Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 20 Jan 2002 22:09:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 20 Jan 2002 22:09:11 -0500 Received: from fe1.rdc-kc.rr.com ([24.94.163.48]:35340 "EHLO mail1.kc.rr.com") by vger.kernel.org with ESMTP id ; Sun, 20 Jan 2002 22:09:02 -0500 To: vic Cc: marcelo@conectiva.com.br, linux-kernel@vger.kernel.org, torvalds@transmeta.com, alan@lxorguk.ukuu.org.uk Subject: Re: [PATCH] ptrace on stopped processes (2.4) In-Reply-To: <87g0632lzw.fsf@mathdogs.com> Date: 20 Jan 2002 21:09:00 -0600 In-Reply-To: Message-ID: <87665wbdtf.fsf@mathdogs.com> Lines: 24 User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/21.1 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii From: "Mike Coleman" X-Delivery-Agent: TMDA/0.44 (Python 2.1.1; linux-i686) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org vic writes: > From: Mike Coleman : > > Also, is this something that used to work? Or would this be a change in the > > semantics of ptrace? > > This is a change of semantics at least going back to 2.2. Okay. Is it at least backward compatible? Or are some tools expected to break? > > Unless I'm missing something (frequently the case), there are two cases here: > > (1) the tracer wants to leave the tracee stopped, and (2) the tracer wants the > > process to continue running in as natural a way as possible, meaning without > > sending it a SIGCONT (which can cause the SIGCONT signal handler to execute). > > As things currently stand, we have behavior (2), and (1) is not possible. > > With your change, we'd have behavior (1), and (2) would not be possible. > > I agree that the ability to do (2) should be preserved, but I don't > see how this patch breaks it; do you have an example? No, I was just going by reading the kernel code. Can you describe how each of (1) and (2) are accomplished by the ptracing program (with your patch)? Mike - 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/