ipc: message queue receive cleanup

Move all message related manipulation into one function msg_fill().
Actually, two functions because of the compat one.

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 26 deletions

diff --git a/ipc/compat.c b/ipc/compat.c
index ad9518eb26e0..eb3ea16d2d1d 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