Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161012AbWHAFWU (ORCPT ); Tue, 1 Aug 2006 01:22:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161058AbWHAFWU (ORCPT ); Tue, 1 Aug 2006 01:22:20 -0400 Received: from nf-out-0910.google.com ([64.233.182.184]:59769 "EHLO nf-out-0910.google.com") by vger.kernel.org with ESMTP id S1161012AbWHAFWT (ORCPT ); Tue, 1 Aug 2006 01:22:19 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=QeglwtEyPRDZ4jpNwuP4bxnGz4T2m9vG/tRNfqXOAeM/OIzk97rW252BQcm7g+5WgJdwOHp9JseSjD0GnKnikXCMkGDERRbJJc+3/5d7v0nx32u5y6yV7CtA+HF6AXHA8zOVpxP4/lqooA2ZZz+aAa1p1qEYYeY20tZsF6SgX3E= Message-ID: <787b0d920607312222v582c3d8dg9a97c80319d9fdc2@mail.gmail.com> Date: Tue, 1 Aug 2006 01:22:17 -0400 From: "Albert Cahalan" To: "Albert Cahalan" , ak@suse.de, mingo@elte.hu, arjan@infradead.org, akpm@osdl.org, linux-kernel@vger.kernel.org, roland@redhat.com Subject: Re: ptrace bugs and related problems In-Reply-To: <20060801013708.GA25965@nevyn.them.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <787b0d920607262355x3f669f0ap544e3166be2dca21@mail.gmail.com> <20060727203128.GA26390@nevyn.them.org> <787b0d920607271817u4978d2bdiac261d916971c1b3@mail.gmail.com> <20060728034741.GA3372@nevyn.them.org> <787b0d920607281528w56472db2u81268aad523d5c72@mail.gmail.com> <20060731190018.GA13735@nevyn.them.org> <787b0d920607311708y3642e41cue49cd47ccc39e77d@mail.gmail.com> <20060801013708.GA25965@nevyn.them.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1435 Lines: 37 On 7/31/06, Daniel Jacobowitz wrote: > On Mon, Jul 31, 2006 at 08:08:35PM -0400, Albert Cahalan wrote: > > The execve event is unreliable anyway. > > Thus, it is necessary to use syscall tracing. > > You keep saying this "unreliable" thing, and I don't think it means > what you think it means. It should always be delivered. When it > isn't, there's a bug. I don't know of any, unless you're talking about > the thread group issue you just reported. Yeah, I figure there is a bug. It'd be great if you could reproduce the bug. My setup: 2-core CPU 64-bit kernel (2.6.17 FC5, next-to-latest revision) 32-bit target app (assembly - no C library) 32-bit debugger The target app does CLONE_THREAD. The child does that again, then execve. The first and last threads spin in a loop, either burning CPU time or doing the pause system call. (the middle thread does the execve) I see the messages just fine on many 32-bit non-SMP systems that I tested with: Gentoo 2.6.16, Gentoo 2.6.13, plain 2.6.16, maybe 2.6.17.7... mostly in VMWare. Perhaps it is the SMP, the 64-bit, or Fedora being broken. I can not say, and most likely can not investigate more. I hope that helps. - 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/