From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262105AbULaPQM (ORCPT ); Fri, 31 Dec 2004 10:16:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262106AbULaPQM (ORCPT ); Fri, 31 Dec 2004 10:16:12 -0500 Received: from x35.xmailserver.org ([69.30.125.51]:44267 "EHLO x35.xmailserver.org") by vger.kernel.org with ESMTP id S262105AbULaPQI (ORCPT ); Fri, 31 Dec 2004 10:16:08 -0500 X-AuthUser: davidel@xmailserver.org Date: Fri, 31 Dec 2004 07:16:00 -0800 (PST) From: Davide Libenzi X-X-Sender: davide@bigblue.dev.mdolabs.com To: Andi Kleen cc: Linus Torvalds , Mike Hearn , Thomas Sailer , Eric Pouech , Daniel Jacobowitz , Roland McGrath , Kernel Mailing List , Andrew Morton , wine-devel Subject: Re: ptrace single-stepping change breaks Wine In-Reply-To: <20041231123538.GA18209@muc.de> Message-ID: References: <53046857041230112742acccbe@mail.gmail.com> <20041231123538.GA18209@muc.de> X-GPG-FINGRPRINT: CFAE 5BEE FD36 F65E E640 56FE 0974 BF23 270F 474E X-GPG-PUBLIC_KEY: http://www.xmailserver.org/davidel.asc MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 31 Dec 2004, Andi Kleen wrote: > > - you couldn't even debug signal handlers, because they were _really_ > > hard to get into unless you knew where they were and put a breakpoint > > on them. > > Ok I see this as being a problem. But I bet it could be fixed > much simpler without doing all this complicated and likely-to-be-buggy > popf parsing you added. I don't think that the Wine problem resolution is due to the POPF instruction handling. Basically Linus patch does a nice cleanup plus POPF handling, so maybe the patch can be split. > > - you couldn't see the instruction after a system call. > > Are you sure? Yes, this was true with 2.4. Than it has been fixed some time ago. But handling that revealed a fragile handling of ptrace event delivery we had in do_syscall_trace(). Part of the Linus patch tries to solve the fact that on one side strace wants things to happen in a certain way, way that seem to break Wine. I think Linus cleanup of the ptrace event delivery can get strace, Wine and single-step-after-syscall right, w/out POPF handling. Then you guys can flame each other over the POPF handling ;) - Davide