Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754136Ab0AWLAX (ORCPT ); Sat, 23 Jan 2010 06:00:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752384Ab0AWLAW (ORCPT ); Sat, 23 Jan 2010 06:00:22 -0500 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:53292 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750941Ab0AWLAU (ORCPT ); Sat, 23 Jan 2010 06:00:20 -0500 Date: Sat, 23 Jan 2010 11:01:21 +0000 From: Alan Cox To: Kyle Moffett Cc: Linus Torvalds , "Frank Ch. Eigler" , Oleg Nesterov , Andrew Morton , Stephen Rothwell , Peter Zijlstra , Peter Zijlstra , "Fr??d??ric Weisbecker" , LKML , Steven Rostedt , Arnaldo Carvalho de Melo , linux-next@vger.kernel.org, "H. Peter Anvin" , utrace-devel@redhat.com, Thomas Gleixner Subject: Re: linux-next: add utrace tree Message-ID: <20100123110121.1ce89bb9@lxorguk.ukuu.org.uk> In-Reply-To: References: <20100121013822.28781960.sfr@canb.auug.org.au> <20100122005147.GD22003@redhat.com> <20100121170541.7425ff10.akpm@linux-foundation.org> <20100122182827.GA13185@redhat.com> <20100122200129.GG22003@redhat.com> <20100122221348.GA4263@redhat.com> X-Mailer: Claws Mail 3.7.3 (GTK+ 2.18.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1199 Lines: 26 > The killer app for this will be the ability to delete thousands of > lines of code from GDB, strace, and all the various other tools that > have to painfully work around the major interface gotchas of ptrace(), > while at the same time making their handling of complex processes much > more robust. Years ago (and it really must be years ago because this was about the time I started hacking on Linux stuff !) there was a proposal to extract and sanitize the arch specific stuff in binutils and in gdb etc into sensible libraries that could be used by other apps. What I don't understand is why that doesn't solve 99% of your problem. ptrace is not perfect but most of the real ptrace limitations actually come about because either the CPU can't do something or because the supporting logic would be too expensive - things like having extra private debugger pages. Yes ptrace needs a lot of icky support code, but it's already been written... Alan -- 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/