[PATCH v8 3/5] ipc: message queue receive cleanup
This patch moves all message related manipulation into one function msg_fill(). Actually, two functions because of the compat one. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> --- include/linux/msg.h | 5 +++-- ipc/compat.c | 45 +++++++++++++++++++-------------------------- ipc/msg.c | 44 +++++++++++++++++++++++--------------------- 3 files changed, 45 insertions(+), 49 deletions(-) diff --git a/include/linux/msg.h b/include/linux/msg.h index 7a4b9e9..f38edba 100644 --- a/include/linux/msg.h +++ b/include/linux/msg.h @@ -34,7 +34,8 @@ struct msg_queue { /* Helper routines for sys_msgsnd and sys_msgrcv */ extern long do_msgsnd(int msqid, long mtype, void __user *mtext, size_t msgsz, int msgflg); -extern long do_msgrcv(int msqid, long *pmtype, void __user *mtext, - size_t msgsz, long msgtyp, int msgflg); +extern long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, + int msgflg, + long (*msg_fill)(void __user *, struct msg_msg *, size_t )); #endif /* _LINUX_MSG_H */ diff --git a/ipc/compat.c b/ipc/compat.c index ad9518e..eb3ea16 100644 --- a/ipc/compat.c +++ b/ipc/compat.c @@ -306,6 +306,20 @@ static long do_compat_semctl(int first, int second, int third, u32 pad) return err; } +long compat_do_msg_fill(void __user *dest, struct msg_msg *msg, size_t bufsz) +{ + struct compat_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_ARCH_WANT_OLD_COMPAT_IPC long compat_sys_semctl(int first, int second, int third, void __user *uptr) { @@ -337,10 +351,6 @@ long compat_sys_msgsnd(int first, int second, int third, void __user *uptr) long compat_sys_msgrcv(int first, int second, int msgtyp, int third, int version, void __user *uptr) { - struct compat_msgbuf __user *up; - long type; - int err; - if (first < 0) return -EINVAL; if (second < 0) @@ -348,23 +358,14 @@ long compat_sys_msgrcv(int first, int second, int msgtyp, int third, if (!version) { struct compat_ipc_kludge ipck; - err = -EINVAL; if (!uptr) - goto out; - err = -EFAULT; + return -EINVAL; if (copy_from_user (&ipck, uptr, sizeof(ipck))) - goto out; + return -EFAULT; uptr = compat_ptr(ipck.msgp); msgtyp = ipck.msgtyp; } - up = uptr; - err = do_msgrcv(first, &type, up->mtext, second, msgtyp, third); - if (err < 0) - goto out; - if (put_user(type, &up->mtype)) - err = -EFAULT; -out: - return err; + return do_msgrcv(first, uptr, second, msgtyp, third, compat_do_msg_fill); } #else long compat_sys_semctl(int semid, int semnum, int cmd, int arg) @@ -385,16 +386,8 @@ long compat_sys_msgsnd(int msqid, struct compat_msgbuf __user *msgp, long compat_sys_msgrcv(int msqid, struct compat_msgbuf __user *msgp, compat_ssize_t msgsz, long msgtyp, int msgflg) { - long err, mtype; - - err = do_msgrcv(msqid, &mtype, msgp->mtext, (ssize_t)msgsz, msgtyp, msgflg); - if (err < 0) - goto out; - - if (put_user(mtype, &msgp->mtype)) - err = -EFAULT; - out: - return err; + return do_msgrcv(msqid, msgp, (ssize_t)msgsz, msgtyp, msgflg, + compat_do_msg_fill); } #endif diff --git a/ipc/msg.c b/ipc/msg.c index 2f272fa..532ebc3 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -755,15 +755,30 @@ static inline int convert_mode(long *msgtyp, int msgflg) 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; +} + +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; - if (msqid < 0 || (long) msgsz < 0) + if (msqid < 0 || (long) bufsz < 0) return -EINVAL; mode = convert_mode(&msgtyp, msgflg); ns = current->nsproxy->ipc_ns; @@ -804,7 +819,7 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext, * 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; } @@ -831,7 +846,7 @@ long do_msgrcv(int msqid, long *pmtype, void __user *mtext, 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); @@ -894,29 +909,16 @@ out_unlock: if (IS_ERR(msg)) 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