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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 | ||
34b56df9 EB |
46 | /* one msq_queue structure for each present queue on the system */ |
47 | struct msg_queue { | |
48 | struct kern_ipc_perm q_perm; | |
49 | time64_t q_stime; /* last msgsnd time */ | |
50 | time64_t q_rtime; /* last msgrcv time */ | |
51 | time64_t q_ctime; /* last change time */ | |
52 | unsigned long q_cbytes; /* current number of bytes on queue */ | |
53 | unsigned long q_qnum; /* number of messages in queue */ | |
54 | unsigned long q_qbytes; /* max number of bytes on queue */ | |
39a4940e EB |
55 | struct pid *q_lspid; /* pid of last msgsnd */ |
56 | struct pid *q_lrpid; /* last receive pid */ | |
34b56df9 EB |
57 | |
58 | struct list_head q_messages; | |
59 | struct list_head q_receivers; | |
60 | struct list_head q_senders; | |
61 | } __randomize_layout; | |
62 | ||
4bb6657d | 63 | /* one msg_receiver structure for each sleeping receiver */ |
1da177e4 | 64 | struct msg_receiver { |
5a06a363 IM |
65 | struct list_head r_list; |
66 | struct task_struct *r_tsk; | |
1da177e4 | 67 | |
5a06a363 IM |
68 | int r_mode; |
69 | long r_msgtype; | |
70 | long r_maxsize; | |
1da177e4 | 71 | |
ee51636c | 72 | struct msg_msg *r_msg; |
1da177e4 LT |
73 | }; |
74 | ||
75 | /* one msg_sender for each sleeping sender */ | |
76 | struct msg_sender { | |
5a06a363 IM |
77 | struct list_head list; |
78 | struct task_struct *tsk; | |
ed27f912 | 79 | size_t msgsz; |
1da177e4 LT |
80 | }; |
81 | ||
82 | #define SEARCH_ANY 1 | |
83 | #define SEARCH_EQUAL 2 | |
84 | #define SEARCH_NOTEQUAL 3 | |
85 | #define SEARCH_LESSEQUAL 4 | |
8ac6ed58 | 86 | #define SEARCH_NUMBER 5 |
1da177e4 | 87 | |
ed2ddbf8 | 88 | #define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS]) |
1da177e4 | 89 | |
a5001a0d DB |
90 | static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id) |
91 | { | |
55b7ae50 | 92 | struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&msg_ids(ns), id); |
a5001a0d DB |
93 | |
94 | if (IS_ERR(ipcp)) | |
95 | return ERR_CAST(ipcp); | |
96 | ||
97 | return container_of(ipcp, struct msg_queue, q_perm); | |
98 | } | |
99 | ||
100 | static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns, | |
101 | int id) | |
102 | { | |
103 | struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id); | |
104 | ||
105 | if (IS_ERR(ipcp)) | |
106 | return ERR_CAST(ipcp); | |
107 | ||
108 | return container_of(ipcp, struct msg_queue, q_perm); | |
109 | } | |
110 | ||
7ca7e564 ND |
111 | static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s) |
112 | { | |
113 | ipc_rmid(&msg_ids(ns), &s->q_perm); | |
114 | } | |
115 | ||
53dad6d3 DB |
116 | static void msg_rcu_free(struct rcu_head *head) |
117 | { | |
dba4cdd3 MS |
118 | struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu); |
119 | struct msg_queue *msq = container_of(p, struct msg_queue, q_perm); | |
53dad6d3 | 120 | |
d8c6e854 | 121 | security_msg_queue_free(&msq->q_perm); |
fb259c31 | 122 | kvfree(msq); |
52f90890 KC |
123 | } |
124 | ||
f4566f04 ND |
125 | /** |
126 | * newque - Create a new msg queue | |
127 | * @ns: namespace | |
128 | * @params: ptr to the structure that contains the key and msgflg | |
129 | * | |
d9a605e4 | 130 | * Called with msg_ids.rwsem held (writer) |
f4566f04 | 131 | */ |
7748dbfa | 132 | static int newque(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4 | 133 | { |
1da177e4 | 134 | struct msg_queue *msq; |
51c23b7b | 135 | int retval; |
7748dbfa ND |
136 | key_t key = params->key; |
137 | int msgflg = params->flg; | |
1da177e4 | 138 | |
fb259c31 KC |
139 | msq = kvmalloc(sizeof(*msq), GFP_KERNEL); |
140 | if (unlikely(!msq)) | |
1da177e4 LT |
141 | return -ENOMEM; |
142 | ||
5a06a363 | 143 | msq->q_perm.mode = msgflg & S_IRWXUGO; |
1da177e4 LT |
144 | msq->q_perm.key = key; |
145 | ||
146 | msq->q_perm.security = NULL; | |
d8c6e854 | 147 | retval = security_msg_queue_alloc(&msq->q_perm); |
1da177e4 | 148 | if (retval) { |
fb259c31 | 149 | kvfree(msq); |
1da177e4 LT |
150 | return retval; |
151 | } | |
152 | ||
1da177e4 | 153 | msq->q_stime = msq->q_rtime = 0; |
50578ea9 | 154 | msq->q_ctime = ktime_get_real_seconds(); |
1da177e4 | 155 | msq->q_cbytes = msq->q_qnum = 0; |
1e786937 | 156 | msq->q_qbytes = ns->msg_ctlmnb; |
39a4940e | 157 | msq->q_lspid = msq->q_lrpid = NULL; |
1da177e4 LT |
158 | INIT_LIST_HEAD(&msq->q_messages); |
159 | INIT_LIST_HEAD(&msq->q_receivers); | |
160 | INIT_LIST_HEAD(&msq->q_senders); | |
7ca7e564 | 161 | |
b9a53227 | 162 | /* ipc_addid() locks msq upon success. */ |
51c23b7b MS |
163 | retval = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni); |
164 | if (retval < 0) { | |
165 | call_rcu(&msq->q_perm.rcu, msg_rcu_free); | |
166 | return retval; | |
b9a53227 LT |
167 | } |
168 | ||
cf9d5d78 | 169 | ipc_unlock_object(&msq->q_perm); |
dbfcd91f | 170 | rcu_read_unlock(); |
1da177e4 | 171 | |
7ca7e564 | 172 | return msq->q_perm.id; |
1da177e4 LT |
173 | } |
174 | ||
ed27f912 DB |
175 | static inline bool msg_fits_inqueue(struct msg_queue *msq, size_t msgsz) |
176 | { | |
177 | return msgsz + msq->q_cbytes <= msq->q_qbytes && | |
178 | 1 + msq->q_qnum <= msq->q_qbytes; | |
179 | } | |
180 | ||
181 | static inline void ss_add(struct msg_queue *msq, | |
182 | struct msg_sender *mss, size_t msgsz) | |
1da177e4 | 183 | { |
5a06a363 | 184 | mss->tsk = current; |
ed27f912 | 185 | mss->msgsz = msgsz; |
f75a2f35 | 186 | __set_current_state(TASK_INTERRUPTIBLE); |
5a06a363 | 187 | list_add_tail(&mss->list, &msq->q_senders); |
1da177e4 LT |
188 | } |
189 | ||
5a06a363 | 190 | static inline void ss_del(struct msg_sender *mss) |
1da177e4 | 191 | { |
ed27f912 | 192 | if (mss->list.next) |
1da177e4 LT |
193 | list_del(&mss->list); |
194 | } | |
195 | ||
ed27f912 | 196 | static void ss_wakeup(struct msg_queue *msq, |
d0d6a2a9 | 197 | struct wake_q_head *wake_q, bool kill) |
1da177e4 | 198 | { |
41239fe8 | 199 | struct msg_sender *mss, *t; |
ed27f912 DB |
200 | struct task_struct *stop_tsk = NULL; |
201 | struct list_head *h = &msq->q_senders; | |
1da177e4 | 202 | |
41239fe8 | 203 | list_for_each_entry_safe(mss, t, h, list) { |
5a06a363 IM |
204 | if (kill) |
205 | mss->list.next = NULL; | |
ed27f912 DB |
206 | |
207 | /* | |
208 | * Stop at the first task we don't wakeup, | |
209 | * we've already iterated the original | |
210 | * sender queue. | |
211 | */ | |
212 | else if (stop_tsk == mss->tsk) | |
213 | break; | |
214 | /* | |
215 | * We are not in an EIDRM scenario here, therefore | |
216 | * verify that we really need to wakeup the task. | |
217 | * To maintain current semantics and wakeup order, | |
218 | * move the sender to the tail on behalf of the | |
219 | * blocked task. | |
220 | */ | |
221 | else if (!msg_fits_inqueue(msq, mss->msgsz)) { | |
222 | if (!stop_tsk) | |
223 | stop_tsk = mss->tsk; | |
224 | ||
225 | list_move_tail(&mss->list, &msq->q_senders); | |
226 | continue; | |
227 | } | |
228 | ||
e3658538 | 229 | wake_q_add(wake_q, mss->tsk); |
1da177e4 LT |
230 | } |
231 | } | |
232 | ||
ee51636c SAS |
233 | static void expunge_all(struct msg_queue *msq, int res, |
234 | struct wake_q_head *wake_q) | |
1da177e4 | 235 | { |
41239fe8 | 236 | struct msg_receiver *msr, *t; |
5a06a363 | 237 | |
41239fe8 | 238 | list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) { |
ee51636c SAS |
239 | wake_q_add(wake_q, msr->r_tsk); |
240 | WRITE_ONCE(msr->r_msg, ERR_PTR(res)); | |
1da177e4 LT |
241 | } |
242 | } | |
5a06a363 IM |
243 | |
244 | /* | |
245 | * freeque() wakes up waiters on the sender and receiver waiting queue, | |
f4566f04 ND |
246 | * removes the message queue from message queue ID IDR, and cleans up all the |
247 | * messages associated with this queue. | |
1da177e4 | 248 | * |
d9a605e4 DB |
249 | * msg_ids.rwsem (writer) and the spinlock for this message queue are held |
250 | * before freeque() is called. msg_ids.rwsem remains locked on exit. | |
1da177e4 | 251 | */ |
01b8b07a | 252 | static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
1da177e4 | 253 | { |
41239fe8 | 254 | struct msg_msg *msg, *t; |
01b8b07a | 255 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); |
194a6b5b | 256 | DEFINE_WAKE_Q(wake_q); |
1da177e4 | 257 | |
ee51636c | 258 | expunge_all(msq, -EIDRM, &wake_q); |
ed27f912 | 259 | ss_wakeup(msq, &wake_q, true); |
7ca7e564 | 260 | msg_rmid(ns, msq); |
4718787d | 261 | ipc_unlock_object(&msq->q_perm); |
ee51636c | 262 | wake_up_q(&wake_q); |
4718787d | 263 | rcu_read_unlock(); |
5a06a363 | 264 | |
41239fe8 | 265 | list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) { |
3ac88a41 | 266 | atomic_dec(&ns->msg_hdrs); |
1da177e4 LT |
267 | free_msg(msg); |
268 | } | |
3ac88a41 | 269 | atomic_sub(msq->q_cbytes, &ns->msg_bytes); |
39a4940e EB |
270 | ipc_update_pid(&msq->q_lspid, NULL); |
271 | ipc_update_pid(&msq->q_lrpid, NULL); | |
dba4cdd3 | 272 | ipc_rcu_putref(&msq->q_perm, msg_rcu_free); |
1da177e4 LT |
273 | } |
274 | ||
3d65661a | 275 | long ksys_msgget(key_t key, int msgflg) |
1da177e4 | 276 | { |
1e786937 | 277 | struct ipc_namespace *ns; |
eb66ec44 MK |
278 | static const struct ipc_ops msg_ops = { |
279 | .getnew = newque, | |
50ab44b1 | 280 | .associate = security_msg_queue_associate, |
eb66ec44 | 281 | }; |
7748dbfa | 282 | struct ipc_params msg_params; |
1e786937 KK |
283 | |
284 | ns = current->nsproxy->ipc_ns; | |
7ca7e564 | 285 | |
7748dbfa ND |
286 | msg_params.key = key; |
287 | msg_params.flg = msgflg; | |
5a06a363 | 288 | |
7748dbfa | 289 | return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params); |
1da177e4 LT |
290 | } |
291 | ||
3d65661a DB |
292 | SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg) |
293 | { | |
294 | return ksys_msgget(key, msgflg); | |
295 | } | |
296 | ||
5a06a363 IM |
297 | static inline unsigned long |
298 | copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version) | |
1da177e4 | 299 | { |
239521f3 | 300 | switch (version) { |
1da177e4 | 301 | case IPC_64: |
5a06a363 | 302 | return copy_to_user(buf, in, sizeof(*in)); |
1da177e4 | 303 | case IPC_OLD: |
5a06a363 | 304 | { |
1da177e4 LT |
305 | struct msqid_ds out; |
306 | ||
5a06a363 | 307 | memset(&out, 0, sizeof(out)); |
1da177e4 LT |
308 | |
309 | ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm); | |
310 | ||
311 | out.msg_stime = in->msg_stime; | |
312 | out.msg_rtime = in->msg_rtime; | |
313 | out.msg_ctime = in->msg_ctime; | |
314 | ||
4be929be AD |
315 | if (in->msg_cbytes > USHRT_MAX) |
316 | out.msg_cbytes = USHRT_MAX; | |
1da177e4 LT |
317 | else |
318 | out.msg_cbytes = in->msg_cbytes; | |
319 | out.msg_lcbytes = in->msg_cbytes; | |
320 | ||
4be929be AD |
321 | if (in->msg_qnum > USHRT_MAX) |
322 | out.msg_qnum = USHRT_MAX; | |
1da177e4 LT |
323 | else |
324 | out.msg_qnum = in->msg_qnum; | |
325 | ||
4be929be AD |
326 | if (in->msg_qbytes > USHRT_MAX) |
327 | out.msg_qbytes = USHRT_MAX; | |
1da177e4 LT |
328 | else |
329 | out.msg_qbytes = in->msg_qbytes; | |
330 | out.msg_lqbytes = in->msg_qbytes; | |
331 | ||
332 | out.msg_lspid = in->msg_lspid; | |
333 | out.msg_lrpid = in->msg_lrpid; | |
334 | ||
5a06a363 IM |
335 | return copy_to_user(buf, &out, sizeof(out)); |
336 | } | |
1da177e4 LT |
337 | default: |
338 | return -EINVAL; | |
339 | } | |
340 | } | |
341 | ||
5a06a363 | 342 | static inline unsigned long |
016d7132 | 343 | copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version) |
1da177e4 | 344 | { |
239521f3 | 345 | switch (version) { |
1da177e4 | 346 | case IPC_64: |
016d7132 | 347 | if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4 | 348 | return -EFAULT; |
1da177e4 | 349 | return 0; |
1da177e4 | 350 | case IPC_OLD: |
5a06a363 | 351 | { |
1da177e4 LT |
352 | struct msqid_ds tbuf_old; |
353 | ||
5a06a363 | 354 | if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) |
1da177e4 LT |
355 | return -EFAULT; |
356 | ||
239521f3 MS |
357 | out->msg_perm.uid = tbuf_old.msg_perm.uid; |
358 | out->msg_perm.gid = tbuf_old.msg_perm.gid; | |
359 | out->msg_perm.mode = tbuf_old.msg_perm.mode; | |
1da177e4 | 360 | |
5a06a363 | 361 | if (tbuf_old.msg_qbytes == 0) |
016d7132 | 362 | out->msg_qbytes = tbuf_old.msg_lqbytes; |
1da177e4 | 363 | else |
016d7132 | 364 | out->msg_qbytes = tbuf_old.msg_qbytes; |
1da177e4 LT |
365 | |
366 | return 0; | |
5a06a363 | 367 | } |
1da177e4 LT |
368 | default: |
369 | return -EINVAL; | |
370 | } | |
371 | } | |
372 | ||
a0d092fc | 373 | /* |
d9a605e4 | 374 | * This function handles some msgctl commands which require the rwsem |
a0d092fc | 375 | * to be held in write mode. |
d9a605e4 | 376 | * NOTE: no locks must be held, the rwsem is taken inside this function. |
a0d092fc PP |
377 | */ |
378 | static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd, | |
156d9ed1 | 379 | struct msqid64_ds *msqid64) |
1da177e4 | 380 | { |
1da177e4 | 381 | struct kern_ipc_perm *ipcp; |
a0d092fc PP |
382 | struct msg_queue *msq; |
383 | int err; | |
384 | ||
d9a605e4 | 385 | down_write(&msg_ids(ns).rwsem); |
7b4cc5d8 DB |
386 | rcu_read_lock(); |
387 | ||
15724ecb | 388 | ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd, |
156d9ed1 | 389 | &msqid64->msg_perm, msqid64->msg_qbytes); |
7b4cc5d8 DB |
390 | if (IS_ERR(ipcp)) { |
391 | err = PTR_ERR(ipcp); | |
7b4cc5d8 DB |
392 | goto out_unlock1; |
393 | } | |
a0d092fc | 394 | |
a5f75e7f | 395 | msq = container_of(ipcp, struct msg_queue, q_perm); |
a0d092fc | 396 | |
d8c6e854 | 397 | err = security_msg_queue_msgctl(&msq->q_perm, cmd); |
a0d092fc | 398 | if (err) |
15724ecb | 399 | goto out_unlock1; |
a0d092fc PP |
400 | |
401 | switch (cmd) { | |
402 | case IPC_RMID: | |
15724ecb | 403 | ipc_lock_object(&msq->q_perm); |
7b4cc5d8 | 404 | /* freeque unlocks the ipc object and rcu */ |
a0d092fc PP |
405 | freeque(ns, ipcp); |
406 | goto out_up; | |
407 | case IPC_SET: | |
e3658538 | 408 | { |
194a6b5b | 409 | DEFINE_WAKE_Q(wake_q); |
e3658538 | 410 | |
156d9ed1 | 411 | if (msqid64->msg_qbytes > ns->msg_ctlmnb && |
a0d092fc PP |
412 | !capable(CAP_SYS_RESOURCE)) { |
413 | err = -EPERM; | |
15724ecb | 414 | goto out_unlock1; |
a0d092fc PP |
415 | } |
416 | ||
15724ecb | 417 | ipc_lock_object(&msq->q_perm); |
156d9ed1 | 418 | err = ipc_update_perm(&msqid64->msg_perm, ipcp); |
1efdb69b | 419 | if (err) |
7b4cc5d8 | 420 | goto out_unlock0; |
1efdb69b | 421 | |
156d9ed1 | 422 | msq->q_qbytes = msqid64->msg_qbytes; |
a0d092fc | 423 | |
50578ea9 | 424 | msq->q_ctime = ktime_get_real_seconds(); |
e3658538 DB |
425 | /* |
426 | * Sleeping receivers might be excluded by | |
a0d092fc PP |
427 | * stricter permissions. |
428 | */ | |
ee51636c | 429 | expunge_all(msq, -EAGAIN, &wake_q); |
e3658538 DB |
430 | /* |
431 | * Sleeping senders might be able to send | |
a0d092fc PP |
432 | * due to a larger queue size. |
433 | */ | |
ed27f912 | 434 | ss_wakeup(msq, &wake_q, false); |
e3658538 DB |
435 | ipc_unlock_object(&msq->q_perm); |
436 | wake_up_q(&wake_q); | |
437 | ||
438 | goto out_unlock1; | |
439 | } | |
a0d092fc PP |
440 | default: |
441 | err = -EINVAL; | |
15724ecb | 442 | goto out_unlock1; |
a0d092fc | 443 | } |
7b4cc5d8 DB |
444 | |
445 | out_unlock0: | |
446 | ipc_unlock_object(&msq->q_perm); | |
447 | out_unlock1: | |
448 | rcu_read_unlock(); | |
a0d092fc | 449 | out_up: |
d9a605e4 | 450 | up_write(&msg_ids(ns).rwsem); |
a0d092fc PP |
451 | return err; |
452 | } | |
453 | ||
156d9ed1 AV |
454 | static int msgctl_info(struct ipc_namespace *ns, int msqid, |
455 | int cmd, struct msginfo *msginfo) | |
a0d092fc | 456 | { |
2cafed30 | 457 | int err; |
156d9ed1 | 458 | int max_id; |
1da177e4 | 459 | |
156d9ed1 AV |
460 | /* |
461 | * We must not return kernel stack data. | |
462 | * due to padding, it's not enough | |
463 | * to set all member fields. | |
464 | */ | |
465 | err = security_msg_queue_msgctl(NULL, cmd); | |
466 | if (err) | |
467 | return err; | |
468 | ||
469 | memset(msginfo, 0, sizeof(*msginfo)); | |
470 | msginfo->msgmni = ns->msg_ctlmni; | |
471 | msginfo->msgmax = ns->msg_ctlmax; | |
472 | msginfo->msgmnb = ns->msg_ctlmnb; | |
473 | msginfo->msgssz = MSGSSZ; | |
474 | msginfo->msgseg = MSGSEG; | |
475 | down_read(&msg_ids(ns).rwsem); | |
476 | if (cmd == MSG_INFO) { | |
477 | msginfo->msgpool = msg_ids(ns).in_use; | |
478 | msginfo->msgmap = atomic_read(&ns->msg_hdrs); | |
479 | msginfo->msgtql = atomic_read(&ns->msg_bytes); | |
480 | } else { | |
481 | msginfo->msgmap = MSGMAP; | |
482 | msginfo->msgpool = MSGPOOL; | |
483 | msginfo->msgtql = MSGTQL; | |
1da177e4 | 484 | } |
156d9ed1 AV |
485 | max_id = ipc_get_maxid(&msg_ids(ns)); |
486 | up_read(&msg_ids(ns).rwsem); | |
487 | return (max_id < 0) ? 0 : max_id; | |
488 | } | |
2cafed30 | 489 | |
156d9ed1 AV |
490 | static int msgctl_stat(struct ipc_namespace *ns, int msqid, |
491 | int cmd, struct msqid64_ds *p) | |
492 | { | |
156d9ed1 | 493 | struct msg_queue *msq; |
87ad4b0d PM |
494 | int id = 0; |
495 | int err; | |
ac0ba20e | 496 | |
156d9ed1 | 497 | memset(p, 0, sizeof(*p)); |
ac0ba20e | 498 | |
156d9ed1 AV |
499 | rcu_read_lock(); |
500 | if (cmd == MSG_STAT) { | |
501 | msq = msq_obtain_object(ns, msqid); | |
502 | if (IS_ERR(msq)) { | |
503 | err = PTR_ERR(msq); | |
1da177e4 | 504 | goto out_unlock; |
1da177e4 | 505 | } |
87ad4b0d | 506 | id = msq->q_perm.id; |
156d9ed1 AV |
507 | } else { |
508 | msq = msq_obtain_object_check(ns, msqid); | |
509 | if (IS_ERR(msq)) { | |
510 | err = PTR_ERR(msq); | |
1da177e4 | 511 | goto out_unlock; |
156d9ed1 | 512 | } |
156d9ed1 | 513 | } |
1da177e4 | 514 | |
156d9ed1 AV |
515 | err = -EACCES; |
516 | if (ipcperms(ns, &msq->q_perm, S_IRUGO)) | |
517 | goto out_unlock; | |
ac0ba20e | 518 | |
d8c6e854 | 519 | err = security_msg_queue_msgctl(&msq->q_perm, cmd); |
156d9ed1 AV |
520 | if (err) |
521 | goto out_unlock; | |
522 | ||
87ad4b0d PM |
523 | ipc_lock_object(&msq->q_perm); |
524 | ||
525 | if (!ipc_valid_object(&msq->q_perm)) { | |
526 | ipc_unlock_object(&msq->q_perm); | |
527 | err = -EIDRM; | |
528 | goto out_unlock; | |
529 | } | |
530 | ||
156d9ed1 AV |
531 | kernel_to_ipc64_perm(&msq->q_perm, &p->msg_perm); |
532 | p->msg_stime = msq->q_stime; | |
533 | p->msg_rtime = msq->q_rtime; | |
534 | p->msg_ctime = msq->q_ctime; | |
535 | p->msg_cbytes = msq->q_cbytes; | |
536 | p->msg_qnum = msq->q_qnum; | |
537 | p->msg_qbytes = msq->q_qbytes; | |
39a4940e EB |
538 | p->msg_lspid = pid_vnr(msq->q_lspid); |
539 | p->msg_lrpid = pid_vnr(msq->q_lrpid); | |
2cafed30 | 540 | |
87ad4b0d PM |
541 | ipc_unlock_object(&msq->q_perm); |
542 | rcu_read_unlock(); | |
543 | return id; | |
1da177e4 | 544 | |
1da177e4 | 545 | out_unlock: |
ac0ba20e | 546 | rcu_read_unlock(); |
1da177e4 LT |
547 | return err; |
548 | } | |
549 | ||
e340db56 | 550 | long ksys_msgctl(int msqid, int cmd, struct msqid_ds __user *buf) |
2cafed30 DB |
551 | { |
552 | int version; | |
553 | struct ipc_namespace *ns; | |
156d9ed1 AV |
554 | struct msqid64_ds msqid64; |
555 | int err; | |
2cafed30 DB |
556 | |
557 | if (msqid < 0 || cmd < 0) | |
558 | return -EINVAL; | |
559 | ||
560 | version = ipc_parse_version(&cmd); | |
561 | ns = current->nsproxy->ipc_ns; | |
562 | ||
563 | switch (cmd) { | |
564 | case IPC_INFO: | |
156d9ed1 AV |
565 | case MSG_INFO: { |
566 | struct msginfo msginfo; | |
567 | err = msgctl_info(ns, msqid, cmd, &msginfo); | |
568 | if (err < 0) | |
569 | return err; | |
570 | if (copy_to_user(buf, &msginfo, sizeof(struct msginfo))) | |
571 | err = -EFAULT; | |
572 | return err; | |
573 | } | |
2cafed30 DB |
574 | case MSG_STAT: /* msqid is an index rather than a msg queue id */ |
575 | case IPC_STAT: | |
156d9ed1 AV |
576 | err = msgctl_stat(ns, msqid, cmd, &msqid64); |
577 | if (err < 0) | |
578 | return err; | |
579 | if (copy_msqid_to_user(buf, &msqid64, version)) | |
580 | err = -EFAULT; | |
581 | return err; | |
2cafed30 | 582 | case IPC_SET: |
156d9ed1 AV |
583 | if (copy_msqid_from_user(&msqid64, buf, version)) |
584 | return -EFAULT; | |
585 | /* fallthru */ | |
2cafed30 | 586 | case IPC_RMID: |
156d9ed1 | 587 | return msgctl_down(ns, msqid, cmd, &msqid64); |
2cafed30 DB |
588 | default: |
589 | return -EINVAL; | |
590 | } | |
591 | } | |
592 | ||
e340db56 DB |
593 | SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf) |
594 | { | |
595 | return ksys_msgctl(msqid, cmd, buf); | |
596 | } | |
597 | ||
46939168 AV |
598 | #ifdef CONFIG_COMPAT |
599 | ||
600 | struct compat_msqid_ds { | |
601 | struct compat_ipc_perm msg_perm; | |
602 | compat_uptr_t msg_first; | |
603 | compat_uptr_t msg_last; | |
604 | compat_time_t msg_stime; | |
605 | compat_time_t msg_rtime; | |
606 | compat_time_t msg_ctime; | |
607 | compat_ulong_t msg_lcbytes; | |
608 | compat_ulong_t msg_lqbytes; | |
609 | unsigned short msg_cbytes; | |
610 | unsigned short msg_qnum; | |
611 | unsigned short msg_qbytes; | |
612 | compat_ipc_pid_t msg_lspid; | |
613 | compat_ipc_pid_t msg_lrpid; | |
614 | }; | |
615 | ||
616 | static int copy_compat_msqid_from_user(struct msqid64_ds *out, void __user *buf, | |
617 | int version) | |
618 | { | |
619 | memset(out, 0, sizeof(*out)); | |
620 | if (version == IPC_64) { | |
6aa211e8 | 621 | struct compat_msqid64_ds __user *p = buf; |
28327fae | 622 | if (get_compat_ipc64_perm(&out->msg_perm, &p->msg_perm)) |
46939168 | 623 | return -EFAULT; |
46939168 AV |
624 | if (get_user(out->msg_qbytes, &p->msg_qbytes)) |
625 | return -EFAULT; | |
626 | } else { | |
6aa211e8 | 627 | struct compat_msqid_ds __user *p = buf; |
28327fae | 628 | if (get_compat_ipc_perm(&out->msg_perm, &p->msg_perm)) |
46939168 | 629 | return -EFAULT; |
46939168 AV |
630 | if (get_user(out->msg_qbytes, &p->msg_qbytes)) |
631 | return -EFAULT; | |
632 | } | |
633 | return 0; | |
634 | } | |
635 | ||
636 | static int copy_compat_msqid_to_user(void __user *buf, struct msqid64_ds *in, | |
637 | int version) | |
638 | { | |
639 | if (version == IPC_64) { | |
640 | struct compat_msqid64_ds v; | |
641 | memset(&v, 0, sizeof(v)); | |
28327fae | 642 | to_compat_ipc64_perm(&v.msg_perm, &in->msg_perm); |
46939168 AV |
643 | v.msg_stime = in->msg_stime; |
644 | v.msg_rtime = in->msg_rtime; | |
645 | v.msg_ctime = in->msg_ctime; | |
646 | v.msg_cbytes = in->msg_cbytes; | |
647 | v.msg_qnum = in->msg_qnum; | |
648 | v.msg_qbytes = in->msg_qbytes; | |
649 | v.msg_lspid = in->msg_lspid; | |
650 | v.msg_lrpid = in->msg_lrpid; | |
651 | return copy_to_user(buf, &v, sizeof(v)); | |
652 | } else { | |
653 | struct compat_msqid_ds v; | |
654 | memset(&v, 0, sizeof(v)); | |
28327fae | 655 | to_compat_ipc_perm(&v.msg_perm, &in->msg_perm); |
46939168 AV |
656 | v.msg_stime = in->msg_stime; |
657 | v.msg_rtime = in->msg_rtime; | |
658 | v.msg_ctime = in->msg_ctime; | |
659 | v.msg_cbytes = in->msg_cbytes; | |
660 | v.msg_qnum = in->msg_qnum; | |
661 | v.msg_qbytes = in->msg_qbytes; | |
662 | v.msg_lspid = in->msg_lspid; | |
663 | v.msg_lrpid = in->msg_lrpid; | |
664 | return copy_to_user(buf, &v, sizeof(v)); | |
665 | } | |
666 | } | |
667 | ||
e340db56 | 668 | long compat_ksys_msgctl(int msqid, int cmd, void __user *uptr) |
46939168 AV |
669 | { |
670 | struct ipc_namespace *ns; | |
671 | int err; | |
672 | struct msqid64_ds msqid64; | |
673 | int version = compat_ipc_parse_version(&cmd); | |
674 | ||
675 | ns = current->nsproxy->ipc_ns; | |
676 | ||
677 | if (msqid < 0 || cmd < 0) | |
678 | return -EINVAL; | |
679 | ||
680 | switch (cmd & (~IPC_64)) { | |
681 | case IPC_INFO: | |
682 | case MSG_INFO: { | |
683 | struct msginfo msginfo; | |
684 | err = msgctl_info(ns, msqid, cmd, &msginfo); | |
685 | if (err < 0) | |
686 | return err; | |
687 | if (copy_to_user(uptr, &msginfo, sizeof(struct msginfo))) | |
688 | err = -EFAULT; | |
689 | return err; | |
690 | } | |
691 | case IPC_STAT: | |
692 | case MSG_STAT: | |
693 | err = msgctl_stat(ns, msqid, cmd, &msqid64); | |
694 | if (err < 0) | |
695 | return err; | |
696 | if (copy_compat_msqid_to_user(uptr, &msqid64, version)) | |
697 | err = -EFAULT; | |
698 | return err; | |
699 | case IPC_SET: | |
700 | if (copy_compat_msqid_from_user(&msqid64, uptr, version)) | |
701 | return -EFAULT; | |
702 | /* fallthru */ | |
703 | case IPC_RMID: | |
704 | return msgctl_down(ns, msqid, cmd, &msqid64); | |
705 | default: | |
706 | return -EINVAL; | |
707 | } | |
708 | } | |
e340db56 DB |
709 | |
710 | COMPAT_SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, void __user *, uptr) | |
711 | { | |
712 | return compat_ksys_msgctl(msqid, cmd, uptr); | |
713 | } | |
46939168 AV |
714 | #endif |
715 | ||
5a06a363 | 716 | static int testmsg(struct msg_msg *msg, long type, int mode) |
1da177e4 | 717 | { |
46c0a8ca PM |
718 | switch (mode) { |
719 | case SEARCH_ANY: | |
720 | case SEARCH_NUMBER: | |
721 | return 1; | |
722 | case SEARCH_LESSEQUAL: | |
723 | if (msg->m_type <= type) | |
724 | return 1; | |
725 | break; | |
726 | case SEARCH_EQUAL: | |
727 | if (msg->m_type == type) | |
1da177e4 | 728 | return 1; |
46c0a8ca PM |
729 | break; |
730 | case SEARCH_NOTEQUAL: | |
731 | if (msg->m_type != type) | |
732 | return 1; | |
733 | break; | |
1da177e4 LT |
734 | } |
735 | return 0; | |
736 | } | |
737 | ||
ee51636c SAS |
738 | static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg, |
739 | struct wake_q_head *wake_q) | |
1da177e4 | 740 | { |
41239fe8 | 741 | struct msg_receiver *msr, *t; |
5a06a363 | 742 | |
41239fe8 | 743 | list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) { |
5a06a363 | 744 | if (testmsg(msg, msr->r_msgtype, msr->r_mode) && |
d8c6e854 | 745 | !security_msg_queue_msgrcv(&msq->q_perm, msg, msr->r_tsk, |
5a06a363 IM |
746 | msr->r_msgtype, msr->r_mode)) { |
747 | ||
1da177e4 | 748 | list_del(&msr->r_list); |
5a06a363 | 749 | if (msr->r_maxsize < msg->m_ts) { |
ee51636c SAS |
750 | wake_q_add(wake_q, msr->r_tsk); |
751 | WRITE_ONCE(msr->r_msg, ERR_PTR(-E2BIG)); | |
1da177e4 | 752 | } else { |
39a4940e | 753 | ipc_update_pid(&msq->q_lrpid, task_pid(msr->r_tsk)); |
1da177e4 | 754 | msq->q_rtime = get_seconds(); |
5a06a363 | 755 | |
ee51636c SAS |
756 | wake_q_add(wake_q, msr->r_tsk); |
757 | WRITE_ONCE(msr->r_msg, msg); | |
1da177e4 LT |
758 | return 1; |
759 | } | |
760 | } | |
761 | } | |
ffa571da | 762 | |
1da177e4 LT |
763 | return 0; |
764 | } | |
765 | ||
9b1404c2 | 766 | static long do_msgsnd(int msqid, long mtype, void __user *mtext, |
651971cb | 767 | size_t msgsz, int msgflg) |
1da177e4 LT |
768 | { |
769 | struct msg_queue *msq; | |
770 | struct msg_msg *msg; | |
1da177e4 | 771 | int err; |
1e786937 | 772 | struct ipc_namespace *ns; |
194a6b5b | 773 | DEFINE_WAKE_Q(wake_q); |
1e786937 KK |
774 | |
775 | ns = current->nsproxy->ipc_ns; | |
5a06a363 | 776 | |
1e786937 | 777 | if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0) |
1da177e4 | 778 | return -EINVAL; |
1da177e4 LT |
779 | if (mtype < 1) |
780 | return -EINVAL; | |
781 | ||
651971cb | 782 | msg = load_msg(mtext, msgsz); |
5a06a363 | 783 | if (IS_ERR(msg)) |
1da177e4 LT |
784 | return PTR_ERR(msg); |
785 | ||
786 | msg->m_type = mtype; | |
787 | msg->m_ts = msgsz; | |
788 | ||
3dd1f784 DB |
789 | rcu_read_lock(); |
790 | msq = msq_obtain_object_check(ns, msqid); | |
023a5355 ND |
791 | if (IS_ERR(msq)) { |
792 | err = PTR_ERR(msq); | |
3dd1f784 | 793 | goto out_unlock1; |
023a5355 | 794 | } |
1da177e4 | 795 | |
bebcb928 MS |
796 | ipc_lock_object(&msq->q_perm); |
797 | ||
1da177e4 LT |
798 | for (;;) { |
799 | struct msg_sender s; | |
800 | ||
5a06a363 | 801 | err = -EACCES; |
b0e77598 | 802 | if (ipcperms(ns, &msq->q_perm, S_IWUGO)) |
bebcb928 | 803 | goto out_unlock0; |
1da177e4 | 804 | |
4271b05a | 805 | /* raced with RMID? */ |
0f3d2b01 | 806 | if (!ipc_valid_object(&msq->q_perm)) { |
4271b05a DB |
807 | err = -EIDRM; |
808 | goto out_unlock0; | |
809 | } | |
810 | ||
d8c6e854 | 811 | err = security_msg_queue_msgsnd(&msq->q_perm, msg, msgflg); |
1da177e4 | 812 | if (err) |
bebcb928 | 813 | goto out_unlock0; |
1da177e4 | 814 | |
ed27f912 | 815 | if (msg_fits_inqueue(msq, msgsz)) |
1da177e4 | 816 | break; |
1da177e4 LT |
817 | |
818 | /* queue full, wait: */ | |
5a06a363 IM |
819 | if (msgflg & IPC_NOWAIT) { |
820 | err = -EAGAIN; | |
bebcb928 | 821 | goto out_unlock0; |
1da177e4 | 822 | } |
3dd1f784 | 823 | |
ffa571da | 824 | /* enqueue the sender and prepare to block */ |
ed27f912 | 825 | ss_add(msq, &s, msgsz); |
6062a8dc | 826 | |
dba4cdd3 | 827 | if (!ipc_rcu_getref(&msq->q_perm)) { |
6062a8dc | 828 | err = -EIDRM; |
3dd1f784 | 829 | goto out_unlock0; |
6062a8dc RR |
830 | } |
831 | ||
3dd1f784 DB |
832 | ipc_unlock_object(&msq->q_perm); |
833 | rcu_read_unlock(); | |
1da177e4 LT |
834 | schedule(); |
835 | ||
3dd1f784 DB |
836 | rcu_read_lock(); |
837 | ipc_lock_object(&msq->q_perm); | |
838 | ||
dba4cdd3 | 839 | ipc_rcu_putref(&msq->q_perm, msg_rcu_free); |
0f3d2b01 RA |
840 | /* raced with RMID? */ |
841 | if (!ipc_valid_object(&msq->q_perm)) { | |
1da177e4 | 842 | err = -EIDRM; |
3dd1f784 | 843 | goto out_unlock0; |
1da177e4 LT |
844 | } |
845 | ss_del(&s); | |
5a06a363 | 846 | |
1da177e4 | 847 | if (signal_pending(current)) { |
5a06a363 | 848 | err = -ERESTARTNOHAND; |
3dd1f784 | 849 | goto out_unlock0; |
1da177e4 | 850 | } |
3dd1f784 | 851 | |
1da177e4 | 852 | } |
ed27f912 | 853 | |
39a4940e | 854 | ipc_update_pid(&msq->q_lspid, task_tgid(current)); |
1da177e4 LT |
855 | msq->q_stime = get_seconds(); |
856 | ||
ee51636c | 857 | if (!pipelined_send(msq, msg, &wake_q)) { |
25985edc | 858 | /* no one is waiting for this message, enqueue it */ |
5a06a363 | 859 | list_add_tail(&msg->m_list, &msq->q_messages); |
1da177e4 LT |
860 | msq->q_cbytes += msgsz; |
861 | msq->q_qnum++; | |
3ac88a41 KK |
862 | atomic_add(msgsz, &ns->msg_bytes); |
863 | atomic_inc(&ns->msg_hdrs); | |
1da177e4 | 864 | } |
5a06a363 | 865 | |
1da177e4 LT |
866 | err = 0; |
867 | msg = NULL; | |
868 | ||
3dd1f784 DB |
869 | out_unlock0: |
870 | ipc_unlock_object(&msq->q_perm); | |
ee51636c | 871 | wake_up_q(&wake_q); |
3dd1f784 DB |
872 | out_unlock1: |
873 | rcu_read_unlock(); | |
5a06a363 | 874 | if (msg != NULL) |
1da177e4 LT |
875 | free_msg(msg); |
876 | return err; | |
877 | } | |
878 | ||
31c213f2 DB |
879 | long ksys_msgsnd(int msqid, struct msgbuf __user *msgp, size_t msgsz, |
880 | int msgflg) | |
651971cb | 881 | { |
882 | long mtype; | |
883 | ||
884 | if (get_user(mtype, &msgp->mtype)) | |
885 | return -EFAULT; | |
886 | return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg); | |
887 | } | |
888 | ||
31c213f2 DB |
889 | SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz, |
890 | int, msgflg) | |
891 | { | |
892 | return ksys_msgsnd(msqid, msgp, msgsz, msgflg); | |
893 | } | |
894 | ||
9b1404c2 AV |
895 | #ifdef CONFIG_COMPAT |
896 | ||
897 | struct compat_msgbuf { | |
898 | compat_long_t mtype; | |
899 | char mtext[1]; | |
900 | }; | |
901 | ||
31c213f2 DB |
902 | long compat_ksys_msgsnd(int msqid, compat_uptr_t msgp, |
903 | compat_ssize_t msgsz, int msgflg) | |
9b1404c2 AV |
904 | { |
905 | struct compat_msgbuf __user *up = compat_ptr(msgp); | |
906 | compat_long_t mtype; | |
907 | ||
908 | if (get_user(mtype, &up->mtype)) | |
909 | return -EFAULT; | |
910 | return do_msgsnd(msqid, mtype, up->mtext, (ssize_t)msgsz, msgflg); | |
911 | } | |
31c213f2 DB |
912 | |
913 | COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp, | |
914 | compat_ssize_t, msgsz, int, msgflg) | |
915 | { | |
916 | return compat_ksys_msgsnd(msqid, msgp, msgsz, msgflg); | |
917 | } | |
9b1404c2 AV |
918 | #endif |
919 | ||
5a06a363 | 920 | static inline int convert_mode(long *msgtyp, int msgflg) |
1da177e4 | 921 | { |
8ac6ed58 PH |
922 | if (msgflg & MSG_COPY) |
923 | return SEARCH_NUMBER; | |
5a06a363 | 924 | /* |
1da177e4 LT |
925 | * find message of correct type. |
926 | * msgtyp = 0 => get first. | |
927 | * msgtyp > 0 => get first message of matching type. | |
5a06a363 | 928 | * msgtyp < 0 => get message with least type must be < abs(msgtype). |
1da177e4 | 929 | */ |
5a06a363 | 930 | if (*msgtyp == 0) |
1da177e4 | 931 | return SEARCH_ANY; |
5a06a363 | 932 | if (*msgtyp < 0) { |
99989835 JS |
933 | if (*msgtyp == LONG_MIN) /* -LONG_MIN is undefined */ |
934 | *msgtyp = LONG_MAX; | |
935 | else | |
936 | *msgtyp = -*msgtyp; | |
1da177e4 LT |
937 | return SEARCH_LESSEQUAL; |
938 | } | |
5a06a363 | 939 | if (msgflg & MSG_EXCEPT) |
1da177e4 LT |
940 | return SEARCH_NOTEQUAL; |
941 | return SEARCH_EQUAL; | |
942 | } | |
943 | ||
f9dd87f4 SK |
944 | static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz) |
945 | { | |
946 | struct msgbuf __user *msgp = dest; | |
947 | size_t msgsz; | |
948 | ||
949 | if (put_user(msg->m_type, &msgp->mtype)) | |
950 | return -EFAULT; | |
951 | ||
952 | msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz; | |
953 | if (store_msg(msgp->mtext, msg, msgsz)) | |
954 | return -EFAULT; | |
955 | return msgsz; | |
956 | } | |
957 | ||
4a674f34 | 958 | #ifdef CONFIG_CHECKPOINT_RESTORE |
3fcfe786 SK |
959 | /* |
960 | * This function creates new kernel message structure, large enough to store | |
961 | * bufsz message bytes. | |
962 | */ | |
8ac6ed58 | 963 | static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz) |
4a674f34 SK |
964 | { |
965 | struct msg_msg *copy; | |
966 | ||
4a674f34 SK |
967 | /* |
968 | * Create dummy message to copy real message to. | |
969 | */ | |
970 | copy = load_msg(buf, bufsz); | |
971 | if (!IS_ERR(copy)) | |
972 | copy->m_ts = bufsz; | |
973 | return copy; | |
974 | } | |
975 | ||
85398aa8 | 976 | static inline void free_copy(struct msg_msg *copy) |
4a674f34 | 977 | { |
85398aa8 | 978 | if (copy) |
4a674f34 SK |
979 | free_msg(copy); |
980 | } | |
981 | #else | |
8ac6ed58 | 982 | static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz) |
b30efe27 SK |
983 | { |
984 | return ERR_PTR(-ENOSYS); | |
985 | } | |
986 | ||
85398aa8 SK |
987 | static inline void free_copy(struct msg_msg *copy) |
988 | { | |
989 | } | |
4a674f34 SK |
990 | #endif |
991 | ||
daaf74cf PH |
992 | static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode) |
993 | { | |
368ae537 | 994 | struct msg_msg *msg, *found = NULL; |
daaf74cf PH |
995 | long count = 0; |
996 | ||
997 | list_for_each_entry(msg, &msq->q_messages, m_list) { | |
998 | if (testmsg(msg, *msgtyp, mode) && | |
d8c6e854 | 999 | !security_msg_queue_msgrcv(&msq->q_perm, msg, current, |
daaf74cf PH |
1000 | *msgtyp, mode)) { |
1001 | if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) { | |
1002 | *msgtyp = msg->m_type - 1; | |
368ae537 | 1003 | found = msg; |
daaf74cf PH |
1004 | } else if (mode == SEARCH_NUMBER) { |
1005 | if (*msgtyp == count) | |
1006 | return msg; | |
1007 | } else | |
1008 | return msg; | |
1009 | count++; | |
1010 | } | |
1011 | } | |
1012 | ||
368ae537 | 1013 | return found ?: ERR_PTR(-EAGAIN); |
daaf74cf PH |
1014 | } |
1015 | ||
9b1404c2 | 1016 | static long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg, |
f9dd87f4 | 1017 | long (*msg_handler)(void __user *, struct msg_msg *, size_t)) |
1da177e4 | 1018 | { |
1da177e4 | 1019 | int mode; |
41a0d523 | 1020 | struct msg_queue *msq; |
1e786937 | 1021 | struct ipc_namespace *ns; |
41a0d523 | 1022 | struct msg_msg *msg, *copy = NULL; |
194a6b5b | 1023 | DEFINE_WAKE_Q(wake_q); |
1da177e4 | 1024 | |
88b9e456 PH |
1025 | ns = current->nsproxy->ipc_ns; |
1026 | ||
f9dd87f4 | 1027 | if (msqid < 0 || (long) bufsz < 0) |
1da177e4 | 1028 | return -EINVAL; |
41a0d523 | 1029 | |
4a674f34 | 1030 | if (msgflg & MSG_COPY) { |
4f87dac3 MK |
1031 | if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT)) |
1032 | return -EINVAL; | |
8ac6ed58 | 1033 | copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax)); |
4a674f34 SK |
1034 | if (IS_ERR(copy)) |
1035 | return PTR_ERR(copy); | |
1036 | } | |
5a06a363 | 1037 | mode = convert_mode(&msgtyp, msgflg); |
1da177e4 | 1038 | |
41a0d523 DB |
1039 | rcu_read_lock(); |
1040 | msq = msq_obtain_object_check(ns, msqid); | |
4a674f34 | 1041 | if (IS_ERR(msq)) { |
41a0d523 | 1042 | rcu_read_unlock(); |
85398aa8 | 1043 | free_copy(copy); |
023a5355 | 1044 | return PTR_ERR(msq); |
4a674f34 | 1045 | } |
1da177e4 LT |
1046 | |
1047 | for (;;) { | |
1048 | struct msg_receiver msr_d; | |
1da177e4 LT |
1049 | |
1050 | msg = ERR_PTR(-EACCES); | |
b0e77598 | 1051 | if (ipcperms(ns, &msq->q_perm, S_IRUGO)) |
41a0d523 | 1052 | goto out_unlock1; |
1da177e4 | 1053 | |
41a0d523 | 1054 | ipc_lock_object(&msq->q_perm); |
4271b05a DB |
1055 | |
1056 | /* raced with RMID? */ | |
0f3d2b01 | 1057 | if (!ipc_valid_object(&msq->q_perm)) { |
4271b05a DB |
1058 | msg = ERR_PTR(-EIDRM); |
1059 | goto out_unlock0; | |
1060 | } | |
1061 | ||
daaf74cf | 1062 | msg = find_msg(msq, &msgtyp, mode); |
5a06a363 IM |
1063 | if (!IS_ERR(msg)) { |
1064 | /* | |
1065 | * Found a suitable message. | |
1066 | * Unlink it from the queue. | |
1067 | */ | |
f9dd87f4 | 1068 | if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) { |
1da177e4 | 1069 | msg = ERR_PTR(-E2BIG); |
41a0d523 | 1070 | goto out_unlock0; |
1da177e4 | 1071 | } |
3fcfe786 SK |
1072 | /* |
1073 | * If we are copying, then do not unlink message and do | |
1074 | * not update queue parameters. | |
1075 | */ | |
852028af PH |
1076 | if (msgflg & MSG_COPY) { |
1077 | msg = copy_msg(msg, copy); | |
41a0d523 | 1078 | goto out_unlock0; |
852028af | 1079 | } |
41a0d523 | 1080 | |
1da177e4 LT |
1081 | list_del(&msg->m_list); |
1082 | msq->q_qnum--; | |
1083 | msq->q_rtime = get_seconds(); | |
39a4940e | 1084 | ipc_update_pid(&msq->q_lrpid, task_tgid(current)); |
1da177e4 | 1085 | msq->q_cbytes -= msg->m_ts; |
3ac88a41 KK |
1086 | atomic_sub(msg->m_ts, &ns->msg_bytes); |
1087 | atomic_dec(&ns->msg_hdrs); | |
ed27f912 | 1088 | ss_wakeup(msq, &wake_q, false); |
41a0d523 DB |
1089 | |
1090 | goto out_unlock0; | |
1da177e4 | 1091 | } |
41a0d523 | 1092 | |
1da177e4 LT |
1093 | /* No message waiting. Wait for a message */ |
1094 | if (msgflg & IPC_NOWAIT) { | |
1095 | msg = ERR_PTR(-ENOMSG); | |
41a0d523 | 1096 | goto out_unlock0; |
1da177e4 | 1097 | } |
41a0d523 | 1098 | |
5a06a363 | 1099 | list_add_tail(&msr_d.r_list, &msq->q_receivers); |
1da177e4 LT |
1100 | msr_d.r_tsk = current; |
1101 | msr_d.r_msgtype = msgtyp; | |
1102 | msr_d.r_mode = mode; | |
5a06a363 | 1103 | if (msgflg & MSG_NOERROR) |
1da177e4 | 1104 | msr_d.r_maxsize = INT_MAX; |
5a06a363 | 1105 | else |
f9dd87f4 | 1106 | msr_d.r_maxsize = bufsz; |
1da177e4 | 1107 | msr_d.r_msg = ERR_PTR(-EAGAIN); |
f75a2f35 | 1108 | __set_current_state(TASK_INTERRUPTIBLE); |
1da177e4 | 1109 | |
41a0d523 DB |
1110 | ipc_unlock_object(&msq->q_perm); |
1111 | rcu_read_unlock(); | |
1da177e4 LT |
1112 | schedule(); |
1113 | ||
ee51636c SAS |
1114 | /* |
1115 | * Lockless receive, part 1: | |
1116 | * We don't hold a reference to the queue and getting a | |
1117 | * reference would defeat the idea of a lockless operation, | |
1118 | * thus the code relies on rcu to guarantee the existence of | |
1119 | * msq: | |
1da177e4 LT |
1120 | * Prior to destruction, expunge_all(-EIRDM) changes r_msg. |
1121 | * Thus if r_msg is -EAGAIN, then the queue not yet destroyed. | |
1da177e4 LT |
1122 | */ |
1123 | rcu_read_lock(); | |
1124 | ||
ee51636c SAS |
1125 | /* |
1126 | * Lockless receive, part 2: | |
1127 | * The work in pipelined_send() and expunge_all(): | |
1128 | * - Set pointer to message | |
1129 | * - Queue the receiver task for later wakeup | |
1130 | * - Wake up the process after the lock is dropped. | |
ff35e5ef | 1131 | * |
ee51636c SAS |
1132 | * Should the process wake up before this wakeup (due to a |
1133 | * signal) it will either see the message and continue ... | |
1da177e4 | 1134 | */ |
ee51636c | 1135 | msg = READ_ONCE(msr_d.r_msg); |
41a0d523 DB |
1136 | if (msg != ERR_PTR(-EAGAIN)) |
1137 | goto out_unlock1; | |
1da177e4 | 1138 | |
ee51636c SAS |
1139 | /* |
1140 | * ... or see -EAGAIN, acquire the lock to check the message | |
1141 | * again. | |
1142 | */ | |
41a0d523 | 1143 | ipc_lock_object(&msq->q_perm); |
1da177e4 | 1144 | |
ee51636c | 1145 | msg = msr_d.r_msg; |
5a06a363 | 1146 | if (msg != ERR_PTR(-EAGAIN)) |
41a0d523 | 1147 | goto out_unlock0; |
1da177e4 LT |
1148 | |
1149 | list_del(&msr_d.r_list); | |
1150 | if (signal_pending(current)) { | |
1151 | msg = ERR_PTR(-ERESTARTNOHAND); | |
41a0d523 | 1152 | goto out_unlock0; |
1da177e4 | 1153 | } |
41a0d523 DB |
1154 | |
1155 | ipc_unlock_object(&msq->q_perm); | |
1da177e4 | 1156 | } |
41a0d523 DB |
1157 | |
1158 | out_unlock0: | |
1159 | ipc_unlock_object(&msq->q_perm); | |
e3658538 | 1160 | wake_up_q(&wake_q); |
41a0d523 DB |
1161 | out_unlock1: |
1162 | rcu_read_unlock(); | |
4a674f34 | 1163 | if (IS_ERR(msg)) { |
85398aa8 | 1164 | free_copy(copy); |
5a06a363 | 1165 | return PTR_ERR(msg); |
4a674f34 | 1166 | } |
1da177e4 | 1167 | |
f9dd87f4 | 1168 | bufsz = msg_handler(buf, msg, bufsz); |
1da177e4 | 1169 | free_msg(msg); |
5a06a363 | 1170 | |
f9dd87f4 | 1171 | return bufsz; |
1da177e4 LT |
1172 | } |
1173 | ||
078faac9 DB |
1174 | long ksys_msgrcv(int msqid, struct msgbuf __user *msgp, size_t msgsz, |
1175 | long msgtyp, int msgflg) | |
1176 | { | |
1177 | return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill); | |
1178 | } | |
1179 | ||
e48fbb69 HC |
1180 | SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz, |
1181 | long, msgtyp, int, msgflg) | |
651971cb | 1182 | { |
078faac9 | 1183 | return ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg); |
651971cb | 1184 | } |
1185 | ||
9b1404c2 AV |
1186 | #ifdef CONFIG_COMPAT |
1187 | static long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz) | |
1188 | { | |
1189 | struct compat_msgbuf __user *msgp = dest; | |
1190 | size_t msgsz; | |
1191 | ||
1192 | if (put_user(msg->m_type, &msgp->mtype)) | |
1193 | return -EFAULT; | |
1194 | ||
1195 | msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz; | |
1196 | if (store_msg(msgp->mtext, msg, msgsz)) | |
1197 | return -EFAULT; | |
1198 | return msgsz; | |
1199 | } | |
1200 | ||
078faac9 DB |
1201 | long compat_ksys_msgrcv(int msqid, compat_uptr_t msgp, compat_ssize_t msgsz, |
1202 | compat_long_t msgtyp, int msgflg) | |
9b1404c2 AV |
1203 | { |
1204 | return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp, | |
1205 | msgflg, compat_do_msg_fill); | |
1206 | } | |
078faac9 DB |
1207 | |
1208 | COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp, | |
1209 | compat_ssize_t, msgsz, compat_long_t, msgtyp, | |
1210 | int, msgflg) | |
1211 | { | |
1212 | return compat_ksys_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg); | |
1213 | } | |
9b1404c2 | 1214 | #endif |
3440a6bd | 1215 | |
0cfb6aee | 1216 | int msg_init_ns(struct ipc_namespace *ns) |
3440a6bd DB |
1217 | { |
1218 | ns->msg_ctlmax = MSGMAX; | |
1219 | ns->msg_ctlmnb = MSGMNB; | |
0050ee05 | 1220 | ns->msg_ctlmni = MSGMNI; |
3440a6bd DB |
1221 | |
1222 | atomic_set(&ns->msg_bytes, 0); | |
1223 | atomic_set(&ns->msg_hdrs, 0); | |
0cfb6aee | 1224 | return ipc_init_ids(&ns->ids[IPC_MSG_IDS]); |
3440a6bd DB |
1225 | } |
1226 | ||
1227 | #ifdef CONFIG_IPC_NS | |
1228 | void msg_exit_ns(struct ipc_namespace *ns) | |
1229 | { | |
1230 | free_ipcs(ns, &msg_ids(ns), freeque); | |
1231 | idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr); | |
0cfb6aee | 1232 | rhashtable_destroy(&ns->ids[IPC_MSG_IDS].key_ht); |
3440a6bd DB |
1233 | } |
1234 | #endif | |
1235 | ||
1da177e4 | 1236 | #ifdef CONFIG_PROC_FS |
19b4946c | 1237 | static int sysvipc_msg_proc_show(struct seq_file *s, void *it) |
1da177e4 | 1238 | { |
39a4940e | 1239 | struct pid_namespace *pid_ns = ipc_seq_pid_ns(s); |
1efdb69b | 1240 | struct user_namespace *user_ns = seq_user_ns(s); |
ade9f91b KC |
1241 | struct kern_ipc_perm *ipcp = it; |
1242 | struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm); | |
19b4946c | 1243 | |
7f032d6e | 1244 | seq_printf(s, |
50578ea9 | 1245 | "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10llu %10llu %10llu\n", |
7f032d6e JP |
1246 | msq->q_perm.key, |
1247 | msq->q_perm.id, | |
1248 | msq->q_perm.mode, | |
1249 | msq->q_cbytes, | |
1250 | msq->q_qnum, | |
39a4940e EB |
1251 | pid_nr_ns(msq->q_lspid, pid_ns), |
1252 | pid_nr_ns(msq->q_lrpid, pid_ns), | |
7f032d6e JP |
1253 | from_kuid_munged(user_ns, msq->q_perm.uid), |
1254 | from_kgid_munged(user_ns, msq->q_perm.gid), | |
1255 | from_kuid_munged(user_ns, msq->q_perm.cuid), | |
1256 | from_kgid_munged(user_ns, msq->q_perm.cgid), | |
1257 | msq->q_stime, | |
1258 | msq->q_rtime, | |
1259 | msq->q_ctime); | |
1260 | ||
1261 | return 0; | |
1da177e4 LT |
1262 | } |
1263 | #endif | |
3440a6bd | 1264 | |
0cfb6aee | 1265 | int __init msg_init(void) |
3440a6bd | 1266 | { |
0cfb6aee | 1267 | const int err = msg_init_ns(&init_ipc_ns); |
3440a6bd | 1268 | |
3440a6bd DB |
1269 | ipc_init_proc_interface("sysvipc/msg", |
1270 | " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n", | |
1271 | IPC_MSG_IDS, sysvipc_msg_proc_show); | |
0cfb6aee | 1272 | return err; |
3440a6bd | 1273 | } |