ipc/compat_sys_msgrcv: change msgtyp type from long to compat_long_t

Change the type of compat_sys_msgrcv's msgtyp parameter from long
to compat_long_t, since compat user space passes only a 32 bit signed
value.
Let the compat wrapper do proper sign extension to 64 bit of this
parameter.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

include/linux/compat.h

@@ -321,7 +321,7 @@ asmlinkage long compat_sys_semctl(int semid, int semnum, int cmd, int arg);
 asmlinkage long compat_sys_msgsnd(int msqid, compat_uptr_t msgp,
 		compat_ssize_t msgsz, int msgflg);
 asmlinkage long compat_sys_msgrcv(int msqid, compat_uptr_t msgp,
-		compat_ssize_t msgsz, long msgtyp, int msgflg);
+		compat_ssize_t msgsz, compat_long_t msgtyp, int msgflg);
 long compat_sys_msgctl(int first, int second, void __user *uptr);
 long compat_sys_shmctl(int first, int second, void __user *uptr);
 long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,

ipc/compat.c

@@ -430,9 +430,9 @@ COMPAT_SYSCALL_DEFINE4(msgsnd, int, msqid, compat_uptr_t, msgp,
 }
 
 COMPAT_SYSCALL_DEFINE5(msgrcv, int, msqid, compat_uptr_t, msgp,
-		       compat_ssize_t, msgsz, long, msgtyp, int, msgflg)
+		       compat_ssize_t, msgsz, compat_long_t, msgtyp, int, msgflg)
 {
-	return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, msgtyp,
+	return do_msgrcv(msqid, compat_ptr(msgp), (ssize_t)msgsz, (long)msgtyp,
 			 msgflg, compat_do_msg_fill);
 }