[MIPS] Fix N32 SysV IPC routines

Add wrappers for N32 msg{snd,rcv}.  compat_sys_msg{snd,rcv} can not not be
used as system call entries as is.  This fix is based on Kaz Kylheku's
patch.

Also change a type of last argument of sysn32_semctl to match its true
size.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/linux32.c

@@ -440,14 +440,26 @@ sys32_ipc (u32 call, int first, int second, int third, u32 ptr, u32 fifth)
 }
 
 #ifdef CONFIG_MIPS32_N32
-asmlinkage long sysn32_semctl(int semid, int semnum, int cmd, union semun arg)
+asmlinkage long sysn32_semctl(int semid, int semnum, int cmd, u32 arg)
 {
 	/* compat_sys_semctl expects a pointer to union semun */
 	u32 __user *uptr = compat_alloc_user_space(sizeof(u32));
-	if (put_user(ptr_to_compat(arg.__pad), uptr))
+	if (put_user(arg, uptr))
 		return -EFAULT;
 	return compat_sys_semctl(semid, semnum, cmd, uptr);
 }
+
+asmlinkage long sysn32_msgsnd(int msqid, u32 msgp, unsigned msgsz, int msgflg)
+{
+	return compat_sys_msgsnd(msqid, msgsz, msgflg, compat_ptr(msgp));
+}
+
+asmlinkage long sysn32_msgrcv(int msqid, u32 msgp, size_t msgsz, int msgtyp,
+			      int msgflg)
+{
+	return compat_sys_msgrcv(msqid, msgsz, msgtyp, msgflg, IPC_64,
+				 compat_ptr(msgp));
+}
 #endif
 
 struct sysctl_args32

arch/mips/kernel/scall64-n32.S

@@ -187,8 +187,8 @@ EXPORT(sysn32_call_table)
 	PTR	sysn32_semctl
 	PTR	sys_shmdt			/* 6065 */
 	PTR	sys_msgget
-	PTR	compat_sys_msgsnd
-	PTR	compat_sys_msgrcv
+	PTR	sysn32_msgsnd
+	PTR	sysn32_msgrcv
 	PTR	compat_sys_msgctl
 	PTR	compat_sys_fcntl		/* 6070 */
 	PTR	sys_flock