Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757435AbYCTQxr (ORCPT ); Thu, 20 Mar 2008 12:53:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754886AbYCTQxi (ORCPT ); Thu, 20 Mar 2008 12:53:38 -0400 Received: from x346.tv-sign.ru ([89.108.83.215]:55281 "EHLO mail.screens.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754452AbYCTQxh (ORCPT ); Thu, 20 Mar 2008 12:53:37 -0400 Date: Thu, 20 Mar 2008 19:57:56 +0300 From: Oleg Nesterov To: Pavel Machek Cc: Andrew Morton , Davide Libenzi , "Eric W. Biederman" , Ingo Molnar , Laurent Riffard , Pavel Emelyanov , Roland McGrath , linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/5] ptrace: it is fun to strace /sbin/init Message-ID: <20080320165756.GA11197@tv-sign.ru> References: <20080316155455.GA20848@tv-sign.ru> <20080320162718.GA4397@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080320162718.GA4397@ucw.cz> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1291 Lines: 31 On 03/20, Pavel Machek wrote: > > > Ptracing of /sbin/init is not allowed. Of course, this is very dangerous, but > > may be useful. Introduce the kernel boot parameter to allow this. > ... > > @@ -803,6 +803,8 @@ and is between 256 and 4096 characters. > > Run specified binary instead of /sbin/init as init > > process. > > > > + init_ptrace [KNL] Allows to ptrace init. Very dangerous. Don't use. > > + > > I don't know what ptracing init is good for, and I believe people > wanting to do this kind of special stuff can patch their own kernel... Yes sure. But could you explain why this can be bad given that ptracing init needs the explicit boot parameter? IOW, could you explain why you don't like this small and trivial change which adds a minimal impact ? Most of the lkml readers can easily implement most of debugging options, do you mean there are useless? I personally like the possibility to trace init without re-compiling the kernel, because I'd like to know why /usr/bin/top sometimes shows init at the top. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/