[PARISC] Allow overriding personality with sys_personality

And now suddenly, linux32 works on parisc...
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

arch/parisc/kernel/sys_parisc.c

@@ -31,6 +31,8 @@
 #include <linux/shm.h>
 #include <linux/smp_lock.h>
 #include <linux/syscalls.h>
+#include <linux/utsname.h>
+#include <linux/personality.h>
 
 int sys_pipe(int __user *fildes)
 {
@@ -248,3 +250,46 @@ asmlinkage int sys_free_hugepages(unsigned long addr)
 {
 	return -EINVAL;
 }
+
+long parisc_personality(unsigned long personality)
+{
+	long err;
+
+	if (personality(current->personality) == PER_LINUX32
+	    && personality == PER_LINUX)
+		personality = PER_LINUX32;
+
+	err = sys_personality(personality);
+	if (err == PER_LINUX32)
+		err = PER_LINUX;
+
+	return err;
+}
+
+static inline int override_machine(char __user *mach) {
+#ifdef CONFIG_COMPAT
+	if (personality(current->personality) == PER_LINUX32) {
+		if (__put_user(0, mach + 6) ||
+		    __put_user(0, mach + 7))
+			return -EFAULT;
+	}
+
+	return 0;
+#else /*!CONFIG_COMPAT*/
+	return 0;
+#endif /*CONFIG_COMPAT*/
+}
+
+long parisc_newuname(struct new_utsname __user *utsname)
+{
+	int err = 0;
+
+	down_read(&uts_sem);
+	if (copy_to_user(utsname, &system_utsname, sizeof(*utsname)))
+		err = -EFAULT;
+	up_read(&uts_sem);
+
+	err = override_machine(utsname->machine);
+
+	return (long)err;
+}

arch/parisc/kernel/syscall_table.S

@@ -132,7 +132,7 @@
 	ENTRY_SAME(socketpair)
 	ENTRY_SAME(setpgid)
 	ENTRY_SAME(send)
-	ENTRY_SAME(newuname)
+	ENTRY_OURS(newuname)
 	ENTRY_SAME(umask)		/* 60 */
 	ENTRY_SAME(chroot)
 	ENTRY_SAME(ustat)
@@ -221,7 +221,7 @@
 	ENTRY_SAME(fchdir)
 	ENTRY_SAME(bdflush)
 	ENTRY_SAME(sysfs)		/* 135 */
-	ENTRY_SAME(personality)
+	ENTRY_OURS(personality)
 	ENTRY_SAME(ni_syscall)	/* for afs_syscall */
 	ENTRY_SAME(setfsuid)
 	ENTRY_SAME(setfsgid)