[PATCH] Fix ioperm bitmap

This makes sure that the ioperm bitmap in the TSS is correctly set up
during the first ioperm() call.  Without this the TSS bitmap contains
random garbage until the next context switch.

arch/i386/kernel/ioport.c

@@ -84,15 +84,17 @@ asmlinkage int sys_ioperm(unsigned long from, unsigned long num, int turn_on)
 		t->ts_io_bitmap = bitmap;
 	}
 
-	tss = init_tss + get_cpu();
-	if (bitmap)
-		tss->bitmap = IO_BITMAP_OFFSET;	/* Activate it in the TSS */
-
 	/*
 	 * do it in the per-thread copy and in the TSS ...
 	 */
 	set_bitmap(t->ts_io_bitmap, from, num, !turn_on);
-	set_bitmap(tss->io_bitmap, from, num, !turn_on);
+	tss = init_tss + get_cpu();
+	if (tss->bitmap == IO_BITMAP_OFFSET) { /* already active? */
+		set_bitmap(tss->io_bitmap, from, num, !turn_on);
+	} else {
+		memcpy(tss->io_bitmap, t->ts_io_bitmap, IO_BITMAP_BYTES);
+		tss->bitmap = IO_BITMAP_OFFSET;	/* Activate it in the TSS */
+	}
 	put_cpu();
 out:
 	return ret;