From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261753AbUL3XRd (ORCPT ); Thu, 30 Dec 2004 18:17:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261750AbUL3XRd (ORCPT ); Thu, 30 Dec 2004 18:17:33 -0500 Received: from fw.osdl.org ([65.172.181.6]:13504 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S261754AbUL3XRY (ORCPT ); Thu, 30 Dec 2004 18:17:24 -0500 Date: Thu, 30 Dec 2004 15:17:01 -0800 (PST) From: Linus Torvalds To: Daniel Jacobowitz cc: Jesse Allen , Davide Libenzi , Mike Hearn , Thomas Sailer , Eric Pouech , Roland McGrath , Kernel Mailing List , Andrew Morton , wine-devel Subject: Re: ptrace single-stepping change breaks Wine In-Reply-To: <20041230230046.GA14843@nevyn.them.org> Message-ID: References: <53046857041230112742acccbe@mail.gmail.com> <20041230230046.GA14843@nevyn.them.org> 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 Thu, 30 Dec 2004, Daniel Jacobowitz wrote: > > does not look right to me. Before, we'd get an 0x80|SIGTRAP result > from wait. Now, you've moved the 0x80 to live only inside the siginfo. > This is accessible to the debugger via ptrace, but only very recently > (late 2.5.x). So this will probably break users of PT_TRACESYSGOOD. I don't see how to easily emulate the old behaviour 100% - see ptrace_notify. We always sent the signal SIGTRAP to the process, and then set "exit_code" tp have the 0x80 marker by calling ptrace_stop() by hand. However, if we make it a real signal (which we need to do to get the continue semantics right), we no longer have that out-of-band info available to us. We could make "get_signal_to_deliver()" pass in some other exit_code to ptrace_stop() than just signr. It would have to pick it up from the siginfo structure, but then we'd have to make sure that _other_ signal users do that properly.. Patches/suggestions welcome. Linus