parisc: convert msgrcv and msgsnd syscalls to use compat layer

Switch over to use the existing compat_* implementation for msgrcv() and
msgsnd().  Existing code was even partly buggy since it returned on some paths
different error codes than the standard.

Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/kernel/sys_parisc32.c

@@ -21,7 +21,6 @@
 #include <linux/time.h>
 #include <linux/smp.h>
 #include <linux/sem.h>
-#include <linux/msg.h>
 #include <linux/shm.h>
 #include <linux/slab.h>
 #include <linux/uio.h>
@@ -73,63 +72,6 @@ asmlinkage long sys32_sched_rr_get_interval(pid_t pid,
 	return ret;
 }
 
-struct msgbuf32 {
-    int mtype;
-    char mtext[1];
-};
-
-asmlinkage long sys32_msgsnd(int msqid,
-				struct msgbuf32 __user *umsgp32,
-				size_t msgsz, int msgflg)
-{
-	struct msgbuf *mb;
-	struct msgbuf32 mb32;
-	int err;
-
-	if ((mb = kmalloc(msgsz + sizeof *mb + 4, GFP_KERNEL)) == NULL)
-		return -ENOMEM;
-
-	err = get_user(mb32.mtype, &umsgp32->mtype);
-	mb->mtype = mb32.mtype;
-	err |= copy_from_user(mb->mtext, &umsgp32->mtext, msgsz);
-
-	if (err)
-		err = -EFAULT;
-	else
-		KERNEL_SYSCALL(err, sys_msgsnd, msqid, (struct msgbuf __user *)mb, msgsz, msgflg);
-
-	kfree(mb);
-	return err;
-}
-
-asmlinkage long sys32_msgrcv(int msqid,
-				struct msgbuf32 __user *umsgp32,
-				size_t msgsz, long msgtyp, int msgflg)
-{
-	struct msgbuf *mb;
-	struct msgbuf32 mb32;
-	int err, len;
-
-	if ((mb = kmalloc(msgsz + sizeof *mb + 4, GFP_KERNEL)) == NULL)
-		return -ENOMEM;
-
-	KERNEL_SYSCALL(err, sys_msgrcv, msqid, (struct msgbuf __user *)mb, msgsz, msgtyp, msgflg);
-
-	if (err >= 0) {
-		len = err;
-		mb32.mtype = mb->mtype;
-		err = put_user(mb32.mtype, &umsgp32->mtype);
-		err |= copy_to_user(&umsgp32->mtext, mb->mtext, len);
-		if (err)
-			err = -EFAULT;
-		else
-			err = len;
-	}
-
-	kfree(mb);
-	return err;
-}
-
 asmlinkage int sys32_sendfile(int out_fd, int in_fd, compat_off_t __user *offset, s32 count)
 {
         mm_segment_t old_fs = get_fs();

arch/parisc/kernel/syscall_table.S

@@ -286,8 +286,8 @@
 	ENTRY_SAME(semop)		/* 185 */
 	ENTRY_SAME(semget)
 	ENTRY_DIFF(semctl)
-	ENTRY_DIFF(msgsnd)
-	ENTRY_DIFF(msgrcv)
+	ENTRY_COMP(msgsnd)
+	ENTRY_COMP(msgrcv)
 	ENTRY_SAME(msgget)		/* 190 */
 	ENTRY_SAME(msgctl)
 	ENTRY_SAME(shmat)