[PARISC] fix personality flag check in copy_thread()

Directly comparing task_struct->personality against PER_* is not fully
correct, as it doesn't take flags potentially stored in top three bytes
into account.

Analogically, directly forcefully setting personality to PER_LINUX32 or
PER_LINUX discards any flags stored in the top three bytes.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

arch/parisc/kernel/process.c

@@ -309,7 +309,7 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
 		cregs->ksp = (unsigned long)stack
 			+ (pregs->gr[21] & (THREAD_SIZE - 1));
 		cregs->gr[30] = usp;
-		if (p->personality == PER_HPUX) {
+		if (personality(p->personality) == PER_HPUX) {
 #ifdef CONFIG_HPUX
 			cregs->kpc = (unsigned long) &hpux_child_return;
 #else

arch/parisc/kernel/sys_parisc.c

@@ -225,12 +225,12 @@ long parisc_personality(unsigned long personality)
 	long err;
 
 	if (personality(current->personality) == PER_LINUX32
-	    && personality == PER_LINUX)
-		personality = PER_LINUX32;
+	    && personality(personality) == PER_LINUX)
+		personality = (personality & ~PER_MASK) | PER_LINUX32;
 
 	err = sys_personality(personality);
-	if (err == PER_LINUX32)
-		err = PER_LINUX;
+	if (personality(err) == PER_LINUX32)
+		err = (err & ~PER_MASK) | PER_LINUX;
 
 	return err;
 }