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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>
42#include <asm/uaccess.h>
43#include "util.h"
44
Ingo Molnar5a06a362006-07-30 03:04:11 -070045/*
46 * one msg_receiver structure for each sleeping receiver:
47 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070048struct msg_receiver {
Ingo Molnar5a06a362006-07-30 03:04:11 -070049 struct list_head r_list;
50 struct task_struct *r_tsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Ingo Molnar5a06a362006-07-30 03:04:11 -070052 int r_mode;
53 long r_msgtype;
54 long r_maxsize;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
Linus Torvalds80491eb2006-11-04 09:55:00 -080056 struct msg_msg *volatile r_msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -070057};
58
59/* one msg_sender for each sleeping sender */
60struct msg_sender {
Ingo Molnar5a06a362006-07-30 03:04:11 -070061 struct list_head list;
62 struct task_struct *tsk;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063};
64
65#define SEARCH_ANY 1
66#define SEARCH_EQUAL 2
67#define SEARCH_NOTEQUAL 3
68#define SEARCH_LESSEQUAL 4
Peter Hurley8ac6ed52013-04-30 19:14:54 -070069#define SEARCH_NUMBER 5
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
Pierre Peiffered2ddbf2008-02-08 04:18:57 -080071#define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS])
Kirill Korotaev1e786932006-10-02 02:18:21 -070072
Pierre Peiffer01b8b072008-02-08 04:18:57 -080073static void freeque(struct ipc_namespace *, struct kern_ipc_perm *);
Nadia Derbey7748dbf2007-10-18 23:40:49 -070074static int newque(struct ipc_namespace *, struct ipc_params *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -070076static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077#endif
78
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070079/*
80 * Scale msgmni with the available lowmem size: the memory dedicated to msg
81 * queues should occupy at most 1/MSG_MEM_SCALE of lowmem.
Nadia Derbey4d89dc62008-04-29 01:00:40 -070082 * Also take into account the number of nsproxies created so far.
83 * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range.
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070084 */
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070085void recompute_msgmni(struct ipc_namespace *ns)
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070086{
87 struct sysinfo i;
88 unsigned long allowed;
Nadia Derbey4d89dc62008-04-29 01:00:40 -070089 int nb_ns;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070090
91 si_meminfo(&i);
92 allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
93 / MSGMNB;
Nadia Derbey4d89dc62008-04-29 01:00:40 -070094 nb_ns = atomic_read(&nr_ipc_ns);
95 allowed /= nb_ns;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070096
97 if (allowed < MSGMNI) {
98 ns->msg_ctlmni = MSGMNI;
Nadia Derbeydfcceb22008-06-05 22:46:38 -070099 return;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -0700100 }
101
Nadia Derbey4d89dc62008-04-29 01:00:40 -0700102 if (allowed > IPCMNI / nb_ns) {
103 ns->msg_ctlmni = IPCMNI / nb_ns;
Nadia Derbeydfcceb22008-06-05 22:46:38 -0700104 return;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -0700105 }
106
107 ns->msg_ctlmni = allowed;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -0700108}
109
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800110void msg_init_ns(struct ipc_namespace *ns)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111{
Kirill Korotaev1e786932006-10-02 02:18:21 -0700112 ns->msg_ctlmax = MSGMAX;
113 ns->msg_ctlmnb = MSGMNB;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -0700114
115 recompute_msgmni(ns);
116
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700117 atomic_set(&ns->msg_bytes, 0);
118 atomic_set(&ns->msg_hdrs, 0);
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800119 ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120}
121
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800122#ifdef CONFIG_IPC_NS
Kirill Korotaev1e786932006-10-02 02:18:21 -0700123void msg_exit_ns(struct ipc_namespace *ns)
124{
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800125 free_ipcs(ns, &msg_ids(ns), freeque);
Serge E. Hallyn7d6feeb2009-12-15 16:47:27 -0800126 idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
Kirill Korotaev1e786932006-10-02 02:18:21 -0700127}
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800128#endif
Kirill Korotaev1e786932006-10-02 02:18:21 -0700129
130void __init msg_init(void)
131{
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800132 msg_init_ns(&init_ipc_ns);
Nadia Derbeydfcceb22008-06-05 22:46:38 -0700133
134 printk(KERN_INFO "msgmni has been set to %d\n",
135 init_ipc_ns.msg_ctlmni);
136
Kirill Korotaev1e786932006-10-02 02:18:21 -0700137 ipc_init_proc_interface("sysvipc/msg",
138 " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n",
139 IPC_MSG_IDS, sysvipc_msg_proc_show);
140}
141
Davidlohr Buesoa5001a02013-07-08 16:01:15 -0700142static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id)
143{
144 struct kern_ipc_perm *ipcp = ipc_obtain_object(&msg_ids(ns), id);
145
146 if (IS_ERR(ipcp))
147 return ERR_CAST(ipcp);
148
149 return container_of(ipcp, struct msg_queue, q_perm);
150}
151
152static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns,
153 int id)
154{
155 struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id);
156
157 if (IS_ERR(ipcp))
158 return ERR_CAST(ipcp);
159
160 return container_of(ipcp, struct msg_queue, q_perm);
161}
162
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700163static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
164{
165 ipc_rmid(&msg_ids(ns), &s->q_perm);
166}
167
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700168static void msg_rcu_free(struct rcu_head *head)
169{
170 struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
171 struct msg_queue *msq = ipc_rcu_to_struct(p);
172
173 security_msg_queue_free(msq);
174 ipc_rcu_free(head);
175}
176
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700177/**
178 * newque - Create a new msg queue
179 * @ns: namespace
180 * @params: ptr to the structure that contains the key and msgflg
181 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700182 * Called with msg_ids.rwsem held (writer)
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700183 */
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700184static int newque(struct ipc_namespace *ns, struct ipc_params *params)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 struct msg_queue *msq;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700187 int id, retval;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700188 key_t key = params->key;
189 int msgflg = params->flg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
Ingo Molnar5a06a362006-07-30 03:04:11 -0700191 msq = ipc_rcu_alloc(sizeof(*msq));
192 if (!msq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 return -ENOMEM;
194
Ingo Molnar5a06a362006-07-30 03:04:11 -0700195 msq->q_perm.mode = msgflg & S_IRWXUGO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 msq->q_perm.key = key;
197
198 msq->q_perm.security = NULL;
199 retval = security_msg_queue_alloc(msq);
200 if (retval) {
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700201 ipc_rcu_putref(msq, ipc_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 return retval;
203 }
204
Davidlohr Buesodbfcd912013-07-08 16:01:09 -0700205 /* ipc_addid() locks msq upon success. */
Kirill Korotaev1e786932006-10-02 02:18:21 -0700206 id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700207 if (id < 0) {
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700208 ipc_rcu_putref(msq, msg_rcu_free);
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700209 return id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 }
211
212 msq->q_stime = msq->q_rtime = 0;
213 msq->q_ctime = get_seconds();
214 msq->q_cbytes = msq->q_qnum = 0;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700215 msq->q_qbytes = ns->msg_ctlmnb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 msq->q_lspid = msq->q_lrpid = 0;
217 INIT_LIST_HEAD(&msq->q_messages);
218 INIT_LIST_HEAD(&msq->q_receivers);
219 INIT_LIST_HEAD(&msq->q_senders);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700220
Davidlohr Buesocf9d5d72013-07-08 16:01:11 -0700221 ipc_unlock_object(&msq->q_perm);
Davidlohr Buesodbfcd912013-07-08 16:01:09 -0700222 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700224 return msq->q_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225}
226
Ingo Molnar5a06a362006-07-30 03:04:11 -0700227static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228{
Ingo Molnar5a06a362006-07-30 03:04:11 -0700229 mss->tsk = current;
230 current->state = TASK_INTERRUPTIBLE;
231 list_add_tail(&mss->list, &msq->q_senders);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232}
233
Ingo Molnar5a06a362006-07-30 03:04:11 -0700234static inline void ss_del(struct msg_sender *mss)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235{
Ingo Molnar5a06a362006-07-30 03:04:11 -0700236 if (mss->list.next != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 list_del(&mss->list);
238}
239
Ingo Molnar5a06a362006-07-30 03:04:11 -0700240static void ss_wakeup(struct list_head *h, int kill)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700242 struct msg_sender *mss, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700244 list_for_each_entry_safe(mss, t, h, list) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700245 if (kill)
246 mss->list.next = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 wake_up_process(mss->tsk);
248 }
249}
250
Ingo Molnar5a06a362006-07-30 03:04:11 -0700251static void expunge_all(struct msg_queue *msq, int res)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700253 struct msg_receiver *msr, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700255 list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
Davidlohr Buesoffa571d2014-01-27 17:07:10 -0800256 msr->r_msg = NULL; /* initialize expunge ordering */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 wake_up_process(msr->r_tsk);
Davidlohr Buesoffa571d2014-01-27 17:07:10 -0800258 /*
259 * Ensure that the wakeup is visible before setting r_msg as
260 * the receiving end depends on it: either spinning on a nil,
261 * or dealing with -EAGAIN cases. See lockless receive part 1
262 * and 2 in do_msgrcv().
263 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 smp_mb();
265 msr->r_msg = ERR_PTR(res);
266 }
267}
Ingo Molnar5a06a362006-07-30 03:04:11 -0700268
269/*
270 * freeque() wakes up waiters on the sender and receiver waiting queue,
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700271 * removes the message queue from message queue ID IDR, and cleans up all the
272 * messages associated with this queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700274 * msg_ids.rwsem (writer) and the spinlock for this message queue are held
275 * before freeque() is called. msg_ids.rwsem remains locked on exit.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 */
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800277static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700279 struct msg_msg *msg, *t;
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800280 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281
Ingo Molnar5a06a362006-07-30 03:04:11 -0700282 expunge_all(msq, -EIDRM);
283 ss_wakeup(&msq->q_senders, 1);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700284 msg_rmid(ns, msq);
Davidlohr Bueso47187872013-09-11 14:26:25 -0700285 ipc_unlock_object(&msq->q_perm);
286 rcu_read_unlock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700287
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700288 list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700289 atomic_dec(&ns->msg_hdrs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 free_msg(msg);
291 }
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700292 atomic_sub(msq->q_cbytes, &ns->msg_bytes);
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700293 ipc_rcu_putref(msq, msg_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294}
295
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700296/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700297 * Called with msg_ids.rwsem and ipcp locked.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700298 */
Nadia Derbey03f02c72007-10-18 23:40:51 -0700299static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700300{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700301 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
302
303 return security_msg_queue_associate(msq, msgflg);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700304}
305
Heiko Carstense48fbb62009-01-14 14:14:26 +0100306SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307{
Kirill Korotaev1e786932006-10-02 02:18:21 -0700308 struct ipc_namespace *ns;
Mathias Krauseeb66ec42014-06-06 14:37:36 -0700309 static const struct ipc_ops msg_ops = {
310 .getnew = newque,
311 .associate = msg_security,
312 };
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700313 struct ipc_params msg_params;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700314
315 ns = current->nsproxy->ipc_ns;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700316
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700317 msg_params.key = key;
318 msg_params.flg = msgflg;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700319
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700320 return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321}
322
Ingo Molnar5a06a362006-07-30 03:04:11 -0700323static inline unsigned long
324copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325{
Manfred Spraul239521f2014-01-27 17:07:04 -0800326 switch (version) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 case IPC_64:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700328 return copy_to_user(buf, in, sizeof(*in));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329 case IPC_OLD:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700330 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 struct msqid_ds out;
332
Ingo Molnar5a06a362006-07-30 03:04:11 -0700333 memset(&out, 0, sizeof(out));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
335 ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
336
337 out.msg_stime = in->msg_stime;
338 out.msg_rtime = in->msg_rtime;
339 out.msg_ctime = in->msg_ctime;
340
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700341 if (in->msg_cbytes > USHRT_MAX)
342 out.msg_cbytes = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 else
344 out.msg_cbytes = in->msg_cbytes;
345 out.msg_lcbytes = in->msg_cbytes;
346
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700347 if (in->msg_qnum > USHRT_MAX)
348 out.msg_qnum = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 else
350 out.msg_qnum = in->msg_qnum;
351
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700352 if (in->msg_qbytes > USHRT_MAX)
353 out.msg_qbytes = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354 else
355 out.msg_qbytes = in->msg_qbytes;
356 out.msg_lqbytes = in->msg_qbytes;
357
358 out.msg_lspid = in->msg_lspid;
359 out.msg_lrpid = in->msg_lrpid;
360
Ingo Molnar5a06a362006-07-30 03:04:11 -0700361 return copy_to_user(buf, &out, sizeof(out));
362 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 default:
364 return -EINVAL;
365 }
366}
367
Ingo Molnar5a06a362006-07-30 03:04:11 -0700368static inline unsigned long
Pierre Peiffer016d7132008-04-29 01:00:50 -0700369copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370{
Manfred Spraul239521f2014-01-27 17:07:04 -0800371 switch (version) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 case IPC_64:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700373 if (copy_from_user(out, buf, sizeof(*out)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 case IPC_OLD:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700377 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 struct msqid_ds tbuf_old;
379
Ingo Molnar5a06a362006-07-30 03:04:11 -0700380 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 return -EFAULT;
382
Manfred Spraul239521f2014-01-27 17:07:04 -0800383 out->msg_perm.uid = tbuf_old.msg_perm.uid;
384 out->msg_perm.gid = tbuf_old.msg_perm.gid;
385 out->msg_perm.mode = tbuf_old.msg_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
Ingo Molnar5a06a362006-07-30 03:04:11 -0700387 if (tbuf_old.msg_qbytes == 0)
Pierre Peiffer016d7132008-04-29 01:00:50 -0700388 out->msg_qbytes = tbuf_old.msg_lqbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 else
Pierre Peiffer016d7132008-04-29 01:00:50 -0700390 out->msg_qbytes = tbuf_old.msg_qbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
392 return 0;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700393 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 default:
395 return -EINVAL;
396 }
397}
398
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700399/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700400 * This function handles some msgctl commands which require the rwsem
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700401 * to be held in write mode.
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700402 * NOTE: no locks must be held, the rwsem is taken inside this function.
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700403 */
404static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
405 struct msqid_ds __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 struct kern_ipc_perm *ipcp;
Felipe Contrerasf1970c42009-10-19 01:54:29 +0300408 struct msqid64_ds uninitialized_var(msqid64);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700409 struct msg_queue *msq;
410 int err;
411
412 if (cmd == IPC_SET) {
Pierre Peiffer016d7132008-04-29 01:00:50 -0700413 if (copy_msqid_from_user(&msqid64, buf, version))
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700414 return -EFAULT;
415 }
416
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700417 down_write(&msg_ids(ns).rwsem);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700418 rcu_read_lock();
419
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700420 ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd,
421 &msqid64.msg_perm, msqid64.msg_qbytes);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700422 if (IS_ERR(ipcp)) {
423 err = PTR_ERR(ipcp);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700424 goto out_unlock1;
425 }
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700426
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700427 msq = container_of(ipcp, struct msg_queue, q_perm);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700428
429 err = security_msg_queue_msgctl(msq, cmd);
430 if (err)
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700431 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700432
433 switch (cmd) {
434 case IPC_RMID:
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700435 ipc_lock_object(&msq->q_perm);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700436 /* freeque unlocks the ipc object and rcu */
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700437 freeque(ns, ipcp);
438 goto out_up;
439 case IPC_SET:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700440 if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700441 !capable(CAP_SYS_RESOURCE)) {
442 err = -EPERM;
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700443 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700444 }
445
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700446 ipc_lock_object(&msq->q_perm);
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800447 err = ipc_update_perm(&msqid64.msg_perm, ipcp);
448 if (err)
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700449 goto out_unlock0;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800450
Pierre Peiffer016d7132008-04-29 01:00:50 -0700451 msq->q_qbytes = msqid64.msg_qbytes;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700452
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700453 msq->q_ctime = get_seconds();
454 /* sleeping receivers might be excluded by
455 * stricter permissions.
456 */
457 expunge_all(msq, -EAGAIN);
458 /* sleeping senders might be able to send
459 * due to a larger queue size.
460 */
461 ss_wakeup(&msq->q_senders, 0);
462 break;
463 default:
464 err = -EINVAL;
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700465 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700466 }
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700467
468out_unlock0:
469 ipc_unlock_object(&msq->q_perm);
470out_unlock1:
471 rcu_read_unlock();
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700472out_up:
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700473 up_write(&msg_ids(ns).rwsem);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700474 return err;
475}
476
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700477static int msgctl_nolock(struct ipc_namespace *ns, int msqid,
478 int cmd, int version, void __user *buf)
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700479{
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700480 int err;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700481 struct msg_queue *msq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
483 switch (cmd) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700484 case IPC_INFO:
485 case MSG_INFO:
486 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 struct msginfo msginfo;
488 int max_id;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700489
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 if (!buf)
491 return -EFAULT;
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700492
Ingo Molnar5a06a362006-07-30 03:04:11 -0700493 /*
494 * We must not return kernel stack data.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 * due to padding, it's not enough
496 * to set all member fields.
497 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 err = security_msg_queue_msgctl(NULL, cmd);
499 if (err)
500 return err;
501
Ingo Molnar5a06a362006-07-30 03:04:11 -0700502 memset(&msginfo, 0, sizeof(msginfo));
Kirill Korotaev1e786932006-10-02 02:18:21 -0700503 msginfo.msgmni = ns->msg_ctlmni;
504 msginfo.msgmax = ns->msg_ctlmax;
505 msginfo.msgmnb = ns->msg_ctlmnb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506 msginfo.msgssz = MSGSSZ;
507 msginfo.msgseg = MSGSEG;
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700508 down_read(&msg_ids(ns).rwsem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 if (cmd == MSG_INFO) {
Kirill Korotaev1e786932006-10-02 02:18:21 -0700510 msginfo.msgpool = msg_ids(ns).in_use;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700511 msginfo.msgmap = atomic_read(&ns->msg_hdrs);
512 msginfo.msgtql = atomic_read(&ns->msg_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 } else {
514 msginfo.msgmap = MSGMAP;
515 msginfo.msgpool = MSGPOOL;
516 msginfo.msgtql = MSGTQL;
517 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700518 max_id = ipc_get_maxid(&msg_ids(ns));
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700519 up_read(&msg_ids(ns).rwsem);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700520 if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 return -EFAULT;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700522 return (max_id < 0) ? 0 : max_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 }
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700524
525 case MSG_STAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 case IPC_STAT:
527 {
528 struct msqid64_ds tbuf;
529 int success_return;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700530
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531 if (!buf)
532 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700534 memset(&tbuf, 0, sizeof(tbuf));
535
536 rcu_read_lock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700537 if (cmd == MSG_STAT) {
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700538 msq = msq_obtain_object(ns, msqid);
539 if (IS_ERR(msq)) {
540 err = PTR_ERR(msq);
541 goto out_unlock;
542 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700543 success_return = msq->q_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 } else {
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700545 msq = msq_obtain_object_check(ns, msqid);
546 if (IS_ERR(msq)) {
547 err = PTR_ERR(msq);
548 goto out_unlock;
549 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 success_return = 0;
551 }
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700552
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700554 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 goto out_unlock;
556
557 err = security_msg_queue_msgctl(msq, cmd);
558 if (err)
559 goto out_unlock;
560
561 kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
562 tbuf.msg_stime = msq->q_stime;
563 tbuf.msg_rtime = msq->q_rtime;
564 tbuf.msg_ctime = msq->q_ctime;
565 tbuf.msg_cbytes = msq->q_cbytes;
566 tbuf.msg_qnum = msq->q_qnum;
567 tbuf.msg_qbytes = msq->q_qbytes;
568 tbuf.msg_lspid = msq->q_lspid;
569 tbuf.msg_lrpid = msq->q_lrpid;
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700570 rcu_read_unlock();
571
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 if (copy_msqid_to_user(buf, &tbuf, version))
573 return -EFAULT;
574 return success_return;
575 }
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700576
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 default:
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700578 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 }
580
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700581 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582out_unlock:
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700583 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 return err;
585}
586
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700587SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
588{
589 int version;
590 struct ipc_namespace *ns;
591
592 if (msqid < 0 || cmd < 0)
593 return -EINVAL;
594
595 version = ipc_parse_version(&cmd);
596 ns = current->nsproxy->ipc_ns;
597
598 switch (cmd) {
599 case IPC_INFO:
600 case MSG_INFO:
601 case MSG_STAT: /* msqid is an index rather than a msg queue id */
602 case IPC_STAT:
603 return msgctl_nolock(ns, msqid, cmd, version, buf);
604 case IPC_SET:
605 case IPC_RMID:
606 return msgctl_down(ns, msqid, cmd, buf, version);
607 default:
608 return -EINVAL;
609 }
610}
611
Ingo Molnar5a06a362006-07-30 03:04:11 -0700612static int testmsg(struct msg_msg *msg, long type, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613{
Manfred Spraul239521f2014-01-27 17:07:04 -0800614 switch (mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 {
616 case SEARCH_ANY:
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700617 case SEARCH_NUMBER:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 return 1;
619 case SEARCH_LESSEQUAL:
Manfred Spraul239521f2014-01-27 17:07:04 -0800620 if (msg->m_type <= type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 return 1;
622 break;
623 case SEARCH_EQUAL:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700624 if (msg->m_type == type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 return 1;
626 break;
627 case SEARCH_NOTEQUAL:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700628 if (msg->m_type != type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 return 1;
630 break;
631 }
632 return 0;
633}
634
Ingo Molnar5a06a362006-07-30 03:04:11 -0700635static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700637 struct msg_receiver *msr, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700639 list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700640 if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
641 !security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
642 msr->r_msgtype, msr->r_mode)) {
643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 list_del(&msr->r_list);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700645 if (msr->r_maxsize < msg->m_ts) {
Davidlohr Buesoffa571d2014-01-27 17:07:10 -0800646 /* initialize pipelined send ordering */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 msr->r_msg = NULL;
648 wake_up_process(msr->r_tsk);
Davidlohr Buesoffa571d2014-01-27 17:07:10 -0800649 smp_mb(); /* see barrier comment below */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 msr->r_msg = ERR_PTR(-E2BIG);
651 } else {
652 msr->r_msg = NULL;
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700653 msq->q_lrpid = task_pid_vnr(msr->r_tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 msq->q_rtime = get_seconds();
655 wake_up_process(msr->r_tsk);
Davidlohr Buesoffa571d2014-01-27 17:07:10 -0800656 /*
657 * Ensure that the wakeup is visible before
658 * setting r_msg, as the receiving end depends
659 * on it. See lockless receive part 1 and 2 in
660 * do_msgrcv().
661 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 smp_mb();
663 msr->r_msg = msg;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700664
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 return 1;
666 }
667 }
668 }
Davidlohr Buesoffa571d2014-01-27 17:07:10 -0800669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 return 0;
671}
672
suzuki651971c2006-12-06 20:37:48 -0800673long do_msgsnd(int msqid, long mtype, void __user *mtext,
674 size_t msgsz, int msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675{
676 struct msg_queue *msq;
677 struct msg_msg *msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 int err;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700679 struct ipc_namespace *ns;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700680
Kirill Korotaev1e786932006-10-02 02:18:21 -0700681 ns = current->nsproxy->ipc_ns;
682
683 if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 if (mtype < 1)
686 return -EINVAL;
687
suzuki651971c2006-12-06 20:37:48 -0800688 msg = load_msg(mtext, msgsz);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700689 if (IS_ERR(msg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 return PTR_ERR(msg);
691
692 msg->m_type = mtype;
693 msg->m_ts = msgsz;
694
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700695 rcu_read_lock();
696 msq = msq_obtain_object_check(ns, msqid);
Nadia Derbey023a5352007-10-18 23:40:51 -0700697 if (IS_ERR(msq)) {
698 err = PTR_ERR(msq);
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700699 goto out_unlock1;
Nadia Derbey023a5352007-10-18 23:40:51 -0700700 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701
Manfred Spraulbebcb922013-09-03 16:00:08 +0200702 ipc_lock_object(&msq->q_perm);
703
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 for (;;) {
705 struct msg_sender s;
706
Ingo Molnar5a06a362006-07-30 03:04:11 -0700707 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700708 if (ipcperms(ns, &msq->q_perm, S_IWUGO))
Manfred Spraulbebcb922013-09-03 16:00:08 +0200709 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710
Davidlohr Bueso4271b052013-09-30 13:45:26 -0700711 /* raced with RMID? */
Rafael Aquini0f3d2b02014-01-27 17:07:01 -0800712 if (!ipc_valid_object(&msq->q_perm)) {
Davidlohr Bueso4271b052013-09-30 13:45:26 -0700713 err = -EIDRM;
714 goto out_unlock0;
715 }
716
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 err = security_msg_queue_msgsnd(msq, msg, msgflg);
718 if (err)
Manfred Spraulbebcb922013-09-03 16:00:08 +0200719 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720
Ingo Molnar5a06a362006-07-30 03:04:11 -0700721 if (msgsz + msq->q_cbytes <= msq->q_qbytes &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 1 + msq->q_qnum <= msq->q_qbytes) {
723 break;
724 }
725
726 /* queue full, wait: */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700727 if (msgflg & IPC_NOWAIT) {
728 err = -EAGAIN;
Manfred Spraulbebcb922013-09-03 16:00:08 +0200729 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700731
Davidlohr Buesoffa571d2014-01-27 17:07:10 -0800732 /* enqueue the sender and prepare to block */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 ss_add(msq, &s);
Rik van Riel6062a8d2013-04-30 19:15:44 -0700734
735 if (!ipc_rcu_getref(msq)) {
736 err = -EIDRM;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700737 goto out_unlock0;
Rik van Riel6062a8d2013-04-30 19:15:44 -0700738 }
739
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700740 ipc_unlock_object(&msq->q_perm);
741 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 schedule();
743
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700744 rcu_read_lock();
745 ipc_lock_object(&msq->q_perm);
746
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700747 ipc_rcu_putref(msq, ipc_rcu_free);
Rafael Aquini0f3d2b02014-01-27 17:07:01 -0800748 /* raced with RMID? */
749 if (!ipc_valid_object(&msq->q_perm)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 err = -EIDRM;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700751 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700753
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 ss_del(&s);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700755
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 if (signal_pending(current)) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700757 err = -ERESTARTNOHAND;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700758 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700760
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 }
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700762 msq->q_lspid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 msq->q_stime = get_seconds();
764
Ingo Molnar5a06a362006-07-30 03:04:11 -0700765 if (!pipelined_send(msq, msg)) {
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300766 /* no one is waiting for this message, enqueue it */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700767 list_add_tail(&msg->m_list, &msq->q_messages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768 msq->q_cbytes += msgsz;
769 msq->q_qnum++;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700770 atomic_add(msgsz, &ns->msg_bytes);
771 atomic_inc(&ns->msg_hdrs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700773
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 err = 0;
775 msg = NULL;
776
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700777out_unlock0:
778 ipc_unlock_object(&msq->q_perm);
779out_unlock1:
780 rcu_read_unlock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700781 if (msg != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 free_msg(msg);
783 return err;
784}
785
Heiko Carstense48fbb62009-01-14 14:14:26 +0100786SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
787 int, msgflg)
suzuki651971c2006-12-06 20:37:48 -0800788{
789 long mtype;
790
791 if (get_user(mtype, &msgp->mtype))
792 return -EFAULT;
793 return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
794}
795
Ingo Molnar5a06a362006-07-30 03:04:11 -0700796static inline int convert_mode(long *msgtyp, int msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797{
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700798 if (msgflg & MSG_COPY)
799 return SEARCH_NUMBER;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700800 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 * find message of correct type.
802 * msgtyp = 0 => get first.
803 * msgtyp > 0 => get first message of matching type.
Ingo Molnar5a06a362006-07-30 03:04:11 -0700804 * msgtyp < 0 => get message with least type must be < abs(msgtype).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700806 if (*msgtyp == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 return SEARCH_ANY;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700808 if (*msgtyp < 0) {
809 *msgtyp = -*msgtyp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 return SEARCH_LESSEQUAL;
811 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700812 if (msgflg & MSG_EXCEPT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 return SEARCH_NOTEQUAL;
814 return SEARCH_EQUAL;
815}
816
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800817static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
818{
819 struct msgbuf __user *msgp = dest;
820 size_t msgsz;
821
822 if (put_user(msg->m_type, &msgp->mtype))
823 return -EFAULT;
824
825 msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
826 if (store_msg(msgp->mtext, msg, msgsz))
827 return -EFAULT;
828 return msgsz;
829}
830
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800831#ifdef CONFIG_CHECKPOINT_RESTORE
Stanislav Kinsbursky3fcfe782013-01-04 15:35:03 -0800832/*
833 * This function creates new kernel message structure, large enough to store
834 * bufsz message bytes.
835 */
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700836static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800837{
838 struct msg_msg *copy;
839
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800840 /*
841 * Create dummy message to copy real message to.
842 */
843 copy = load_msg(buf, bufsz);
844 if (!IS_ERR(copy))
845 copy->m_ts = bufsz;
846 return copy;
847}
848
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800849static inline void free_copy(struct msg_msg *copy)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800850{
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800851 if (copy)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800852 free_msg(copy);
853}
854#else
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700855static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
Stanislav Kinsburskyb30efe22013-01-04 15:35:00 -0800856{
857 return ERR_PTR(-ENOSYS);
858}
859
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800860static inline void free_copy(struct msg_msg *copy)
861{
862}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800863#endif
864
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700865static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
866{
Svenning Sørensen368ae532013-08-28 16:35:17 -0700867 struct msg_msg *msg, *found = NULL;
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700868 long count = 0;
869
870 list_for_each_entry(msg, &msq->q_messages, m_list) {
871 if (testmsg(msg, *msgtyp, mode) &&
872 !security_msg_queue_msgrcv(msq, msg, current,
873 *msgtyp, mode)) {
874 if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
875 *msgtyp = msg->m_type - 1;
Svenning Sørensen368ae532013-08-28 16:35:17 -0700876 found = msg;
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700877 } else if (mode == SEARCH_NUMBER) {
878 if (*msgtyp == count)
879 return msg;
880 } else
881 return msg;
882 count++;
883 }
884 }
885
Svenning Sørensen368ae532013-08-28 16:35:17 -0700886 return found ?: ERR_PTR(-EAGAIN);
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700887}
888
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700889long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800890 long (*msg_handler)(void __user *, struct msg_msg *, size_t))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 int mode;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700893 struct msg_queue *msq;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700894 struct ipc_namespace *ns;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700895 struct msg_msg *msg, *copy = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896
Peter Hurley88b9e452013-03-08 12:43:27 -0800897 ns = current->nsproxy->ipc_ns;
898
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800899 if (msqid < 0 || (long) bufsz < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 return -EINVAL;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700901
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800902 if (msgflg & MSG_COPY) {
Michael Kerrisk4f87dac2014-03-10 14:46:07 +0100903 if ((msgflg & MSG_EXCEPT) || !(msgflg & IPC_NOWAIT))
904 return -EINVAL;
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700905 copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800906 if (IS_ERR(copy))
907 return PTR_ERR(copy);
908 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700909 mode = convert_mode(&msgtyp, msgflg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700911 rcu_read_lock();
912 msq = msq_obtain_object_check(ns, msqid);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800913 if (IS_ERR(msq)) {
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700914 rcu_read_unlock();
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800915 free_copy(copy);
Nadia Derbey023a5352007-10-18 23:40:51 -0700916 return PTR_ERR(msq);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800917 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918
919 for (;;) {
920 struct msg_receiver msr_d;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921
922 msg = ERR_PTR(-EACCES);
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700923 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700924 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700926 ipc_lock_object(&msq->q_perm);
Davidlohr Bueso4271b052013-09-30 13:45:26 -0700927
928 /* raced with RMID? */
Rafael Aquini0f3d2b02014-01-27 17:07:01 -0800929 if (!ipc_valid_object(&msq->q_perm)) {
Davidlohr Bueso4271b052013-09-30 13:45:26 -0700930 msg = ERR_PTR(-EIDRM);
931 goto out_unlock0;
932 }
933
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700934 msg = find_msg(msq, &msgtyp, mode);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700935 if (!IS_ERR(msg)) {
936 /*
937 * Found a suitable message.
938 * Unlink it from the queue.
939 */
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800940 if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 msg = ERR_PTR(-E2BIG);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700942 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 }
Stanislav Kinsbursky3fcfe782013-01-04 15:35:03 -0800944 /*
945 * If we are copying, then do not unlink message and do
946 * not update queue parameters.
947 */
Peter Hurley852028a2013-04-30 19:14:48 -0700948 if (msgflg & MSG_COPY) {
949 msg = copy_msg(msg, copy);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700950 goto out_unlock0;
Peter Hurley852028a2013-04-30 19:14:48 -0700951 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700952
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 list_del(&msg->m_list);
954 msq->q_qnum--;
955 msq->q_rtime = get_seconds();
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700956 msq->q_lrpid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 msq->q_cbytes -= msg->m_ts;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700958 atomic_sub(msg->m_ts, &ns->msg_bytes);
959 atomic_dec(&ns->msg_hdrs);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700960 ss_wakeup(&msq->q_senders, 0);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700961
962 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700964
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 /* No message waiting. Wait for a message */
966 if (msgflg & IPC_NOWAIT) {
967 msg = ERR_PTR(-ENOMSG);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700968 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700970
Ingo Molnar5a06a362006-07-30 03:04:11 -0700971 list_add_tail(&msr_d.r_list, &msq->q_receivers);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 msr_d.r_tsk = current;
973 msr_d.r_msgtype = msgtyp;
974 msr_d.r_mode = mode;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700975 if (msgflg & MSG_NOERROR)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 msr_d.r_maxsize = INT_MAX;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700977 else
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800978 msr_d.r_maxsize = bufsz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 msr_d.r_msg = ERR_PTR(-EAGAIN);
980 current->state = TASK_INTERRUPTIBLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700982 ipc_unlock_object(&msq->q_perm);
983 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 schedule();
985
986 /* Lockless receive, part 1:
987 * Disable preemption. We don't hold a reference to the queue
988 * and getting a reference would defeat the idea of a lockless
989 * operation, thus the code relies on rcu to guarantee the
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300990 * existence of msq:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
992 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
993 * rcu_read_lock() prevents preemption between reading r_msg
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700994 * and acquiring the q_perm.lock in ipc_lock_object().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 */
996 rcu_read_lock();
997
998 /* Lockless receive, part 2:
999 * Wait until pipelined_send or expunge_all are outside of
1000 * wake_up_process(). There is a race with exit(), see
1001 * ipc/mqueue.c for the details.
1002 */
Manfred Spraul239521f2014-01-27 17:07:04 -08001003 msg = (struct msg_msg *)msr_d.r_msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004 while (msg == NULL) {
1005 cpu_relax();
Ingo Molnar5a06a362006-07-30 03:04:11 -07001006 msg = (struct msg_msg *)msr_d.r_msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 }
1008
1009 /* Lockless receive, part 3:
1010 * If there is a message or an error then accept it without
1011 * locking.
1012 */
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001013 if (msg != ERR_PTR(-EAGAIN))
1014 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015
1016 /* Lockless receive, part 3:
1017 * Acquire the queue spinlock.
1018 */
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001019 ipc_lock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020
1021 /* Lockless receive, part 4:
1022 * Repeat test after acquiring the spinlock.
1023 */
Manfred Spraul239521f2014-01-27 17:07:04 -08001024 msg = (struct msg_msg *)msr_d.r_msg;
Ingo Molnar5a06a362006-07-30 03:04:11 -07001025 if (msg != ERR_PTR(-EAGAIN))
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001026 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027
1028 list_del(&msr_d.r_list);
1029 if (signal_pending(current)) {
1030 msg = ERR_PTR(-ERESTARTNOHAND);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001031 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001033
1034 ipc_unlock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001036
1037out_unlock0:
1038 ipc_unlock_object(&msq->q_perm);
1039out_unlock1:
1040 rcu_read_unlock();
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -08001041 if (IS_ERR(msg)) {
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -08001042 free_copy(copy);
Ingo Molnar5a06a362006-07-30 03:04:11 -07001043 return PTR_ERR(msg);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -08001044 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001046 bufsz = msg_handler(buf, msg, bufsz);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 free_msg(msg);
Ingo Molnar5a06a362006-07-30 03:04:11 -07001048
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001049 return bufsz;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050}
1051
Heiko Carstense48fbb62009-01-14 14:14:26 +01001052SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
1053 long, msgtyp, int, msgflg)
suzuki651971c2006-12-06 20:37:48 -08001054{
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001055 return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
suzuki651971c2006-12-06 20:37:48 -08001056}
1057
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -07001059static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060{
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001061 struct user_namespace *user_ns = seq_user_ns(s);
Mike Waychison19b49462005-09-06 15:17:10 -07001062 struct msg_queue *msq = it;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063
Mike Waychison19b49462005-09-06 15:17:10 -07001064 return seq_printf(s,
Ingo Molnar5a06a362006-07-30 03:04:11 -07001065 "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
1066 msq->q_perm.key,
Nadia Derbey7ca7e562007-10-18 23:40:48 -07001067 msq->q_perm.id,
Ingo Molnar5a06a362006-07-30 03:04:11 -07001068 msq->q_perm.mode,
1069 msq->q_cbytes,
1070 msq->q_qnum,
1071 msq->q_lspid,
1072 msq->q_lrpid,
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001073 from_kuid_munged(user_ns, msq->q_perm.uid),
1074 from_kgid_munged(user_ns, msq->q_perm.gid),
1075 from_kuid_munged(user_ns, msq->q_perm.cuid),
1076 from_kgid_munged(user_ns, msq->q_perm.cgid),
Ingo Molnar5a06a362006-07-30 03:04:11 -07001077 msq->q_stime,
1078 msq->q_rtime,
1079 msq->q_ctime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080}
1081#endif