From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 D4151C282C7 for ; Tue, 29 Jan 2019 11:39:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A607D2148E for ; Tue, 29 Jan 2019 11:39:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548761964; bh=4GioorKk7EUnjVuM1v6EvE6VBkxkD1Le/LCEWDYLwwM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=2ci1llOayBQLWQkjxETpWi9KVWA4DdlpiLPfBjzDBF8bjztPLNI3/2ckFZ2Z03h5H F7+Af32ZOV3z+sS+42sgXvyrbLLBcyf2IuxkltWWJvv82E4Bw/wvIvvgbOCxHAV60J ZxZfrK2K5TBdTKUjONnZGh/CHHYOJHNicErKOgRw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729419AbfA2LjW (ORCPT ); Tue, 29 Jan 2019 06:39:22 -0500 Received: from mail.kernel.org ([198.145.29.99]:56044 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729413AbfA2LjV (ORCPT ); Tue, 29 Jan 2019 06:39:21 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9D95320857; Tue, 29 Jan 2019 11:39:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548761961; bh=4GioorKk7EUnjVuM1v6EvE6VBkxkD1Le/LCEWDYLwwM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bPjPZq7+Milr7U75Q5orXlQV3x8PUaSa5LxOAMggiiCnAQSLdT/f/MSLFhnVJFwj2 MUDtGtxUZSOznLmttIGThLtnd4UbS1CEMcvttIC/tosdL12b8YapgDiBrTHjMhAhy5 eL+/4MBc1DRnct8iJVYRmbURttXuFCgCCK631dXQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicolas Pitre Subject: [PATCH 4.20 060/117] vgacon: unconfuse vc_origin when using soft scrollback Date: Tue, 29 Jan 2019 12:35:11 +0100 Message-Id: <20190129113210.661815079@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190129113207.477505932@linuxfoundation.org> References: <20190129113207.477505932@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicolas Pitre commit bfd8d8fe98b8792f362cd210a7873969f8d2fc04 upstream. When CONFIG_VGACON_SOFT_SCROLLBACK is selected, the VGA display memory index and vc_visible_origin don't change when scrollback is activated. The actual screen content is saved away and the scrollbackdata is copied over it. However the vt code, and /dev/vcs devices in particular, still expect vc_origin to always point at the actual screen content not the displayed scrollback content. So adjust vc_origin to point at the saved screen content when scrollback is active and set it back to vc_visible_origin when restoring the screen. This fixes /dev/vcsa that return scrollback content when they shouldn't (onli /dev/vcsa without a number should), and also fixes /dev/vcsu that should return scrollback content when scrollback is active but currently doesn't. An unnecessary call to vga_set_mem_top() is also removed. Signed-off-by: Nicolas Pitre Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Greg Kroah-Hartman --- drivers/video/console/vgacon.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -271,6 +271,7 @@ static void vgacon_scrollback_update(str static void vgacon_restore_screen(struct vc_data *c) { + c->vc_origin = c->vc_visible_origin; vgacon_scrollback_cur->save = 0; if (!vga_is_gfx && !vgacon_scrollback_cur->restore) { @@ -287,8 +288,7 @@ static void vgacon_scrolldelta(struct vc int start, end, count, soff; if (!lines) { - c->vc_visible_origin = c->vc_origin; - vga_set_mem_top(c); + vgacon_restore_screen(c); return; } @@ -298,6 +298,7 @@ static void vgacon_scrolldelta(struct vc if (!vgacon_scrollback_cur->save) { vgacon_cursor(c, CM_ERASE); vgacon_save_screen(c); + c->vc_origin = (unsigned long)c->vc_screenbuf; vgacon_scrollback_cur->save = 1; } @@ -335,7 +336,7 @@ static void vgacon_scrolldelta(struct vc int copysize; int diff = c->vc_rows - count; - void *d = (void *) c->vc_origin; + void *d = (void *) c->vc_visible_origin; void *s = (void *) c->vc_screenbuf; count *= c->vc_size_row;