3 * Copyright (C) 1992 Krishna Balasubramanian
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
11 * /proc/sysvipc/msg support (c) 1999 Dragos Acostachioaie <dragos@iname.com>
13 * mostly rewritten, threaded and wake-one semantics added
14 * MSGMAX limit removed, sysctl's added
15 * (c) 1999 Manfred Spraul <manfred@colorfullife.com>
17 * support for audit of ipc object properties and permission changes
18 * Dustin Kirkland <dustin.kirkland@us.ibm.com>
22 * Pavel Emelianov <xemul@openvz.org>
25 #include <linux/capability.h>
26 #include <linux/msg.h>
27 #include <linux/spinlock.h>
28 #include <linux/init.h>
30 #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>
36 #include <linux/seq_file.h>
37 #include <linux/rwsem.h>
38 #include <linux/nsproxy.h>
39 #include <linux/ipc_namespace.h>
41 #include <asm/current.h>
42 #include <asm/uaccess.h>
46 * one msg_receiver structure for each sleeping receiver:
49 struct list_head r_list;
50 struct task_struct *r_tsk;
56 struct msg_msg *volatile r_msg;
59 /* one msg_sender for each sleeping sender */
61 struct list_head list;
62 struct task_struct *tsk;
66 #define SEARCH_EQUAL 2
67 #define SEARCH_NOTEQUAL 3
68 #define SEARCH_LESSEQUAL 4
69 #define SEARCH_NUMBER 5
71 #define msg_ids(ns) ((ns)->ids[IPC_MSG_IDS])
73 static void freeque(struct ipc_namespace *, struct kern_ipc_perm *);
74 static int newque(struct ipc_namespace *, struct ipc_params *);
76 static int sysvipc_msg_proc_show(struct seq_file *s, void *it);
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.
82 * 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.
85 void recompute_msgmni(struct ipc_namespace *ns)
88 unsigned long allowed;
92 allowed = (((i.totalram - i.totalhigh) / MSG_MEM_SCALE) * i.mem_unit)
94 nb_ns = atomic_read(&nr_ipc_ns);
97 if (allowed < MSGMNI) {
98 ns->msg_ctlmni = MSGMNI;
102 if (allowed > IPCMNI / nb_ns) {
103 ns->msg_ctlmni = IPCMNI / nb_ns;
107 ns->msg_ctlmni = allowed;
110 void msg_init_ns(struct ipc_namespace *ns)
112 ns->msg_ctlmax = MSGMAX;
113 ns->msg_ctlmnb = MSGMNB;
115 recompute_msgmni(ns);
117 atomic_set(&ns->msg_bytes, 0);
118 atomic_set(&ns->msg_hdrs, 0);
119 ipc_init_ids(&ns->ids[IPC_MSG_IDS]);
123 void msg_exit_ns(struct ipc_namespace *ns)
125 free_ipcs(ns, &msg_ids(ns), freeque);
126 idr_destroy(&ns->ids[IPC_MSG_IDS].ipcs_idr);
130 void __init msg_init(void)
132 msg_init_ns(&init_ipc_ns);
134 printk(KERN_INFO "msgmni has been set to %d\n",
135 init_ipc_ns.msg_ctlmni);
137 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);
142 static inline struct msg_queue *msq_obtain_object(struct ipc_namespace *ns, int id)
144 struct kern_ipc_perm *ipcp = ipc_obtain_object(&msg_ids(ns), id);
147 return ERR_CAST(ipcp);
149 return container_of(ipcp, struct msg_queue, q_perm);
152 static inline struct msg_queue *msq_obtain_object_check(struct ipc_namespace *ns,
155 struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&msg_ids(ns), id);
158 return ERR_CAST(ipcp);
160 return container_of(ipcp, struct msg_queue, q_perm);
163 static inline void msg_rmid(struct ipc_namespace *ns, struct msg_queue *s)
165 ipc_rmid(&msg_ids(ns), &s->q_perm);
168 static void msg_rcu_free(struct rcu_head *head)
170 struct ipc_rcu *p = container_of(head, struct ipc_rcu, rcu);
171 struct msg_queue *msq = ipc_rcu_to_struct(p);
173 security_msg_queue_free(msq);
178 * newque - Create a new msg queue
180 * @params: ptr to the structure that contains the key and msgflg
182 * Called with msg_ids.rwsem held (writer)
184 static int newque(struct ipc_namespace *ns, struct ipc_params *params)
186 struct msg_queue *msq;
188 key_t key = params->key;
189 int msgflg = params->flg;
191 msq = ipc_rcu_alloc(sizeof(*msq));
195 msq->q_perm.mode = msgflg & S_IRWXUGO;
196 msq->q_perm.key = key;
198 msq->q_perm.security = NULL;
199 retval = security_msg_queue_alloc(msq);
201 ipc_rcu_putref(msq, ipc_rcu_free);
205 /* ipc_addid() locks msq upon success. */
206 id = ipc_addid(&msg_ids(ns), &msq->q_perm, ns->msg_ctlmni);
208 ipc_rcu_putref(msq, msg_rcu_free);
212 msq->q_stime = msq->q_rtime = 0;
213 msq->q_ctime = get_seconds();
214 msq->q_cbytes = msq->q_qnum = 0;
215 msq->q_qbytes = ns->msg_ctlmnb;
216 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);
221 ipc_unlock_object(&msq->q_perm);
224 return msq->q_perm.id;
227 static inline void ss_add(struct msg_queue *msq, struct msg_sender *mss)
230 current->state = TASK_INTERRUPTIBLE;
231 list_add_tail(&mss->list, &msq->q_senders);
234 static inline void ss_del(struct msg_sender *mss)
236 if (mss->list.next != NULL)
237 list_del(&mss->list);
240 static void ss_wakeup(struct list_head *h, int kill)
242 struct msg_sender *mss, *t;
244 list_for_each_entry_safe(mss, t, h, list) {
246 mss->list.next = NULL;
247 wake_up_process(mss->tsk);
251 static void expunge_all(struct msg_queue *msq, int res)
253 struct msg_receiver *msr, *t;
255 list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
257 wake_up_process(msr->r_tsk);
259 msr->r_msg = ERR_PTR(res);
264 * freeque() wakes up waiters on the sender and receiver waiting queue,
265 * removes the message queue from message queue ID IDR, and cleans up all the
266 * messages associated with this queue.
268 * 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.
271 static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
273 struct msg_msg *msg, *t;
274 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
276 expunge_all(msq, -EIDRM);
277 ss_wakeup(&msq->q_senders, 1);
279 ipc_unlock_object(&msq->q_perm);
282 list_for_each_entry_safe(msg, t, &msq->q_messages, m_list) {
283 atomic_dec(&ns->msg_hdrs);
286 atomic_sub(msq->q_cbytes, &ns->msg_bytes);
287 ipc_rcu_putref(msq, msg_rcu_free);
291 * Called with msg_ids.rwsem and ipcp locked.
293 static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
295 struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
297 return security_msg_queue_associate(msq, msgflg);
300 SYSCALL_DEFINE2(msgget, key_t, key, int, msgflg)
302 struct ipc_namespace *ns;
303 struct ipc_ops msg_ops;
304 struct ipc_params msg_params;
306 ns = current->nsproxy->ipc_ns;
308 msg_ops.getnew = newque;
309 msg_ops.associate = msg_security;
310 msg_ops.more_checks = NULL;
312 msg_params.key = key;
313 msg_params.flg = msgflg;
315 return ipcget(ns, &msg_ids(ns), &msg_ops, &msg_params);
318 static inline unsigned long
319 copy_msqid_to_user(void __user *buf, struct msqid64_ds *in, int version)
323 return copy_to_user(buf, in, sizeof(*in));
328 memset(&out, 0, sizeof(out));
330 ipc64_perm_to_ipc_perm(&in->msg_perm, &out.msg_perm);
332 out.msg_stime = in->msg_stime;
333 out.msg_rtime = in->msg_rtime;
334 out.msg_ctime = in->msg_ctime;
336 if (in->msg_cbytes > USHRT_MAX)
337 out.msg_cbytes = USHRT_MAX;
339 out.msg_cbytes = in->msg_cbytes;
340 out.msg_lcbytes = in->msg_cbytes;
342 if (in->msg_qnum > USHRT_MAX)
343 out.msg_qnum = USHRT_MAX;
345 out.msg_qnum = in->msg_qnum;
347 if (in->msg_qbytes > USHRT_MAX)
348 out.msg_qbytes = USHRT_MAX;
350 out.msg_qbytes = in->msg_qbytes;
351 out.msg_lqbytes = in->msg_qbytes;
353 out.msg_lspid = in->msg_lspid;
354 out.msg_lrpid = in->msg_lrpid;
356 return copy_to_user(buf, &out, sizeof(out));
363 static inline unsigned long
364 copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version)
368 if (copy_from_user(out, buf, sizeof(*out)))
373 struct msqid_ds tbuf_old;
375 if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old)))
378 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;
382 if (tbuf_old.msg_qbytes == 0)
383 out->msg_qbytes = tbuf_old.msg_lqbytes;
385 out->msg_qbytes = tbuf_old.msg_qbytes;
395 * This function handles some msgctl commands which require the rwsem
396 * to be held in write mode.
397 * NOTE: no locks must be held, the rwsem is taken inside this function.
399 static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
400 struct msqid_ds __user *buf, int version)
402 struct kern_ipc_perm *ipcp;
403 struct msqid64_ds uninitialized_var(msqid64);
404 struct msg_queue *msq;
407 if (cmd == IPC_SET) {
408 if (copy_msqid_from_user(&msqid64, buf, version))
412 down_write(&msg_ids(ns).rwsem);
415 ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd,
416 &msqid64.msg_perm, msqid64.msg_qbytes);
422 msq = container_of(ipcp, struct msg_queue, q_perm);
424 err = security_msg_queue_msgctl(msq, cmd);
430 ipc_lock_object(&msq->q_perm);
431 /* freeque unlocks the ipc object and rcu */
435 if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
436 !capable(CAP_SYS_RESOURCE)) {
441 ipc_lock_object(&msq->q_perm);
442 err = ipc_update_perm(&msqid64.msg_perm, ipcp);
446 msq->q_qbytes = msqid64.msg_qbytes;
448 msq->q_ctime = get_seconds();
449 /* sleeping receivers might be excluded by
450 * stricter permissions.
452 expunge_all(msq, -EAGAIN);
453 /* sleeping senders might be able to send
454 * due to a larger queue size.
456 ss_wakeup(&msq->q_senders, 0);
464 ipc_unlock_object(&msq->q_perm);
468 up_write(&msg_ids(ns).rwsem);
472 static int msgctl_nolock(struct ipc_namespace *ns, int msqid,
473 int cmd, int version, void __user *buf)
476 struct msg_queue *msq;
482 struct msginfo msginfo;
489 * We must not return kernel stack data.
490 * due to padding, it's not enough
491 * to set all member fields.
493 err = security_msg_queue_msgctl(NULL, cmd);
497 memset(&msginfo, 0, sizeof(msginfo));
498 msginfo.msgmni = ns->msg_ctlmni;
499 msginfo.msgmax = ns->msg_ctlmax;
500 msginfo.msgmnb = ns->msg_ctlmnb;
501 msginfo.msgssz = MSGSSZ;
502 msginfo.msgseg = MSGSEG;
503 down_read(&msg_ids(ns).rwsem);
504 if (cmd == MSG_INFO) {
505 msginfo.msgpool = msg_ids(ns).in_use;
506 msginfo.msgmap = atomic_read(&ns->msg_hdrs);
507 msginfo.msgtql = atomic_read(&ns->msg_bytes);
509 msginfo.msgmap = MSGMAP;
510 msginfo.msgpool = MSGPOOL;
511 msginfo.msgtql = MSGTQL;
513 max_id = ipc_get_maxid(&msg_ids(ns));
514 up_read(&msg_ids(ns).rwsem);
515 if (copy_to_user(buf, &msginfo, sizeof(struct msginfo)))
517 return (max_id < 0) ? 0 : max_id;
523 struct msqid64_ds tbuf;
529 memset(&tbuf, 0, sizeof(tbuf));
532 if (cmd == MSG_STAT) {
533 msq = msq_obtain_object(ns, msqid);
538 success_return = msq->q_perm.id;
540 msq = msq_obtain_object_check(ns, msqid);
549 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
552 err = security_msg_queue_msgctl(msq, cmd);
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;
567 if (copy_msqid_to_user(buf, &tbuf, version))
569 return success_return;
582 SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
585 struct ipc_namespace *ns;
587 if (msqid < 0 || cmd < 0)
590 version = ipc_parse_version(&cmd);
591 ns = current->nsproxy->ipc_ns;
596 case MSG_STAT: /* msqid is an index rather than a msg queue id */
598 return msgctl_nolock(ns, msqid, cmd, version, buf);
601 return msgctl_down(ns, msqid, cmd, buf, version);
607 static int testmsg(struct msg_msg *msg, long type, int mode)
614 case SEARCH_LESSEQUAL:
615 if (msg->m_type <=type)
619 if (msg->m_type == type)
622 case SEARCH_NOTEQUAL:
623 if (msg->m_type != type)
630 static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg)
632 struct msg_receiver *msr, *t;
634 list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
635 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)) {
639 list_del(&msr->r_list);
640 if (msr->r_maxsize < msg->m_ts) {
642 wake_up_process(msr->r_tsk);
644 msr->r_msg = ERR_PTR(-E2BIG);
647 msq->q_lrpid = task_pid_vnr(msr->r_tsk);
648 msq->q_rtime = get_seconds();
649 wake_up_process(msr->r_tsk);
660 long do_msgsnd(int msqid, long mtype, void __user *mtext,
661 size_t msgsz, int msgflg)
663 struct msg_queue *msq;
666 struct ipc_namespace *ns;
668 ns = current->nsproxy->ipc_ns;
670 if (msgsz > ns->msg_ctlmax || (long) msgsz < 0 || msqid < 0)
675 msg = load_msg(mtext, msgsz);
683 msq = msq_obtain_object_check(ns, msqid);
689 ipc_lock_object(&msq->q_perm);
695 if (ipcperms(ns, &msq->q_perm, S_IWUGO))
698 /* raced with RMID? */
699 if (msq->q_perm.deleted) {
704 err = security_msg_queue_msgsnd(msq, msg, msgflg);
708 if (msgsz + msq->q_cbytes <= msq->q_qbytes &&
709 1 + msq->q_qnum <= msq->q_qbytes) {
713 /* queue full, wait: */
714 if (msgflg & IPC_NOWAIT) {
721 if (!ipc_rcu_getref(msq)) {
726 ipc_unlock_object(&msq->q_perm);
731 ipc_lock_object(&msq->q_perm);
733 ipc_rcu_putref(msq, ipc_rcu_free);
734 if (msq->q_perm.deleted) {
741 if (signal_pending(current)) {
742 err = -ERESTARTNOHAND;
747 msq->q_lspid = task_tgid_vnr(current);
748 msq->q_stime = get_seconds();
750 if (!pipelined_send(msq, msg)) {
751 /* no one is waiting for this message, enqueue it */
752 list_add_tail(&msg->m_list, &msq->q_messages);
753 msq->q_cbytes += msgsz;
755 atomic_add(msgsz, &ns->msg_bytes);
756 atomic_inc(&ns->msg_hdrs);
763 ipc_unlock_object(&msq->q_perm);
771 SYSCALL_DEFINE4(msgsnd, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
776 if (get_user(mtype, &msgp->mtype))
778 return do_msgsnd(msqid, mtype, msgp->mtext, msgsz, msgflg);
781 static inline int convert_mode(long *msgtyp, int msgflg)
783 if (msgflg & MSG_COPY)
784 return SEARCH_NUMBER;
786 * find message of correct type.
787 * msgtyp = 0 => get first.
788 * msgtyp > 0 => get first message of matching type.
789 * msgtyp < 0 => get message with least type must be < abs(msgtype).
795 return SEARCH_LESSEQUAL;
797 if (msgflg & MSG_EXCEPT)
798 return SEARCH_NOTEQUAL;
802 static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
804 struct msgbuf __user *msgp = dest;
807 if (put_user(msg->m_type, &msgp->mtype))
810 msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
811 if (store_msg(msgp->mtext, msg, msgsz))
816 #ifdef CONFIG_CHECKPOINT_RESTORE
818 * This function creates new kernel message structure, large enough to store
819 * bufsz message bytes.
821 static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
823 struct msg_msg *copy;
826 * Create dummy message to copy real message to.
828 copy = load_msg(buf, bufsz);
834 static inline void free_copy(struct msg_msg *copy)
840 static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz)
842 return ERR_PTR(-ENOSYS);
845 static inline void free_copy(struct msg_msg *copy)
850 static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
852 struct msg_msg *msg, *found = NULL;
855 list_for_each_entry(msg, &msq->q_messages, m_list) {
856 if (testmsg(msg, *msgtyp, mode) &&
857 !security_msg_queue_msgrcv(msq, msg, current,
859 if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
860 *msgtyp = msg->m_type - 1;
862 } else if (mode == SEARCH_NUMBER) {
863 if (*msgtyp == count)
871 return found ?: ERR_PTR(-EAGAIN);
874 long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, int msgflg,
875 long (*msg_handler)(void __user *, struct msg_msg *, size_t))
878 struct msg_queue *msq;
879 struct ipc_namespace *ns;
880 struct msg_msg *msg, *copy = NULL;
882 ns = current->nsproxy->ipc_ns;
884 if (msqid < 0 || (long) bufsz < 0)
887 if (msgflg & MSG_COPY) {
888 copy = prepare_copy(buf, min_t(size_t, bufsz, ns->msg_ctlmax));
890 return PTR_ERR(copy);
892 mode = convert_mode(&msgtyp, msgflg);
895 msq = msq_obtain_object_check(ns, msqid);
903 struct msg_receiver msr_d;
905 msg = ERR_PTR(-EACCES);
906 if (ipcperms(ns, &msq->q_perm, S_IRUGO))
909 ipc_lock_object(&msq->q_perm);
911 /* raced with RMID? */
912 if (msq->q_perm.deleted) {
913 msg = ERR_PTR(-EIDRM);
917 msg = find_msg(msq, &msgtyp, mode);
920 * Found a suitable message.
921 * Unlink it from the queue.
923 if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
924 msg = ERR_PTR(-E2BIG);
928 * If we are copying, then do not unlink message and do
929 * not update queue parameters.
931 if (msgflg & MSG_COPY) {
932 msg = copy_msg(msg, copy);
936 list_del(&msg->m_list);
938 msq->q_rtime = get_seconds();
939 msq->q_lrpid = task_tgid_vnr(current);
940 msq->q_cbytes -= msg->m_ts;
941 atomic_sub(msg->m_ts, &ns->msg_bytes);
942 atomic_dec(&ns->msg_hdrs);
943 ss_wakeup(&msq->q_senders, 0);
948 /* No message waiting. Wait for a message */
949 if (msgflg & IPC_NOWAIT) {
950 msg = ERR_PTR(-ENOMSG);
954 list_add_tail(&msr_d.r_list, &msq->q_receivers);
955 msr_d.r_tsk = current;
956 msr_d.r_msgtype = msgtyp;
958 if (msgflg & MSG_NOERROR)
959 msr_d.r_maxsize = INT_MAX;
961 msr_d.r_maxsize = bufsz;
962 msr_d.r_msg = ERR_PTR(-EAGAIN);
963 current->state = TASK_INTERRUPTIBLE;
965 ipc_unlock_object(&msq->q_perm);
969 /* Lockless receive, part 1:
970 * Disable preemption. We don't hold a reference to the queue
971 * and getting a reference would defeat the idea of a lockless
972 * operation, thus the code relies on rcu to guarantee the
974 * Prior to destruction, expunge_all(-EIRDM) changes r_msg.
975 * Thus if r_msg is -EAGAIN, then the queue not yet destroyed.
976 * rcu_read_lock() prevents preemption between reading r_msg
977 * and acquiring the q_perm.lock in ipc_lock_object().
981 /* Lockless receive, part 2:
982 * Wait until pipelined_send or expunge_all are outside of
983 * wake_up_process(). There is a race with exit(), see
984 * ipc/mqueue.c for the details.
986 msg = (struct msg_msg*)msr_d.r_msg;
987 while (msg == NULL) {
989 msg = (struct msg_msg *)msr_d.r_msg;
992 /* Lockless receive, part 3:
993 * If there is a message or an error then accept it without
996 if (msg != ERR_PTR(-EAGAIN))
999 /* Lockless receive, part 3:
1000 * Acquire the queue spinlock.
1002 ipc_lock_object(&msq->q_perm);
1004 /* Lockless receive, part 4:
1005 * Repeat test after acquiring the spinlock.
1007 msg = (struct msg_msg*)msr_d.r_msg;
1008 if (msg != ERR_PTR(-EAGAIN))
1011 list_del(&msr_d.r_list);
1012 if (signal_pending(current)) {
1013 msg = ERR_PTR(-ERESTARTNOHAND);
1017 ipc_unlock_object(&msq->q_perm);
1021 ipc_unlock_object(&msq->q_perm);
1026 return PTR_ERR(msg);
1029 bufsz = msg_handler(buf, msg, bufsz);
1035 SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
1036 long, msgtyp, int, msgflg)
1038 return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
1041 #ifdef CONFIG_PROC_FS
1042 static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
1044 struct user_namespace *user_ns = seq_user_ns(s);
1045 struct msg_queue *msq = it;
1047 return seq_printf(s,
1048 "%10d %10d %4o %10lu %10lu %5u %5u %5u %5u %5u %5u %10lu %10lu %10lu\n",
1056 from_kuid_munged(user_ns, msq->q_perm.uid),
1057 from_kgid_munged(user_ns, msq->q_perm.gid),
1058 from_kuid_munged(user_ns, msq->q_perm.cuid),
1059 from_kgid_munged(user_ns, msq->q_perm.cgid),