blob: 14fb6d67e6a3efc339dd8aee3b7b8a5e57245c51 [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) {
Christoph Hellwig85fe4022010-10-23 11:19:54 -0400119 inode->i_ino = get_next_ino();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 inode->i_mode = mode;
David Howells414c0702008-11-14 10:39:06 +1100121 inode->i_uid = current_fsuid();
122 inode->i_gid = current_fsgid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 inode->i_mtime = inode->i_ctime = inode->i_atime =
124 CURRENT_TIME;
125
126 if (S_ISREG(mode)) {
127 struct mqueue_inode_info *info;
128 struct task_struct *p = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 unsigned long mq_bytes, mq_msg_tblsz;
130
131 inode->i_fop = &mqueue_file_operations;
132 inode->i_size = FILENT_SIZE;
133 /* mqueue specific info */
134 info = MQUEUE_I(inode);
135 spin_lock_init(&info->lock);
136 init_waitqueue_head(&info->wait_q);
137 INIT_LIST_HEAD(&info->e_wait_q[0].list);
138 INIT_LIST_HEAD(&info->e_wait_q[1].list);
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700139 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 info->qsize = 0;
141 info->user = NULL; /* set when all is ok */
142 memset(&info->attr, 0, sizeof(info->attr));
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700143 info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
144 info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 if (attr) {
146 info->attr.mq_maxmsg = attr->mq_maxmsg;
147 info->attr.mq_msgsize = attr->mq_msgsize;
148 }
149 mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
André Goddard Rosac8308b12010-02-23 04:04:23 -0300150 info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
151 if (!info->messages)
152 goto out_inode;
153
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 mq_bytes = (mq_msg_tblsz +
155 (info->attr.mq_maxmsg * info->attr.mq_msgsize));
156
157 spin_lock(&mq_lock);
158 if (u->mq_bytes + mq_bytes < u->mq_bytes ||
159 u->mq_bytes + mq_bytes >
Jiri Slabyf1eb1332010-03-10 15:23:05 -0800160 task_rlimit(p, RLIMIT_MSGQUEUE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 spin_unlock(&mq_lock);
Al Viro6d8af642010-06-05 16:29:45 -0400162 /* mqueue_evict_inode() releases info->messages */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 goto out_inode;
164 }
165 u->mq_bytes += mq_bytes;
166 spin_unlock(&mq_lock);
167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 /* all is ok */
169 info->user = get_uid(u);
170 } else if (S_ISDIR(mode)) {
Dave Hansend8c76e62006-09-30 23:29:04 -0700171 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 /* Some things misbehave if size == 0 on a directory */
173 inode->i_size = 2 * DIRENT_SIZE;
174 inode->i_op = &mqueue_dir_inode_operations;
175 inode->i_fop = &simple_dir_operations;
176 }
177 }
178 return inode;
179out_inode:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 iput(inode);
181 return NULL;
182}
183
184static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
185{
186 struct inode *inode;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700187 struct ipc_namespace *ns = data;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300188 int error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189
190 sb->s_blocksize = PAGE_CACHE_SIZE;
191 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
192 sb->s_magic = MQUEUE_MAGIC;
193 sb->s_op = &mqueue_super_ops;
194
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700195 inode = mqueue_get_inode(sb, ns, S_IFDIR | S_ISVTX | S_IRWXUGO,
196 NULL);
197 if (!inode) {
198 error = -ENOMEM;
199 goto out;
200 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
202 sb->s_root = d_alloc_root(inode);
203 if (!sb->s_root) {
204 iput(inode);
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700205 error = -ENOMEM;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300206 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 }
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300208 error = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700210out:
211 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212}
213
Al Viroceefda62010-07-26 13:16:50 +0400214static struct dentry *mqueue_mount(struct file_system_type *fs_type,
David Howells454e2392006-06-23 02:02:57 -0700215 int flags, const char *dev_name,
Al Viroceefda62010-07-26 13:16:50 +0400216 void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217{
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700218 if (!(flags & MS_KERNMOUNT))
219 data = current->nsproxy->ipc_ns;
Al Viroceefda62010-07-26 13:16:50 +0400220 return mount_ns(fs_type, flags, data, mqueue_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221}
222
Alexey Dobriyan51cc5062008-07-25 19:45:34 -0700223static void init_once(void *foo)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224{
225 struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
226
Christoph Lametera35afb82007-05-16 22:10:57 -0700227 inode_init_once(&p->vfs_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228}
229
230static struct inode *mqueue_alloc_inode(struct super_block *sb)
231{
232 struct mqueue_inode_info *ei;
233
Christoph Lametere94b1762006-12-06 20:33:17 -0800234 ei = kmem_cache_alloc(mqueue_inode_cachep, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 if (!ei)
236 return NULL;
237 return &ei->vfs_inode;
238}
239
Nick Pigginfa0d7e32011-01-07 17:49:49 +1100240static void mqueue_i_callback(struct rcu_head *head)
241{
242 struct inode *inode = container_of(head, struct inode, i_rcu);
243 INIT_LIST_HEAD(&inode->i_dentry);
244 kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
245}
246
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247static void mqueue_destroy_inode(struct inode *inode)
248{
Nick Pigginfa0d7e32011-01-07 17:49:49 +1100249 call_rcu(&inode->i_rcu, mqueue_i_callback);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250}
251
Al Viro6d8af642010-06-05 16:29:45 -0400252static void mqueue_evict_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253{
254 struct mqueue_inode_info *info;
255 struct user_struct *user;
256 unsigned long mq_bytes;
257 int i;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700258 struct ipc_namespace *ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
Al Viro6d8af642010-06-05 16:29:45 -0400260 end_writeback(inode);
261
262 if (S_ISDIR(inode->i_mode))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263 return;
Al Viro6d8af642010-06-05 16:29:45 -0400264
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700265 ipc_ns = get_ns_from_inode(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266 info = MQUEUE_I(inode);
267 spin_lock(&info->lock);
268 for (i = 0; i < info->attr.mq_curmsgs; i++)
269 free_msg(info->messages[i]);
270 kfree(info->messages);
271 spin_unlock(&info->lock);
272
André Goddard Rosa8834cf72010-02-23 04:04:24 -0300273 /* Total amount of bytes accounted for the mqueue */
274 mq_bytes = info->attr.mq_maxmsg * (sizeof(struct msg_msg *)
275 + info->attr.mq_msgsize);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 user = info->user;
277 if (user) {
278 spin_lock(&mq_lock);
279 user->mq_bytes -= mq_bytes;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700280 /*
281 * get_ns_from_inode() ensures that the
282 * (ipc_ns = sb->s_fs_info) is either a valid ipc_ns
283 * to which we now hold a reference, or it is NULL.
284 * We can't put it here under mq_lock, though.
285 */
286 if (ipc_ns)
287 ipc_ns->mq_queues_count--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 spin_unlock(&mq_lock);
289 free_uid(user);
290 }
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700291 if (ipc_ns)
292 put_ipc_ns(ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293}
294
295static int mqueue_create(struct inode *dir, struct dentry *dentry,
296 int mode, struct nameidata *nd)
297{
298 struct inode *inode;
299 struct mq_attr *attr = dentry->d_fsdata;
300 int error;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700301 struct ipc_namespace *ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302
303 spin_lock(&mq_lock);
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700304 ipc_ns = __get_ns_from_inode(dir);
305 if (!ipc_ns) {
306 error = -EACCES;
307 goto out_unlock;
308 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700309 if (ipc_ns->mq_queues_count >= ipc_ns->mq_queues_max &&
310 !capable(CAP_SYS_RESOURCE)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 error = -ENOSPC;
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700312 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700314 ipc_ns->mq_queues_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 spin_unlock(&mq_lock);
316
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700317 inode = mqueue_get_inode(dir->i_sb, ipc_ns, mode, attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 if (!inode) {
319 error = -ENOMEM;
320 spin_lock(&mq_lock);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700321 ipc_ns->mq_queues_count--;
322 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 }
324
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700325 put_ipc_ns(ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 dir->i_size += DIRENT_SIZE;
327 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
328
329 d_instantiate(dentry, inode);
330 dget(dentry);
331 return 0;
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700332out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 spin_unlock(&mq_lock);
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700334 if (ipc_ns)
335 put_ipc_ns(ipc_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 return error;
337}
338
339static int mqueue_unlink(struct inode *dir, struct dentry *dentry)
340{
341 struct inode *inode = dentry->d_inode;
342
343 dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
344 dir->i_size -= DIRENT_SIZE;
Dave Hansen9a53c3a2006-09-30 23:29:03 -0700345 drop_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 dput(dentry);
347 return 0;
348}
349
350/*
351* This is routine for system read from queue file.
352* To avoid mess with doing here some sort of mq_receive we allow
353* to read only queue size & notification info (the only values
354* that are interesting from user point of view and aren't accessible
355* through std routines)
356*/
357static ssize_t mqueue_read_file(struct file *filp, char __user *u_data,
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700358 size_t count, loff_t *off)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359{
Josef Sipek6d630792006-12-08 02:37:11 -0800360 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 char buffer[FILENT_SIZE];
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700362 ssize_t ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363
364 spin_lock(&info->lock);
365 snprintf(buffer, sizeof(buffer),
366 "QSIZE:%-10lu NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
367 info->qsize,
368 info->notify_owner ? info->notify.sigev_notify : 0,
369 (info->notify_owner &&
370 info->notify.sigev_notify == SIGEV_SIGNAL) ?
371 info->notify.sigev_signo : 0,
Pavel Emelyanov6c5f3e72008-02-08 04:19:20 -0800372 pid_vnr(info->notify_owner));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 spin_unlock(&info->lock);
374 buffer[sizeof(buffer)-1] = '\0';
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
Akinobu Mitaf1a43f92008-07-25 01:48:07 -0700376 ret = simple_read_from_buffer(u_data, count, off, buffer,
377 strlen(buffer));
378 if (ret <= 0)
379 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
Josef Sipek6d630792006-12-08 02:37:11 -0800381 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 -0700382 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383}
384
Miklos Szeredi75e1fcc2006-06-23 02:05:12 -0700385static int mqueue_flush_file(struct file *filp, fl_owner_t id)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386{
Josef Sipek6d630792006-12-08 02:37:11 -0800387 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
389 spin_lock(&info->lock);
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700390 if (task_tgid(current) == info->notify_owner)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 remove_notification(info);
392
393 spin_unlock(&info->lock);
394 return 0;
395}
396
397static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
398{
Josef Sipek6d630792006-12-08 02:37:11 -0800399 struct mqueue_inode_info *info = MQUEUE_I(filp->f_path.dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 int retval = 0;
401
402 poll_wait(filp, &info->wait_q, poll_tab);
403
404 spin_lock(&info->lock);
405 if (info->attr.mq_curmsgs)
406 retval = POLLIN | POLLRDNORM;
407
408 if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
409 retval |= POLLOUT | POLLWRNORM;
410 spin_unlock(&info->lock);
411
412 return retval;
413}
414
415/* Adds current to info->e_wait_q[sr] before element with smaller prio */
416static void wq_add(struct mqueue_inode_info *info, int sr,
417 struct ext_wait_queue *ewp)
418{
419 struct ext_wait_queue *walk;
420
421 ewp->task = current;
422
423 list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
424 if (walk->task->static_prio <= current->static_prio) {
425 list_add_tail(&ewp->list, &walk->list);
426 return;
427 }
428 }
429 list_add_tail(&ewp->list, &info->e_wait_q[sr].list);
430}
431
432/*
433 * Puts current task to sleep. Caller must hold queue lock. After return
434 * lock isn't held.
435 * sr: SEND or RECV
436 */
437static int wq_sleep(struct mqueue_inode_info *info, int sr,
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200438 ktime_t *timeout, struct ext_wait_queue *ewp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439{
440 int retval;
441 signed long time;
442
443 wq_add(info, sr, ewp);
444
445 for (;;) {
446 set_current_state(TASK_INTERRUPTIBLE);
447
448 spin_unlock(&info->lock);
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200449 time = schedule_hrtimeout_range_clock(timeout,
450 HRTIMER_MODE_ABS, 0, CLOCK_REALTIME);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451
452 while (ewp->state == STATE_PENDING)
453 cpu_relax();
454
455 if (ewp->state == STATE_READY) {
456 retval = 0;
457 goto out;
458 }
459 spin_lock(&info->lock);
460 if (ewp->state == STATE_READY) {
461 retval = 0;
462 goto out_unlock;
463 }
464 if (signal_pending(current)) {
465 retval = -ERESTARTSYS;
466 break;
467 }
468 if (time == 0) {
469 retval = -ETIMEDOUT;
470 break;
471 }
472 }
473 list_del(&ewp->list);
474out_unlock:
475 spin_unlock(&info->lock);
476out:
477 return retval;
478}
479
480/*
481 * Returns waiting task that should be serviced first or NULL if none exists
482 */
483static struct ext_wait_queue *wq_get_first_waiter(
484 struct mqueue_inode_info *info, int sr)
485{
486 struct list_head *ptr;
487
488 ptr = info->e_wait_q[sr].list.prev;
489 if (ptr == &info->e_wait_q[sr].list)
490 return NULL;
491 return list_entry(ptr, struct ext_wait_queue, list);
492}
493
494/* Auxiliary functions to manipulate messages' list */
495static void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
496{
497 int k;
498
499 k = info->attr.mq_curmsgs - 1;
500 while (k >= 0 && info->messages[k]->m_type >= ptr->m_type) {
501 info->messages[k + 1] = info->messages[k];
502 k--;
503 }
504 info->attr.mq_curmsgs++;
505 info->qsize += ptr->m_ts;
506 info->messages[k + 1] = ptr;
507}
508
509static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
510{
511 info->qsize -= info->messages[--info->attr.mq_curmsgs]->m_ts;
512 return info->messages[info->attr.mq_curmsgs];
513}
514
515static inline void set_cookie(struct sk_buff *skb, char code)
516{
517 ((char*)skb->data)[NOTIFY_COOKIE_LEN-1] = code;
518}
519
520/*
521 * The next function is only to split too long sys_mq_timedsend
522 */
523static void __do_notify(struct mqueue_inode_info *info)
524{
525 /* notification
526 * invoked when there is registered process and there isn't process
527 * waiting synchronously for message AND state of queue changed from
528 * empty to not empty. Here we are sure that no one is waiting
529 * synchronously. */
530 if (info->notify_owner &&
531 info->attr.mq_curmsgs == 1) {
532 struct siginfo sig_i;
533 switch (info->notify.sigev_notify) {
534 case SIGEV_NONE:
535 break;
536 case SIGEV_SIGNAL:
537 /* sends signal */
538
539 sig_i.si_signo = info->notify.sigev_signo;
540 sig_i.si_errno = 0;
541 sig_i.si_code = SI_MESGQ;
542 sig_i.si_value = info->notify.sigev_value;
Sukadev Bhattiprolua6684992009-01-07 18:08:50 -0800543 sig_i.si_pid = task_tgid_nr_ns(current,
544 ns_of_pid(info->notify_owner));
David Howells414c0702008-11-14 10:39:06 +1100545 sig_i.si_uid = current_uid();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700547 kill_pid_info(info->notify.sigev_signo,
548 &sig_i, info->notify_owner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 break;
550 case SIGEV_THREAD:
551 set_cookie(info->notify_cookie, NOTIFY_WOKENUP);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700552 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 break;
554 }
555 /* after notification unregisters process */
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700556 put_pid(info->notify_owner);
557 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 }
559 wake_up(&info->wait_q);
560}
561
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200562static int prepare_timeout(const struct timespec __user *u_abs_timeout,
563 ktime_t *expires, struct timespec *ts)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564{
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200565 if (copy_from_user(ts, u_abs_timeout, sizeof(struct timespec)))
566 return -EFAULT;
567 if (!timespec_valid(ts))
568 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200570 *expires = timespec_to_ktime(*ts);
571 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572}
573
574static void remove_notification(struct mqueue_inode_info *info)
575{
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700576 if (info->notify_owner != NULL &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 info->notify.sigev_notify == SIGEV_THREAD) {
578 set_cookie(info->notify_cookie, NOTIFY_REMOVED);
Denis V. Lunev7ee015e2007-10-10 21:14:03 -0700579 netlink_sendskb(info->notify_sock, info->notify_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -0700581 put_pid(info->notify_owner);
582 info->notify_owner = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583}
584
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700585static int mq_attr_ok(struct ipc_namespace *ipc_ns, struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586{
587 if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0)
588 return 0;
589 if (capable(CAP_SYS_RESOURCE)) {
590 if (attr->mq_maxmsg > HARD_MSGMAX)
591 return 0;
592 } else {
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700593 if (attr->mq_maxmsg > ipc_ns->mq_msg_max ||
594 attr->mq_msgsize > ipc_ns->mq_msgsize_max)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 return 0;
596 }
597 /* check for overflow */
598 if (attr->mq_msgsize > ULONG_MAX/attr->mq_maxmsg)
599 return 0;
André Goddard Rosa8834cf72010-02-23 04:04:24 -0300600 if ((unsigned long)(attr->mq_maxmsg * (attr->mq_msgsize
601 + sizeof (struct msg_msg *))) <
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 (unsigned long)(attr->mq_maxmsg * attr->mq_msgsize))
603 return 0;
604 return 1;
605}
606
607/*
608 * Invoked when creating a new queue via sys_mq_open
609 */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700610static struct file *do_create(struct ipc_namespace *ipc_ns, struct dentry *dir,
611 struct dentry *dentry, int oflag, mode_t mode,
612 struct mq_attr *attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613{
David Howells745ca242008-11-14 10:39:22 +1100614 const struct cred *cred = current_cred();
Dave Hansen4a3fd212008-02-15 14:37:48 -0800615 struct file *result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 int ret;
617
Al Viro564f6992008-12-14 04:02:26 -0500618 if (attr) {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300619 if (!mq_attr_ok(ipc_ns, attr)) {
620 ret = -EINVAL;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500621 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300622 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 /* store for use during create */
Al Viro564f6992008-12-14 04:02:26 -0500624 dentry->d_fsdata = attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 }
626
Al Viroce3b0f82009-03-29 19:08:22 -0400627 mode &= ~current_umask();
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700628 ret = mnt_want_write(ipc_ns->mq_mnt);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800629 if (ret)
630 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 ret = vfs_create(dir->d_inode, dentry, mode, NULL);
632 dentry->d_fsdata = NULL;
633 if (ret)
Dave Hansen4a3fd212008-02-15 14:37:48 -0800634 goto out_drop_write;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700636 result = dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800637 /*
638 * dentry_open() took a persistent mnt_want_write(),
639 * so we can now drop this one.
640 */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700641 mnt_drop_write(ipc_ns->mq_mnt);
Dave Hansen4a3fd212008-02-15 14:37:48 -0800642 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643
Dave Hansen4a3fd212008-02-15 14:37:48 -0800644out_drop_write:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700645 mnt_drop_write(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500646out:
647 dput(dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700648 mntput(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500649 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650}
651
652/* Opens existing queue */
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700653static struct file *do_open(struct ipc_namespace *ipc_ns,
654 struct dentry *dentry, int oflag)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655{
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300656 int ret;
David Howells745ca242008-11-14 10:39:22 +1100657 const struct cred *cred = current_cred();
658
659 static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
660 MAY_READ | MAY_WRITE };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
Alexander Viro7c7dce92006-01-14 15:29:55 -0500662 if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY)) {
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300663 ret = -EINVAL;
664 goto err;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500665 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666
Al Virof419a2e2008-07-22 00:07:17 -0400667 if (inode_permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE])) {
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300668 ret = -EACCES;
669 goto err;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500670 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700672 return dentry_open(dentry, ipc_ns->mq_mnt, oflag, cred);
André Goddard Rosa04db0dd2010-02-23 04:04:25 -0300673
674err:
675 dput(dentry);
676 mntput(ipc_ns->mq_mnt);
677 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678}
679
Heiko Carstensd5460c92009-01-14 14:14:27 +0100680SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, mode_t, mode,
681 struct mq_attr __user *, u_attr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682{
683 struct dentry *dentry;
684 struct file *filp;
685 char *name;
Al Viro564f6992008-12-14 04:02:26 -0500686 struct mq_attr attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 int fd, error;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700688 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
Al Viro564f6992008-12-14 04:02:26 -0500690 if (u_attr && copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
691 return -EFAULT;
692
693 audit_mq_open(oflag, mode, u_attr ? &attr : NULL);
George C. Wilson20ca73b2006-05-24 16:09:55 -0500694
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 if (IS_ERR(name = getname(u_name)))
696 return PTR_ERR(name);
697
Ulrich Drepper269f2132008-05-03 15:28:45 -0400698 fd = get_unused_fd_flags(O_CLOEXEC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 if (fd < 0)
700 goto out_putname;
701
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700702 mutex_lock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
703 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 if (IS_ERR(dentry)) {
705 error = PTR_ERR(dentry);
André Goddard Rosa4294a8e2010-02-23 04:04:28 -0300706 goto out_putfd;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700708 mntget(ipc_ns->mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
710 if (oflag & O_CREAT) {
711 if (dentry->d_inode) { /* entry already exists */
Al Viro5a190ae2007-06-07 12:19:32 -0400712 audit_inode(name, dentry);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300713 if (oflag & O_EXCL) {
714 error = -EEXIST;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500715 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300716 }
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700717 filp = do_open(ipc_ns, dentry, oflag);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 } else {
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700719 filp = do_create(ipc_ns, ipc_ns->mq_mnt->mnt_root,
720 dentry, oflag, mode,
Al Viro564f6992008-12-14 04:02:26 -0500721 u_attr ? &attr : NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 }
Alexander Viro7c7dce92006-01-14 15:29:55 -0500723 } else {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300724 if (!dentry->d_inode) {
725 error = -ENOENT;
Alexander Viro7c7dce92006-01-14 15:29:55 -0500726 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300727 }
Al Viro5a190ae2007-06-07 12:19:32 -0400728 audit_inode(name, dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700729 filp = do_open(ipc_ns, dentry, oflag);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500730 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731
732 if (IS_ERR(filp)) {
733 error = PTR_ERR(filp);
734 goto out_putfd;
735 }
736
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 fd_install(fd, filp);
738 goto out_upsem;
739
Alexander Viro7c7dce92006-01-14 15:29:55 -0500740out:
741 dput(dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700742 mntput(ipc_ns->mq_mnt);
Alexander Viro7c7dce92006-01-14 15:29:55 -0500743out_putfd:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 put_unused_fd(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 fd = error;
746out_upsem:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700747 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748out_putname:
749 putname(name);
750 return fd;
751}
752
Heiko Carstensd5460c92009-01-14 14:14:27 +0100753SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754{
755 int err;
756 char *name;
757 struct dentry *dentry;
758 struct inode *inode = NULL;
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -0700759 struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
761 name = getname(u_name);
762 if (IS_ERR(name))
763 return PTR_ERR(name);
764
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700765 mutex_lock_nested(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex,
Peter Zijlstra7a434812007-03-06 01:42:09 -0800766 I_MUTEX_PARENT);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700767 dentry = lookup_one_len(name, ipc_ns->mq_mnt->mnt_root, strlen(name));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 if (IS_ERR(dentry)) {
769 err = PTR_ERR(dentry);
770 goto out_unlock;
771 }
772
773 if (!dentry->d_inode) {
774 err = -ENOENT;
775 goto out_err;
776 }
777
778 inode = dentry->d_inode;
779 if (inode)
Al Viro7de9c6e2010-10-23 11:11:40 -0400780 ihold(inode);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700781 err = mnt_want_write(ipc_ns->mq_mnt);
Dave Hansen06227532008-02-15 14:37:34 -0800782 if (err)
783 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 err = vfs_unlink(dentry->d_parent->d_inode, dentry);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700785 mnt_drop_write(ipc_ns->mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786out_err:
787 dput(dentry);
788
789out_unlock:
Serge E. Hallyn614b84c2009-04-06 19:01:08 -0700790 mutex_unlock(&ipc_ns->mq_mnt->mnt_root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 putname(name);
792 if (inode)
793 iput(inode);
794
795 return err;
796}
797
798/* Pipelined send and receive functions.
799 *
800 * If a receiver finds no waiting message, then it registers itself in the
801 * list of waiting receivers. A sender checks that list before adding the new
802 * message into the message array. If there is a waiting receiver, then it
803 * bypasses the message array and directly hands the message over to the
804 * receiver.
805 * The receiver accepts the message and returns without grabbing the queue
806 * spinlock. Therefore an intermediate STATE_PENDING state and memory barriers
807 * are necessary. The same algorithm is used for sysv semaphores, see
Serge E. Hallyn7b7a3172006-03-28 01:56:23 -0800808 * ipc/sem.c for more details.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 *
810 * The same algorithm is used for senders.
811 */
812
813/* pipelined_send() - send a message directly to the task waiting in
814 * sys_mq_timedreceive() (without inserting message into a queue).
815 */
816static inline void pipelined_send(struct mqueue_inode_info *info,
817 struct msg_msg *message,
818 struct ext_wait_queue *receiver)
819{
820 receiver->msg = message;
821 list_del(&receiver->list);
822 receiver->state = STATE_PENDING;
823 wake_up_process(receiver->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700824 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 receiver->state = STATE_READY;
826}
827
828/* pipelined_receive() - if there is task waiting in sys_mq_timedsend()
829 * gets its message and put to the queue (we have one free place for sure). */
830static inline void pipelined_receive(struct mqueue_inode_info *info)
831{
832 struct ext_wait_queue *sender = wq_get_first_waiter(info, SEND);
833
834 if (!sender) {
835 /* for poll */
836 wake_up_interruptible(&info->wait_q);
837 return;
838 }
839 msg_insert(sender->msg, info);
840 list_del(&sender->list);
841 sender->state = STATE_PENDING;
842 wake_up_process(sender->task);
akpm@osdl.orgd59dd462005-05-01 08:58:47 -0700843 smp_wmb();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 sender->state = STATE_READY;
845}
846
Heiko Carstensc4ea37c2009-01-14 14:14:28 +0100847SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
848 size_t, msg_len, unsigned int, msg_prio,
849 const struct timespec __user *, u_abs_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850{
851 struct file *filp;
852 struct inode *inode;
853 struct ext_wait_queue wait;
854 struct ext_wait_queue *receiver;
855 struct msg_msg *msg_ptr;
856 struct mqueue_inode_info *info;
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200857 ktime_t expires, *timeout = NULL;
858 struct timespec ts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 int ret;
860
Al Viroc32c8af2008-12-14 03:46:48 -0500861 if (u_abs_timeout) {
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200862 int res = prepare_timeout(u_abs_timeout, &expires, &ts);
863 if (res)
864 return res;
865 timeout = &expires;
Al Viroc32c8af2008-12-14 03:46:48 -0500866 }
George C. Wilson20ca73b2006-05-24 16:09:55 -0500867
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 if (unlikely(msg_prio >= (unsigned long) MQ_PRIO_MAX))
869 return -EINVAL;
870
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200871 audit_mq_sendrecv(mqdes, msg_len, msg_prio, timeout ? &ts : NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300874 if (unlikely(!filp)) {
875 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300877 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878
Josef Sipek6d630792006-12-08 02:37:11 -0800879 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300880 if (unlikely(filp->f_op != &mqueue_file_operations)) {
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 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400885 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300887 if (unlikely(!(filp->f_mode & FMODE_WRITE))) {
888 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300890 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
892 if (unlikely(msg_len > info->attr.mq_msgsize)) {
893 ret = -EMSGSIZE;
894 goto out_fput;
895 }
896
897 /* First try to allocate memory, before doing anything with
898 * existing queues. */
899 msg_ptr = load_msg(u_msg_ptr, msg_len);
900 if (IS_ERR(msg_ptr)) {
901 ret = PTR_ERR(msg_ptr);
902 goto out_fput;
903 }
904 msg_ptr->m_ts = msg_len;
905 msg_ptr->m_type = msg_prio;
906
907 spin_lock(&info->lock);
908
909 if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
910 if (filp->f_flags & O_NONBLOCK) {
911 spin_unlock(&info->lock);
912 ret = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 } else {
914 wait.task = current;
915 wait.msg = (void *) msg_ptr;
916 wait.state = STATE_NONE;
917 ret = wq_sleep(info, SEND, timeout, &wait);
918 }
919 if (ret < 0)
920 free_msg(msg_ptr);
921 } else {
922 receiver = wq_get_first_waiter(info, RECV);
923 if (receiver) {
924 pipelined_send(info, msg_ptr, receiver);
925 } else {
926 /* adds message to the queue */
927 msg_insert(msg_ptr, info);
928 __do_notify(info);
929 }
930 inode->i_atime = inode->i_mtime = inode->i_ctime =
931 CURRENT_TIME;
932 spin_unlock(&info->lock);
933 ret = 0;
934 }
935out_fput:
936 fput(filp);
937out:
938 return ret;
939}
940
Heiko Carstensc4ea37c2009-01-14 14:14:28 +0100941SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
942 size_t, msg_len, unsigned int __user *, u_msg_prio,
943 const struct timespec __user *, u_abs_timeout)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 ssize_t ret;
946 struct msg_msg *msg_ptr;
947 struct file *filp;
948 struct inode *inode;
949 struct mqueue_inode_info *info;
950 struct ext_wait_queue wait;
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200951 ktime_t expires, *timeout = NULL;
952 struct timespec ts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953
Al Viroc32c8af2008-12-14 03:46:48 -0500954 if (u_abs_timeout) {
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200955 int res = prepare_timeout(u_abs_timeout, &expires, &ts);
956 if (res)
957 return res;
958 timeout = &expires;
Al Viroc32c8af2008-12-14 03:46:48 -0500959 }
George C. Wilson20ca73b2006-05-24 16:09:55 -0500960
Carsten Emde9ca7d8e2010-04-02 22:40:20 +0200961 audit_mq_sendrecv(mqdes, msg_len, 0, timeout ? &ts : NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300964 if (unlikely(!filp)) {
965 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300967 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
Josef Sipek6d630792006-12-08 02:37:11 -0800969 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300970 if (unlikely(filp->f_op != &mqueue_file_operations)) {
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 info = MQUEUE_I(inode);
Al Viro5a190ae2007-06-07 12:19:32 -0400975 audit_inode(NULL, filp->f_path.dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300977 if (unlikely(!(filp->f_mode & FMODE_READ))) {
978 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -0300980 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981
982 /* checks if buffer is big enough */
983 if (unlikely(msg_len < info->attr.mq_msgsize)) {
984 ret = -EMSGSIZE;
985 goto out_fput;
986 }
987
988 spin_lock(&info->lock);
989 if (info->attr.mq_curmsgs == 0) {
990 if (filp->f_flags & O_NONBLOCK) {
991 spin_unlock(&info->lock);
992 ret = -EAGAIN;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 } else {
994 wait.task = current;
995 wait.state = STATE_NONE;
996 ret = wq_sleep(info, RECV, timeout, &wait);
997 msg_ptr = wait.msg;
998 }
999 } else {
1000 msg_ptr = msg_get(info);
1001
1002 inode->i_atime = inode->i_mtime = inode->i_ctime =
1003 CURRENT_TIME;
1004
1005 /* There is now free space in queue. */
1006 pipelined_receive(info);
1007 spin_unlock(&info->lock);
1008 ret = 0;
1009 }
1010 if (ret == 0) {
1011 ret = msg_ptr->m_ts;
1012
1013 if ((u_msg_prio && put_user(msg_ptr->m_type, u_msg_prio)) ||
1014 store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts)) {
1015 ret = -EFAULT;
1016 }
1017 free_msg(msg_ptr);
1018 }
1019out_fput:
1020 fput(filp);
1021out:
1022 return ret;
1023}
1024
1025/*
1026 * Notes: the case when user wants us to deregister (with NULL as pointer)
1027 * and he isn't currently owner of notification, will be silently discarded.
1028 * It isn't explicitly defined in the POSIX.
1029 */
Heiko Carstensc4ea37c2009-01-14 14:14:28 +01001030SYSCALL_DEFINE2(mq_notify, mqd_t, mqdes,
1031 const struct sigevent __user *, u_notification)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032{
1033 int ret;
1034 struct file *filp;
1035 struct sock *sock;
1036 struct inode *inode;
1037 struct sigevent notification;
1038 struct mqueue_inode_info *info;
1039 struct sk_buff *nc;
1040
Al Viro20114f72008-12-10 07:16:12 -05001041 if (u_notification) {
1042 if (copy_from_user(&notification, u_notification,
1043 sizeof(struct sigevent)))
1044 return -EFAULT;
1045 }
1046
1047 audit_mq_notify(mqdes, u_notification ? &notification : NULL);
George C. Wilson20ca73b2006-05-24 16:09:55 -05001048
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 nc = NULL;
1050 sock = NULL;
1051 if (u_notification != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 if (unlikely(notification.sigev_notify != SIGEV_NONE &&
1053 notification.sigev_notify != SIGEV_SIGNAL &&
1054 notification.sigev_notify != SIGEV_THREAD))
1055 return -EINVAL;
1056 if (notification.sigev_notify == SIGEV_SIGNAL &&
Jesper Juhl7ed20e12005-05-01 08:59:14 -07001057 !valid_signal(notification.sigev_signo)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 return -EINVAL;
1059 }
1060 if (notification.sigev_notify == SIGEV_THREAD) {
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -08001061 long timeo;
1062
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063 /* create the notify skb */
1064 nc = alloc_skb(NOTIFY_COOKIE_LEN, GFP_KERNEL);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001065 if (!nc) {
1066 ret = -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001068 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069 if (copy_from_user(nc->data,
1070 notification.sigev_value.sival_ptr,
1071 NOTIFY_COOKIE_LEN)) {
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001072 ret = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073 goto out;
1074 }
1075
1076 /* TODO: add a header? */
1077 skb_put(nc, NOTIFY_COOKIE_LEN);
1078 /* and attach it to the socket */
1079retry:
1080 filp = fget(notification.sigev_signo);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001081 if (!filp) {
1082 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001084 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085 sock = netlink_getsockbyfilp(filp);
1086 fput(filp);
1087 if (IS_ERR(sock)) {
1088 ret = PTR_ERR(sock);
1089 sock = NULL;
1090 goto out;
1091 }
1092
Patrick McHardyc3d8d1e2007-11-07 02:42:09 -08001093 timeo = MAX_SCHEDULE_TIMEOUT;
Denis V. Lunev9457afe2008-06-05 11:23:39 -07001094 ret = netlink_attachskb(sock, nc, &timeo, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 if (ret == 1)
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001096 goto retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097 if (ret) {
1098 sock = NULL;
1099 nc = NULL;
1100 goto out;
1101 }
1102 }
1103 }
1104
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001106 if (!filp) {
1107 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001109 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110
Josef Sipek6d630792006-12-08 02:37:11 -08001111 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001112 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1113 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001115 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116 info = MQUEUE_I(inode);
1117
1118 ret = 0;
1119 spin_lock(&info->lock);
1120 if (u_notification == NULL) {
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001121 if (info->notify_owner == task_tgid(current)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 remove_notification(info);
1123 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1124 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001125 } else if (info->notify_owner != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126 ret = -EBUSY;
1127 } else {
1128 switch (notification.sigev_notify) {
1129 case SIGEV_NONE:
1130 info->notify.sigev_notify = SIGEV_NONE;
1131 break;
1132 case SIGEV_THREAD:
1133 info->notify_sock = sock;
1134 info->notify_cookie = nc;
1135 sock = NULL;
1136 nc = NULL;
1137 info->notify.sigev_notify = SIGEV_THREAD;
1138 break;
1139 case SIGEV_SIGNAL:
1140 info->notify.sigev_signo = notification.sigev_signo;
1141 info->notify.sigev_value = notification.sigev_value;
1142 info->notify.sigev_notify = SIGEV_SIGNAL;
1143 break;
1144 }
Cedric Le Goatera03fcb72006-10-02 02:17:26 -07001145
1146 info->notify_owner = get_pid(task_tgid(current));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1148 }
1149 spin_unlock(&info->lock);
1150out_fput:
1151 fput(filp);
1152out:
1153 if (sock) {
1154 netlink_detachskb(sock, nc);
1155 } else if (nc) {
1156 dev_kfree_skb(nc);
1157 }
1158 return ret;
1159}
1160
Heiko Carstensc4ea37c2009-01-14 14:14:28 +01001161SYSCALL_DEFINE3(mq_getsetattr, mqd_t, mqdes,
1162 const struct mq_attr __user *, u_mqstat,
1163 struct mq_attr __user *, u_omqstat)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164{
1165 int ret;
1166 struct mq_attr mqstat, omqstat;
1167 struct file *filp;
1168 struct inode *inode;
1169 struct mqueue_inode_info *info;
1170
1171 if (u_mqstat != NULL) {
1172 if (copy_from_user(&mqstat, u_mqstat, sizeof(struct mq_attr)))
1173 return -EFAULT;
1174 if (mqstat.mq_flags & (~O_NONBLOCK))
1175 return -EINVAL;
1176 }
1177
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178 filp = fget(mqdes);
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001179 if (!filp) {
1180 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181 goto out;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001182 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183
Josef Sipek6d630792006-12-08 02:37:11 -08001184 inode = filp->f_path.dentry->d_inode;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001185 if (unlikely(filp->f_op != &mqueue_file_operations)) {
1186 ret = -EBADF;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187 goto out_fput;
André Goddard Rosa8d8ffef2010-02-23 04:04:26 -03001188 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 info = MQUEUE_I(inode);
1190
1191 spin_lock(&info->lock);
1192
1193 omqstat = info->attr;
1194 omqstat.mq_flags = filp->f_flags & O_NONBLOCK;
1195 if (u_mqstat) {
Al Viro73929062008-12-10 06:58:59 -05001196 audit_mq_getsetattr(mqdes, &mqstat);
Jonathan Corbetdb1dd4d2009-02-06 15:25:24 -07001197 spin_lock(&filp->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 if (mqstat.mq_flags & O_NONBLOCK)
1199 filp->f_flags |= O_NONBLOCK;
1200 else
1201 filp->f_flags &= ~O_NONBLOCK;
Jonathan Corbetdb1dd4d2009-02-06 15:25:24 -07001202 spin_unlock(&filp->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203
1204 inode->i_atime = inode->i_ctime = CURRENT_TIME;
1205 }
1206
1207 spin_unlock(&info->lock);
1208
1209 ret = 0;
1210 if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat,
1211 sizeof(struct mq_attr)))
1212 ret = -EFAULT;
1213
1214out_fput:
1215 fput(filp);
1216out:
1217 return ret;
1218}
1219
Arjan van de Ven92e1d5b2007-02-12 00:55:39 -08001220static const struct inode_operations mqueue_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001221 .lookup = simple_lookup,
1222 .create = mqueue_create,
1223 .unlink = mqueue_unlink,
1224};
1225
Arjan van de Ven9a321442007-02-12 00:55:35 -08001226static const struct file_operations mqueue_file_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227 .flush = mqueue_flush_file,
1228 .poll = mqueue_poll_file,
1229 .read = mqueue_read_file,
Arnd Bergmann6038f372010-08-15 18:52:59 +02001230 .llseek = default_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231};
1232
Alexey Dobriyanb87221d2009-09-21 17:01:09 -07001233static const struct super_operations mqueue_super_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234 .alloc_inode = mqueue_alloc_inode,
1235 .destroy_inode = mqueue_destroy_inode,
Al Viro6d8af642010-06-05 16:29:45 -04001236 .evict_inode = mqueue_evict_inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237 .statfs = simple_statfs,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238};
1239
1240static struct file_system_type mqueue_fs_type = {
1241 .name = "mqueue",
Al Viroceefda62010-07-26 13:16:50 +04001242 .mount = mqueue_mount,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001243 .kill_sb = kill_litter_super,
1244};
1245
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -07001246int mq_init_ns(struct ipc_namespace *ns)
1247{
1248 ns->mq_queues_count = 0;
1249 ns->mq_queues_max = DFLT_QUEUESMAX;
1250 ns->mq_msg_max = DFLT_MSGMAX;
1251 ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
1252
1253 ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
1254 if (IS_ERR(ns->mq_mnt)) {
1255 int err = PTR_ERR(ns->mq_mnt);
1256 ns->mq_mnt = NULL;
1257 return err;
1258 }
1259 return 0;
1260}
1261
1262void mq_clear_sbinfo(struct ipc_namespace *ns)
1263{
1264 ns->mq_mnt->mnt_sb->s_fs_info = NULL;
1265}
1266
1267void mq_put_mnt(struct ipc_namespace *ns)
1268{
1269 mntput(ns->mq_mnt);
1270}
1271
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272static int __init init_mqueue_fs(void)
1273{
1274 int error;
1275
1276 mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
1277 sizeof(struct mqueue_inode_info), 0,
Paul Mundt20c2df82007-07-20 10:11:58 +09001278 SLAB_HWCACHE_ALIGN, init_once);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279 if (mqueue_inode_cachep == NULL)
1280 return -ENOMEM;
1281
André Goddard Rosa2329e392010-02-23 04:04:27 -03001282 /* ignore failures - they are not fatal */
Serge E. Hallynbdc8e5f2009-04-06 19:01:11 -07001283 mq_sysctl_table = mq_register_sysctl_table();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284
1285 error = register_filesystem(&mqueue_fs_type);
1286 if (error)
1287 goto out_sysctl;
1288
Serge E. Hallyn7eafd7c2009-04-06 19:01:10 -07001289 spin_lock_init(&mq_lock);
1290
1291 init_ipc_ns.mq_mnt = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
Serge E. Hallyn614b84c2009-04-06 19:01:08 -07001292 if (IS_ERR(init_ipc_ns.mq_mnt)) {
1293 error = PTR_ERR(init_ipc_ns.mq_mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 goto out_filesystem;
1295 }
1296
Linus Torvalds1da177e2005-04-16 15:20:36 -07001297 return 0;
1298
1299out_filesystem:
1300 unregister_filesystem(&mqueue_fs_type);
1301out_sysctl:
1302 if (mq_sysctl_table)
1303 unregister_sysctl_table(mq_sysctl_table);
Alexey Dobriyan1a1d92c2006-09-27 01:49:40 -07001304 kmem_cache_destroy(mqueue_inode_cachep);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305 return error;
1306}
1307
1308__initcall(init_mqueue_fs);