blob: e12307d0c920ccd9e50168ed890c5b6057206a52 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/ipc/msg.c
Ingo Molnar5a06a362006-07-30 03:04:11 -07003 * Copyright (C) 1992 Krishna Balasubramanian
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * Removed all the remaining kerneld mess
6 * Catch the -EFAULT stuff properly
7 * Use GFP_KERNEL for messages as in 1.2
8 * Fixed up the unchecked user space derefs
9 * Copyright (C) 1998 Alan Cox & Andi Kleen
10 *
11 * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
12 *
13 * mostly rewritten, threaded and wake-one semantics added
14 * MSGMAX limit removed, sysctl's added
Christian Kujau624dffc2006-01-15 02:43:54 +010015 * (c) 1999 Manfred Spraul <manfred@colorfullife.com>
Steve Grubb073115d2006-04-02 17:07:33 -040016 *
17 * support for audit of ipc object properties and permission changes
18 * Dustin Kirkland <dustin.kirkland@us.ibm.com>
Kirill Korotaev1e786932006-10-02 02:18:21 -070019 *
20 * namespaces support
21 * OpenVZ, SWsoft Inc.
22 * Pavel Emelianov <xemul@openvz.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 */
24
Randy.Dunlapc59ede72006-01-11 12:17:46 -080025#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/msg.h>
27#include <linux/spinlock.h>
28#include <linux/init.h>
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070029#include <linux/mm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/proc_fs.h>
31#include <linux/list.h>
32#include <linux/security.h>
33#include <linux/sched.h>
34#include <linux/syscalls.h>
35#include <linux/audit.h>
Mike Waychison19b49462005-09-06 15:17:10 -070036#include <linux/seq_file.h>
Nadia Derbey3e148c72007-10-18 23:40:54 -070037#include <linux/rwsem.h>
Kirill Korotaev1e786932006-10-02 02:18:21 -070038#include <linux/nsproxy.h>
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080039#include <linux/ipc_namespace.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080040
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <asm/current.h>
Paul McQuade7153e402014-06-06 14:37:37 -070042#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#include "util.h"
44
Davidlohr Bueso4bb66572014-06-06 14:37:46 -070045/* one msg_receiver structure for each sleeping receiver */
Linus Torvalds1da177e2005-04-16 15:20:36 -070046struct msg_receiver {
Ingo Molnar5a06a362006-07-30 03:04:11 -070047 struct list_head r_list;
48 struct task_struct *r_tsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049
Ingo Molnar5a06a362006-07-30 03:04:11 -070050 int r_mode;
51 long r_msgtype;
52 long r_maxsize;
Linus Torvalds1da177e2005-04-16 15:20:36 -070053
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -070054 struct msg_msg *r_msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055};
56
57/* one msg_sender for each sleeping sender */
58struct msg_sender {
Ingo Molnar5a06a362006-07-30 03:04:11 -070059 struct list_head list;
60 struct task_struct *tsk;
Davidlohr Buesoed27f912016-10-11 13:55:02 -070061 size_t msgsz;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062};
63
64#define SEARCH_ANY 1
65#define SEARCH_EQUAL 2
66#define SEARCH_NOTEQUAL 3
67#define SEARCH_LESSEQUAL 4
Peter Hurley8ac6ed52013-04-30 19:14:54 -070068#define SEARCH_NUMBER 5
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080070#define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS])
Kirill Korotaev1e786932006-10-02 02:18:21 -070071
Davidlohr Buesoa5001a02013-07-08 16:01:15 -070072static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id)
73{
Davidlohr Bueso55b7ae52015-06-30 14:58:42 -070074 struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&msg_ids(ns), id);
Davidlohr Buesoa5001a02013-07-08 16:01:15 -070075
76 if (IS_ERR(ipcp))
77 return ERR_CAST(ipcp);
78
79 return container_of(ipcp, struct msg_queue, q_perm);
80}
81
82static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns,
83 int id)
84{
85 struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id);
86
87 if (IS_ERR(ipcp))
88 return ERR_CAST(ipcp);
89
90 return container_of(ipcp, struct msg_queue, q_perm);
91}
92
Nadia Derbey7ca7e562007-10-18 23:40:48 -070093static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
94{
95 ipc_rmid(&msg_ids(ns), &s->q_perm);
96}
97
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -070098static void msg_rcu_free(struct rcu_head *head)
99{
100 struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
101 struct msg_queue *msq = ipc_rcu_to_struct(p);
102
103 security_msg_queue_free(msq);
104 ipc_rcu_free(head);
105}
106
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700107/**
108 * newque - Create a new msg queue
109 * @ns: namespace
110 * @params: ptr to the structure that contains the key and msgflg
111 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700112 * Called with msg_ids.rwsem held (writer)
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700113 */
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700114static int newque(struct ipc_namespace *ns, struct ipc_params *params)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 struct msg_queue *msq;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700117 int id, retval;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700118 key_t key = params->key;
119 int msgflg = params->flg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Ingo Molnar5a06a362006-07-30 03:04:11 -0700121 msq = ipc_rcu_alloc(sizeof(*msq));
122 if (!msq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 return -ENOMEM;
124
Ingo Molnar5a06a362006-07-30 03:04:11 -0700125 msq->q_perm.mode = msgflg & S_IRWXUGO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 msq->q_perm.key = key;
127
128 msq->q_perm.security = NULL;
129 retval = security_msg_queue_alloc(msq);
130 if (retval) {
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700131 ipc_rcu_putref(msq, ipc_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 return retval;
133 }
134
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 msq->q_stime = msq->q_rtime = 0;
136 msq->q_ctime = get_seconds();
137 msq->q_cbytes = msq->q_qnum = 0;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700138 msq->q_qbytes = ns->msg_ctlmnb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 msq->q_lspid = msq->q_lrpid = 0;
140 INIT_LIST_HEAD(&msq->q_messages);
141 INIT_LIST_HEAD(&msq->q_receivers);
142 INIT_LIST_HEAD(&msq->q_senders);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700143
Linus Torvaldsb9a53222015-09-30 12:48:40 -0400144 /* ipc_addid() locks msq upon success. */
145 id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
146 if (id < 0) {
147 ipc_rcu_putref(msq, msg_rcu_free);
148 return id;
149 }
150
Davidlohr Buesocf9d5d72013-07-08 16:01:11 -0700151 ipc_unlock_object(&msq->q_perm);
Davidlohr Buesodbfcd912013-07-08 16:01:09 -0700152 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700154 return msq->q_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700157static inline bool msg_fits_inqueue(struct msg_queue *msq, size_t msgsz)
158{
159 return msgsz + msq->q_cbytes <= msq->q_qbytes &&
160 1 + msq->q_qnum <= msq->q_qbytes;
161}
162
163static inline void ss_add(struct msg_queue *msq,
164 struct msg_sender *mss, size_t msgsz)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165{
Ingo Molnar5a06a362006-07-30 03:04:11 -0700166 mss->tsk = current;
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700167 mss->msgsz = msgsz;
Davidlohr Buesof75a2f32014-06-06 14:37:44 -0700168 __set_current_state(TASK_INTERRUPTIBLE);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700169 list_add_tail(&mss->list, &msq->q_senders);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170}
171
Ingo Molnar5a06a362006-07-30 03:04:11 -0700172static inline void ss_del(struct msg_sender *mss)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173{
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700174 if (mss->list.next)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 list_del(&mss->list);
176}
177
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700178static void ss_wakeup(struct msg_queue *msq,
Davidlohr Buesod0d6a2a2016-10-11 13:54:59 -0700179 struct wake_q_head *wake_q, bool kill)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700181 struct msg_sender *mss, *t;
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700182 struct task_struct *stop_tsk = NULL;
183 struct list_head *h = &msq->q_senders;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700185 list_for_each_entry_safe(mss, t, h, list) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700186 if (kill)
187 mss->list.next = NULL;
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700188
189 /*
190 * Stop at the first task we don't wakeup,
191 * we've already iterated the original
192 * sender queue.
193 */
194 else if (stop_tsk == mss->tsk)
195 break;
196 /*
197 * We are not in an EIDRM scenario here, therefore
198 * verify that we really need to wakeup the task.
199 * To maintain current semantics and wakeup order,
200 * move the sender to the tail on behalf of the
201 * blocked task.
202 */
203 else if (!msg_fits_inqueue(msq, mss->msgsz)) {
204 if (!stop_tsk)
205 stop_tsk = mss->tsk;
206
207 list_move_tail(&mss->list, &msq->q_senders);
208 continue;
209 }
210
Davidlohr Buesoe3658532016-10-11 13:54:56 -0700211 wake_q_add(wake_q, mss->tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 }
213}
214
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700215static void expunge_all(struct msg_queue *msq, int res,
216 struct wake_q_head *wake_q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700218 struct msg_receiver *msr, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700220 list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700221 wake_q_add(wake_q, msr->r_tsk);
222 WRITE_ONCE(msr->r_msg, ERR_PTR(res));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 }
224}
Ingo Molnar5a06a362006-07-30 03:04:11 -0700225
226/*
227 * freeque() wakes up waiters on the sender and receiver waiting queue,
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700228 * removes the message queue from message queue ID IDR, and cleans up all the
229 * messages associated with this queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700231 * msg_ids.rwsem (writer) and the spinlock for this message queue are held
232 * before freeque() is called. msg_ids.rwsem remains locked on exit.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 */
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800234static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700236 struct msg_msg *msg, *t;
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800237 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700238 WAKE_Q(wake_q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700240 expunge_all(msq, -EIDRM, &wake_q);
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700241 ss_wakeup(msq, &wake_q, true);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700242 msg_rmid(ns, msq);
Davidlohr Bueso47187872013-09-11 14:26:25 -0700243 ipc_unlock_object(&msq->q_perm);
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700244 wake_up_q(&wake_q);
Davidlohr Bueso47187872013-09-11 14:26:25 -0700245 rcu_read_unlock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700246
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700247 list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700248 atomic_dec(&ns->msg_hdrs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 free_msg(msg);
250 }
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700251 atomic_sub(msq->q_cbytes, &ns->msg_bytes);
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700252 ipc_rcu_putref(msq, msg_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253}
254
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700255/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700256 * Called with msg_ids.rwsem and ipcp locked.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700257 */
Nadia Derbey03f02c72007-10-18 23:40:51 -0700258static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700259{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700260 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
261
262 return security_msg_queue_associate(msq, msgflg);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700263}
264
Heiko Carstense48fbb62009-01-14 14:14:26 +0100265SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266{
Kirill Korotaev1e786932006-10-02 02:18:21 -0700267 struct ipc_namespace *ns;
Mathias Krauseeb66ec42014-06-06 14:37:36 -0700268 static const struct ipc_ops msg_ops = {
269 .getnew = newque,
270 .associate = msg_security,
271 };
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700272 struct ipc_params msg_params;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700273
274 ns = current->nsproxy->ipc_ns;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700275
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700276 msg_params.key = key;
277 msg_params.flg = msgflg;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700278
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700279 return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280}
281
Ingo Molnar5a06a362006-07-30 03:04:11 -0700282static inline unsigned long
283copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284{
Manfred Spraul239521f2014-01-27 17:07:04 -0800285 switch (version) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 case IPC_64:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700287 return copy_to_user(buf, in, sizeof(*in));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 case IPC_OLD:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700289 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 struct msqid_ds out;
291
Ingo Molnar5a06a362006-07-30 03:04:11 -0700292 memset(&out, 0, sizeof(out));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
294 ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
295
296 out.msg_stime = in->msg_stime;
297 out.msg_rtime = in->msg_rtime;
298 out.msg_ctime = in->msg_ctime;
299
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700300 if (in->msg_cbytes > USHRT_MAX)
301 out.msg_cbytes = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 else
303 out.msg_cbytes = in->msg_cbytes;
304 out.msg_lcbytes = in->msg_cbytes;
305
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700306 if (in->msg_qnum > USHRT_MAX)
307 out.msg_qnum = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 else
309 out.msg_qnum = in->msg_qnum;
310
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700311 if (in->msg_qbytes > USHRT_MAX)
312 out.msg_qbytes = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 else
314 out.msg_qbytes = in->msg_qbytes;
315 out.msg_lqbytes = in->msg_qbytes;
316
317 out.msg_lspid = in->msg_lspid;
318 out.msg_lrpid = in->msg_lrpid;
319
Ingo Molnar5a06a362006-07-30 03:04:11 -0700320 return copy_to_user(buf, &out, sizeof(out));
321 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 default:
323 return -EINVAL;
324 }
325}
326
Ingo Molnar5a06a362006-07-30 03:04:11 -0700327static inline unsigned long
Pierre Peiffer016d7132008-04-29 01:00:50 -0700328copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329{
Manfred Spraul239521f2014-01-27 17:07:04 -0800330 switch (version) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 case IPC_64:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700332 if (copy_from_user(out, buf, sizeof(*out)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 case IPC_OLD:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700336 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 struct msqid_ds tbuf_old;
338
Ingo Molnar5a06a362006-07-30 03:04:11 -0700339 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 return -EFAULT;
341
Manfred Spraul239521f2014-01-27 17:07:04 -0800342 out->msg_perm.uid = tbuf_old.msg_perm.uid;
343 out->msg_perm.gid = tbuf_old.msg_perm.gid;
344 out->msg_perm.mode = tbuf_old.msg_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
Ingo Molnar5a06a362006-07-30 03:04:11 -0700346 if (tbuf_old.msg_qbytes == 0)
Pierre Peiffer016d7132008-04-29 01:00:50 -0700347 out->msg_qbytes = tbuf_old.msg_lqbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 else
Pierre Peiffer016d7132008-04-29 01:00:50 -0700349 out->msg_qbytes = tbuf_old.msg_qbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
351 return 0;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700352 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 default:
354 return -EINVAL;
355 }
356}
357
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700358/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700359 * This function handles some msgctl commands which require the rwsem
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700360 * to be held in write mode.
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700361 * NOTE: no locks must be held, the rwsem is taken inside this function.
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700362 */
363static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
364 struct msqid_ds __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 struct kern_ipc_perm *ipcp;
Felipe Contrerasf1970c42009-10-19 01:54:29 +0300367 struct msqid64_ds uninitialized_var(msqid64);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700368 struct msg_queue *msq;
369 int err;
370
371 if (cmd == IPC_SET) {
Pierre Peiffer016d7132008-04-29 01:00:50 -0700372 if (copy_msqid_from_user(&msqid64, buf, version))
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700373 return -EFAULT;
374 }
375
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700376 down_write(&msg_ids(ns).rwsem);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700377 rcu_read_lock();
378
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700379 ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd,
380 &msqid64.msg_perm, msqid64.msg_qbytes);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700381 if (IS_ERR(ipcp)) {
382 err = PTR_ERR(ipcp);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700383 goto out_unlock1;
384 }
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700385
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700386 msq = container_of(ipcp, struct msg_queue, q_perm);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700387
388 err = security_msg_queue_msgctl(msq, cmd);
389 if (err)
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700390 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700391
392 switch (cmd) {
393 case IPC_RMID:
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700394 ipc_lock_object(&msq->q_perm);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700395 /* freeque unlocks the ipc object and rcu */
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700396 freeque(ns, ipcp);
397 goto out_up;
398 case IPC_SET:
Davidlohr Buesoe3658532016-10-11 13:54:56 -0700399 {
400 WAKE_Q(wake_q);
401
Pierre Peiffer016d7132008-04-29 01:00:50 -0700402 if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700403 !capable(CAP_SYS_RESOURCE)) {
404 err = -EPERM;
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700405 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700406 }
407
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700408 ipc_lock_object(&msq->q_perm);
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800409 err = ipc_update_perm(&msqid64.msg_perm, ipcp);
410 if (err)
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700411 goto out_unlock0;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800412
Pierre Peiffer016d7132008-04-29 01:00:50 -0700413 msq->q_qbytes = msqid64.msg_qbytes;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700414
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700415 msq->q_ctime = get_seconds();
Davidlohr Buesoe3658532016-10-11 13:54:56 -0700416 /*
417 * Sleeping receivers might be excluded by
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700418 * stricter permissions.
419 */
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700420 expunge_all(msq, -EAGAIN, &wake_q);
Davidlohr Buesoe3658532016-10-11 13:54:56 -0700421 /*
422 * Sleeping senders might be able to send
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700423 * due to a larger queue size.
424 */
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700425 ss_wakeup(msq, &wake_q, false);
Davidlohr Buesoe3658532016-10-11 13:54:56 -0700426 ipc_unlock_object(&msq->q_perm);
427 wake_up_q(&wake_q);
428
429 goto out_unlock1;
430 }
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700431 default:
432 err = -EINVAL;
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700433 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700434 }
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700435
436out_unlock0:
437 ipc_unlock_object(&msq->q_perm);
438out_unlock1:
439 rcu_read_unlock();
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700440out_up:
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700441 up_write(&msg_ids(ns).rwsem);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700442 return err;
443}
444
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700445static int msgctl_nolock(struct ipc_namespace *ns, int msqid,
446 int cmd, int version, void __user *buf)
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700447{
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700448 int err;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700449 struct msg_queue *msq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450
451 switch (cmd) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700452 case IPC_INFO:
453 case MSG_INFO:
454 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 struct msginfo msginfo;
456 int max_id;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700457
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 if (!buf)
459 return -EFAULT;
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700460
Ingo Molnar5a06a362006-07-30 03:04:11 -0700461 /*
462 * We must not return kernel stack data.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 * due to padding, it's not enough
464 * to set all member fields.
465 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 err = security_msg_queue_msgctl(NULL, cmd);
467 if (err)
468 return err;
469
Ingo Molnar5a06a362006-07-30 03:04:11 -0700470 memset(&msginfo, 0, sizeof(msginfo));
Kirill Korotaev1e786932006-10-02 02:18:21 -0700471 msginfo.msgmni = ns->msg_ctlmni;
472 msginfo.msgmax = ns->msg_ctlmax;
473 msginfo.msgmnb = ns->msg_ctlmnb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 msginfo.msgssz = MSGSSZ;
475 msginfo.msgseg = MSGSEG;
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700476 down_read(&msg_ids(ns).rwsem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 if (cmd == MSG_INFO) {
Kirill Korotaev1e786932006-10-02 02:18:21 -0700478 msginfo.msgpool = msg_ids(ns).in_use;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700479 msginfo.msgmap = atomic_read(&ns->msg_hdrs);
480 msginfo.msgtql = atomic_read(&ns->msg_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 } else {
482 msginfo.msgmap = MSGMAP;
483 msginfo.msgpool = MSGPOOL;
484 msginfo.msgtql = MSGTQL;
485 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700486 max_id = ipc_get_maxid(&msg_ids(ns));
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700487 up_read(&msg_ids(ns).rwsem);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700488 if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 return -EFAULT;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700490 return (max_id < 0) ? 0 : max_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 }
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700492
493 case MSG_STAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 case IPC_STAT:
495 {
496 struct msqid64_ds tbuf;
497 int success_return;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700498
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 if (!buf)
500 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700502 memset(&tbuf, 0, sizeof(tbuf));
503
504 rcu_read_lock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700505 if (cmd == MSG_STAT) {
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700506 msq = msq_obtain_object(ns, msqid);
507 if (IS_ERR(msq)) {
508 err = PTR_ERR(msq);
509 goto out_unlock;
510 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700511 success_return = msq->q_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 } else {
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700513 msq = msq_obtain_object_check(ns, msqid);
514 if (IS_ERR(msq)) {
515 err = PTR_ERR(msq);
516 goto out_unlock;
517 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 success_return = 0;
519 }
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700520
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700522 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 goto out_unlock;
524
525 err = security_msg_queue_msgctl(msq, cmd);
526 if (err)
527 goto out_unlock;
528
529 kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
530 tbuf.msg_stime = msq->q_stime;
531 tbuf.msg_rtime = msq->q_rtime;
532 tbuf.msg_ctime = msq->q_ctime;
533 tbuf.msg_cbytes = msq->q_cbytes;
534 tbuf.msg_qnum = msq->q_qnum;
535 tbuf.msg_qbytes = msq->q_qbytes;
536 tbuf.msg_lspid = msq->q_lspid;
537 tbuf.msg_lrpid = msq->q_lrpid;
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700538 rcu_read_unlock();
539
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 if (copy_msqid_to_user(buf, &tbuf, version))
541 return -EFAULT;
542 return success_return;
543 }
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700544
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 default:
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700546 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 }
548
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700549 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550out_unlock:
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700551 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 return err;
553}
554
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700555SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
556{
557 int version;
558 struct ipc_namespace *ns;
559
560 if (msqid < 0 || cmd < 0)
561 return -EINVAL;
562
563 version = ipc_parse_version(&cmd);
564 ns = current->nsproxy->ipc_ns;
565
566 switch (cmd) {
567 case IPC_INFO:
568 case MSG_INFO:
569 case MSG_STAT: /* msqid is an index rather than a msg queue id */
570 case IPC_STAT:
571 return msgctl_nolock(ns, msqid, cmd, version, buf);
572 case IPC_SET:
573 case IPC_RMID:
574 return msgctl_down(ns, msqid, cmd, buf, version);
575 default:
576 return -EINVAL;
577 }
578}
579
Ingo Molnar5a06a362006-07-30 03:04:11 -0700580static int testmsg(struct msg_msg *msg, long type, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581{
Paul McQuade46c0a8c2014-06-06 14:37:37 -0700582 switch (mode) {
583 case SEARCH_ANY:
584 case SEARCH_NUMBER:
585 return 1;
586 case SEARCH_LESSEQUAL:
587 if (msg->m_type <= type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 return 1;
Paul McQuade46c0a8c2014-06-06 14:37:37 -0700589 break;
590 case SEARCH_EQUAL:
591 if (msg->m_type == type)
592 return 1;
593 break;
594 case SEARCH_NOTEQUAL:
595 if (msg->m_type != type)
596 return 1;
597 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 }
599 return 0;
600}
601
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700602static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg,
603 struct wake_q_head *wake_q)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700605 struct msg_receiver *msr, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700607 list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700608 if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
609 !security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
610 msr->r_msgtype, msr->r_mode)) {
611
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 list_del(&msr->r_list);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700613 if (msr->r_maxsize < msg->m_ts) {
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700614 wake_q_add(wake_q, msr->r_tsk);
615 WRITE_ONCE(msr->r_msg, ERR_PTR(-E2BIG));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 } else {
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700617 msq->q_lrpid = task_pid_vnr(msr->r_tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 msq->q_rtime = get_seconds();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700619
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700620 wake_q_add(wake_q, msr->r_tsk);
621 WRITE_ONCE(msr->r_msg, msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 return 1;
623 }
624 }
625 }
Davidlohr Buesoffa571d2014-01-27 17:07:10 -0800626
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 return 0;
628}
629
suzuki651971c2006-12-06 20:37:48 -0800630long do_msgsnd(int msqid, long mtype, void __user *mtext,
631 size_t msgsz, int msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632{
633 struct msg_queue *msq;
634 struct msg_msg *msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 int err;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700636 struct ipc_namespace *ns;
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700637 WAKE_Q(wake_q);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700638
Kirill Korotaev1e786932006-10-02 02:18:21 -0700639 ns = current->nsproxy->ipc_ns;
640
641 if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 if (mtype < 1)
644 return -EINVAL;
645
suzuki651971c2006-12-06 20:37:48 -0800646 msg = load_msg(mtext, msgsz);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700647 if (IS_ERR(msg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 return PTR_ERR(msg);
649
650 msg->m_type = mtype;
651 msg->m_ts = msgsz;
652
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700653 rcu_read_lock();
654 msq = msq_obtain_object_check(ns, msqid);
Nadia Derbey023a5352007-10-18 23:40:51 -0700655 if (IS_ERR(msq)) {
656 err = PTR_ERR(msq);
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700657 goto out_unlock1;
Nadia Derbey023a5352007-10-18 23:40:51 -0700658 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659
Manfred Spraulbebcb922013-09-03 16:00:08 +0200660 ipc_lock_object(&msq->q_perm);
661
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 for (;;) {
663 struct msg_sender s;
664
Ingo Molnar5a06a362006-07-30 03:04:11 -0700665 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700666 if (ipcperms(ns, &msq->q_perm, S_IWUGO))
Manfred Spraulbebcb922013-09-03 16:00:08 +0200667 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
Davidlohr Bueso4271b052013-09-30 13:45:26 -0700669 /* raced with RMID? */
Rafael Aquini0f3d2b02014-01-27 17:07:01 -0800670 if (!ipc_valid_object(&msq->q_perm)) {
Davidlohr Bueso4271b052013-09-30 13:45:26 -0700671 err = -EIDRM;
672 goto out_unlock0;
673 }
674
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 err = security_msg_queue_msgsnd(msq, msg, msgflg);
676 if (err)
Manfred Spraulbebcb922013-09-03 16:00:08 +0200677 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700679 if (msg_fits_inqueue(msq, msgsz))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681
682 /* queue full, wait: */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700683 if (msgflg & IPC_NOWAIT) {
684 err = -EAGAIN;
Manfred Spraulbebcb922013-09-03 16:00:08 +0200685 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700687
Davidlohr Buesoffa571d2014-01-27 17:07:10 -0800688 /* enqueue the sender and prepare to block */
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700689 ss_add(msq, &s, msgsz);
Rik van Riel6062a8d2013-04-30 19:15:44 -0700690
691 if (!ipc_rcu_getref(msq)) {
692 err = -EIDRM;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700693 goto out_unlock0;
Rik van Riel6062a8d2013-04-30 19:15:44 -0700694 }
695
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700696 ipc_unlock_object(&msq->q_perm);
697 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 schedule();
699
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700700 rcu_read_lock();
701 ipc_lock_object(&msq->q_perm);
702
Fabian Frederick9b24fef2016-08-02 14:03:07 -0700703 ipc_rcu_putref(msq, msg_rcu_free);
Rafael Aquini0f3d2b02014-01-27 17:07:01 -0800704 /* raced with RMID? */
705 if (!ipc_valid_object(&msq->q_perm)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 err = -EIDRM;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700707 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 }
709 ss_del(&s);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700710
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 if (signal_pending(current)) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700712 err = -ERESTARTNOHAND;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700713 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700715
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 }
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700717
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700718 msq->q_lspid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 msq->q_stime = get_seconds();
720
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700721 if (!pipelined_send(msq, msg, &wake_q)) {
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300722 /* no one is waiting for this message, enqueue it */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700723 list_add_tail(&msg->m_list, &msq->q_messages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 msq->q_cbytes += msgsz;
725 msq->q_qnum++;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700726 atomic_add(msgsz, &ns->msg_bytes);
727 atomic_inc(&ns->msg_hdrs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700729
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 err = 0;
731 msg = NULL;
732
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700733out_unlock0:
734 ipc_unlock_object(&msq->q_perm);
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700735 wake_up_q(&wake_q);
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700736out_unlock1:
737 rcu_read_unlock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700738 if (msg != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 free_msg(msg);
740 return err;
741}
742
Heiko Carstense48fbb62009-01-14 14:14:26 +0100743SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
744 int, msgflg)
suzuki651971c2006-12-06 20:37:48 -0800745{
746 long mtype;
747
748 if (get_user(mtype, &msgp->mtype))
749 return -EFAULT;
750 return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
751}
752
Ingo Molnar5a06a362006-07-30 03:04:11 -0700753static inline int convert_mode(long *msgtyp, int msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754{
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700755 if (msgflg & MSG_COPY)
756 return SEARCH_NUMBER;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700757 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 * find message of correct type.
759 * msgtyp = 0 => get first.
760 * msgtyp > 0 => get first message of matching type.
Ingo Molnar5a06a362006-07-30 03:04:11 -0700761 * msgtyp < 0 => get message with least type must be < abs(msgtype).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700763 if (*msgtyp == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 return SEARCH_ANY;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700765 if (*msgtyp < 0) {
766 *msgtyp = -*msgtyp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 return SEARCH_LESSEQUAL;
768 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700769 if (msgflg & MSG_EXCEPT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 return SEARCH_NOTEQUAL;
771 return SEARCH_EQUAL;
772}
773
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800774static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
775{
776 struct msgbuf __user *msgp = dest;
777 size_t msgsz;
778
779 if (put_user(msg->m_type, &msgp->mtype))
780 return -EFAULT;
781
782 msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
783 if (store_msg(msgp->mtext, msg, msgsz))
784 return -EFAULT;
785 return msgsz;
786}
787
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800788#ifdef CONFIG_CHECKPOINT_RESTORE
Stanislav Kinsbursky3fcfe782013-01-04 15:35:03 -0800789/*
790 * This function creates new kernel message structure, large enough to store
791 * bufsz message bytes.
792 */
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700793static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800794{
795 struct msg_msg *copy;
796
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800797 /*
798 * Create dummy message to copy real message to.
799 */
800 copy = load_msg(buf, bufsz);
801 if (!IS_ERR(copy))
802 copy->m_ts = bufsz;
803 return copy;
804}
805
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800806static inline void free_copy(struct msg_msg *copy)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800807{
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800808 if (copy)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800809 free_msg(copy);
810}
811#else
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700812static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
Stanislav Kinsburskyb30efe22013-01-04 15:35:00 -0800813{
814 return ERR_PTR(-ENOSYS);
815}
816
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800817static inline void free_copy(struct msg_msg *copy)
818{
819}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800820#endif
821
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700822static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
823{
Svenning Sørensen368ae532013-08-28 16:35:17 -0700824 struct msg_msg *msg, *found = NULL;
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700825 long count = 0;
826
827 list_for_each_entry(msg, &msq->q_messages, m_list) {
828 if (testmsg(msg, *msgtyp, mode) &&
829 !security_msg_queue_msgrcv(msq, msg, current,
830 *msgtyp, mode)) {
831 if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
832 *msgtyp = msg->m_type - 1;
Svenning Sørensen368ae532013-08-28 16:35:17 -0700833 found = msg;
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700834 } else if (mode == SEARCH_NUMBER) {
835 if (*msgtyp == count)
836 return msg;
837 } else
838 return msg;
839 count++;
840 }
841 }
842
Svenning Sørensen368ae532013-08-28 16:35:17 -0700843 return found ?: ERR_PTR(-EAGAIN);
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700844}
845
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700846long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800847 long (*msg_handler)(void __user *, struct msg_msg *, size_t))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 int mode;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700850 struct msg_queue *msq;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700851 struct ipc_namespace *ns;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700852 struct msg_msg *msg, *copy = NULL;
Davidlohr Buesoe3658532016-10-11 13:54:56 -0700853 WAKE_Q(wake_q);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854
Peter Hurley88b9e452013-03-08 12:43:27 -0800855 ns = current->nsproxy->ipc_ns;
856
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800857 if (msqid < 0 || (long) bufsz < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 return -EINVAL;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700859
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800860 if (msgflg & MSG_COPY) {
Michael Kerrisk4f87dac2014-03-10 14:46:07 +0100861 if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT))
862 return -EINVAL;
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700863 copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800864 if (IS_ERR(copy))
865 return PTR_ERR(copy);
866 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700867 mode = convert_mode(&msgtyp, msgflg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700869 rcu_read_lock();
870 msq = msq_obtain_object_check(ns, msqid);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800871 if (IS_ERR(msq)) {
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700872 rcu_read_unlock();
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800873 free_copy(copy);
Nadia Derbey023a5352007-10-18 23:40:51 -0700874 return PTR_ERR(msq);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800875 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876
877 for (;;) {
878 struct msg_receiver msr_d;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
880 msg = ERR_PTR(-EACCES);
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700881 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700882 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700884 ipc_lock_object(&msq->q_perm);
Davidlohr Bueso4271b052013-09-30 13:45:26 -0700885
886 /* raced with RMID? */
Rafael Aquini0f3d2b02014-01-27 17:07:01 -0800887 if (!ipc_valid_object(&msq->q_perm)) {
Davidlohr Bueso4271b052013-09-30 13:45:26 -0700888 msg = ERR_PTR(-EIDRM);
889 goto out_unlock0;
890 }
891
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700892 msg = find_msg(msq, &msgtyp, mode);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700893 if (!IS_ERR(msg)) {
894 /*
895 * Found a suitable message.
896 * Unlink it from the queue.
897 */
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800898 if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 msg = ERR_PTR(-E2BIG);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700900 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901 }
Stanislav Kinsbursky3fcfe782013-01-04 15:35:03 -0800902 /*
903 * If we are copying, then do not unlink message and do
904 * not update queue parameters.
905 */
Peter Hurley852028a2013-04-30 19:14:48 -0700906 if (msgflg & MSG_COPY) {
907 msg = copy_msg(msg, copy);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700908 goto out_unlock0;
Peter Hurley852028a2013-04-30 19:14:48 -0700909 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700910
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 list_del(&msg->m_list);
912 msq->q_qnum--;
913 msq->q_rtime = get_seconds();
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700914 msq->q_lrpid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 msq->q_cbytes -= msg->m_ts;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700916 atomic_sub(msg->m_ts, &ns->msg_bytes);
917 atomic_dec(&ns->msg_hdrs);
Davidlohr Buesoed27f912016-10-11 13:55:02 -0700918 ss_wakeup(msq, &wake_q, false);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700919
920 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700922
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 /* No message waiting. Wait for a message */
924 if (msgflg & IPC_NOWAIT) {
925 msg = ERR_PTR(-ENOMSG);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700926 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700928
Ingo Molnar5a06a362006-07-30 03:04:11 -0700929 list_add_tail(&msr_d.r_list, &msq->q_receivers);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 msr_d.r_tsk = current;
931 msr_d.r_msgtype = msgtyp;
932 msr_d.r_mode = mode;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700933 if (msgflg & MSG_NOERROR)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 msr_d.r_maxsize = INT_MAX;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700935 else
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800936 msr_d.r_maxsize = bufsz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 msr_d.r_msg = ERR_PTR(-EAGAIN);
Davidlohr Buesof75a2f32014-06-06 14:37:44 -0700938 __set_current_state(TASK_INTERRUPTIBLE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700940 ipc_unlock_object(&msq->q_perm);
941 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942 schedule();
943
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700944 /*
945 * Lockless receive, part 1:
946 * We don't hold a reference to the queue and getting a
947 * reference would defeat the idea of a lockless operation,
948 * thus the code relies on rcu to guarantee the existence of
949 * msq:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
951 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952 */
953 rcu_read_lock();
954
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700955 /*
956 * Lockless receive, part 2:
957 * The work in pipelined_send() and expunge_all():
958 * - Set pointer to message
959 * - Queue the receiver task for later wakeup
960 * - Wake up the process after the lock is dropped.
Davidlohr Buesoff35e5e2015-06-30 14:58:39 -0700961 *
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700962 * Should the process wake up before this wakeup (due to a
963 * signal) it will either see the message and continue ...
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 */
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700965 msg = READ_ONCE(msr_d.r_msg);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700966 if (msg != ERR_PTR(-EAGAIN))
967 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700969 /*
970 * ... or see -EAGAIN, acquire the lock to check the message
971 * again.
972 */
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700973 ipc_lock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974
Sebastian Andrzej Siewioree516362016-10-11 13:54:53 -0700975 msg = msr_d.r_msg;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700976 if (msg != ERR_PTR(-EAGAIN))
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700977 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978
979 list_del(&msr_d.r_list);
980 if (signal_pending(current)) {
981 msg = ERR_PTR(-ERESTARTNOHAND);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700982 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700984
985 ipc_unlock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700987
988out_unlock0:
989 ipc_unlock_object(&msq->q_perm);
Davidlohr Buesoe3658532016-10-11 13:54:56 -0700990 wake_up_q(&wake_q);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700991out_unlock1:
992 rcu_read_unlock();
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800993 if (IS_ERR(msg)) {
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800994 free_copy(copy);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700995 return PTR_ERR(msg);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800996 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800998 bufsz = msg_handler(buf, msg, bufsz);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999 free_msg(msg);
Ingo Molnar5a06a362006-07-30 03:04:11 -07001000
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001001 return bufsz;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002}
1003
Heiko Carstense48fbb62009-01-14 14:14:26 +01001004SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
1005 long, msgtyp, int, msgflg)
suzuki651971c2006-12-06 20:37:48 -08001006{
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001007 return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
suzuki651971c2006-12-06 20:37:48 -08001008}
1009
Davidlohr Bueso3440a6b2014-06-06 14:37:45 -07001010
1011void msg_init_ns(struct ipc_namespace *ns)
1012{
1013 ns->msg_ctlmax = MSGMAX;
1014 ns->msg_ctlmnb = MSGMNB;
Manfred Spraul0050ee02014-12-12 16:58:17 -08001015 ns->msg_ctlmni = MSGMNI;
Davidlohr Bueso3440a6b2014-06-06 14:37:45 -07001016
1017 atomic_set(&ns->msg_bytes, 0);
1018 atomic_set(&ns->msg_hdrs, 0);
1019 ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
1020}
1021
1022#ifdef CONFIG_IPC_NS
1023void msg_exit_ns(struct ipc_namespace *ns)
1024{
1025 free_ipcs(ns, &msg_ids(ns), freeque);
1026 idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
1027}
1028#endif
1029
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -07001031static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032{
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001033 struct user_namespace *user_ns = seq_user_ns(s);
Mike Waychison19b49462005-09-06 15:17:10 -07001034 struct msg_queue *msq = it;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035
Joe Perches7f032d62015-04-15 16:17:54 -07001036 seq_printf(s,
1037 "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
1038 msq->q_perm.key,
1039 msq->q_perm.id,
1040 msq->q_perm.mode,
1041 msq->q_cbytes,
1042 msq->q_qnum,
1043 msq->q_lspid,
1044 msq->q_lrpid,
1045 from_kuid_munged(user_ns, msq->q_perm.uid),
1046 from_kgid_munged(user_ns, msq->q_perm.gid),
1047 from_kuid_munged(user_ns, msq->q_perm.cuid),
1048 from_kgid_munged(user_ns, msq->q_perm.cgid),
1049 msq->q_stime,
1050 msq->q_rtime,
1051 msq->q_ctime);
1052
1053 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054}
1055#endif
Davidlohr Bueso3440a6b2014-06-06 14:37:45 -07001056
1057void __init msg_init(void)
1058{
1059 msg_init_ns(&init_ipc_ns);
1060
Davidlohr Bueso3440a6b2014-06-06 14:37:45 -07001061 ipc_init_proc_interface("sysvipc/msg",
1062 " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n",
1063 IPC_MSG_IDS, sysvipc_msg_proc_show);
1064}