From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751969AbcG1W4W (ORCPT ); Thu, 28 Jul 2016 18:56:22 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50536 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751438AbcG1W4T (ORCPT ); Thu, 28 Jul 2016 18:56:19 -0400 Date: Thu, 28 Jul 2016 18:56:13 -0400 (EDT) From: Mikulas Patocka X-X-Sender: mpatocka@file01.intranet.prod.int.rdu2.redhat.com To: Ben Skeggs cc: dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org, Tomi Valkeinen , Jean-Christophe Plagniol-Villard Subject: [PATCH] drm/nouveau/fbcon: fix font width not divisible by 8 Message-ID: User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 28 Jul 2016 22:56:18 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The patch f045f459d925 ("drm/nouveau/fbcon: fix out-of-bounds memory accesses") tries to fix some out of memory accesses. Unfortunatelly, the patch breaks the display when using fonts with width that is not divisiable by 8. The monochrome bitmap for each character is stored in memory by lines from top to bottom. Each line is padded to a full byte. For example, for 22x11 font, each line is padded to 16 bits, so each character is consuming 44 bytes total, that is 11 32-bit words. The patch f045f459d925 changed the logic to "dsize = ALIGN(image->width * image->height, 32) >> 5", that is just 8 words - this is incorrect and it causes display corruption. This patch adds the necesary padding of lines to 8 bytes. This patch should be backported to stable kernels where f045f459d925 was backported. Signed-off-by: Mikulas Patocka Fixes: f045f459d925 ("drm/nouveau/fbcon: fix out-of-bounds memory accesses") Cc: stable@vger.kernel.org Index: linux-2.6/drivers/gpu/drm/nouveau/nvc0_fbcon.c =================================================================== --- linux-2.6.orig/drivers/gpu/drm/nouveau/nvc0_fbcon.c +++ linux-2.6/drivers/gpu/drm/nouveau/nvc0_fbcon.c @@ -125,7 +125,7 @@ nvc0_fbcon_imageblit(struct fb_info *inf OUT_RING (chan, 0); OUT_RING (chan, image->dy); - dwords = ALIGN(image->width * image->height, 32) >> 5; + dwords = ALIGN(ALIGN(image->width, 8) * image->height, 32) >> 5; while (dwords) { int push = dwords > 2047 ? 2047 : dwords; Index: linux-2.6/drivers/gpu/drm/nouveau/nv04_fbcon.c =================================================================== --- linux-2.6.orig/drivers/gpu/drm/nouveau/nv04_fbcon.c +++ linux-2.6/drivers/gpu/drm/nouveau/nv04_fbcon.c @@ -107,11 +107,11 @@ nv04_fbcon_imageblit(struct fb_info *inf ((image->dx + image->width) & 0xffff)); OUT_RING(chan, bg); OUT_RING(chan, fg); - OUT_RING(chan, (image->height << 16) | image->width); + OUT_RING(chan, (image->height << 16) | ALIGN(image->width, 8)); OUT_RING(chan, (image->height << 16) | image->width); OUT_RING(chan, (image->dy << 16) | (image->dx & 0xffff)); - dsize = ALIGN(image->width * image->height, 32) >> 5; + dsize = ALIGN(ALIGN(image->width, 8) * image->height, 32) >> 5; while (dsize) { int iter_len = dsize > 128 ? 128 : dsize; Index: linux-2.6/drivers/gpu/drm/nouveau/nv50_fbcon.c =================================================================== --- linux-2.6.orig/drivers/gpu/drm/nouveau/nv50_fbcon.c +++ linux-2.6/drivers/gpu/drm/nouveau/nv50_fbcon.c @@ -125,7 +125,7 @@ nv50_fbcon_imageblit(struct fb_info *inf OUT_RING(chan, 0); OUT_RING(chan, image->dy); - dwords = ALIGN(image->width * image->height, 32) >> 5; + dwords = ALIGN(ALIGN(image->width, 8) * image->height, 32) >> 5; while (dwords) { int push = dwords > 2047 ? 2047 : dwords;