From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755874AbaEaJts (ORCPT ); Sat, 31 May 2014 05:49:48 -0400 Received: from mout.gmx.net ([212.227.17.21]:61129 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752917AbaEaJtq convert rfc822-to-8bit (ORCPT ); Sat, 31 May 2014 05:49:46 -0400 Message-ID: <1401529764.4646.12.camel@schoellingm.dzne.de> Subject: Re: [PATCH] console: Add persistent scrollback buffers for all VGA consoles From: Manuel Schoelling To: Jakub Wilk Cc: plagnioj@jcrosoft.com, tomi.valkeinen@ti.com, geert@linux-m68k.org, broonie@linaro.org, rdunlap@infradead.org, dh.herrmann@gmail.com, airlied@redhat.com, mtosatti@redhat.com, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Sat, 31 May 2014 11:49:24 +0200 In-Reply-To: <20140530222622.GA1385@jwilk.net> References: <1401456425-15931-1-git-send-email-manuel.schoelling@gmx.de> <20140530222622.GA1385@jwilk.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-3 Mime-Version: 1.0 Content-Transfer-Encoding: 8BIT X-Provags-ID: V03:K0:mCxjNQaQ/DbhQGtgKOmgDMs9XMYi83VmfNMUdSxZulZbb+kyJVb TteC5dpg82VO0308s7gDdRLfbgxSuDA2Uf571tHtQRWi6MwIb1APM5L3lRA2+iBd1TH/0Zq sE36vEYPejB9Kg7iyQyUpRymt/8mNOG2DSg1IbcHDWSTUspeIheGa+PwwrrCwdU9qy4RaOh D9URrap0nnpC6Uby+HFUw== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sa, 2014-05-31 at 00:26 +0200, Jakub Wilk wrote: > * Manuel Schölling , 2014-05-30, 15:27: > >Add a scrollback buffers for each VGA console. The benefit is that the > >scrollback history is not flushed when switching between consoles but > >is persistent. > > Some people rely on this scrollback flushing as a security feature. Is > there even another way to clear the scrollback, than to switch to > another vt and then back again? Thanks for raising this security issue! Maybe we should add something like VT_FLUSH_SCROLLBACK to vt_ioctl()? [1] I'm open for better ways to flush the scrollback history. [1] http://lxr.free-electrons.com/source/drivers/tty/vt/vt_ioctl.c#L334 > Debian ships this: > http://manpages.debian.org/cgi-bin/man.cgi?query=clear_console > https://sources.debian.net/src/bash/4.2%2Bdfsg-0.1/debian/clear_console.c >