From patchwork Mon May 24 15:25:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 448113 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE94BC2B9F8 for ; Mon, 24 May 2021 15:33:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9443E6141F for ; Mon, 24 May 2021 15:33:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233126AbhEXPef (ORCPT ); Mon, 24 May 2021 11:34:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:50506 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233461AbhEXPdd (ORCPT ); Mon, 24 May 2021 11:33:33 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6C2D061376; Mon, 24 May 2021 15:31:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621870277; bh=4A60Kp4Galht+txE64K/9ptp8sNYlq4knm/mek7Ml6E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qCxIzRdpjU8koc5nirz0DfjNgRYpHdi7U9euN+TKYjd3MGl3Ii1wDq64vQwyZ6Ude 3mBR0CiMuqJ5j3hm/T+4h2TalNHsCQyvXSKPrTQFJuhffXrFxQ8cAv3NeargL7Hqz2 wIGOWas021WkkZjv05K6kmS/qXsyIzcTexJGgvZA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Maciej W. Rozycki" , Linus Torvalds Subject: [PATCH 4.4 29/31] vgacon: Record video mode changes with VT_RESIZEX Date: Mon, 24 May 2021 17:25:12 +0200 Message-Id: <20210524152323.863587615@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210524152322.919918360@linuxfoundation.org> References: <20210524152322.919918360@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Maciej W. Rozycki commit d4d0ad57b3865795c4cde2fb5094c594c2e8f469 upstream. Fix an issue with VGA console font size changes made after the initial video text mode has been changed with a user tool like `svgatextmode' calling the VT_RESIZEX ioctl. As it stands in that case the original screen geometry continues being used to validate further VT resizing. Consequently when the video adapter is firstly reprogrammed from the original say 80x25 text mode using a 9x16 character cell (720x400 pixel resolution) to say 80x37 text mode and the same character cell (720x592 pixel resolution), and secondly the CRTC character cell updated to 9x8 (by loading a suitable font with the KD_FONT_OP_SET request of the KDFONTOP ioctl), the VT geometry does not get further updated from 80x37 and only upper half of the screen is used for the VT, with the lower half showing rubbish corresponding to whatever happens to be there in the video memory that maps to that part of the screen. Of course the proportions change according to text mode geometries and font sizes chosen. Address the problem then, by updating the text mode geometry defaults rather than checking against them whenever the VT is resized via a user ioctl. Signed-off-by: Maciej W. Rozycki Fixes: e400b6ec4ede ("vt/vgacon: Check if screen resize request comes from userspace") Cc: stable@vger.kernel.org # v2.6.24+ Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/video/console/vgacon.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -1179,12 +1179,20 @@ static int vgacon_resize(struct vc_data if ((width << 1) * height > vga_vram_size) return -EINVAL; + if (user) { + /* + * Ho ho! Someone (svgatextmode, eh?) may have reprogrammed + * the video mode! Set the new defaults then and go away. + */ + screen_info.orig_video_cols = width; + screen_info.orig_video_lines = height; + vga_default_font_height = c->vc_font.height; + return 0; + } if (width % 2 || width > screen_info.orig_video_cols || height > (screen_info.orig_video_lines * vga_default_font_height)/ c->vc_font.height) - /* let svgatextmode tinker with video timings and - return success */ - return (user) ? 0 : -EINVAL; + return -EINVAL; if (CON_IS_VISIBLE(c) && !vga_is_gfx) /* who knows */ vgacon_doresize(c, width, height);