return SEARCH_EQUAL;
}
-long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
- size_t msgsz, long msgtyp, int msgflg)
+static long do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz)
+{
+ struct msgbuf __user *msgp = dest;
+ size_t msgsz;
+
+ if (put_user(msg->m_type, &msgp->mtype))
+ return -EFAULT;
+
+ msgsz = (bufsz > msg->m_ts) ? msg->m_ts : bufsz;
+ if (store_msg(msgp->mtext, msg, msgsz))
+ return -EFAULT;
+ return msgsz;
+}
+
+#ifdef CONFIG_CHECKPOINT_RESTORE
+static inline struct msg_msg *fill_copy(unsigned long copy_nr,
+ unsigned long msg_nr,
+ struct msg_msg *msg,
+ struct msg_msg *copy)
+{
+ if (copy_nr == msg_nr)
+ return copy_msg(msg, copy);
+ return NULL;
+}
+
+static inline struct msg_msg *prepare_copy(void __user *buf, size_t bufsz,
+ int msgflg, long *msgtyp,
+ unsigned long *copy_number)
+{
+ struct msg_msg *copy;
+
+ *copy_number = *msgtyp;
+ *msgtyp = 0;
+ /*
+ * Create dummy message to copy real message to.
+ */
+ copy = load_msg(buf, bufsz);
+ if (!IS_ERR(copy))
+ copy->m_ts = bufsz;
+ return copy;
+}
+
+static inline void free_copy(int msgflg, struct msg_msg *copy)
+{
+ if (msgflg & MSG_COPY)
+ free_msg(copy);
+}
+#else
+#define free_copy(msgflg, copy) do {} while (0)
+#define prepare_copy(buf, sz, msgflg, msgtyp, copy_nr) ERR_PTR(-ENOSYS)
+#define fill_copy(copy_nr, msg_nr, msg, copy) NULL
+#endif
+
+long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp,
+ int msgflg,
+ long (*msg_handler)(void __user *, struct msg_msg *, size_t))
{
struct msg_queue *msq;
struct msg_msg *msg;
int mode;
struct ipc_namespace *ns;
+ struct msg_msg *copy;
+ unsigned long __maybe_unused copy_number;
- if (msqid < 0 || (long) msgsz < 0)
+ if (msqid < 0 || (long) bufsz < 0)
return -EINVAL;
+ if (msgflg & MSG_COPY) {
+ copy = prepare_copy(buf, bufsz, msgflg, &msgtyp, ©_number);
+ if (IS_ERR(copy))
+ return PTR_ERR(copy);
+ }
mode = convert_mode(&msgtyp, msgflg);
ns = current->nsproxy->ipc_ns;
msq = msg_lock_check(ns, msqid);
- if (IS_ERR(msq))
+ if (IS_ERR(msq)) {
+ free_copy(msgflg, copy);
return PTR_ERR(msq);
+ }
for (;;) {
struct msg_receiver msr_d;
struct list_head *tmp;
+ long msg_counter = 0;
msg = ERR_PTR(-EACCES);
if (ipcperms(ns, &msq->q_perm, S_IRUGO))
msg = walk_msg;
if (mode == SEARCH_LESSEQUAL &&
walk_msg->m_type != 1) {
- msg = walk_msg;
msgtyp = walk_msg->m_type - 1;
- } else {
- msg = walk_msg;
+ } else if (msgflg & MSG_COPY) {
+ msg = fill_copy(copy_number,
+ msg_counter,
+ walk_msg, copy);
+ if (msg)
+ break;
+ } else
break;
- }
+ msg_counter++;
}
tmp = tmp->next;
}
* Found a suitable message.
* Unlink it from the queue.
*/
- if ((msgsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
+ if ((bufsz < msg->m_ts) && !(msgflg & MSG_NOERROR)) {
msg = ERR_PTR(-E2BIG);
goto out_unlock;
}
+ if (msgflg & MSG_COPY)
+ goto out_unlock;
list_del(&msg->m_list);
msq->q_qnum--;
msq->q_rtime = get_seconds();
if (msgflg & MSG_NOERROR)
msr_d.r_maxsize = INT_MAX;
else
- msr_d.r_maxsize = msgsz;
+ msr_d.r_maxsize = bufsz;
msr_d.r_msg = ERR_PTR(-EAGAIN);
current->state = TASK_INTERRUPTIBLE;
msg_unlock(msq);
break;
}
}
- if (IS_ERR(msg))
+ if (IS_ERR(msg)) {
+ free_copy(msgflg, copy);
return PTR_ERR(msg);
+ }
- msgsz = (msgsz > msg->m_ts) ? msg->m_ts : msgsz;
- *pmtype = msg->m_type;
- if (store_msg(mtext, msg, msgsz))
- msgsz = -EFAULT;
-
+ bufsz = msg_handler(buf, msg, bufsz);
free_msg(msg);
- return msgsz;
+ return bufsz;
}
SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
long, msgtyp, int, msgflg)
{
- long err, mtype;
-
- err = do_msgrcv(msqid, &mtype, msgp->mtext, msgsz, msgtyp, msgflg);
- if (err < 0)
- goto out;
-
- if (put_user(mtype, &msgp->mtype))
- err = -EFAULT;
-out:
- return err;
+ return do_msgrcv(msqid, msgp, msgsz, msgtyp, msgflg, do_msg_fill);
}
#ifdef CONFIG_PROC_FS