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=unavailable 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 223DAC169C4 for ; Tue, 29 Jan 2019 12:07:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E65B220881 for ; Tue, 29 Jan 2019 12:07:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548763622; bh=F4rmoACIa+t6IAwdwXHPiMuj8PxeQP8m55tVDQ/a8wE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wBssMa+NtG4dLYP3XuTOviqbEkQZGe/qUe5o6EnBX++xdo5ncFlTbxL2TwbH9K/+/ uOybncWzaoU153ofKkkfJBUN5qCDB0QtM1CIhg7xdyWhKvFNsiIK24QyAMJiPf3Smv HyxiTzjLujL9NB5NzV6Pn8bx2i9P14YOTNXtFRCI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728624AbfA2MG4 (ORCPT ); Tue, 29 Jan 2019 07:06:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:57940 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728673AbfA2Lkt (ORCPT ); Tue, 29 Jan 2019 06:40:49 -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 408D820857; Tue, 29 Jan 2019 11:40:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548762047; bh=F4rmoACIa+t6IAwdwXHPiMuj8PxeQP8m55tVDQ/a8wE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XQMCUUBuzSAwViBRBfuhBfk9eEzIQlLufVzjniqYMkKkI6jlEkBYwCoslekc+sb+O IuzyfCmfFKWJ5CtXnyeD/cK2e72eyHUCIa02eCc5/IN/c3yxbV3Qqda0+wRF1IpDQV K4aXA9q58BLuCjQjSnIpQKWKJve1Eno6T/U5UYNs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nicolas Pitre Subject: [PATCH 4.20 090/117] vt: make vt_console_print() compatible with the unicode screen buffer Date: Tue, 29 Jan 2019 12:35:41 +0100 Message-Id: <20190129113211.873375967@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 6609cff65c5b184ab889880ef5d41189611ea05f upstream. When kernel messages are printed to the console, they appear blank on the unicode screen. This is because vt_console_print() is lacking a call to vc_uniscr_putc(). However the later function assumes vc->vc_x is always up to date when called, which is not the case here as vt_console_print() uses it to mark the beginning of the display update. This patch reworks (and simplifies) vt_console_print() so that vc->vc_x is always valid and keeps the start of display update in a local variable instead, which finally allows for adding the missing vc_uniscr_putc() call. Signed-off-by: Nicolas Pitre Cc: stable@vger.kernel.org # v4.19+ Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/vt.c | 47 +++++++++++++++-------------------------------- 1 file changed, 15 insertions(+), 32 deletions(-) --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -2884,8 +2884,7 @@ static void vt_console_print(struct cons unsigned char c; static DEFINE_SPINLOCK(printing_lock); const ushort *start; - ushort cnt = 0; - ushort myx; + ushort start_x, cnt; int kmsg_console; /* console busy or not yet initialized */ @@ -2898,10 +2897,6 @@ static void vt_console_print(struct cons if (kmsg_console && vc_cons_allocated(kmsg_console - 1)) vc = vc_cons[kmsg_console - 1].d; - /* read `x' only after setting currcons properly (otherwise - the `x' macro will read the x of the foreground console). */ - myx = vc->vc_x; - if (!vc_cons_allocated(fg_console)) { /* impossible */ /* printk("vt_console_print: tty %d not allocated ??\n", currcons+1); */ @@ -2916,53 +2911,41 @@ static void vt_console_print(struct cons hide_cursor(vc); start = (ushort *)vc->vc_pos; - - /* Contrived structure to try to emulate original need_wrap behaviour - * Problems caused when we have need_wrap set on '\n' character */ + start_x = vc->vc_x; + cnt = 0; while (count--) { c = *b++; if (c == 10 || c == 13 || c == 8 || vc->vc_need_wrap) { - if (cnt > 0) { - if (con_is_visible(vc)) - vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x); - vc->vc_x += cnt; - if (vc->vc_need_wrap) - vc->vc_x--; - cnt = 0; - } + if (cnt && con_is_visible(vc)) + vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x); + cnt = 0; if (c == 8) { /* backspace */ bs(vc); start = (ushort *)vc->vc_pos; - myx = vc->vc_x; + start_x = vc->vc_x; continue; } if (c != 13) lf(vc); cr(vc); start = (ushort *)vc->vc_pos; - myx = vc->vc_x; + start_x = vc->vc_x; if (c == 10 || c == 13) continue; } + vc_uniscr_putc(vc, c); scr_writew((vc->vc_attr << 8) + c, (unsigned short *)vc->vc_pos); notify_write(vc, c); cnt++; - if (myx == vc->vc_cols - 1) { - vc->vc_need_wrap = 1; - continue; - } - vc->vc_pos += 2; - myx++; - } - if (cnt > 0) { - if (con_is_visible(vc)) - vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, vc->vc_x); - vc->vc_x += cnt; - if (vc->vc_x == vc->vc_cols) { - vc->vc_x--; + if (vc->vc_x == vc->vc_cols - 1) { vc->vc_need_wrap = 1; + } else { + vc->vc_pos += 2; + vc->vc_x++; } } + if (cnt && con_is_visible(vc)) + vc->vc_sw->con_putcs(vc, start, cnt, vc->vc_y, start_x); set_cursor(vc); notify_update(vc);