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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
Ingo Molnar5a06a362006-07-30 03:04:11 -070073#define msg_unlock(msq) ipc_unlock(&(msq)->q_perm)
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Pierre Peiffer01b8b072008-02-08 04:18:57 -080075static void freeque(struct ipc_namespace *, struct kern_ipc_perm *);
Nadia Derbey7748dbf2007-10-18 23:40:49 -070076static int newque(struct ipc_namespace *, struct ipc_params *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -070078static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079#endif
80
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070081/*
82 * Scale msgmni with the available lowmem size: the memory dedicated to msg
83 * queues should occupy at most 1/MSG_MEM_SCALE of lowmem.
Nadia Derbey4d89dc62008-04-29 01:00:40 -070084 * Also take into account the number of nsproxies created so far.
85 * This should be done staying within the (MSGMNI , IPCMNI/nr_ipc_ns) range.
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070086 */
Nadia Derbeyb6b337a2008-04-29 01:00:42 -070087void recompute_msgmni(struct ipc_namespace *ns)
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070088{
89 struct sysinfo i;
90 unsigned long allowed;
Nadia Derbey4d89dc62008-04-29 01:00:40 -070091 int nb_ns;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070092
93 si_meminfo(&i);
94 allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
95 / MSGMNB;
Nadia Derbey4d89dc62008-04-29 01:00:40 -070096 nb_ns = atomic_read(&nr_ipc_ns);
97 allowed /= nb_ns;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070098
99 if (allowed < MSGMNI) {
100 ns->msg_ctlmni = MSGMNI;
Nadia Derbeydfcceb22008-06-05 22:46:38 -0700101 return;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -0700102 }
103
Nadia Derbey4d89dc62008-04-29 01:00:40 -0700104 if (allowed > IPCMNI / nb_ns) {
105 ns->msg_ctlmni = IPCMNI / nb_ns;
Nadia Derbeydfcceb22008-06-05 22:46:38 -0700106 return;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -0700107 }
108
109 ns->msg_ctlmni = allowed;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -0700110}
111
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800112void msg_init_ns(struct ipc_namespace *ns)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113{
Kirill Korotaev1e786932006-10-02 02:18:21 -0700114 ns->msg_ctlmax = MSGMAX;
115 ns->msg_ctlmnb = MSGMNB;
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -0700116
117 recompute_msgmni(ns);
118
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700119 atomic_set(&ns->msg_bytes, 0);
120 atomic_set(&ns->msg_hdrs, 0);
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800121 ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122}
123
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800124#ifdef CONFIG_IPC_NS
Kirill Korotaev1e786932006-10-02 02:18:21 -0700125void msg_exit_ns(struct ipc_namespace *ns)
126{
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800127 free_ipcs(ns, &msg_ids(ns), freeque);
Serge E. Hallyn7d6feeb2009-12-15 16:47:27 -0800128 idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
Kirill Korotaev1e786932006-10-02 02:18:21 -0700129}
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -0800130#endif
Kirill Korotaev1e786932006-10-02 02:18:21 -0700131
132void __init msg_init(void)
133{
Pierre Peiffered2ddbf2008-02-08 04:18:57 -0800134 msg_init_ns(&init_ipc_ns);
Nadia Derbeydfcceb22008-06-05 22:46:38 -0700135
136 printk(KERN_INFO "msgmni has been set to %d\n",
137 init_ipc_ns.msg_ctlmni);
138
Kirill Korotaev1e786932006-10-02 02:18:21 -0700139 ipc_init_proc_interface("sysvipc/msg",
140 " key msqid perms cbytes qnum lspid lrpid uid gid cuid cgid stime rtime ctime\n",
141 IPC_MSG_IDS, sysvipc_msg_proc_show);
142}
143
Davidlohr Buesoa5001a02013-07-08 16:01:15 -0700144static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id)
145{
146 struct kern_ipc_perm *ipcp = ipc_obtain_object(&msg_ids(ns), id);
147
148 if (IS_ERR(ipcp))
149 return ERR_CAST(ipcp);
150
151 return container_of(ipcp, struct msg_queue, q_perm);
152}
153
154static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns,
155 int id)
156{
157 struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id);
158
159 if (IS_ERR(ipcp))
160 return ERR_CAST(ipcp);
161
162 return container_of(ipcp, struct msg_queue, q_perm);
163}
164
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700165static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
166{
167 ipc_rmid(&msg_ids(ns), &s->q_perm);
168}
169
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700170/**
171 * newque - Create a new msg queue
172 * @ns: namespace
173 * @params: ptr to the structure that contains the key and msgflg
174 *
Nadia Derbey3e148c72007-10-18 23:40:54 -0700175 * Called with msg_ids.rw_mutex held (writer)
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700176 */
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700177static int newque(struct ipc_namespace *ns, struct ipc_params *params)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 struct msg_queue *msq;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700180 int id, retval;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700181 key_t key = params->key;
182 int msgflg = params->flg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Ingo Molnar5a06a362006-07-30 03:04:11 -0700184 msq = ipc_rcu_alloc(sizeof(*msq));
185 if (!msq)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 return -ENOMEM;
187
Ingo Molnar5a06a362006-07-30 03:04:11 -0700188 msq->q_perm.mode = msgflg & S_IRWXUGO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 msq->q_perm.key = key;
190
191 msq->q_perm.security = NULL;
192 retval = security_msg_queue_alloc(msq);
193 if (retval) {
194 ipc_rcu_putref(msq);
195 return retval;
196 }
197
Davidlohr Buesodbfcd912013-07-08 16:01:09 -0700198 /* ipc_addid() locks msq upon success. */
Kirill Korotaev1e786932006-10-02 02:18:21 -0700199 id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700200 if (id < 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 security_msg_queue_free(msq);
202 ipc_rcu_putref(msq);
Pierre Peiffer283bb7f2007-10-18 23:40:57 -0700203 return id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 }
205
206 msq->q_stime = msq->q_rtime = 0;
207 msq->q_ctime = get_seconds();
208 msq->q_cbytes = msq->q_qnum = 0;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700209 msq->q_qbytes = ns->msg_ctlmnb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 msq->q_lspid = msq->q_lrpid = 0;
211 INIT_LIST_HEAD(&msq->q_messages);
212 INIT_LIST_HEAD(&msq->q_receivers);
213 INIT_LIST_HEAD(&msq->q_senders);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700214
Davidlohr Buesocf9d5d72013-07-08 16:01:11 -0700215 ipc_unlock_object(&msq->q_perm);
Davidlohr Buesodbfcd912013-07-08 16:01:09 -0700216 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700218 return msq->q_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219}
220
Ingo Molnar5a06a362006-07-30 03:04:11 -0700221static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222{
Ingo Molnar5a06a362006-07-30 03:04:11 -0700223 mss->tsk = current;
224 current->state = TASK_INTERRUPTIBLE;
225 list_add_tail(&mss->list, &msq->q_senders);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226}
227
Ingo Molnar5a06a362006-07-30 03:04:11 -0700228static inline void ss_del(struct msg_sender *mss)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229{
Ingo Molnar5a06a362006-07-30 03:04:11 -0700230 if (mss->list.next != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 list_del(&mss->list);
232}
233
Ingo Molnar5a06a362006-07-30 03:04:11 -0700234static void ss_wakeup(struct list_head *h, int kill)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700236 struct msg_sender *mss, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700238 list_for_each_entry_safe(mss, t, h, list) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700239 if (kill)
240 mss->list.next = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 wake_up_process(mss->tsk);
242 }
243}
244
Ingo Molnar5a06a362006-07-30 03:04:11 -0700245static void expunge_all(struct msg_queue *msq, int res)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700247 struct msg_receiver *msr, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700249 list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 msr->r_msg = NULL;
251 wake_up_process(msr->r_tsk);
252 smp_mb();
253 msr->r_msg = ERR_PTR(res);
254 }
255}
Ingo Molnar5a06a362006-07-30 03:04:11 -0700256
257/*
258 * freeque() wakes up waiters on the sender and receiver waiting queue,
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700259 * removes the message queue from message queue ID IDR, and cleans up all the
260 * messages associated with this queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 *
Nadia Derbey3e148c72007-10-18 23:40:54 -0700262 * msg_ids.rw_mutex (writer) and the spinlock for this message queue are held
263 * before freeque() is called. msg_ids.rw_mutex remains locked on exit.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 */
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800265static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700267 struct msg_msg *msg, *t;
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800268 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
Ingo Molnar5a06a362006-07-30 03:04:11 -0700270 expunge_all(msq, -EIDRM);
271 ss_wakeup(&msq->q_senders, 1);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700272 msg_rmid(ns, msq);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 msg_unlock(msq);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700274
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700275 list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700276 atomic_dec(&ns->msg_hdrs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 free_msg(msg);
278 }
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700279 atomic_sub(msq->q_cbytes, &ns->msg_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 security_msg_queue_free(msq);
281 ipc_rcu_putref(msq);
282}
283
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700284/*
Nadia Derbey3e148c72007-10-18 23:40:54 -0700285 * Called with msg_ids.rw_mutex and ipcp locked.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700286 */
Nadia Derbey03f02c72007-10-18 23:40:51 -0700287static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700288{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700289 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
290
291 return security_msg_queue_associate(msq, msgflg);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700292}
293
Heiko Carstense48fbb62009-01-14 14:14:26 +0100294SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295{
Kirill Korotaev1e786932006-10-02 02:18:21 -0700296 struct ipc_namespace *ns;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700297 struct ipc_ops msg_ops;
298 struct ipc_params msg_params;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700299
300 ns = current->nsproxy->ipc_ns;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700301
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700302 msg_ops.getnew = newque;
303 msg_ops.associate = msg_security;
304 msg_ops.more_checks = NULL;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700305
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700306 msg_params.key = key;
307 msg_params.flg = msgflg;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700308
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700309 return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310}
311
Ingo Molnar5a06a362006-07-30 03:04:11 -0700312static inline unsigned long
313copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314{
315 switch(version) {
316 case IPC_64:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700317 return copy_to_user(buf, in, sizeof(*in));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318 case IPC_OLD:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700319 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 struct msqid_ds out;
321
Ingo Molnar5a06a362006-07-30 03:04:11 -0700322 memset(&out, 0, sizeof(out));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323
324 ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
325
326 out.msg_stime = in->msg_stime;
327 out.msg_rtime = in->msg_rtime;
328 out.msg_ctime = in->msg_ctime;
329
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700330 if (in->msg_cbytes > USHRT_MAX)
331 out.msg_cbytes = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 else
333 out.msg_cbytes = in->msg_cbytes;
334 out.msg_lcbytes = in->msg_cbytes;
335
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700336 if (in->msg_qnum > USHRT_MAX)
337 out.msg_qnum = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 else
339 out.msg_qnum = in->msg_qnum;
340
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700341 if (in->msg_qbytes > USHRT_MAX)
342 out.msg_qbytes = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 else
344 out.msg_qbytes = in->msg_qbytes;
345 out.msg_lqbytes = in->msg_qbytes;
346
347 out.msg_lspid = in->msg_lspid;
348 out.msg_lrpid = in->msg_lrpid;
349
Ingo Molnar5a06a362006-07-30 03:04:11 -0700350 return copy_to_user(buf, &out, sizeof(out));
351 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 default:
353 return -EINVAL;
354 }
355}
356
Ingo Molnar5a06a362006-07-30 03:04:11 -0700357static inline unsigned long
Pierre Peiffer016d7132008-04-29 01:00:50 -0700358copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359{
360 switch(version) {
361 case IPC_64:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700362 if (copy_from_user(out, buf, sizeof(*out)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 case IPC_OLD:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700366 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 struct msqid_ds tbuf_old;
368
Ingo Molnar5a06a362006-07-30 03:04:11 -0700369 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 return -EFAULT;
371
Pierre Peiffer016d7132008-04-29 01:00:50 -0700372 out->msg_perm.uid = tbuf_old.msg_perm.uid;
373 out->msg_perm.gid = tbuf_old.msg_perm.gid;
374 out->msg_perm.mode = tbuf_old.msg_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
Ingo Molnar5a06a362006-07-30 03:04:11 -0700376 if (tbuf_old.msg_qbytes == 0)
Pierre Peiffer016d7132008-04-29 01:00:50 -0700377 out->msg_qbytes = tbuf_old.msg_lqbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 else
Pierre Peiffer016d7132008-04-29 01:00:50 -0700379 out->msg_qbytes = tbuf_old.msg_qbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380
381 return 0;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700382 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 default:
384 return -EINVAL;
385 }
386}
387
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700388/*
389 * This function handles some msgctl commands which require the rw_mutex
390 * to be held in write mode.
391 * NOTE: no locks must be held, the rw_mutex is taken inside this function.
392 */
393static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
394 struct msqid_ds __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 struct kern_ipc_perm *ipcp;
Felipe Contrerasf1970c42009-10-19 01:54:29 +0300397 struct msqid64_ds uninitialized_var(msqid64);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700398 struct msg_queue *msq;
399 int err;
400
401 if (cmd == IPC_SET) {
Pierre Peiffer016d7132008-04-29 01:00:50 -0700402 if (copy_msqid_from_user(&msqid64, buf, version))
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700403 return -EFAULT;
404 }
405
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700406 down_write(&msg_ids(ns).rw_mutex);
407 rcu_read_lock();
408
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700409 ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd,
410 &msqid64.msg_perm, msqid64.msg_qbytes);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700411 if (IS_ERR(ipcp)) {
412 err = PTR_ERR(ipcp);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700413 goto out_unlock1;
414 }
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700415
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700416 msq = container_of(ipcp, struct msg_queue, q_perm);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700417
418 err = security_msg_queue_msgctl(msq, cmd);
419 if (err)
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700420 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700421
422 switch (cmd) {
423 case IPC_RMID:
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700424 ipc_lock_object(&msq->q_perm);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700425 /* freeque unlocks the ipc object and rcu */
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700426 freeque(ns, ipcp);
427 goto out_up;
428 case IPC_SET:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700429 if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700430 !capable(CAP_SYS_RESOURCE)) {
431 err = -EPERM;
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700432 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700433 }
434
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700435 ipc_lock_object(&msq->q_perm);
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800436 err = ipc_update_perm(&msqid64.msg_perm, ipcp);
437 if (err)
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700438 goto out_unlock0;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800439
Pierre Peiffer016d7132008-04-29 01:00:50 -0700440 msq->q_qbytes = msqid64.msg_qbytes;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700441
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700442 msq->q_ctime = get_seconds();
443 /* sleeping receivers might be excluded by
444 * stricter permissions.
445 */
446 expunge_all(msq, -EAGAIN);
447 /* sleeping senders might be able to send
448 * due to a larger queue size.
449 */
450 ss_wakeup(&msq->q_senders, 0);
451 break;
452 default:
453 err = -EINVAL;
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700454 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700455 }
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700456
457out_unlock0:
458 ipc_unlock_object(&msq->q_perm);
459out_unlock1:
460 rcu_read_unlock();
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700461out_up:
462 up_write(&msg_ids(ns).rw_mutex);
463 return err;
464}
465
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700466static int msgctl_nolock(struct ipc_namespace *ns, int msqid,
467 int cmd, int version, void __user *buf)
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700468{
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700469 int err;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700470 struct msg_queue *msq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
472 switch (cmd) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700473 case IPC_INFO:
474 case MSG_INFO:
475 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 struct msginfo msginfo;
477 int max_id;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700478
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 if (!buf)
480 return -EFAULT;
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700481
Ingo Molnar5a06a362006-07-30 03:04:11 -0700482 /*
483 * We must not return kernel stack data.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 * due to padding, it's not enough
485 * to set all member fields.
486 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 err = security_msg_queue_msgctl(NULL, cmd);
488 if (err)
489 return err;
490
Ingo Molnar5a06a362006-07-30 03:04:11 -0700491 memset(&msginfo, 0, sizeof(msginfo));
Kirill Korotaev1e786932006-10-02 02:18:21 -0700492 msginfo.msgmni = ns->msg_ctlmni;
493 msginfo.msgmax = ns->msg_ctlmax;
494 msginfo.msgmnb = ns->msg_ctlmnb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 msginfo.msgssz = MSGSSZ;
496 msginfo.msgseg = MSGSEG;
Nadia Derbey3e148c72007-10-18 23:40:54 -0700497 down_read(&msg_ids(ns).rw_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 if (cmd == MSG_INFO) {
Kirill Korotaev1e786932006-10-02 02:18:21 -0700499 msginfo.msgpool = msg_ids(ns).in_use;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700500 msginfo.msgmap = atomic_read(&ns->msg_hdrs);
501 msginfo.msgtql = atomic_read(&ns->msg_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 } else {
503 msginfo.msgmap = MSGMAP;
504 msginfo.msgpool = MSGPOOL;
505 msginfo.msgtql = MSGTQL;
506 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700507 max_id = ipc_get_maxid(&msg_ids(ns));
Nadia Derbey3e148c72007-10-18 23:40:54 -0700508 up_read(&msg_ids(ns).rw_mutex);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700509 if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 return -EFAULT;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700511 return (max_id < 0) ? 0 : max_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 }
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700513
514 case MSG_STAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 case IPC_STAT:
516 {
517 struct msqid64_ds tbuf;
518 int success_return;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700519
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 if (!buf)
521 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700523 memset(&tbuf, 0, sizeof(tbuf));
524
525 rcu_read_lock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700526 if (cmd == MSG_STAT) {
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700527 msq = msq_obtain_object(ns, msqid);
528 if (IS_ERR(msq)) {
529 err = PTR_ERR(msq);
530 goto out_unlock;
531 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700532 success_return = msq->q_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 } else {
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700534 msq = msq_obtain_object_check(ns, msqid);
535 if (IS_ERR(msq)) {
536 err = PTR_ERR(msq);
537 goto out_unlock;
538 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 success_return = 0;
540 }
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700541
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700543 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 goto out_unlock;
545
546 err = security_msg_queue_msgctl(msq, cmd);
547 if (err)
548 goto out_unlock;
549
550 kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
551 tbuf.msg_stime = msq->q_stime;
552 tbuf.msg_rtime = msq->q_rtime;
553 tbuf.msg_ctime = msq->q_ctime;
554 tbuf.msg_cbytes = msq->q_cbytes;
555 tbuf.msg_qnum = msq->q_qnum;
556 tbuf.msg_qbytes = msq->q_qbytes;
557 tbuf.msg_lspid = msq->q_lspid;
558 tbuf.msg_lrpid = msq->q_lrpid;
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700559 rcu_read_unlock();
560
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 if (copy_msqid_to_user(buf, &tbuf, version))
562 return -EFAULT;
563 return success_return;
564 }
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700565
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566 default:
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700567 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 }
569
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700570 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571out_unlock:
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700572 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 return err;
574}
575
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700576SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
577{
578 int version;
579 struct ipc_namespace *ns;
580
581 if (msqid < 0 || cmd < 0)
582 return -EINVAL;
583
584 version = ipc_parse_version(&cmd);
585 ns = current->nsproxy->ipc_ns;
586
587 switch (cmd) {
588 case IPC_INFO:
589 case MSG_INFO:
590 case MSG_STAT: /* msqid is an index rather than a msg queue id */
591 case IPC_STAT:
592 return msgctl_nolock(ns, msqid, cmd, version, buf);
593 case IPC_SET:
594 case IPC_RMID:
595 return msgctl_down(ns, msqid, cmd, buf, version);
596 default:
597 return -EINVAL;
598 }
599}
600
Ingo Molnar5a06a362006-07-30 03:04:11 -0700601static int testmsg(struct msg_msg *msg, long type, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602{
603 switch(mode)
604 {
605 case SEARCH_ANY:
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700606 case SEARCH_NUMBER:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 return 1;
608 case SEARCH_LESSEQUAL:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700609 if (msg->m_type <=type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 return 1;
611 break;
612 case SEARCH_EQUAL:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700613 if (msg->m_type == type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 return 1;
615 break;
616 case SEARCH_NOTEQUAL:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700617 if (msg->m_type != type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 return 1;
619 break;
620 }
621 return 0;
622}
623
Ingo Molnar5a06a362006-07-30 03:04:11 -0700624static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700626 struct msg_receiver *msr, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700628 list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700629 if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
630 !security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
631 msr->r_msgtype, msr->r_mode)) {
632
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 list_del(&msr->r_list);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700634 if (msr->r_maxsize < msg->m_ts) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 msr->r_msg = NULL;
636 wake_up_process(msr->r_tsk);
637 smp_mb();
638 msr->r_msg = ERR_PTR(-E2BIG);
639 } else {
640 msr->r_msg = NULL;
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700641 msq->q_lrpid = task_pid_vnr(msr->r_tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 msq->q_rtime = get_seconds();
643 wake_up_process(msr->r_tsk);
644 smp_mb();
645 msr->r_msg = msg;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700646
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 return 1;
648 }
649 }
650 }
651 return 0;
652}
653
suzuki651971c2006-12-06 20:37:48 -0800654long do_msgsnd(int msqid, long mtype, void __user *mtext,
655 size_t msgsz, int msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656{
657 struct msg_queue *msq;
658 struct msg_msg *msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 int err;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700660 struct ipc_namespace *ns;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700661
Kirill Korotaev1e786932006-10-02 02:18:21 -0700662 ns = current->nsproxy->ipc_ns;
663
664 if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 if (mtype < 1)
667 return -EINVAL;
668
suzuki651971c2006-12-06 20:37:48 -0800669 msg = load_msg(mtext, msgsz);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700670 if (IS_ERR(msg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 return PTR_ERR(msg);
672
673 msg->m_type = mtype;
674 msg->m_ts = msgsz;
675
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700676 rcu_read_lock();
677 msq = msq_obtain_object_check(ns, msqid);
Nadia Derbey023a5352007-10-18 23:40:51 -0700678 if (IS_ERR(msq)) {
679 err = PTR_ERR(msq);
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700680 goto out_unlock1;
Nadia Derbey023a5352007-10-18 23:40:51 -0700681 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682
683 for (;;) {
684 struct msg_sender s;
685
Ingo Molnar5a06a362006-07-30 03:04:11 -0700686 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700687 if (ipcperms(ns, &msq->q_perm, S_IWUGO))
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700688 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
690 err = security_msg_queue_msgsnd(msq, msg, msgflg);
691 if (err)
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700692 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693
Ingo Molnar5a06a362006-07-30 03:04:11 -0700694 if (msgsz + msq->q_cbytes <= msq->q_qbytes &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 1 + msq->q_qnum <= msq->q_qbytes) {
696 break;
697 }
698
699 /* queue full, wait: */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700700 if (msgflg & IPC_NOWAIT) {
701 err = -EAGAIN;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700702 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700704
705 ipc_lock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 ss_add(msq, &s);
Rik van Riel6062a8d2013-04-30 19:15:44 -0700707
708 if (!ipc_rcu_getref(msq)) {
709 err = -EIDRM;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700710 goto out_unlock0;
Rik van Riel6062a8d2013-04-30 19:15:44 -0700711 }
712
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700713 ipc_unlock_object(&msq->q_perm);
714 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 schedule();
716
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700717 rcu_read_lock();
718 ipc_lock_object(&msq->q_perm);
719
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720 ipc_rcu_putref(msq);
721 if (msq->q_perm.deleted) {
722 err = -EIDRM;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700723 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700725
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 ss_del(&s);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700727
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 if (signal_pending(current)) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700729 err = -ERESTARTNOHAND;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700730 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700732
733 ipc_unlock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 }
735
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700736 ipc_lock_object(&msq->q_perm);
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700737 msq->q_lspid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 msq->q_stime = get_seconds();
739
Ingo Molnar5a06a362006-07-30 03:04:11 -0700740 if (!pipelined_send(msq, msg)) {
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300741 /* no one is waiting for this message, enqueue it */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700742 list_add_tail(&msg->m_list, &msq->q_messages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 msq->q_cbytes += msgsz;
744 msq->q_qnum++;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700745 atomic_add(msgsz, &ns->msg_bytes);
746 atomic_inc(&ns->msg_hdrs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700748
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 err = 0;
750 msg = NULL;
751
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700752out_unlock0:
753 ipc_unlock_object(&msq->q_perm);
754out_unlock1:
755 rcu_read_unlock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700756 if (msg != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 free_msg(msg);
758 return err;
759}
760
Heiko Carstense48fbb62009-01-14 14:14:26 +0100761SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
762 int, msgflg)
suzuki651971c2006-12-06 20:37:48 -0800763{
764 long mtype;
765
766 if (get_user(mtype, &msgp->mtype))
767 return -EFAULT;
768 return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
769}
770
Ingo Molnar5a06a362006-07-30 03:04:11 -0700771static inline int convert_mode(long *msgtyp, int msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772{
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700773 if (msgflg & MSG_COPY)
774 return SEARCH_NUMBER;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700775 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 * find message of correct type.
777 * msgtyp = 0 => get first.
778 * msgtyp > 0 => get first message of matching type.
Ingo Molnar5a06a362006-07-30 03:04:11 -0700779 * msgtyp < 0 => get message with least type must be < abs(msgtype).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700781 if (*msgtyp == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 return SEARCH_ANY;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700783 if (*msgtyp < 0) {
784 *msgtyp = -*msgtyp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 return SEARCH_LESSEQUAL;
786 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700787 if (msgflg & MSG_EXCEPT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 return SEARCH_NOTEQUAL;
789 return SEARCH_EQUAL;
790}
791
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800792static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
793{
794 struct msgbuf __user *msgp = dest;
795 size_t msgsz;
796
797 if (put_user(msg->m_type, &msgp->mtype))
798 return -EFAULT;
799
800 msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
801 if (store_msg(msgp->mtext, msg, msgsz))
802 return -EFAULT;
803 return msgsz;
804}
805
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800806#ifdef CONFIG_CHECKPOINT_RESTORE
Stanislav Kinsbursky3fcfe782013-01-04 15:35:03 -0800807/*
808 * This function creates new kernel message structure, large enough to store
809 * bufsz message bytes.
810 */
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700811static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800812{
813 struct msg_msg *copy;
814
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800815 /*
816 * Create dummy message to copy real message to.
817 */
818 copy = load_msg(buf, bufsz);
819 if (!IS_ERR(copy))
820 copy->m_ts = bufsz;
821 return copy;
822}
823
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800824static inline void free_copy(struct msg_msg *copy)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800825{
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800826 if (copy)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800827 free_msg(copy);
828}
829#else
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700830static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
Stanislav Kinsburskyb30efe22013-01-04 15:35:00 -0800831{
832 return ERR_PTR(-ENOSYS);
833}
834
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800835static inline void free_copy(struct msg_msg *copy)
836{
837}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800838#endif
839
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700840static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
841{
842 struct msg_msg *msg;
843 long count = 0;
844
845 list_for_each_entry(msg, &msq->q_messages, m_list) {
846 if (testmsg(msg, *msgtyp, mode) &&
847 !security_msg_queue_msgrcv(msq, msg, current,
848 *msgtyp, mode)) {
849 if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
850 *msgtyp = msg->m_type - 1;
851 } else if (mode == SEARCH_NUMBER) {
852 if (*msgtyp == count)
853 return msg;
854 } else
855 return msg;
856 count++;
857 }
858 }
859
860 return ERR_PTR(-EAGAIN);
861}
862
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700863long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800864 long (*msg_handler)(void __user *, struct msg_msg *, size_t))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 int mode;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700867 struct msg_queue *msq;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700868 struct ipc_namespace *ns;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700869 struct msg_msg *msg, *copy = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870
Peter Hurley88b9e452013-03-08 12:43:27 -0800871 ns = current->nsproxy->ipc_ns;
872
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800873 if (msqid < 0 || (long) bufsz < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 return -EINVAL;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700875
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800876 if (msgflg & MSG_COPY) {
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700877 copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800878 if (IS_ERR(copy))
879 return PTR_ERR(copy);
880 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700881 mode = convert_mode(&msgtyp, msgflg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700883 rcu_read_lock();
884 msq = msq_obtain_object_check(ns, msqid);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800885 if (IS_ERR(msq)) {
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700886 rcu_read_unlock();
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800887 free_copy(copy);
Nadia Derbey023a5352007-10-18 23:40:51 -0700888 return PTR_ERR(msq);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800889 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890
891 for (;;) {
892 struct msg_receiver msr_d;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893
894 msg = ERR_PTR(-EACCES);
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700895 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700896 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700898 ipc_lock_object(&msq->q_perm);
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700899 msg = find_msg(msq, &msgtyp, mode);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700900 if (!IS_ERR(msg)) {
901 /*
902 * Found a suitable message.
903 * Unlink it from the queue.
904 */
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800905 if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 msg = ERR_PTR(-E2BIG);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700907 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 }
Stanislav Kinsbursky3fcfe782013-01-04 15:35:03 -0800909 /*
910 * If we are copying, then do not unlink message and do
911 * not update queue parameters.
912 */
Peter Hurley852028a2013-04-30 19:14:48 -0700913 if (msgflg & MSG_COPY) {
914 msg = copy_msg(msg, copy);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700915 goto out_unlock0;
Peter Hurley852028a2013-04-30 19:14:48 -0700916 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700917
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918 list_del(&msg->m_list);
919 msq->q_qnum--;
920 msq->q_rtime = get_seconds();
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700921 msq->q_lrpid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 msq->q_cbytes -= msg->m_ts;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700923 atomic_sub(msg->m_ts, &ns->msg_bytes);
924 atomic_dec(&ns->msg_hdrs);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700925 ss_wakeup(&msq->q_senders, 0);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700926
927 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700929
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930 /* No message waiting. Wait for a message */
931 if (msgflg & IPC_NOWAIT) {
932 msg = ERR_PTR(-ENOMSG);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700933 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700935
Ingo Molnar5a06a362006-07-30 03:04:11 -0700936 list_add_tail(&msr_d.r_list, &msq->q_receivers);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 msr_d.r_tsk = current;
938 msr_d.r_msgtype = msgtyp;
939 msr_d.r_mode = mode;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700940 if (msgflg & MSG_NOERROR)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 msr_d.r_maxsize = INT_MAX;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700942 else
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800943 msr_d.r_maxsize = bufsz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 msr_d.r_msg = ERR_PTR(-EAGAIN);
945 current->state = TASK_INTERRUPTIBLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700947 ipc_unlock_object(&msq->q_perm);
948 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 schedule();
950
951 /* Lockless receive, part 1:
952 * Disable preemption. We don't hold a reference to the queue
953 * and getting a reference would defeat the idea of a lockless
954 * operation, thus the code relies on rcu to guarantee the
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300955 * existence of msq:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
957 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
958 * rcu_read_lock() prevents preemption between reading r_msg
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700959 * and acquiring the q_perm.lock in ipc_lock_object().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 */
961 rcu_read_lock();
962
963 /* Lockless receive, part 2:
964 * Wait until pipelined_send or expunge_all are outside of
965 * wake_up_process(). There is a race with exit(), see
966 * ipc/mqueue.c for the details.
967 */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700968 msg = (struct msg_msg*)msr_d.r_msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 while (msg == NULL) {
970 cpu_relax();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700971 msg = (struct msg_msg *)msr_d.r_msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 }
973
974 /* Lockless receive, part 3:
975 * If there is a message or an error then accept it without
976 * locking.
977 */
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700978 if (msg != ERR_PTR(-EAGAIN))
979 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980
981 /* Lockless receive, part 3:
982 * Acquire the queue spinlock.
983 */
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700984 ipc_lock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985
986 /* Lockless receive, part 4:
987 * Repeat test after acquiring the spinlock.
988 */
989 msg = (struct msg_msg*)msr_d.r_msg;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700990 if (msg != ERR_PTR(-EAGAIN))
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700991 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992
993 list_del(&msr_d.r_list);
994 if (signal_pending(current)) {
995 msg = ERR_PTR(-ERESTARTNOHAND);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700996 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700998
999 ipc_unlock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001001
1002out_unlock0:
1003 ipc_unlock_object(&msq->q_perm);
1004out_unlock1:
1005 rcu_read_unlock();
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -08001006 if (IS_ERR(msg)) {
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -08001007 free_copy(copy);
Ingo Molnar5a06a362006-07-30 03:04:11 -07001008 return PTR_ERR(msg);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -08001009 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001011 bufsz = msg_handler(buf, msg, bufsz);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 free_msg(msg);
Ingo Molnar5a06a362006-07-30 03:04:11 -07001013
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001014 return bufsz;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015}
1016
Heiko Carstense48fbb62009-01-14 14:14:26 +01001017SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
1018 long, msgtyp, int, msgflg)
suzuki651971c2006-12-06 20:37:48 -08001019{
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001020 return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
suzuki651971c2006-12-06 20:37:48 -08001021}
1022
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -07001024static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025{
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001026 struct user_namespace *user_ns = seq_user_ns(s);
Mike Waychison19b49462005-09-06 15:17:10 -07001027 struct msg_queue *msq = it;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028
Mike Waychison19b49462005-09-06 15:17:10 -07001029 return seq_printf(s,
Ingo Molnar5a06a362006-07-30 03:04:11 -07001030 "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
1031 msq->q_perm.key,
Nadia Derbey7ca7e562007-10-18 23:40:48 -07001032 msq->q_perm.id,
Ingo Molnar5a06a362006-07-30 03:04:11 -07001033 msq->q_perm.mode,
1034 msq->q_cbytes,
1035 msq->q_qnum,
1036 msq->q_lspid,
1037 msq->q_lrpid,
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001038 from_kuid_munged(user_ns, msq->q_perm.uid),
1039 from_kgid_munged(user_ns, msq->q_perm.gid),
1040 from_kuid_munged(user_ns, msq->q_perm.cuid),
1041 from_kgid_munged(user_ns, msq->q_perm.cgid),
Ingo Molnar5a06a362006-07-30 03:04:11 -07001042 msq->q_stime,
1043 msq->q_rtime,
1044 msq->q_ctime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045}
1046#endif