Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * linux/ipc/msg.c | |
5a06a363 | 4 | * Copyright (C) 1992 Krishna Balasubramanian |
1da177e4 LT |
5 | * |
6 | * Removed all the remaining kerneld mess | |
7 | * Catch the -EFAULT stuff properly | |
8 | * Use GFP_KERNEL for messages as in 1.2 | |
9 | * Fixed up the unchecked user space derefs | |
10 | * Copyright (C) 1998 Alan Cox & Andi Kleen | |
11 | * | |
12 | * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com> | |
13 | * | |
14 | * mostly rewritten, threaded and wake-one semantics added | |
15 | * MSGMAX limit removed, sysctl's added | |
624dffcb | 16 | * (c) 1999 Manfred Spraul <manfred@colorfullife.com> |
073115d6 SG |
17 | * |
18 | * support for audit of ipc object properties and permission changes | |
19 | * Dustin Kirkland <dustin.kirkland@us.ibm.com> | |
1e786937 KK |
20 | * |
21 | * namespaces support | |
22 | * OpenVZ, SWsoft Inc. | |
23 | * Pavel Emelianov <xemul@openvz.org> | |
1da177e4 LT |
24 | */ |
25 | ||
c59ede7b | 26 | #include <linux/capability.h> |
1da177e4 LT |
27 | #include <linux/msg.h> |
28 | #include <linux/spinlock.h> | |
29 | #include <linux/init.h> | |
f7bf3df8 | 30 | #include <linux/mm.h> |
1da177e4 LT |
31 | #include <linux/proc_fs.h> |
32 | #include <linux/list.h> | |
33 | #include <linux/security.h> | |
84f001e1 | 34 | #include <linux/sched/wake_q.h> |
1da177e4 LT |
35 | #include <linux/syscalls.h> |
36 | #include <linux/audit.h> | |
19b4946c | 37 | #include <linux/seq_file.h> |
3e148c79 | 38 | #include <linux/rwsem.h> |
1e786937 | 39 | #include <linux/nsproxy.h> |
ae5e1b22 | 40 | #include <linux/ipc_namespace.h> |
5f921ae9 | 41 | |
1da177e4 | 42 | #include <asm/current.h> |
7153e402 | 43 | #include <linux/uaccess.h> |
1da177e4 LT |
44 | #include "util.h" |
45 | ||
4bb6657d | 46 | /* one msg_receiver structure for each sleeping receiver */ |
1da177e4 | 47 | struct msg_receiver { |
5a06a363 IM |
48 | struct list_head r_list; |
49 | struct task_struct *r_tsk; | |
1da177e4 | 50 | |
5a06a363 IM |
51 | int r_mode; |
52 | long r_msgtype; | |
53 | long r_maxsize; | |
1da177e4 | 54 | |
ee51636c | 55 | struct msg_msg *r_msg; |
1da177e4 LT |
56 | }; |
57 | ||
58 | /* one msg_sender for each sleeping sender */ | |
59 | struct msg_sender { | |
5a06a363 IM |
60 | struct list_head list; |
61 | struct task_struct *tsk; | |
ed27f912 | 62 | size_t msgsz; |
1da177e4 LT |
63 | }; |
64 | ||
65 | #define SEARCH_ANY 1 | |
66 | #define SEARCH_EQUAL 2 | |
67 | #define SEARCH_NOTEQUAL 3 | |
68 | #define SEARCH_LESSEQUAL 4 | |
8ac6ed58 | 69 | #define SEARCH_NUMBER 5 |
1da177e4 | 70 | |
ed2ddbf8 | 71 | #define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS]) |
1da177e4 | 72 | |
a5001a0d DB |
73 | static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id) |
74 | { | |
55b7ae50 | 75 | struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&msg_ids(ns), id); |
a5001a0d DB |
76 | |
77 | if (IS_ERR(ipcp)) | |
78 | return ERR_CAST(ipcp); | |
79 | ||
80 | return container_of(ipcp, struct msg_queue, q_perm); | |
81 | } | |
82 | ||
83 | static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns, | |
84 | int id) | |
85 | { | |
86 | struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id); | |
87 | ||
88 | if (IS_ERR(ipcp)) | |
89 | return ERR_CAST(ipcp); | |
90 | ||
91 | return container_of(ipcp, struct msg_queue, q_perm); | |
92 | } | |
93 | ||
7ca7e564 ND |
94 | static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) |
95 | { | |
96 | ipc_rmid(&msg_ids(ns), &s->q_perm); | |
97 | } | |
98 | ||
53dad6d3 DB |
99 | static void msg_rcu_free(struct rcu_head *head) |
100 | { | |
dba4cdd3 MS |
101 | struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu); |
102 | struct msg_queue *msq = container_of(p, struct msg_queue, q_perm); | |
53dad6d3 DB |
103 | |
104 | security_msg_queue_free(msq); | |
fb259c31 | 105 | kvfree(msq); |
52f90890 KC |
106 | } |
107 | ||
f4566f04 ND |
108 | /** |
109 | * newque - Create a new msg queue | |
110 | * @ns: namespace | |
111 | * @params: ptr to the structure that contains the key and msgflg | |
112 | * | |
d9a605e4 | 113 | * Called with msg_ids.rwsem held (writer) |
f4566f04 | 114 | */ |
7748dbfa | 115 | static int newque(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 116 | { |
1da177e4 | 117 | struct msg_queue *msq; |
51c23b7b | 118 | int retval; |
7748dbfa ND |
119 | key_t key = params->key; |
120 | int msgflg = params->flg; | |
1da177e4 | 121 | |
fb259c31 KC |
122 | msq = kvmalloc(sizeof(*msq), GFP_KERNEL); |
123 | if (unlikely(!msq)) | |
1da177e4 LT |
124 | return -ENOMEM; |
125 | ||
5a06a363 | 126 | msq->q_perm.mode = msgflg & S_IRWXUGO; |
1da177e4 LT |
127 | msq->q_perm.key = key; |
128 | ||
129 | msq->q_perm.security = NULL; | |
130 | retval = security_msg_queue_alloc(msq); | |
131 | if (retval) { | |
fb259c31 | 132 | kvfree(msq); |
1da177e4 LT |
133 | return retval; |
134 | } | |
135 | ||
1da177e4 | 136 | msq->q_stime = msq->q_rtime = 0; |
50578ea9 | 137 | msq->q_ctime = ktime_get_real_seconds(); |
1da177e4 | 138 | msq->q_cbytes = msq->q_qnum = 0; |
1e786937 | 139 | msq->q_qbytes = ns->msg_ctlmnb; |
1da177e4 LT |
140 | msq->q_lspid = msq->q_lrpid = 0; |
141 | INIT_LIST_HEAD(&msq->q_messages); | |
142 | INIT_LIST_HEAD(&msq->q_receivers); | |
143 | INIT_LIST_HEAD(&msq->q_senders); | |
7ca7e564 | 144 | |
b9a53227 | 145 | /* ipc_addid() locks msq upon success. */ |
51c23b7b MS |
146 | retval = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); |
147 | if (retval < 0) { | |
148 | call_rcu(&msq->q_perm.rcu, msg_rcu_free); | |
149 | return retval; | |
b9a53227 LT |
150 | } |
151 | ||
cf9d5d78 | 152 | ipc_unlock_object(&msq->q_perm); |
dbfcd91f | 153 | rcu_read_unlock(); |
1da177e4 | 154 | |
7ca7e564 | 155 | return msq->q_perm.id; |
1da177e4 LT |
156 | } |
157 | ||
ed27f912 DB |
158 | static inline bool msg_fits_inqueue(struct msg_queue *msq, size_t msgsz) |
159 | { | |
160 | return msgsz + msq->q_cbytes <= msq->q_qbytes && | |
161 | 1 + msq->q_qnum <= msq->q_qbytes; | |
162 | } | |
163 | ||
164 | static inline void ss_add(struct msg_queue *msq, | |
165 | struct msg_sender *mss, size_t msgsz) | |
1da177e4 | 166 | { |
5a06a363 | 167 | mss->tsk = current; |
ed27f912 | 168 | mss->msgsz = msgsz; |
f75a2f35 | 169 | __set_current_state(TASK_INTERRUPTIBLE); |
5a06a363 | 170 | list_add_tail(&mss->list, &msq->q_senders); |
1da177e4 LT |
171 | } |
172 | ||
5a06a363 | 173 | static inline void ss_del(struct msg_sender *mss) |
1da177e4 | 174 | { |
ed27f912 | 175 | if (mss->list.next) |
1da177e4 LT |
176 | list_del(&mss->list); |
177 | } | |
178 | ||
ed27f912 | 179 | static void ss_wakeup(struct msg_queue *msq, |
d0d6a2a9 | 180 | struct wake_q_head *wake_q, bool kill) |
1da177e4 | 181 | { |
41239fe8 | 182 | struct msg_sender *mss, *t; |
ed27f912 DB |
183 | struct task_struct *stop_tsk = NULL; |
184 | struct list_head *h = &msq->q_senders; | |
1da177e4 | 185 | |
41239fe8 | 186 | list_for_each_entry_safe(mss, t, h, list) { |
5a06a363 IM |
187 | if (kill) |
188 | mss->list.next = NULL; | |
ed27f912 DB |
189 | |
190 | /* | |
191 | * Stop at the first task we don't wakeup, | |
192 | * we've already iterated the original | |
193 | * sender queue. | |
194 | */ | |
195 | else if (stop_tsk == mss->tsk) | |
196 | break; | |
197 | /* | |
198 | * We are not in an EIDRM scenario here, therefore | |
199 | * verify that we really need to wakeup the task. | |
200 | * To maintain current semantics and wakeup order, | |
201 | * move the sender to the tail on behalf of the | |
202 | * blocked task. | |
203 | */ | |
204 | else if (!msg_fits_inqueue(msq, mss->msgsz)) { | |
205 | if (!stop_tsk) | |
206 | stop_tsk = mss->tsk; | |
207 | ||
208 | list_move_tail(&mss->list, &msq->q_senders); | |
209 | continue; | |
210 | } | |
211 | ||
e3658538 | 212 | wake_q_add(wake_q, mss->tsk); |
1da177e4 LT |
213 | } |
214 | } | |
215 | ||
ee51636c SAS |
216 | static void expunge_all(struct msg_queue *msq, int res, |
217 | struct wake_q_head *wake_q) | |
1da177e4 | 218 | { |
41239fe8 | 219 | struct msg_receiver *msr, *t; |
5a06a363 | 220 | |
41239fe8 | 221 | list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) { |
ee51636c SAS |
222 | wake_q_add(wake_q, msr->r_tsk); |
223 | WRITE_ONCE(msr->r_msg, ERR_PTR(res)); | |
1da177e4 LT |
224 | } |
225 | } | |
5a06a363 IM |
226 | |
227 | /* | |
228 | * freeque() wakes up waiters on the sender and receiver waiting queue, | |
f4566f04 ND |
229 | * removes the message queue from message queue ID IDR, and cleans up all the |
230 | * messages associated with this queue. | |
1da177e4 | 231 | * |
d9a605e4 DB |
232 | * msg_ids.rwsem (writer) and the spinlock for this message queue are held |
233 | * before freeque() is called. msg_ids.rwsem remains locked on exit. | |
1da177e4 | 234 | */ |
01b8b07a | 235 | static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
1da177e4 | 236 | { |
41239fe8 | 237 | struct msg_msg *msg, *t; |
01b8b07a | 238 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); |
194a6b5b | 239 | DEFINE_WAKE_Q(wake_q); |
1da177e4 | 240 | |
ee51636c | 241 | expunge_all(msq, -EIDRM, &wake_q); |
ed27f912 | 242 | ss_wakeup(msq, &wake_q, true); |
7ca7e564 | 243 | msg_rmid(ns, msq); |
4718787d | 244 | ipc_unlock_object(&msq->q_perm); |
ee51636c | 245 | wake_up_q(&wake_q); |
4718787d | 246 | rcu_read_unlock(); |
5a06a363 | 247 | |
41239fe8 | 248 | list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) { |
3ac88a41 | 249 | atomic_dec(&ns->msg_hdrs); |
1da177e4 LT |
250 | free_msg(msg); |
251 | } | |
3ac88a41 | 252 | atomic_sub(msq->q_cbytes, &ns->msg_bytes); |
dba4cdd3 | 253 | ipc_rcu_putref(&msq->q_perm, msg_rcu_free); |
1da177e4 LT |
254 | } |
255 | ||
f4566f04 | 256 | /* |
d9a605e4 | 257 | * Called with msg_ids.rwsem and ipcp locked. |
f4566f04 | 258 | */ |
03f02c76 | 259 | static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg) |
7748dbfa | 260 | { |
03f02c76 ND |
261 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); |
262 | ||
263 | return security_msg_queue_associate(msq, msgflg); | |
7748dbfa ND |
264 | } |
265 | ||
3d65661a | 266 | long ksys_msgget(key_t key, int msgflg) |
1da177e4 | 267 | { |
1e786937 | 268 | struct ipc_namespace *ns; |
eb66ec44 MK |
269 | static const struct ipc_ops msg_ops = { |
270 | .getnew = newque, | |
271 | .associate = msg_security, | |
272 | }; | |
7748dbfa | 273 | struct ipc_params msg_params; |
1e786937 KK |
274 | |
275 | ns = current->nsproxy->ipc_ns; | |
7ca7e564 | 276 | |
7748dbfa ND |
277 | msg_params.key = key; |
278 | msg_params.flg = msgflg; | |
5a06a363 | 279 | |
7748dbfa | 280 | return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params); |
1da177e4 LT |
281 | } |
282 | ||
3d65661a DB |
283 | SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg) |
284 | { | |
285 | return ksys_msgget(key, msgflg); | |
286 | } | |
287 | ||
5a06a363 IM |
288 | static inline unsigned long |
289 | copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version) | |
1da177e4 | 290 | { |
239521f3 | 291 | switch (version) { |
1da177e4 | 292 | case IPC_64: |
5a06a363 | 293 | return copy_to_user(buf, in, sizeof(*in)); |
1da177e4 | 294 | case IPC_OLD: |
5a06a363 | 295 | { |
1da177e4 LT |
296 | struct msqid_ds out; |
297 | ||
5a06a363 | 298 | memset(&out, 0, sizeof(out)); |
1da177e4 LT |
299 | |
300 | ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); | |
301 | ||
302 | out.msg_stime = in->msg_stime; | |
303 | out.msg_rtime = in->msg_rtime; | |
304 | out.msg_ctime = in->msg_ctime; | |
305 | ||
4be929be AD |
306 | if (in->msg_cbytes > USHRT_MAX) |
307 | out.msg_cbytes = USHRT_MAX; | |
1da177e4 LT |
308 | else |
309 | out.msg_cbytes = in->msg_cbytes; | |
310 | out.msg_lcbytes = in->msg_cbytes; | |
311 | ||
4be929be AD |
312 | if (in->msg_qnum > USHRT_MAX) |
313 | out.msg_qnum = USHRT_MAX; | |
1da177e4 LT |
314 | else |
315 | out.msg_qnum = in->msg_qnum; | |
316 | ||
4be929be AD |
317 | if (in->msg_qbytes > USHRT_MAX) |
318 | out.msg_qbytes = USHRT_MAX; | |
1da177e4 LT |
319 | else |
320 | out.msg_qbytes = in->msg_qbytes; | |
321 | out.msg_lqbytes = in->msg_qbytes; | |
322 | ||
323 | out.msg_lspid = in->msg_lspid; | |
324 | out.msg_lrpid = in->msg_lrpid; | |
325 | ||
5a06a363 IM |
326 | return copy_to_user(buf, &out, sizeof(out)); |
327 | } | |
1da177e4 LT |
328 | default: |
329 | return -EINVAL; | |
330 | } | |
331 | } | |
332 | ||
5a06a363 | 333 | static inline unsigned long |
016d7132 | 334 | copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version) |
1da177e4 | 335 | { |
239521f3 | 336 | switch (version) { |
1da177e4 | 337 | case IPC_64: |
016d7132 | 338 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 339 | return -EFAULT; |
1da177e4 | 340 | return 0; |
1da177e4 | 341 | case IPC_OLD: |
5a06a363 | 342 | { |
1da177e4 LT |
343 | struct msqid_ds tbuf_old; |
344 | ||
5a06a363 | 345 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) |
1da177e4 LT |
346 | return -EFAULT; |
347 | ||
239521f3 MS |
348 | out->msg_perm.uid = tbuf_old.msg_perm.uid; |
349 | out->msg_perm.gid = tbuf_old.msg_perm.gid; | |
350 | out->msg_perm.mode = tbuf_old.msg_perm.mode; | |
1da177e4 | 351 | |
5a06a363 | 352 | if (tbuf_old.msg_qbytes == 0) |
016d7132 | 353 | out->msg_qbytes = tbuf_old.msg_lqbytes; |
1da177e4 | 354 | else |
016d7132 | 355 | out->msg_qbytes = tbuf_old.msg_qbytes; |
1da177e4 LT |
356 | |
357 | return 0; | |
5a06a363 | 358 | } |
1da177e4 LT |
359 | default: |
360 | return -EINVAL; | |
361 | } | |
362 | } | |
363 | ||
a0d092fc | 364 | /* |
d9a605e4 | 365 | * This function handles some msgctl commands which require the rwsem |
a0d092fc | 366 | * to be held in write mode. |
d9a605e4 | 367 | * NOTE: no locks must be held, the rwsem is taken inside this function. |
a0d092fc PP |
368 | */ |
369 | static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd, | |
156d9ed1 | 370 | struct msqid64_ds *msqid64) |
1da177e4 | 371 | { |
1da177e4 | 372 | struct kern_ipc_perm *ipcp; |
a0d092fc PP |
373 | struct msg_queue *msq; |
374 | int err; | |
375 | ||
d9a605e4 | 376 | down_write(&msg_ids(ns).rwsem); |
7b4cc5d8 DB |
377 | rcu_read_lock(); |
378 | ||
15724ecb | 379 | ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd, |
156d9ed1 | 380 | &msqid64->msg_perm, msqid64->msg_qbytes); |
7b4cc5d8 DB |
381 | if (IS_ERR(ipcp)) { |
382 | err = PTR_ERR(ipcp); | |
7b4cc5d8 DB |
383 | goto out_unlock1; |
384 | } | |
a0d092fc | 385 | |
a5f75e7f | 386 | msq = container_of(ipcp, struct msg_queue, q_perm); |
a0d092fc PP |
387 | |
388 | err = security_msg_queue_msgctl(msq, cmd); | |
389 | if (err) | |
15724ecb | 390 | goto out_unlock1; |
a0d092fc PP |
391 | |
392 | switch (cmd) { | |
393 | case IPC_RMID: | |
15724ecb | 394 | ipc_lock_object(&msq->q_perm); |
7b4cc5d8 | 395 | /* freeque unlocks the ipc object and rcu */ |
a0d092fc PP |
396 | freeque(ns, ipcp); |
397 | goto out_up; | |
398 | case IPC_SET: | |
e3658538 | 399 | { |
194a6b5b | 400 | DEFINE_WAKE_Q(wake_q); |
e3658538 | 401 | |
156d9ed1 | 402 | if (msqid64->msg_qbytes > ns->msg_ctlmnb && |
a0d092fc PP |
403 | !capable(CAP_SYS_RESOURCE)) { |
404 | err = -EPERM; | |
15724ecb | 405 | goto out_unlock1; |
a0d092fc PP |
406 | } |
407 | ||
15724ecb | 408 | ipc_lock_object(&msq->q_perm); |
156d9ed1 | 409 | err = ipc_update_perm(&msqid64->msg_perm, ipcp); |
1efdb69b | 410 | if (err) |
7b4cc5d8 | 411 | goto out_unlock0; |
1efdb69b | 412 | |
156d9ed1 | 413 | msq->q_qbytes = msqid64->msg_qbytes; |
a0d092fc | 414 | |
50578ea9 | 415 | msq->q_ctime = ktime_get_real_seconds(); |
e3658538 DB |
416 | /* |
417 | * Sleeping receivers might be excluded by | |
a0d092fc PP |
418 | * stricter permissions. |
419 | */ | |
ee51636c | 420 | expunge_all(msq, -EAGAIN, &wake_q); |
e3658538 DB |
421 | /* |
422 | * Sleeping senders might be able to send | |
a0d092fc PP |
423 | * due to a larger queue size. |
424 | */ | |
ed27f912 | 425 | ss_wakeup(msq, &wake_q, false); |
e3658538 DB |
426 | ipc_unlock_object(&msq->q_perm); |
427 | wake_up_q(&wake_q); | |
428 | ||
429 | goto out_unlock1; | |
430 | } | |
a0d092fc PP |
431 | default: |
432 | err = -EINVAL; | |
15724ecb | 433 | goto out_unlock1; |
a0d092fc | 434 | } |
7b4cc5d8 DB |
435 | |
436 | out_unlock0: | |
437 | ipc_unlock_object(&msq->q_perm); | |
438 | out_unlock1: | |
439 | rcu_read_unlock(); | |
a0d092fc | 440 | out_up: |
d9a605e4 | 441 | up_write(&msg_ids(ns).rwsem); |
a0d092fc PP |
442 | return err; |
443 | } | |
444 | ||
156d9ed1 AV |
445 | static int msgctl_info(struct ipc_namespace *ns, int msqid, |
446 | int cmd, struct msginfo *msginfo) | |
a0d092fc | 447 | { |
2cafed30 | 448 | int err; |
156d9ed1 | 449 | int max_id; |
1da177e4 | 450 | |
156d9ed1 AV |
451 | /* |
452 | * We must not return kernel stack data. | |
453 | * due to padding, it's not enough | |
454 | * to set all member fields. | |
455 | */ | |
456 | err = security_msg_queue_msgctl(NULL, cmd); | |
457 | if (err) | |
458 | return err; | |
459 | ||
460 | memset(msginfo, 0, sizeof(*msginfo)); | |
461 | msginfo->msgmni = ns->msg_ctlmni; | |
462 | msginfo->msgmax = ns->msg_ctlmax; | |
463 | msginfo->msgmnb = ns->msg_ctlmnb; | |
464 | msginfo->msgssz = MSGSSZ; | |
465 | msginfo->msgseg = MSGSEG; | |
466 | down_read(&msg_ids(ns).rwsem); | |
467 | if (cmd == MSG_INFO) { | |
468 | msginfo->msgpool = msg_ids(ns).in_use; | |
469 | msginfo->msgmap = atomic_read(&ns->msg_hdrs); | |
470 | msginfo->msgtql = atomic_read(&ns->msg_bytes); | |
471 | } else { | |
472 | msginfo->msgmap = MSGMAP; | |
473 | msginfo->msgpool = MSGPOOL; | |
474 | msginfo->msgtql = MSGTQL; | |
1da177e4 | 475 | } |
156d9ed1 AV |
476 | max_id = ipc_get_maxid(&msg_ids(ns)); |
477 | up_read(&msg_ids(ns).rwsem); | |
478 | return (max_id < 0) ? 0 : max_id; | |
479 | } | |
2cafed30 | 480 | |
156d9ed1 AV |
481 | static int msgctl_stat(struct ipc_namespace *ns, int msqid, |
482 | int cmd, struct msqid64_ds *p) | |
483 | { | |
156d9ed1 | 484 | struct msg_queue *msq; |
87ad4b0d PM |
485 | int id = 0; |
486 | int err; | |
ac0ba20e | 487 | |
156d9ed1 | 488 | memset(p, 0, sizeof(*p)); |
ac0ba20e | 489 | |
156d9ed1 AV |
490 | rcu_read_lock(); |
491 | if (cmd == MSG_STAT) { | |
492 | msq = msq_obtain_object(ns, msqid); | |
493 | if (IS_ERR(msq)) { | |
494 | err = PTR_ERR(msq); | |
1da177e4 | 495 | goto out_unlock; |
1da177e4 | 496 | } |
87ad4b0d | 497 | id = msq->q_perm.id; |
156d9ed1 AV |
498 | } else { |
499 | msq = msq_obtain_object_check(ns, msqid); | |
500 | if (IS_ERR(msq)) { | |
501 | err = PTR_ERR(msq); | |
1da177e4 | 502 | goto out_unlock; |
156d9ed1 | 503 | } |
156d9ed1 | 504 | } |
1da177e4 | 505 | |
156d9ed1 AV |
506 | err = -EACCES; |
507 | if (ipcperms(ns, &msq->q_perm, S_IRUGO)) | |
508 | goto out_unlock; | |
ac0ba20e | 509 | |
156d9ed1 AV |
510 | err = security_msg_queue_msgctl(msq, cmd); |
511 | if (err) | |
512 | goto out_unlock; | |
513 | ||
87ad4b0d PM |
514 | ipc_lock_object(&msq->q_perm); |
515 | ||
516 | if (!ipc_valid_object(&msq->q_perm)) { | |
517 | ipc_unlock_object(&msq->q_perm); | |
518 | err = -EIDRM; | |
519 | goto out_unlock; | |
520 | } | |
521 | ||
156d9ed1 AV |
522 | kernel_to_ipc64_perm(&msq->q_perm, &p->msg_perm); |
523 | p->msg_stime = msq->q_stime; | |
524 | p->msg_rtime = msq->q_rtime; | |
525 | p->msg_ctime = msq->q_ctime; | |
526 | p->msg_cbytes = msq->q_cbytes; | |
527 | p->msg_qnum = msq->q_qnum; | |
528 | p->msg_qbytes = msq->q_qbytes; | |
529 | p->msg_lspid = msq->q_lspid; | |
530 | p->msg_lrpid = msq->q_lrpid; | |
2cafed30 | 531 | |
87ad4b0d PM |
532 | ipc_unlock_object(&msq->q_perm); |
533 | rcu_read_unlock(); | |
534 | return id; | |
1da177e4 | 535 | |
1da177e4 | 536 | out_unlock: |
ac0ba20e | 537 | rcu_read_unlock(); |
1da177e4 LT |
538 | return err; |
539 | } | |
540 | ||
2cafed30 DB |
541 | SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf) |
542 | { | |
543 | int version; | |
544 | struct ipc_namespace *ns; | |
156d9ed1 AV |
545 | struct msqid64_ds msqid64; |
546 | int err; | |
2cafed30 DB |
547 | |
548 | if (msqid < 0 || cmd < 0) | |
549 | return -EINVAL; | |
550 | ||
551 | version = ipc_parse_version(&cmd); | |
552 | ns = current->nsproxy->ipc_ns; | |
553 | ||
554 | switch (cmd) { | |
555 | case IPC_INFO: | |
156d9ed1 AV |
556 | case MSG_INFO: { |
557 | struct msginfo msginfo; | |
558 | err = msgctl_info(ns, msqid, cmd, &msginfo); | |
559 | if (err < 0) | |
560 | return err; | |
561 | if (copy_to_user(buf, &msginfo, sizeof(struct msginfo))) | |
562 | err = -EFAULT; | |
563 | return err; | |
564 | } | |
2cafed30 DB |
565 | case MSG_STAT: /* msqid is an index rather than a msg queue id */ |
566 | case IPC_STAT: | |
156d9ed1 AV |
567 | err = msgctl_stat(ns, msqid, cmd, &msqid64); |
568 | if (err < 0) | |
569 | return err; | |
570 | if (copy_msqid_to_user(buf, &msqid64, version)) | |
571 | err = -EFAULT; | |
572 | return err; | |
2cafed30 | 573 | case IPC_SET: |
156d9ed1 AV |
574 | if (copy_msqid_from_user(&msqid64, buf, version)) |
575 | return -EFAULT; | |
576 | /* fallthru */ | |
2cafed30 | 577 | case IPC_RMID: |
156d9ed1 | 578 | return msgctl_down(ns, msqid, cmd, &msqid64); |
2cafed30 DB |
579 | default: |
580 | return -EINVAL; | |
581 | } | |
582 | } | |
583 | ||
46939168 AV |
584 | #ifdef CONFIG_COMPAT |
585 | ||
586 | struct compat_msqid_ds { | |
587 | struct compat_ipc_perm msg_perm; | |
588 | compat_uptr_t msg_first; | |
589 | compat_uptr_t msg_last; | |
590 | compat_time_t msg_stime; | |
591 | compat_time_t msg_rtime; | |
592 | compat_time_t msg_ctime; | |
593 | compat_ulong_t msg_lcbytes; | |
594 | compat_ulong_t msg_lqbytes; | |
595 | unsigned short msg_cbytes; | |
596 | unsigned short msg_qnum; | |
597 | unsigned short msg_qbytes; | |
598 | compat_ipc_pid_t msg_lspid; | |
599 | compat_ipc_pid_t msg_lrpid; | |
600 | }; | |
601 | ||
602 | static int copy_compat_msqid_from_user(struct msqid64_ds *out, void __user *buf, | |
603 | int version) | |
604 | { | |
605 | memset(out, 0, sizeof(*out)); | |
606 | if (version == IPC_64) { | |
6aa211e8 | 607 | struct compat_msqid64_ds __user *p = buf; |
28327fae | 608 | if (get_compat_ipc64_perm(&out->msg_perm, &p->msg_perm)) |
46939168 | 609 | return -EFAULT; |
46939168 AV |
610 | if (get_user(out->msg_qbytes, &p->msg_qbytes)) |
611 | return -EFAULT; | |
612 | } else { | |
6aa211e8 | 613 | struct compat_msqid_ds __user *p = buf; |
28327fae | 614 | if (get_compat_ipc_perm(&out->msg_perm, &p->msg_perm)) |
46939168 | 615 | return -EFAULT; |
46939168 AV |
616 | if (get_user(out->msg_qbytes, &p->msg_qbytes)) |
617 | return -EFAULT; | |
618 | } | |
619 | return 0; | |
620 | } | |
621 | ||
622 | static int copy_compat_msqid_to_user(void __user *buf, struct msqid64_ds *in, | |
623 | int version) | |
624 | { | |
625 | if (version == IPC_64) { | |
626 | struct compat_msqid64_ds v; | |
627 | memset(&v, 0, sizeof(v)); | |
28327fae | 628 | to_compat_ipc64_perm(&v.msg_perm, &in->msg_perm); |
46939168 AV |
629 | v.msg_stime = in->msg_stime; |
630 | v.msg_rtime = in->msg_rtime; | |
631 | v.msg_ctime = in->msg_ctime; | |
632 | v.msg_cbytes = in->msg_cbytes; | |
633 | v.msg_qnum = in->msg_qnum; | |
634 | v.msg_qbytes = in->msg_qbytes; | |
635 | v.msg_lspid = in->msg_lspid; | |
636 | v.msg_lrpid = in->msg_lrpid; | |
637 | return copy_to_user(buf, &v, sizeof(v)); | |
638 | } else { | |
639 | struct compat_msqid_ds v; | |
640 | memset(&v, 0, sizeof(v)); | |
28327fae | 641 | to_compat_ipc_perm(&v.msg_perm, &in->msg_perm); |
46939168 AV |
642 | v.msg_stime = in->msg_stime; |
643 | v.msg_rtime = in->msg_rtime; | |
644 | v.msg_ctime = in->msg_ctime; | |
645 | v.msg_cbytes = in->msg_cbytes; | |
646 | v.msg_qnum = in->msg_qnum; | |
647 | v.msg_qbytes = in->msg_qbytes; | |
648 | v.msg_lspid = in->msg_lspid; | |
649 | v.msg_lrpid = in->msg_lrpid; | |
650 | return copy_to_user(buf, &v, sizeof(v)); | |
651 | } | |
652 | } | |
653 | ||
654 | COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr) | |
655 | { | |
656 | struct ipc_namespace *ns; | |
657 | int err; | |
658 | struct msqid64_ds msqid64; | |
659 | int version = compat_ipc_parse_version(&cmd); | |
660 | ||
661 | ns = current->nsproxy->ipc_ns; | |
662 | ||
663 | if (msqid < 0 || cmd < 0) | |
664 | return -EINVAL; | |
665 | ||
666 | switch (cmd & (~IPC_64)) { | |
667 | case IPC_INFO: | |
668 | case MSG_INFO: { | |
669 | struct msginfo msginfo; | |
670 | err = msgctl_info(ns, msqid, cmd, &msginfo); | |
671 | if (err < 0) | |
672 | return err; | |
673 | if (copy_to_user(uptr, &msginfo, sizeof(struct msginfo))) | |
674 | err = -EFAULT; | |
675 | return err; | |
676 | } | |
677 | case IPC_STAT: | |
678 | case MSG_STAT: | |
679 | err = msgctl_stat(ns, msqid, cmd, &msqid64); | |
680 | if (err < 0) | |
681 | return err; | |
682 | if (copy_compat_msqid_to_user(uptr, &msqid64, version)) | |
683 | err = -EFAULT; | |
684 | return err; | |
685 | case IPC_SET: | |
686 | if (copy_compat_msqid_from_user(&msqid64, uptr, version)) | |
687 | return -EFAULT; | |
688 | /* fallthru */ | |
689 | case IPC_RMID: | |
690 | return msgctl_down(ns, msqid, cmd, &msqid64); | |
691 | default: | |
692 | return -EINVAL; | |
693 | } | |
694 | } | |
695 | #endif | |
696 | ||
5a06a363 | 697 | static int testmsg(struct msg_msg *msg, long type, int mode) |
1da177e4 | 698 | { |
46c0a8ca PM |
699 | switch (mode) { |
700 | case SEARCH_ANY: | |
701 | case SEARCH_NUMBER: | |
702 | return 1; | |
703 | case SEARCH_LESSEQUAL: | |
704 | if (msg->m_type <= type) | |
705 | return 1; | |
706 | break; | |
707 | case SEARCH_EQUAL: | |
708 | if (msg->m_type == type) | |
1da177e4 | 709 | return 1; |
46c0a8ca PM |
710 | break; |
711 | case SEARCH_NOTEQUAL: | |
712 | if (msg->m_type != type) | |
713 | return 1; | |
714 | break; | |
1da177e4 LT |
715 | } |
716 | return 0; | |
717 | } | |
718 | ||
ee51636c SAS |
719 | static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg, |
720 | struct wake_q_head *wake_q) | |
1da177e4 | 721 | { |
41239fe8 | 722 | struct msg_receiver *msr, *t; |
5a06a363 | 723 | |
41239fe8 | 724 | list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) { |
5a06a363 IM |
725 | if (testmsg(msg, msr->r_msgtype, msr->r_mode) && |
726 | !security_msg_queue_msgrcv(msq, msg, msr->r_tsk, | |
727 | msr->r_msgtype, msr->r_mode)) { | |
728 | ||
1da177e4 | 729 | list_del(&msr->r_list); |
5a06a363 | 730 | if (msr->r_maxsize < msg->m_ts) { |
ee51636c SAS |
731 | wake_q_add(wake_q, msr->r_tsk); |
732 | WRITE_ONCE(msr->r_msg, ERR_PTR(-E2BIG)); | |
1da177e4 | 733 | } else { |
b488893a | 734 | msq->q_lrpid = task_pid_vnr(msr->r_tsk); |
1da177e4 | 735 | msq->q_rtime = get_seconds(); |
5a06a363 | 736 | |
ee51636c SAS |
737 | wake_q_add(wake_q, msr->r_tsk); |
738 | WRITE_ONCE(msr->r_msg, msg); | |
1da177e4 LT |
739 | return 1; |
740 | } | |
741 | } | |
742 | } | |
ffa571da | 743 | |
1da177e4 LT |
744 | return 0; |
745 | } | |
746 | ||
9b1404c2 | 747 | static long do_msgsnd(int msqid, long mtype, void __user *mtext, |
651971cb | 748 | size_t msgsz, int msgflg) |
1da177e4 LT |
749 | { |
750 | struct msg_queue *msq; | |
751 | struct msg_msg *msg; | |
1da177e4 | 752 | int err; |
1e786937 | 753 | struct ipc_namespace *ns; |
194a6b5b | 754 | DEFINE_WAKE_Q(wake_q); |
1e786937 KK |
755 | |
756 | ns = current->nsproxy->ipc_ns; | |
5a06a363 | 757 | |
1e786937 | 758 | if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0) |
1da177e4 | 759 | return -EINVAL; |
1da177e4 LT |
760 | if (mtype < 1) |
761 | return -EINVAL; | |
762 | ||
651971cb | 763 | msg = load_msg(mtext, msgsz); |
5a06a363 | 764 | if (IS_ERR(msg)) |
1da177e4 LT |
765 | return PTR_ERR(msg); |
766 | ||
767 | msg->m_type = mtype; | |
768 | msg->m_ts = msgsz; | |
769 | ||
3dd1f784 DB |
770 | rcu_read_lock(); |
771 | msq = msq_obtain_object_check(ns, msqid); | |
023a5355 ND |
772 | if (IS_ERR(msq)) { |
773 | err = PTR_ERR(msq); | |
3dd1f784 | 774 | goto out_unlock1; |
023a5355 | 775 | } |
1da177e4 | 776 | |
bebcb928 MS |
777 | ipc_lock_object(&msq->q_perm); |
778 | ||
1da177e4 LT |
779 | for (;;) { |
780 | struct msg_sender s; | |
781 | ||
5a06a363 | 782 | err = -EACCES; |
b0e77598 | 783 | if (ipcperms(ns, &msq->q_perm, S_IWUGO)) |
bebcb928 | 784 | goto out_unlock0; |
1da177e4 | 785 | |
4271b05a | 786 | /* raced with RMID? */ |
0f3d2b01 | 787 | if (!ipc_valid_object(&msq->q_perm)) { |
4271b05a DB |
788 | err = -EIDRM; |
789 | goto out_unlock0; | |
790 | } | |
791 | ||
1da177e4 LT |
792 | err = security_msg_queue_msgsnd(msq, msg, msgflg); |
793 | if (err) | |
bebcb928 | 794 | goto out_unlock0; |
1da177e4 | 795 | |
ed27f912 | 796 | if (msg_fits_inqueue(msq, msgsz)) |
1da177e4 | 797 | break; |
1da177e4 LT |
798 | |
799 | /* queue full, wait: */ | |
5a06a363 IM |
800 | if (msgflg & IPC_NOWAIT) { |
801 | err = -EAGAIN; | |
bebcb928 | 802 | goto out_unlock0; |
1da177e4 | 803 | } |
3dd1f784 | 804 | |
ffa571da | 805 | /* enqueue the sender and prepare to block */ |
ed27f912 | 806 | ss_add(msq, &s, msgsz); |
6062a8dc | 807 | |
dba4cdd3 | 808 | if (!ipc_rcu_getref(&msq->q_perm)) { |
6062a8dc | 809 | err = -EIDRM; |
3dd1f784 | 810 | goto out_unlock0; |
6062a8dc RR |
811 | } |
812 | ||
3dd1f784 DB |
813 | ipc_unlock_object(&msq->q_perm); |
814 | rcu_read_unlock(); | |
1da177e4 LT |
815 | schedule(); |
816 | ||
3dd1f784 DB |
817 | rcu_read_lock(); |
818 | ipc_lock_object(&msq->q_perm); | |
819 | ||
dba4cdd3 | 820 | ipc_rcu_putref(&msq->q_perm, msg_rcu_free); |
0f3d2b01 RA |
821 | /* raced with RMID? */ |
822 | if (!ipc_valid_object(&msq->q_perm)) { | |
1da177e4 | 823 | err = -EIDRM; |
3dd1f784 | 824 | goto out_unlock0; |
1da177e4 LT |
825 | } |
826 | ss_del(&s); | |
5a06a363 | 827 | |
1da177e4 | 828 | if (signal_pending(current)) { |
5a06a363 | 829 | err = -ERESTARTNOHAND; |
3dd1f784 | 830 | goto out_unlock0; |
1da177e4 | 831 | } |
3dd1f784 | 832 | |
1da177e4 | 833 | } |
ed27f912 | 834 | |
b488893a | 835 | msq->q_lspid = task_tgid_vnr(current); |
1da177e4 LT |
836 | msq->q_stime = get_seconds(); |
837 | ||
ee51636c | 838 | if (!pipelined_send(msq, msg, &wake_q)) { |
25985edc | 839 | /* no one is waiting for this message, enqueue it */ |
5a06a363 | 840 | list_add_tail(&msg->m_list, &msq->q_messages); |
1da177e4 LT |
841 | msq->q_cbytes += msgsz; |
842 | msq->q_qnum++; | |
3ac88a41 KK |
843 | atomic_add(msgsz, &ns->msg_bytes); |
844 | atomic_inc(&ns->msg_hdrs); | |
1da177e4 | 845 | } |
5a06a363 | 846 | |
1da177e4 LT |
847 | err = 0; |
848 | msg = NULL; | |
849 | ||
3dd1f784 DB |
850 | out_unlock0: |
851 | ipc_unlock_object(&msq->q_perm); | |
ee51636c | 852 | wake_up_q(&wake_q); |
3dd1f784 DB |
853 | out_unlock1: |
854 | rcu_read_unlock(); | |
5a06a363 | 855 | if (msg != NULL) |
1da177e4 LT |
856 | free_msg(msg); |
857 | return err; | |
858 | } | |
859 | ||
e48fbb69 HC |
860 | SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz, |
861 | int, msgflg) | |
651971cb | 862 | { |
863 | long mtype; | |
864 | ||
865 | if (get_user(mtype, &msgp->mtype)) | |
866 | return -EFAULT; | |
867 | return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg); | |
868 | } | |
869 | ||
9b1404c2 AV |
870 | #ifdef CONFIG_COMPAT |
871 | ||
872 | struct compat_msgbuf { | |
873 | compat_long_t mtype; | |
874 | char mtext[1]; | |
875 | }; | |
876 | ||
877 | COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp, | |
878 | compat_ssize_t, msgsz, int, msgflg) | |
879 | { | |
880 | struct compat_msgbuf __user *up = compat_ptr(msgp); | |
881 | compat_long_t mtype; | |
882 | ||
883 | if (get_user(mtype, &up->mtype)) | |
884 | return -EFAULT; | |
885 | return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg); | |
886 | } | |
887 | #endif | |
888 | ||
5a06a363 | 889 | static inline int convert_mode(long *msgtyp, int msgflg) |
1da177e4 | 890 | { |
8ac6ed58 PH |
891 | if (msgflg & MSG_COPY) |
892 | return SEARCH_NUMBER; | |
5a06a363 | 893 | /* |
1da177e4 LT |
894 | * find message of correct type. |
895 | * msgtyp = 0 => get first. | |
896 | * msgtyp > 0 => get first message of matching type. | |
5a06a363 | 897 | * msgtyp < 0 => get message with least type must be < abs(msgtype). |
1da177e4 | 898 | */ |
5a06a363 | 899 | if (*msgtyp == 0) |
1da177e4 | 900 | return SEARCH_ANY; |
5a06a363 | 901 | if (*msgtyp < 0) { |
99989835 JS |
902 | if (*msgtyp == LONG_MIN) /* -LONG_MIN is undefined */ |
903 | *msgtyp = LONG_MAX; | |
904 | else | |
905 | *msgtyp = -*msgtyp; | |
1da177e4 LT |
906 | return SEARCH_LESSEQUAL; |
907 | } | |
5a06a363 | 908 | if (msgflg & MSG_EXCEPT) |
1da177e4 LT |
909 | return SEARCH_NOTEQUAL; |
910 | return SEARCH_EQUAL; | |
911 | } | |
912 | ||
f9dd87f4 SK |
913 | static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz) |
914 | { | |
915 | struct msgbuf __user *msgp = dest; | |
916 | size_t msgsz; | |
917 | ||
918 | if (put_user(msg->m_type, &msgp->mtype)) | |
919 | return -EFAULT; | |
920 | ||
921 | msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz; | |
922 | if (store_msg(msgp->mtext, msg, msgsz)) | |
923 | return -EFAULT; | |
924 | return msgsz; | |
925 | } | |
926 | ||
4a674f34 | 927 | #ifdef CONFIG_CHECKPOINT_RESTORE |
3fcfe786 SK |
928 | /* |
929 | * This function creates new kernel message structure, large enough to store | |
930 | * bufsz message bytes. | |
931 | */ | |
8ac6ed58 | 932 | static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz) |
4a674f34 SK |
933 | { |
934 | struct msg_msg *copy; | |
935 | ||
4a674f34 SK |
936 | /* |
937 | * Create dummy message to copy real message to. | |
938 | */ | |
939 | copy = load_msg(buf, bufsz); | |
940 | if (!IS_ERR(copy)) | |
941 | copy->m_ts = bufsz; | |
942 | return copy; | |
943 | } | |
944 | ||
85398aa8 | 945 | static inline void free_copy(struct msg_msg *copy) |
4a674f34 | 946 | { |
85398aa8 | 947 | if (copy) |
4a674f34 SK |
948 | free_msg(copy); |
949 | } | |
950 | #else | |
8ac6ed58 | 951 | static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz) |
b30efe27 SK |
952 | { |
953 | return ERR_PTR(-ENOSYS); | |
954 | } | |
955 | ||
85398aa8 SK |
956 | static inline void free_copy(struct msg_msg *copy) |
957 | { | |
958 | } | |
4a674f34 SK |
959 | #endif |
960 | ||
daaf74cf PH |
961 | static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode) |
962 | { | |
368ae537 | 963 | struct msg_msg *msg, *found = NULL; |
daaf74cf PH |
964 | long count = 0; |
965 | ||
966 | list_for_each_entry(msg, &msq->q_messages, m_list) { | |
967 | if (testmsg(msg, *msgtyp, mode) && | |
968 | !security_msg_queue_msgrcv(msq, msg, current, | |
969 | *msgtyp, mode)) { | |
970 | if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) { | |
971 | *msgtyp = msg->m_type - 1; | |
368ae537 | 972 | found = msg; |
daaf74cf PH |
973 | } else if (mode == SEARCH_NUMBER) { |
974 | if (*msgtyp == count) | |
975 | return msg; | |
976 | } else | |
977 | return msg; | |
978 | count++; | |
979 | } | |
980 | } | |
981 | ||
368ae537 | 982 | return found ?: ERR_PTR(-EAGAIN); |
daaf74cf PH |
983 | } |
984 | ||
9b1404c2 | 985 | static long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg, |
f9dd87f4 | 986 | long (*msg_handler)(void __user *, struct msg_msg *, size_t)) |
1da177e4 | 987 | { |
1da177e4 | 988 | int mode; |
41a0d523 | 989 | struct msg_queue *msq; |
1e786937 | 990 | struct ipc_namespace *ns; |
41a0d523 | 991 | struct msg_msg *msg, *copy = NULL; |
194a6b5b | 992 | DEFINE_WAKE_Q(wake_q); |
1da177e4 | 993 | |
88b9e456 PH |
994 | ns = current->nsproxy->ipc_ns; |
995 | ||
f9dd87f4 | 996 | if (msqid < 0 || (long) bufsz < 0) |
1da177e4 | 997 | return -EINVAL; |
41a0d523 | 998 | |
4a674f34 | 999 | if (msgflg & MSG_COPY) { |
4f87dac3 MK |
1000 | if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT)) |
1001 | return -EINVAL; | |
8ac6ed58 | 1002 | copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax)); |
4a674f34 SK |
1003 | if (IS_ERR(copy)) |
1004 | return PTR_ERR(copy); | |
1005 | } | |
5a06a363 | 1006 | mode = convert_mode(&msgtyp, msgflg); |
1da177e4 | 1007 | |
41a0d523 DB |
1008 | rcu_read_lock(); |
1009 | msq = msq_obtain_object_check(ns, msqid); | |
4a674f34 | 1010 | if (IS_ERR(msq)) { |
41a0d523 | 1011 | rcu_read_unlock(); |
85398aa8 | 1012 | free_copy(copy); |
023a5355 | 1013 | return PTR_ERR(msq); |
4a674f34 | 1014 | } |
1da177e4 LT |
1015 | |
1016 | for (;;) { | |
1017 | struct msg_receiver msr_d; | |
1da177e4 LT |
1018 | |
1019 | msg = ERR_PTR(-EACCES); | |
b0e77598 | 1020 | if (ipcperms(ns, &msq->q_perm, S_IRUGO)) |
41a0d523 | 1021 | goto out_unlock1; |
1da177e4 | 1022 | |
41a0d523 | 1023 | ipc_lock_object(&msq->q_perm); |
4271b05a DB |
1024 | |
1025 | /* raced with RMID? */ | |
0f3d2b01 | 1026 | if (!ipc_valid_object(&msq->q_perm)) { |
4271b05a DB |
1027 | msg = ERR_PTR(-EIDRM); |
1028 | goto out_unlock0; | |
1029 | } | |
1030 | ||
daaf74cf | 1031 | msg = find_msg(msq, &msgtyp, mode); |
5a06a363 IM |
1032 | if (!IS_ERR(msg)) { |
1033 | /* | |
1034 | * Found a suitable message. | |
1035 | * Unlink it from the queue. | |
1036 | */ | |
f9dd87f4 | 1037 | if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) { |
1da177e4 | 1038 | msg = ERR_PTR(-E2BIG); |
41a0d523 | 1039 | goto out_unlock0; |
1da177e4 | 1040 | } |
3fcfe786 SK |
1041 | /* |
1042 | * If we are copying, then do not unlink message and do | |
1043 | * not update queue parameters. | |
1044 | */ | |
852028af PH |
1045 | if (msgflg & MSG_COPY) { |
1046 | msg = copy_msg(msg, copy); | |
41a0d523 | 1047 | goto out_unlock0; |
852028af | 1048 | } |
41a0d523 | 1049 | |
1da177e4 LT |
1050 | list_del(&msg->m_list); |
1051 | msq->q_qnum--; | |
1052 | msq->q_rtime = get_seconds(); | |
b488893a | 1053 | msq->q_lrpid = task_tgid_vnr(current); |
1da177e4 | 1054 | msq->q_cbytes -= msg->m_ts; |
3ac88a41 KK |
1055 | atomic_sub(msg->m_ts, &ns->msg_bytes); |
1056 | atomic_dec(&ns->msg_hdrs); | |
ed27f912 | 1057 | ss_wakeup(msq, &wake_q, false); |
41a0d523 DB |
1058 | |
1059 | goto out_unlock0; | |
1da177e4 | 1060 | } |
41a0d523 | 1061 | |
1da177e4 LT |
1062 | /* No message waiting. Wait for a message */ |
1063 | if (msgflg & IPC_NOWAIT) { | |
1064 | msg = ERR_PTR(-ENOMSG); | |
41a0d523 | 1065 | goto out_unlock0; |
1da177e4 | 1066 | } |
41a0d523 | 1067 | |
5a06a363 | 1068 | list_add_tail(&msr_d.r_list, &msq->q_receivers); |
1da177e4 LT |
1069 | msr_d.r_tsk = current; |
1070 | msr_d.r_msgtype = msgtyp; | |
1071 | msr_d.r_mode = mode; | |
5a06a363 | 1072 | if (msgflg & MSG_NOERROR) |
1da177e4 | 1073 | msr_d.r_maxsize = INT_MAX; |
5a06a363 | 1074 | else |
f9dd87f4 | 1075 | msr_d.r_maxsize = bufsz; |
1da177e4 | 1076 | msr_d.r_msg = ERR_PTR(-EAGAIN); |
f75a2f35 | 1077 | __set_current_state(TASK_INTERRUPTIBLE); |
1da177e4 | 1078 | |
41a0d523 DB |
1079 | ipc_unlock_object(&msq->q_perm); |
1080 | rcu_read_unlock(); | |
1da177e4 LT |
1081 | schedule(); |
1082 | ||
ee51636c SAS |
1083 | /* |
1084 | * Lockless receive, part 1: | |
1085 | * We don't hold a reference to the queue and getting a | |
1086 | * reference would defeat the idea of a lockless operation, | |
1087 | * thus the code relies on rcu to guarantee the existence of | |
1088 | * msq: | |
1da177e4 LT |
1089 | * Prior to destruction, expunge_all(-EIRDM) changes r_msg. |
1090 | * Thus if r_msg is -EAGAIN, then the queue not yet destroyed. | |
1da177e4 LT |
1091 | */ |
1092 | rcu_read_lock(); | |
1093 | ||
ee51636c SAS |
1094 | /* |
1095 | * Lockless receive, part 2: | |
1096 | * The work in pipelined_send() and expunge_all(): | |
1097 | * - Set pointer to message | |
1098 | * - Queue the receiver task for later wakeup | |
1099 | * - Wake up the process after the lock is dropped. | |
ff35e5ef | 1100 | * |
ee51636c SAS |
1101 | * Should the process wake up before this wakeup (due to a |
1102 | * signal) it will either see the message and continue ... | |
1da177e4 | 1103 | */ |
ee51636c | 1104 | msg = READ_ONCE(msr_d.r_msg); |
41a0d523 DB |
1105 | if (msg != ERR_PTR(-EAGAIN)) |
1106 | goto out_unlock1; | |
1da177e4 | 1107 | |
ee51636c SAS |
1108 | /* |
1109 | * ... or see -EAGAIN, acquire the lock to check the message | |
1110 | * again. | |
1111 | */ | |
41a0d523 | 1112 | ipc_lock_object(&msq->q_perm); |
1da177e4 | 1113 | |
ee51636c | 1114 | msg = msr_d.r_msg; |
5a06a363 | 1115 | if (msg != ERR_PTR(-EAGAIN)) |
41a0d523 | 1116 | goto out_unlock0; |
1da177e4 LT |
1117 | |
1118 | list_del(&msr_d.r_list); | |
1119 | if (signal_pending(current)) { | |
1120 | msg = ERR_PTR(-ERESTARTNOHAND); | |
41a0d523 | 1121 | goto out_unlock0; |
1da177e4 | 1122 | } |
41a0d523 DB |
1123 | |
1124 | ipc_unlock_object(&msq->q_perm); | |
1da177e4 | 1125 | } |
41a0d523 DB |
1126 | |
1127 | out_unlock0: | |
1128 | ipc_unlock_object(&msq->q_perm); | |
e3658538 | 1129 | wake_up_q(&wake_q); |
41a0d523 DB |
1130 | out_unlock1: |
1131 | rcu_read_unlock(); | |
4a674f34 | 1132 | if (IS_ERR(msg)) { |
85398aa8 | 1133 | free_copy(copy); |
5a06a363 | 1134 | return PTR_ERR(msg); |
4a674f34 | 1135 | } |
1da177e4 | 1136 | |
f9dd87f4 | 1137 | bufsz = msg_handler(buf, msg, bufsz); |
1da177e4 | 1138 | free_msg(msg); |
5a06a363 | 1139 | |
f9dd87f4 | 1140 | return bufsz; |
1da177e4 LT |
1141 | } |
1142 | ||
e48fbb69 HC |
1143 | SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz, |
1144 | long, msgtyp, int, msgflg) | |
651971cb | 1145 | { |
f9dd87f4 | 1146 | return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill); |
651971cb | 1147 | } |
1148 | ||
9b1404c2 AV |
1149 | #ifdef CONFIG_COMPAT |
1150 | static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz) | |
1151 | { | |
1152 | struct compat_msgbuf __user *msgp = dest; | |
1153 | size_t msgsz; | |
1154 | ||
1155 | if (put_user(msg->m_type, &msgp->mtype)) | |
1156 | return -EFAULT; | |
1157 | ||
1158 | msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz; | |
1159 | if (store_msg(msgp->mtext, msg, msgsz)) | |
1160 | return -EFAULT; | |
1161 | return msgsz; | |
1162 | } | |
1163 | ||
1164 | COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp, | |
1165 | compat_ssize_t, msgsz, compat_long_t, msgtyp, int, msgflg) | |
1166 | { | |
1167 | return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp, | |
1168 | msgflg, compat_do_msg_fill); | |
1169 | } | |
1170 | #endif | |
3440a6bd | 1171 | |
0cfb6aee | 1172 | int msg_init_ns(struct ipc_namespace *ns) |
3440a6bd DB |
1173 | { |
1174 | ns->msg_ctlmax = MSGMAX; | |
1175 | ns->msg_ctlmnb = MSGMNB; | |
0050ee05 | 1176 | ns->msg_ctlmni = MSGMNI; |
3440a6bd DB |
1177 | |
1178 | atomic_set(&ns->msg_bytes, 0); | |
1179 | atomic_set(&ns->msg_hdrs, 0); | |
0cfb6aee | 1180 | return ipc_init_ids(&ns->ids[IPC_MSG_IDS]); |
3440a6bd DB |
1181 | } |
1182 | ||
1183 | #ifdef CONFIG_IPC_NS | |
1184 | void msg_exit_ns(struct ipc_namespace *ns) | |
1185 | { | |
1186 | free_ipcs(ns, &msg_ids(ns), freeque); | |
1187 | idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr); | |
0cfb6aee | 1188 | rhashtable_destroy(&ns->ids[IPC_MSG_IDS].key_ht); |
3440a6bd DB |
1189 | } |
1190 | #endif | |
1191 | ||
1da177e4 | 1192 | #ifdef CONFIG_PROC_FS |
19b4946c | 1193 | static int sysvipc_msg_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1194 | { |
1efdb69b | 1195 | struct user_namespace *user_ns = seq_user_ns(s); |
ade9f91b KC |
1196 | struct kern_ipc_perm *ipcp = it; |
1197 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); | |
19b4946c | 1198 | |
7f032d6e | 1199 | seq_printf(s, |
50578ea9 | 1200 | "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10llu %10llu %10llu\n", |
7f032d6e JP |
1201 | msq->q_perm.key, |
1202 | msq->q_perm.id, | |
1203 | msq->q_perm.mode, | |
1204 | msq->q_cbytes, | |
1205 | msq->q_qnum, | |
1206 | msq->q_lspid, | |
1207 | msq->q_lrpid, | |
1208 | from_kuid_munged(user_ns, msq->q_perm.uid), | |
1209 | from_kgid_munged(user_ns, msq->q_perm.gid), | |
1210 | from_kuid_munged(user_ns, msq->q_perm.cuid), | |
1211 | from_kgid_munged(user_ns, msq->q_perm.cgid), | |
1212 | msq->q_stime, | |
1213 | msq->q_rtime, | |
1214 | msq->q_ctime); | |
1215 | ||
1216 | return 0; | |
1da177e4 LT |
1217 | } |
1218 | #endif | |
3440a6bd | 1219 | |
0cfb6aee | 1220 | int __init msg_init(void) |
3440a6bd | 1221 | { |
0cfb6aee | 1222 | const int err = msg_init_ns(&init_ipc_ns); |
3440a6bd | 1223 | |
3440a6bd DB |
1224 | ipc_init_proc_interface("sysvipc/msg", |
1225 | " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n", | |
1226 | IPC_MSG_IDS, sysvipc_msg_proc_show); | |
0cfb6aee | 1227 | return err; |
3440a6bd | 1228 | } |