Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751768AbWIRPTq (ORCPT ); Mon, 18 Sep 2006 11:19:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751769AbWIRPTq (ORCPT ); Mon, 18 Sep 2006 11:19:46 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:14470 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S1751768AbWIRPTn (ORCPT ); Mon, 18 Sep 2006 11:19:43 -0400 Date: Mon, 18 Sep 2006 17:11:00 +0200 From: Ingo Molnar To: Mathieu Desnoyers Cc: Theodore Tso , Nicholas Miell , Paul Mundt , linux-kernel , Ingo Molnar , Jes Sorensen , Andrew Morton , Tom Zanussi , Richard J Moore , "Frank Ch. Eigler" , Michel Dagenais , Christoph Hellwig , Greg Kroah-Hartman , Thomas Gleixner , William Cohen , "Martin J. Bligh" Subject: Re: LTTng and SystemTAP (Everyone who is scared to read this huge thread, skip to here) Message-ID: <20060918151059.GA10106@elte.hu> References: <1158524390.2471.49.camel@entropy> <20060917230623.GD8791@elte.hu> <450DEEA5.7080808@opersys.com> <20060918005624.GA30835@elte.hu> <450DFFC8.5080005@opersys.com> <20060918033027.GB11894@elte.hu> <20060918035216.GF9049@thunk.org> <450E1F6F.7040401@opersys.com> <20060918043248.GB19843@elte.hu> <20060918050310.GC15930@Krystal> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060918050310.GC15930@Krystal> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -2.9 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.9 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts 0.5 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5000] -0.1 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1025 Lines: 24 * Mathieu Desnoyers wrote: > > Some of the extensive hooking you do in LTT could be aleviated to a > > great degree if you used dynamic probes. For example the syscall > > entry hackery in LTT looks truly scary. > > Yes, agreed. The last time I checked, I thought about moving this > tracing code to the syscall_trace_entry/exit (used for security hooks > and ptrace if I remember well). I just didn't have the time to do it > yet. correct, that's where all such things (auditing, seccomp, ptrace, sigstop, freezing, etc.) hook into. Much (all?) of the current entry.S hacks can go away in favor of a much easier .c patch to do_syscall_trace() and this would reduce a significantion portion of the present intrusiveness of LTTng. Ingo - 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/