blob: 9e4310c546ae93fa85f3932675bcd53ae33ece7a [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/ipc/msg.c
Ingo Molnar5a06a362006-07-30 03:04:11 -07003 * Copyright (C) 1992 Krishna Balasubramanian
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
5 * Removed all the remaining kerneld mess
6 * Catch the -EFAULT stuff properly
7 * Use GFP_KERNEL for messages as in 1.2
8 * Fixed up the unchecked user space derefs
9 * Copyright (C) 1998 Alan Cox & Andi Kleen
10 *
11 * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
12 *
13 * mostly rewritten, threaded and wake-one semantics added
14 * MSGMAX limit removed, sysctl's added
Christian Kujau624dffc2006-01-15 02:43:54 +010015 * (c) 1999 Manfred Spraul <manfred@colorfullife.com>
Steve Grubb073115d2006-04-02 17:07:33 -040016 *
17 * support for audit of ipc object properties and permission changes
18 * Dustin Kirkland <dustin.kirkland@us.ibm.com>
Kirill Korotaev1e786932006-10-02 02:18:21 -070019 *
20 * namespaces support
21 * OpenVZ, SWsoft Inc.
22 * Pavel Emelianov <xemul@openvz.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023 */
24
Randy.Dunlapc59ede72006-01-11 12:17:46 -080025#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/msg.h>
27#include <linux/spinlock.h>
28#include <linux/init.h>
Nadia Derbeyf7bf3df2008-04-29 01:00:39 -070029#include <linux/mm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/proc_fs.h>
31#include <linux/list.h>
32#include <linux/security.h>
33#include <linux/sched.h>
34#include <linux/syscalls.h>
35#include <linux/audit.h>
Mike Waychison19b49462005-09-06 15:17:10 -070036#include <linux/seq_file.h>
Nadia Derbey3e148c72007-10-18 23:40:54 -070037#include <linux/rwsem.h>
Kirill Korotaev1e786932006-10-02 02:18:21 -070038#include <linux/nsproxy.h>
Pavel Emelyanovae5e1b22008-02-08 04:18:22 -080039#include <linux/ipc_namespace.h>
Ingo Molnar5f921ae2006-03-26 01:37:17 -080040
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <asm/current.h>
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) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 msr->r_msg = NULL;
257 wake_up_process(msr->r_tsk);
258 smp_mb();
259 msr->r_msg = ERR_PTR(res);
260 }
261}
Ingo Molnar5a06a362006-07-30 03:04:11 -0700262
263/*
264 * freeque() wakes up waiters on the sender and receiver waiting queue,
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700265 * removes the message queue from message queue ID IDR, and cleans up all the
266 * messages associated with this queue.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 *
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700268 * msg_ids.rwsem (writer) and the spinlock for this message queue are held
269 * before freeque() is called. msg_ids.rwsem remains locked on exit.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 */
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800271static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700273 struct msg_msg *msg, *t;
Pierre Peiffer01b8b072008-02-08 04:18:57 -0800274 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
Ingo Molnar5a06a362006-07-30 03:04:11 -0700276 expunge_all(msq, -EIDRM);
277 ss_wakeup(&msq->q_senders, 1);
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700278 msg_rmid(ns, msq);
Davidlohr Bueso47187872013-09-11 14:26:25 -0700279 ipc_unlock_object(&msq->q_perm);
280 rcu_read_unlock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700281
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700282 list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700283 atomic_dec(&ns->msg_hdrs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 free_msg(msg);
285 }
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700286 atomic_sub(msq->q_cbytes, &ns->msg_bytes);
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700287 ipc_rcu_putref(msq, msg_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288}
289
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700290/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700291 * Called with msg_ids.rwsem and ipcp locked.
Nadia Derbeyf4566f02007-10-18 23:40:53 -0700292 */
Nadia Derbey03f02c72007-10-18 23:40:51 -0700293static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700294{
Nadia Derbey03f02c72007-10-18 23:40:51 -0700295 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
296
297 return security_msg_queue_associate(msq, msgflg);
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700298}
299
Heiko Carstense48fbb62009-01-14 14:14:26 +0100300SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301{
Kirill Korotaev1e786932006-10-02 02:18:21 -0700302 struct ipc_namespace *ns;
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700303 struct ipc_ops msg_ops;
304 struct ipc_params msg_params;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700305
306 ns = current->nsproxy->ipc_ns;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700307
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700308 msg_ops.getnew = newque;
309 msg_ops.associate = msg_security;
310 msg_ops.more_checks = NULL;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700311
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700312 msg_params.key = key;
313 msg_params.flg = msgflg;
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700314
Nadia Derbey7748dbf2007-10-18 23:40:49 -0700315 return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316}
317
Ingo Molnar5a06a362006-07-30 03:04:11 -0700318static inline unsigned long
319copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320{
321 switch(version) {
322 case IPC_64:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700323 return copy_to_user(buf, in, sizeof(*in));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 case IPC_OLD:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700325 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 struct msqid_ds out;
327
Ingo Molnar5a06a362006-07-30 03:04:11 -0700328 memset(&out, 0, sizeof(out));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
330 ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
331
332 out.msg_stime = in->msg_stime;
333 out.msg_rtime = in->msg_rtime;
334 out.msg_ctime = in->msg_ctime;
335
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700336 if (in->msg_cbytes > USHRT_MAX)
337 out.msg_cbytes = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 else
339 out.msg_cbytes = in->msg_cbytes;
340 out.msg_lcbytes = in->msg_cbytes;
341
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700342 if (in->msg_qnum > USHRT_MAX)
343 out.msg_qnum = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 else
345 out.msg_qnum = in->msg_qnum;
346
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700347 if (in->msg_qbytes > USHRT_MAX)
348 out.msg_qbytes = USHRT_MAX;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 else
350 out.msg_qbytes = in->msg_qbytes;
351 out.msg_lqbytes = in->msg_qbytes;
352
353 out.msg_lspid = in->msg_lspid;
354 out.msg_lrpid = in->msg_lrpid;
355
Ingo Molnar5a06a362006-07-30 03:04:11 -0700356 return copy_to_user(buf, &out, sizeof(out));
357 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 default:
359 return -EINVAL;
360 }
361}
362
Ingo Molnar5a06a362006-07-30 03:04:11 -0700363static inline unsigned long
Pierre Peiffer016d7132008-04-29 01:00:50 -0700364copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365{
366 switch(version) {
367 case IPC_64:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700368 if (copy_from_user(out, buf, sizeof(*out)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 case IPC_OLD:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700372 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 struct msqid_ds tbuf_old;
374
Ingo Molnar5a06a362006-07-30 03:04:11 -0700375 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 return -EFAULT;
377
Pierre Peiffer016d7132008-04-29 01:00:50 -0700378 out->msg_perm.uid = tbuf_old.msg_perm.uid;
379 out->msg_perm.gid = tbuf_old.msg_perm.gid;
380 out->msg_perm.mode = tbuf_old.msg_perm.mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381
Ingo Molnar5a06a362006-07-30 03:04:11 -0700382 if (tbuf_old.msg_qbytes == 0)
Pierre Peiffer016d7132008-04-29 01:00:50 -0700383 out->msg_qbytes = tbuf_old.msg_lqbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 else
Pierre Peiffer016d7132008-04-29 01:00:50 -0700385 out->msg_qbytes = tbuf_old.msg_qbytes;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
387 return 0;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700388 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 default:
390 return -EINVAL;
391 }
392}
393
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700394/*
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700395 * This function handles some msgctl commands which require the rwsem
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700396 * to be held in write mode.
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700397 * NOTE: no locks must be held, the rwsem is taken inside this function.
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700398 */
399static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
400 struct msqid_ds __user *buf, int version)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 struct kern_ipc_perm *ipcp;
Felipe Contrerasf1970c42009-10-19 01:54:29 +0300403 struct msqid64_ds uninitialized_var(msqid64);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700404 struct msg_queue *msq;
405 int err;
406
407 if (cmd == IPC_SET) {
Pierre Peiffer016d7132008-04-29 01:00:50 -0700408 if (copy_msqid_from_user(&msqid64, buf, version))
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700409 return -EFAULT;
410 }
411
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700412 down_write(&msg_ids(ns).rwsem);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700413 rcu_read_lock();
414
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700415 ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd,
416 &msqid64.msg_perm, msqid64.msg_qbytes);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700417 if (IS_ERR(ipcp)) {
418 err = PTR_ERR(ipcp);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700419 goto out_unlock1;
420 }
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700421
Pierre Peiffera5f75e72008-04-29 01:00:54 -0700422 msq = container_of(ipcp, struct msg_queue, q_perm);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700423
424 err = security_msg_queue_msgctl(msq, cmd);
425 if (err)
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700426 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700427
428 switch (cmd) {
429 case IPC_RMID:
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700430 ipc_lock_object(&msq->q_perm);
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700431 /* freeque unlocks the ipc object and rcu */
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700432 freeque(ns, ipcp);
433 goto out_up;
434 case IPC_SET:
Pierre Peiffer016d7132008-04-29 01:00:50 -0700435 if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700436 !capable(CAP_SYS_RESOURCE)) {
437 err = -EPERM;
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700438 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700439 }
440
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700441 ipc_lock_object(&msq->q_perm);
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800442 err = ipc_update_perm(&msqid64.msg_perm, ipcp);
443 if (err)
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700444 goto out_unlock0;
Eric W. Biederman1efdb692012-02-07 16:54:11 -0800445
Pierre Peiffer016d7132008-04-29 01:00:50 -0700446 msq->q_qbytes = msqid64.msg_qbytes;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700447
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700448 msq->q_ctime = get_seconds();
449 /* sleeping receivers might be excluded by
450 * stricter permissions.
451 */
452 expunge_all(msq, -EAGAIN);
453 /* sleeping senders might be able to send
454 * due to a larger queue size.
455 */
456 ss_wakeup(&msq->q_senders, 0);
457 break;
458 default:
459 err = -EINVAL;
Davidlohr Bueso15724ec2013-07-08 16:01:13 -0700460 goto out_unlock1;
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700461 }
Davidlohr Bueso7b4cc5d2013-07-08 16:01:12 -0700462
463out_unlock0:
464 ipc_unlock_object(&msq->q_perm);
465out_unlock1:
466 rcu_read_unlock();
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700467out_up:
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700468 up_write(&msg_ids(ns).rwsem);
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700469 return err;
470}
471
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700472static int msgctl_nolock(struct ipc_namespace *ns, int msqid,
473 int cmd, int version, void __user *buf)
Pierre Peiffera0d092f2008-04-29 01:00:48 -0700474{
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700475 int err;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700476 struct msg_queue *msq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477
478 switch (cmd) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700479 case IPC_INFO:
480 case MSG_INFO:
481 {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 struct msginfo msginfo;
483 int max_id;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700484
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 if (!buf)
486 return -EFAULT;
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700487
Ingo Molnar5a06a362006-07-30 03:04:11 -0700488 /*
489 * We must not return kernel stack data.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 * due to padding, it's not enough
491 * to set all member fields.
492 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 err = security_msg_queue_msgctl(NULL, cmd);
494 if (err)
495 return err;
496
Ingo Molnar5a06a362006-07-30 03:04:11 -0700497 memset(&msginfo, 0, sizeof(msginfo));
Kirill Korotaev1e786932006-10-02 02:18:21 -0700498 msginfo.msgmni = ns->msg_ctlmni;
499 msginfo.msgmax = ns->msg_ctlmax;
500 msginfo.msgmnb = ns->msg_ctlmnb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 msginfo.msgssz = MSGSSZ;
502 msginfo.msgseg = MSGSEG;
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700503 down_read(&msg_ids(ns).rwsem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 if (cmd == MSG_INFO) {
Kirill Korotaev1e786932006-10-02 02:18:21 -0700505 msginfo.msgpool = msg_ids(ns).in_use;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700506 msginfo.msgmap = atomic_read(&ns->msg_hdrs);
507 msginfo.msgtql = atomic_read(&ns->msg_bytes);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 } else {
509 msginfo.msgmap = MSGMAP;
510 msginfo.msgpool = MSGPOOL;
511 msginfo.msgtql = MSGTQL;
512 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700513 max_id = ipc_get_maxid(&msg_ids(ns));
Davidlohr Buesod9a605e2013-09-11 14:26:24 -0700514 up_read(&msg_ids(ns).rwsem);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700515 if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 return -EFAULT;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700517 return (max_id < 0) ? 0 : max_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 }
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700519
520 case MSG_STAT:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 case IPC_STAT:
522 {
523 struct msqid64_ds tbuf;
524 int success_return;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700525
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 if (!buf)
527 return -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700529 memset(&tbuf, 0, sizeof(tbuf));
530
531 rcu_read_lock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700532 if (cmd == MSG_STAT) {
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700533 msq = msq_obtain_object(ns, msqid);
534 if (IS_ERR(msq)) {
535 err = PTR_ERR(msq);
536 goto out_unlock;
537 }
Nadia Derbey7ca7e562007-10-18 23:40:48 -0700538 success_return = msq->q_perm.id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 } else {
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700540 msq = msq_obtain_object_check(ns, msqid);
541 if (IS_ERR(msq)) {
542 err = PTR_ERR(msq);
543 goto out_unlock;
544 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 success_return = 0;
546 }
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700547
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700549 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 goto out_unlock;
551
552 err = security_msg_queue_msgctl(msq, cmd);
553 if (err)
554 goto out_unlock;
555
556 kernel_to_ipc64_perm(&msq->q_perm, &tbuf.msg_perm);
557 tbuf.msg_stime = msq->q_stime;
558 tbuf.msg_rtime = msq->q_rtime;
559 tbuf.msg_ctime = msq->q_ctime;
560 tbuf.msg_cbytes = msq->q_cbytes;
561 tbuf.msg_qnum = msq->q_qnum;
562 tbuf.msg_qbytes = msq->q_qbytes;
563 tbuf.msg_lspid = msq->q_lspid;
564 tbuf.msg_lrpid = msq->q_lrpid;
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700565 rcu_read_unlock();
566
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 if (copy_msqid_to_user(buf, &tbuf, version))
568 return -EFAULT;
569 return success_return;
570 }
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700571
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 default:
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700573 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 }
575
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700576 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577out_unlock:
Davidlohr Buesoac0ba202013-07-08 16:01:16 -0700578 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 return err;
580}
581
Davidlohr Bueso2cafed32013-07-08 16:01:14 -0700582SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
583{
584 int version;
585 struct ipc_namespace *ns;
586
587 if (msqid < 0 || cmd < 0)
588 return -EINVAL;
589
590 version = ipc_parse_version(&cmd);
591 ns = current->nsproxy->ipc_ns;
592
593 switch (cmd) {
594 case IPC_INFO:
595 case MSG_INFO:
596 case MSG_STAT: /* msqid is an index rather than a msg queue id */
597 case IPC_STAT:
598 return msgctl_nolock(ns, msqid, cmd, version, buf);
599 case IPC_SET:
600 case IPC_RMID:
601 return msgctl_down(ns, msqid, cmd, buf, version);
602 default:
603 return -EINVAL;
604 }
605}
606
Ingo Molnar5a06a362006-07-30 03:04:11 -0700607static int testmsg(struct msg_msg *msg, long type, int mode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608{
609 switch(mode)
610 {
611 case SEARCH_ANY:
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700612 case SEARCH_NUMBER:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 return 1;
614 case SEARCH_LESSEQUAL:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700615 if (msg->m_type <=type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616 return 1;
617 break;
618 case SEARCH_EQUAL:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700619 if (msg->m_type == type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 return 1;
621 break;
622 case SEARCH_NOTEQUAL:
Ingo Molnar5a06a362006-07-30 03:04:11 -0700623 if (msg->m_type != type)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 return 1;
625 break;
626 }
627 return 0;
628}
629
Ingo Molnar5a06a362006-07-30 03:04:11 -0700630static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631{
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700632 struct msg_receiver *msr, *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633
Nikola Pajkovsky41239fe2013-04-30 19:15:49 -0700634 list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700635 if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
636 !security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
637 msr->r_msgtype, msr->r_mode)) {
638
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 list_del(&msr->r_list);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700640 if (msr->r_maxsize < msg->m_ts) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 msr->r_msg = NULL;
642 wake_up_process(msr->r_tsk);
643 smp_mb();
644 msr->r_msg = ERR_PTR(-E2BIG);
645 } else {
646 msr->r_msg = NULL;
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700647 msq->q_lrpid = task_pid_vnr(msr->r_tsk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 msq->q_rtime = get_seconds();
649 wake_up_process(msr->r_tsk);
650 smp_mb();
651 msr->r_msg = msg;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700652
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 return 1;
654 }
655 }
656 }
657 return 0;
658}
659
suzuki651971c2006-12-06 20:37:48 -0800660long do_msgsnd(int msqid, long mtype, void __user *mtext,
661 size_t msgsz, int msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662{
663 struct msg_queue *msq;
664 struct msg_msg *msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 int err;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700666 struct ipc_namespace *ns;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700667
Kirill Korotaev1e786932006-10-02 02:18:21 -0700668 ns = current->nsproxy->ipc_ns;
669
670 if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 if (mtype < 1)
673 return -EINVAL;
674
suzuki651971c2006-12-06 20:37:48 -0800675 msg = load_msg(mtext, msgsz);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700676 if (IS_ERR(msg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 return PTR_ERR(msg);
678
679 msg->m_type = mtype;
680 msg->m_ts = msgsz;
681
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700682 rcu_read_lock();
683 msq = msq_obtain_object_check(ns, msqid);
Nadia Derbey023a5352007-10-18 23:40:51 -0700684 if (IS_ERR(msq)) {
685 err = PTR_ERR(msq);
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700686 goto out_unlock1;
Nadia Derbey023a5352007-10-18 23:40:51 -0700687 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688
Manfred Spraulbebcb922013-09-03 16:00:08 +0200689 ipc_lock_object(&msq->q_perm);
690
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 for (;;) {
692 struct msg_sender s;
693
Ingo Molnar5a06a362006-07-30 03:04:11 -0700694 err = -EACCES;
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700695 if (ipcperms(ns, &msq->q_perm, S_IWUGO))
Manfred Spraulbebcb922013-09-03 16:00:08 +0200696 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697
698 err = security_msg_queue_msgsnd(msq, msg, msgflg);
699 if (err)
Manfred Spraulbebcb922013-09-03 16:00:08 +0200700 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701
Ingo Molnar5a06a362006-07-30 03:04:11 -0700702 if (msgsz + msq->q_cbytes <= msq->q_qbytes &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 1 + msq->q_qnum <= msq->q_qbytes) {
704 break;
705 }
706
707 /* queue full, wait: */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700708 if (msgflg & IPC_NOWAIT) {
709 err = -EAGAIN;
Manfred Spraulbebcb922013-09-03 16:00:08 +0200710 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700712
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 ss_add(msq, &s);
Rik van Riel6062a8d2013-04-30 19:15:44 -0700714
715 if (!ipc_rcu_getref(msq)) {
716 err = -EIDRM;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700717 goto out_unlock0;
Rik van Riel6062a8d2013-04-30 19:15:44 -0700718 }
719
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700720 ipc_unlock_object(&msq->q_perm);
721 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 schedule();
723
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700724 rcu_read_lock();
725 ipc_lock_object(&msq->q_perm);
726
Davidlohr Bueso53dad6d2013-09-23 17:04:45 -0700727 ipc_rcu_putref(msq, ipc_rcu_free);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 if (msq->q_perm.deleted) {
729 err = -EIDRM;
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733 ss_del(&s);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700734
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 if (signal_pending(current)) {
Ingo Molnar5a06a362006-07-30 03:04:11 -0700736 err = -ERESTARTNOHAND;
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700737 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 }
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 }
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700741 msq->q_lspid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 msq->q_stime = get_seconds();
743
Ingo Molnar5a06a362006-07-30 03:04:11 -0700744 if (!pipelined_send(msq, msg)) {
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300745 /* no one is waiting for this message, enqueue it */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700746 list_add_tail(&msg->m_list, &msq->q_messages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 msq->q_cbytes += msgsz;
748 msq->q_qnum++;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700749 atomic_add(msgsz, &ns->msg_bytes);
750 atomic_inc(&ns->msg_hdrs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700752
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 err = 0;
754 msg = NULL;
755
Davidlohr Bueso3dd1f782013-07-08 16:01:17 -0700756out_unlock0:
757 ipc_unlock_object(&msq->q_perm);
758out_unlock1:
759 rcu_read_unlock();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700760 if (msg != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 free_msg(msg);
762 return err;
763}
764
Heiko Carstense48fbb62009-01-14 14:14:26 +0100765SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
766 int, msgflg)
suzuki651971c2006-12-06 20:37:48 -0800767{
768 long mtype;
769
770 if (get_user(mtype, &msgp->mtype))
771 return -EFAULT;
772 return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
773}
774
Ingo Molnar5a06a362006-07-30 03:04:11 -0700775static inline int convert_mode(long *msgtyp, int msgflg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776{
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700777 if (msgflg & MSG_COPY)
778 return SEARCH_NUMBER;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700779 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 * find message of correct type.
781 * msgtyp = 0 => get first.
782 * msgtyp > 0 => get first message of matching type.
Ingo Molnar5a06a362006-07-30 03:04:11 -0700783 * msgtyp < 0 => get message with least type must be < abs(msgtype).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700785 if (*msgtyp == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 return SEARCH_ANY;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700787 if (*msgtyp < 0) {
788 *msgtyp = -*msgtyp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 return SEARCH_LESSEQUAL;
790 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700791 if (msgflg & MSG_EXCEPT)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 return SEARCH_NOTEQUAL;
793 return SEARCH_EQUAL;
794}
795
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800796static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
797{
798 struct msgbuf __user *msgp = dest;
799 size_t msgsz;
800
801 if (put_user(msg->m_type, &msgp->mtype))
802 return -EFAULT;
803
804 msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
805 if (store_msg(msgp->mtext, msg, msgsz))
806 return -EFAULT;
807 return msgsz;
808}
809
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800810#ifdef CONFIG_CHECKPOINT_RESTORE
Stanislav Kinsbursky3fcfe782013-01-04 15:35:03 -0800811/*
812 * This function creates new kernel message structure, large enough to store
813 * bufsz message bytes.
814 */
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700815static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800816{
817 struct msg_msg *copy;
818
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800819 /*
820 * Create dummy message to copy real message to.
821 */
822 copy = load_msg(buf, bufsz);
823 if (!IS_ERR(copy))
824 copy->m_ts = bufsz;
825 return copy;
826}
827
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800828static inline void free_copy(struct msg_msg *copy)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800829{
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800830 if (copy)
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800831 free_msg(copy);
832}
833#else
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700834static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
Stanislav Kinsburskyb30efe22013-01-04 15:35:00 -0800835{
836 return ERR_PTR(-ENOSYS);
837}
838
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800839static inline void free_copy(struct msg_msg *copy)
840{
841}
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800842#endif
843
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700844static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
845{
Svenning Sørensen368ae532013-08-28 16:35:17 -0700846 struct msg_msg *msg, *found = NULL;
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700847 long count = 0;
848
849 list_for_each_entry(msg, &msq->q_messages, m_list) {
850 if (testmsg(msg, *msgtyp, mode) &&
851 !security_msg_queue_msgrcv(msq, msg, current,
852 *msgtyp, mode)) {
853 if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
854 *msgtyp = msg->m_type - 1;
Svenning Sørensen368ae532013-08-28 16:35:17 -0700855 found = msg;
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700856 } else if (mode == SEARCH_NUMBER) {
857 if (*msgtyp == count)
858 return msg;
859 } else
860 return msg;
861 count++;
862 }
863 }
864
Svenning Sørensen368ae532013-08-28 16:35:17 -0700865 return found ?: ERR_PTR(-EAGAIN);
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700866}
867
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700868long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800869 long (*msg_handler)(void __user *, struct msg_msg *, size_t))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871 int mode;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700872 struct msg_queue *msq;
Kirill Korotaev1e786932006-10-02 02:18:21 -0700873 struct ipc_namespace *ns;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700874 struct msg_msg *msg, *copy = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875
Peter Hurley88b9e452013-03-08 12:43:27 -0800876 ns = current->nsproxy->ipc_ns;
877
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800878 if (msqid < 0 || (long) bufsz < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 return -EINVAL;
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700880
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800881 if (msgflg & MSG_COPY) {
Peter Hurley8ac6ed52013-04-30 19:14:54 -0700882 copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800883 if (IS_ERR(copy))
884 return PTR_ERR(copy);
885 }
Ingo Molnar5a06a362006-07-30 03:04:11 -0700886 mode = convert_mode(&msgtyp, msgflg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700888 rcu_read_lock();
889 msq = msq_obtain_object_check(ns, msqid);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800890 if (IS_ERR(msq)) {
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700891 rcu_read_unlock();
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -0800892 free_copy(copy);
Nadia Derbey023a5352007-10-18 23:40:51 -0700893 return PTR_ERR(msq);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -0800894 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895
896 for (;;) {
897 struct msg_receiver msr_d;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898
899 msg = ERR_PTR(-EACCES);
Serge E. Hallynb0e77592011-03-23 16:43:24 -0700900 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700901 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700903 ipc_lock_object(&msq->q_perm);
Peter Hurleydaaf74c2013-04-30 19:15:04 -0700904 msg = find_msg(msq, &msgtyp, mode);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700905 if (!IS_ERR(msg)) {
906 /*
907 * Found a suitable message.
908 * Unlink it from the queue.
909 */
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800910 if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 msg = ERR_PTR(-E2BIG);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700912 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 }
Stanislav Kinsbursky3fcfe782013-01-04 15:35:03 -0800914 /*
915 * If we are copying, then do not unlink message and do
916 * not update queue parameters.
917 */
Peter Hurley852028a2013-04-30 19:14:48 -0700918 if (msgflg & MSG_COPY) {
919 msg = copy_msg(msg, copy);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700920 goto out_unlock0;
Peter Hurley852028a2013-04-30 19:14:48 -0700921 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700922
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 list_del(&msg->m_list);
924 msq->q_qnum--;
925 msq->q_rtime = get_seconds();
Pavel Emelyanovb4888932007-10-18 23:40:14 -0700926 msq->q_lrpid = task_tgid_vnr(current);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 msq->q_cbytes -= msg->m_ts;
Kirill Korotaev3ac88a42007-10-18 23:40:56 -0700928 atomic_sub(msg->m_ts, &ns->msg_bytes);
929 atomic_dec(&ns->msg_hdrs);
Ingo Molnar5a06a362006-07-30 03:04:11 -0700930 ss_wakeup(&msq->q_senders, 0);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700931
932 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700934
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 /* No message waiting. Wait for a message */
936 if (msgflg & IPC_NOWAIT) {
937 msg = ERR_PTR(-ENOMSG);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700938 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700940
Ingo Molnar5a06a362006-07-30 03:04:11 -0700941 list_add_tail(&msr_d.r_list, &msq->q_receivers);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700942 msr_d.r_tsk = current;
943 msr_d.r_msgtype = msgtyp;
944 msr_d.r_mode = mode;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700945 if (msgflg & MSG_NOERROR)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 msr_d.r_maxsize = INT_MAX;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700947 else
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -0800948 msr_d.r_maxsize = bufsz;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 msr_d.r_msg = ERR_PTR(-EAGAIN);
950 current->state = TASK_INTERRUPTIBLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700952 ipc_unlock_object(&msq->q_perm);
953 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 schedule();
955
956 /* Lockless receive, part 1:
957 * Disable preemption. We don't hold a reference to the queue
958 * and getting a reference would defeat the idea of a lockless
959 * operation, thus the code relies on rcu to guarantee the
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300960 * existence of msq:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
962 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
963 * rcu_read_lock() prevents preemption between reading r_msg
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700964 * and acquiring the q_perm.lock in ipc_lock_object().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 */
966 rcu_read_lock();
967
968 /* Lockless receive, part 2:
969 * Wait until pipelined_send or expunge_all are outside of
970 * wake_up_process(). There is a race with exit(), see
971 * ipc/mqueue.c for the details.
972 */
Ingo Molnar5a06a362006-07-30 03:04:11 -0700973 msg = (struct msg_msg*)msr_d.r_msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 while (msg == NULL) {
975 cpu_relax();
Ingo Molnar5a06a362006-07-30 03:04:11 -0700976 msg = (struct msg_msg *)msr_d.r_msg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 }
978
979 /* Lockless receive, part 3:
980 * If there is a message or an error then accept it without
981 * locking.
982 */
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700983 if (msg != ERR_PTR(-EAGAIN))
984 goto out_unlock1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985
986 /* Lockless receive, part 3:
987 * Acquire the queue spinlock.
988 */
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700989 ipc_lock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990
991 /* Lockless receive, part 4:
992 * Repeat test after acquiring the spinlock.
993 */
994 msg = (struct msg_msg*)msr_d.r_msg;
Ingo Molnar5a06a362006-07-30 03:04:11 -0700995 if (msg != ERR_PTR(-EAGAIN))
Davidlohr Bueso41a0d522013-07-08 16:01:18 -0700996 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997
998 list_del(&msr_d.r_list);
999 if (signal_pending(current)) {
1000 msg = ERR_PTR(-ERESTARTNOHAND);
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001001 goto out_unlock0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001003
1004 ipc_unlock_object(&msq->q_perm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 }
Davidlohr Bueso41a0d522013-07-08 16:01:18 -07001006
1007out_unlock0:
1008 ipc_unlock_object(&msq->q_perm);
1009out_unlock1:
1010 rcu_read_unlock();
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -08001011 if (IS_ERR(msg)) {
Stanislav Kinsbursky85398aa2013-01-04 15:34:58 -08001012 free_copy(copy);
Ingo Molnar5a06a362006-07-30 03:04:11 -07001013 return PTR_ERR(msg);
Stanislav Kinsbursky4a674f32013-01-04 15:34:55 -08001014 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001016 bufsz = msg_handler(buf, msg, bufsz);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 free_msg(msg);
Ingo Molnar5a06a362006-07-30 03:04:11 -07001018
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001019 return bufsz;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020}
1021
Heiko Carstense48fbb62009-01-14 14:14:26 +01001022SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
1023 long, msgtyp, int, msgflg)
suzuki651971c2006-12-06 20:37:48 -08001024{
Stanislav Kinsburskyf9dd87f2013-01-04 15:34:52 -08001025 return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
suzuki651971c2006-12-06 20:37:48 -08001026}
1027
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028#ifdef CONFIG_PROC_FS
Mike Waychison19b49462005-09-06 15:17:10 -07001029static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030{
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001031 struct user_namespace *user_ns = seq_user_ns(s);
Mike Waychison19b49462005-09-06 15:17:10 -07001032 struct msg_queue *msq = it;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033
Mike Waychison19b49462005-09-06 15:17:10 -07001034 return seq_printf(s,
Ingo Molnar5a06a362006-07-30 03:04:11 -07001035 "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
1036 msq->q_perm.key,
Nadia Derbey7ca7e562007-10-18 23:40:48 -07001037 msq->q_perm.id,
Ingo Molnar5a06a362006-07-30 03:04:11 -07001038 msq->q_perm.mode,
1039 msq->q_cbytes,
1040 msq->q_qnum,
1041 msq->q_lspid,
1042 msq->q_lrpid,
Eric W. Biederman1efdb692012-02-07 16:54:11 -08001043 from_kuid_munged(user_ns, msq->q_perm.uid),
1044 from_kgid_munged(user_ns, msq->q_perm.gid),
1045 from_kuid_munged(user_ns, msq->q_perm.cuid),
1046 from_kgid_munged(user_ns, msq->q_perm.cgid),
Ingo Molnar5a06a362006-07-30 03:04:11 -07001047 msq->q_stime,
1048 msq->q_rtime,
1049 msq->q_ctime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050}
1051#endif