[PATCH] con_font_copy sanitized

->con_font_copy() sanitized.  We extract the number of console to copy the
font from in the caller (it's taken from the field of console_font_op that
is normally used for font height - messy even for an ioctl, but that animal
used to be passed all the way down into console drivers).

With decoding done in con_font_copy(), we simply pass source console number
into the method.
Signed-off-by: Al Viro <viro@parcelfarce.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/char/vt.c

@@ -3170,16 +3170,23 @@ int con_font_default(int currcons, struct console_font_op *op)
 
 int con_font_copy(int currcons, struct console_font_op *op)
 {
+	int con = op->height;
+	struct vc_data *vc;
 	int rc;
 
 	if (vt_cons[currcons]->vc_mode != KD_TEXT)
 		return -EINVAL;
 
 	acquire_console_sem();
-	if (sw->con_font_copy)
-		rc = sw->con_font_copy(vc_cons[currcons].d, op);
-	else
+	vc = vc_cons[currcons].d;
+	if (!sw->con_font_copy)
 		rc = -ENOSYS;
+	else if (con < 0 || !vc_cons_allocated(con))
+		rc = -ENOTTY;
+	else if (con == vc->vc_num)	/* nothing to do */
+		rc = 0;
+	else
+		rc = sw->con_font_copy(vc, con);
 	release_console_sem();
 	return rc;
 }

drivers/video/console/fbcon.c

@@ -2167,21 +2167,17 @@ static int fbcon_do_set_font(struct vc_data *vc, struct console_font_op *op,
 	return 0;
 }
 
-static int fbcon_copy_font(struct vc_data *vc, struct console_font_op *op)
+static int fbcon_copy_font(struct vc_data *vc, int con)
 {
-	struct display *od;
-	int h = op->height;
+	struct display *od = &fb_display[con];
+	struct console_font_op crap;
 
-	if (h < 0 || !vc_cons_allocated(h))
-		return -ENOTTY;
-	if (h == vc->vc_num)
-		return 0;	/* nothing to do */
-	od = &fb_display[h];
 	if (od->fontdata == vc->vc_font.data)
 		return 0;	/* already the same font... */
-	op->width = vc->vc_font.width;
-	op->height = vc->vc_font.height;
-	return fbcon_do_set_font(vc, op, od->fontdata, od->userfont);
+	crap.op = KD_FONT_OP_COPY;
+	crap.width = vc->vc_font.width;
+	crap.height = vc->vc_font.height;
+	return fbcon_do_set_font(vc, &crap, od->fontdata, od->userfont);
 }
 
 static int fbcon_set_font(struct vc_data *vc, struct console_font_op *op)

include/linux/console.h

@@ -44,7 +44,7 @@ struct consw {
 	int	(*con_font_set)(struct vc_data *, struct console_font_op *);
 	int	(*con_font_get)(struct vc_data *, struct console_font_op *);
 	int	(*con_font_default)(struct vc_data *, struct console_font *, char *);
-	int	(*con_font_copy)(struct vc_data *, struct console_font_op *);
+	int	(*con_font_copy)(struct vc_data *, int);
 	int	(*con_resize)(struct vc_data *, unsigned int, unsigned int);
 	int	(*con_set_palette)(struct vc_data *, unsigned char *);
 	int	(*con_scrolldelta)(struct vc_data *, int);