINVAL;
863
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200864 audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300867 if (unlikely(!filp)) {
868 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300870 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871
Josef Sipek6d630792006-12-08 02:37:11 -0800872 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300873 if (unlikely(filp->f_op != &mqueue_file_operations)) {
874 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300876 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400878 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300880 if (unlikely(!(filp->f_mode & FMODE_WRITE))) {
881 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300883 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884
885 if (unlikely(msg_len > info->attr.mq_msgsize)) {
886 ret = -EMSGSIZE;
887 goto out_fput;
888 }
889
890 /* First try to allocate memory, before doing anything with
891 * existing queues. */
892 msg_ptr = load_msg(u_msg_ptr, msg_len);
893 if (IS_ERR(msg_ptr)) {
894 ret = PTR_ERR(msg_ptr);
895 goto out_fput;
896 }
897 msg_ptr->m_ts = msg_len;
898 msg_ptr->m_type = msg_prio;
899
900 spin_lock(&info->lock);
901
902 if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
903 if (filp->f_flags & O_NONBLOCK) {
904 spin_unlock(&info->lock);
905 ret = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 } else {
907 wait.task = current;
908 wait.msg = (void *) msg_ptr;
909 wait.state = STATE_NONE;
910 ret = wq_sleep(info, SEND, timeout, &wait);
911 }
912 if (ret < 0)
913 free_msg(msg_ptr);
914 } else {
915 receiver = wq_get_first_waiter(info, RECV);
916 if (receiver) {
917 pipelined_send(info, msg_ptr, receiver);
918 } else {
919 /* adds message to the queue */
920 msg_insert(msg_ptr, info);
921 __do_notify(info);
922 }
923 inode->i_atime = inode->i_mtime = inode->i_ctime =
924 CURRENT_TIME;
925 spin_unlock(&info->lock);
926 ret = 0;
927 }
928out_fput:
929 fput(filp);
930out:
931 return ret;
932}
933
Heiko Carstensc4ea37c2009-01-14 14:14:28 +0100934SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
935 size_t, msg_len, unsigned int __user *, u_msg_prio,
936 const struct timespec __user *, u_abs_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 ssize_t ret;
939 struct msg_msg *msg_ptr;
940 struct file *filp;
941 struct inode *inode;
942 struct mqueue_inode_info *info;
943 struct ext_wait_queue wait;
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200944 ktime_t expires, *timeout = NULL;
945 struct timespec ts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946
Al Viroc32c8af2008-12-14 03:46:48 -0500947 if (u_abs_timeout) {
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200948 int res = prepare_timeout(u_abs_timeout, &expires, &ts);
949 if (res)
950 return res;
951 timeout = &expires;
Al Viroc32c8af2008-12-14 03:46:48 -0500952 }
George C. Wilson20ca73b2006-05-24 16:09:55 -0500953
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200954 audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300957 if (unlikely(!filp)) {
958 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300960 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961
Josef Sipek6d630792006-12-08 02:37:11 -0800962 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300963 if (unlikely(filp->f_op != &mqueue_file_operations)) {
964 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300966 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400968 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300970 if (unlikely(!(filp->f_mode & FMODE_READ))) {
971 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300973 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974
975 /* checks if buffer is big enough */
976 if (unlikely(msg_len < info->attr.mq_msgsize)) {
977 ret = -EMSGSIZE;
978 goto out_fput;
979 }
980
981 spin_lock(&info->lock);
982 if (info->attr.mq_curmsgs == 0) {
983 if (filp->f_flags & O_NONBLOCK) {
984 spin_unlock(&info->lock);
985 ret = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 } else {
987 wait.task = current;
988 wait.state = STATE_NONE;
989 ret = wq_sleep(info, RECV, timeout, &wait);
990 msg_ptr = wait.msg;
991 }
992 } else {
993 msg_ptr = msg_get(info);
994
995 inode->i_atime = inode->i_mtime = inode->i_ctime =
996 CURRENT_TIME;
997
998 /* There is now free space in queue. */
999 pipelined_receive(info);
1000 spin_unlock(&info->lock);
1001 ret = 0;
1002 }
1003 if (ret == 0) {
1004 ret = msg_ptr->m_ts;
1005
1006 if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
1007 store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
1008 ret = -EFAULT;
1009 }
1010 free_msg(msg_ptr);
1011 }
1012out_fput:
1013 fput(filp);
1014out:
1015 return ret;
1016}
1017
1018/*
1019 * Notes: the case when user wants us to deregister (with NULL as pointer)
1020 * and he isn't currently owner of notification, will be silently discarded.
1021 * It isn't explicitly defined in the POSIX.
1022 */
Heiko Carstensc4ea37c2009-01-14 14:14:28 +01001023SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
1024 const struct sigevent __user *, u_notification)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025{
1026 int ret;
1027 struct file *filp;
1028 struct sock *sock;
1029 struct inode *inode;
1030 struct sigevent notification;
1031 struct mqueue_inode_info *info;
1032 struct sk_buff *nc;
1033
Al Viro20114f72008-12-10 07:16:12 -05001034 if (u_notification) {
1035 if (copy_from_user(&notification, u_notification,
1036 sizeof(struct sigevent)))
1037 return -EFAULT;
1038 }
1039
1040 audit_mq_notify(mqdes, u_notification ? &notification : NULL);
George C. Wilson20ca73b2006-05-24 16:09:55 -05001041
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042 nc = NULL;
1043 sock = NULL;
1044 if (u_notification != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045 if (unlikely(notification.sigev_notify != SIGEV_NONE &&
1046 notification.sigev_notify != SIGEV_SIGNAL &&
1047 notification.sigev_notify != SIGEV_THREAD))
1048 return -EINVAL;
1049 if (notification.sigev_notify == SIGEV_SIGNAL &&
Jesper Juhl7ed20e12005-05-01 08:59:14 -07001050 !valid_signal(notification.sigev_signo)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051 return -EINVAL;
1052 }
1053 if (notification.sigev_notify == SIGEV_THREAD) {
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -08001054 long timeo;
1055
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056 /* create the notify skb */
1057 nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001058 if (!nc) {
1059 ret = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001061 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 if (copy_from_user(nc->data,
1063 notification.sigev_value.sival_ptr,
1064 NOTIFY_COOKIE_LEN)) {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001065 ret = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001066 goto out;
1067 }
1068
1069 /* TODO: add a header? */
1070 skb_put(nc, NOTIFY_COOKIE_LEN);
1071 /* and attach it to the socket */
1072retry:
1073 filp = fget(notification.sigev_signo);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001074 if (!filp) {
1075 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001076 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001077 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078 sock = netlink_getsockbyfilp(filp);
1079 fput(filp);
1080 if (IS_ERR(sock)) {
1081 ret = PTR_ERR(sock);
1082 sock = NULL;
1083 goto out;
1084 }
1085
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -08001086 timeo = MAX_SCHEDULE_TIMEOUT;
Denis V. Lunev9457afe2008-06-05 11:23:39 -07001087 ret = netlink_attachskb(sock, nc, &timeo, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088 if (ret == 1)
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001089 goto retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090 if (ret) {
1091 sock = NULL;
1092 nc = NULL;
1093 goto out;
1094 }
1095 }
1096 }
1097
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001099 if (!filp) {
1100 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001102 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103
Josef Sipek6d630792006-12-08 02:37:11 -08001104 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001105 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1106 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001108 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109 info = MQUEUE_I(inode);
1110
1111 ret = 0;
1112 spin_lock(&info->lock);
1113 if (u_notification == NULL) {
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001114 if (info->notify_owner == task_tgid(current)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 remove_notification(info);
1116 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1117 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001118 } else if (info->notify_owner != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 ret = -EBUSY;
1120 } else {
1121 switch (notification.sigev_notify) {
1122 case SIGEV_NONE:
1123 info->notify.sigev_notify = SIGEV_NONE;
1124 break;
1125 case SIGEV_THREAD:
1126 info->notify_sock = sock;
1127 info->notify_cookie = nc;
1128 sock = NULL;
1129 nc = NULL;
1130 info->notify.sigev_notify = SIGEV_THREAD;
1131 break;
1132 case SIGEV_SIGNAL:
1133 info->notify.sigev_signo = notification.sigev_signo;
1134 info->notify.sigev_value = notification.sigev_value;
1135 info->notify.sigev_notify = SIGEV_SIGNAL;
1136 break;
1137 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001138
1139 info->notify_owner = get_pid(task_tgid(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1141 }
1142 spin_unlock(&info->lock);
1143out_fput:
1144 fput(filp);
1145out:
1146 if (sock) {
1147 netlink_detachskb(sock, nc);
1148 } else if (nc) {
1149 dev_kfree_skb(nc);
1150 }
1151 return ret;
1152}
1153
Heiko Carstensc4ea37c2009-01-14 14:14:28 +01001154SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
1155 const struct mq_attr __user *, u_mqstat,
1156 struct mq_attr __user *, u_omqstat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157{
1158 int ret;
1159 struct mq_attr mqstat, omqstat;
1160 struct file *filp;
1161 struct inode *inode;
1162 struct mqueue_inode_info *info;
1163
1164 if (u_mqstat != NULL) {
1165 if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr)))
1166 return -EFAULT;
1167 if (mqstat.mq_flags & (~O_NONBLOCK))
1168 return -EINVAL;
1169 }
1170
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001172 if (!filp) {
1173 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001175 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176
Josef Sipek6d630792006-12-08 02:37:11 -08001177 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001178 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1179 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001181 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182 info = MQUEUE_I(inode);
1183
1184 spin_lock(&info->lock);
1185
1186 omqstat = info->attr;
1187 omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
1188 if (u_mqstat) {
Al Viro73929062008-12-10 06:58:59 -05001189 audit_mq_getsetattr(mqdes, &mqstat);
Jonathan Corbetdb1dd4d2009-02-06 15:25:24 -07001190 spin_lock(&filp->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 if (mqstat.mq_flags & O_NONBLOCK)
1192 filp->f_flags |= O_NONBLOCK;
1193 else
1194 filp->f_flags &= ~O_NONBLOCK;
Jonathan Corbetdb1dd4d2009-02-06 15:25:24 -07001195 spin_unlock(&filp->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196
1197 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1198 }
1199
1200 spin_unlock(&info->lock);
1201
1202 ret = 0;
1203 if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat,
1204 sizeof(struct mq_attr)))
1205 ret = -EFAULT;
1206
1207out_fput:
1208 fput(filp);
1209out:
1210 return ret;
1211}
1212
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -08001213static const struct inode_operations mqueue_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 .lookup = simple_lookup,
1215 .create = mqueue_create,
1216 .unlink = mqueue_unlink,
1217};
1218
Arjan van de Ven9a321442007-02-12 00:55:35 -08001219static const struct file_operations mqueue_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220 .flush = mqueue_flush_file,
1221 .poll = mqueue_poll_file,
1222 .read = mqueue_read_file,
1223};
1224
Alexey Dobriyanb87221d2009-09-21 17:01:09 -07001225static const struct super_operations mqueue_super_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 .alloc_inode = mqueue_alloc_inode,
1227 .destroy_inode = mqueue_destroy_inode,
1228 .statfs = simple_statfs,
1229 .delete_inode = mqueue_delete_inode,
1230 .drop_inode = generic_delete_inode,
1231};
1232
1233static struct file_system_type mqueue_fs_type = {
1234 .name = "mqueue",
1235 .get_sb = mqueue_get_sb,
1236 .kill_sb = kill_litter_super,
1237};
1238
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -07001239int mq_init_ns(struct ipc_namespace *ns)
1240{
1241 ns->mq_queues_count = 0;
1242 ns->mq_queues_max = DFLT_QUEUESMAX;
1243 ns->mq_msg_max = DFLT_MSGMAX;
1244 ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
1245
1246 ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
1247 if (IS_ERR(ns->mq_mnt)) {
1248 int err = PTR_ERR(ns->mq_mnt);
1249 ns->mq_mnt = NULL;
1250 return err;
1251 }
1252 return 0;
1253}
1254
1255void mq_clear_sbinfo(struct ipc_namespace *ns)
1256{
1257 ns->mq_mnt->mnt_sb->s_fs_info = NULL;
1258}
1259
1260void mq_put_mnt(struct ipc_namespace *ns)
1261{
1262 mntput(ns->mq_mnt);
1263}
1264
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265static int __init init_mqueue_fs(void)
1266{
1267 int error;
1268
1269 mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
1270 sizeof(struct mqueue_inode_info), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001271 SLAB_HWCACHE_ALIGN, init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 if (mqueue_inode_cachep == NULL)
1273 return -ENOMEM;
1274
André Goddard Rosa2329e3922010-02-23 04:04:27 -03001275 /* ignore failures - they are not fatal */
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -07001276 mq_sysctl_table = mq_register_sysctl_table();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277
1278 error = register_filesystem(&mqueue_fs_type);
1279 if (error)
1280 goto out_sysctl;
1281
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -07001282 spin_lock_init(&mq_lock);
1283
1284 init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001285 if (IS_ERR(init_ipc_ns.mq_mnt)) {
1286 error = PTR_ERR(init_ipc_ns.mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001287 goto out_filesystem;
1288 }
1289
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290 return 0;
1291
1292out_filesystem:
1293 unregister_filesystem(&mqueue_fs_type);
1294out_sysctl:
1295 if (mq_sysctl_table)
1296 unregister_sysctl_table(mq_sysctl_table);
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -07001297 kmem_cache_destroy(mqueue_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298 return error;
1299}
1300
1301__initcall(init_mqueue_fs);