From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269058AbUIAAcq (ORCPT ); Tue, 31 Aug 2004 20:32:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269019AbUIAA23 (ORCPT ); Tue, 31 Aug 2004 20:28:29 -0400 Received: from mail2.speakeasy.net ([216.254.0.202]:8342 "EHLO mail2.speakeasy.net") by vger.kernel.org with ESMTP id S269291AbUIAA2E (ORCPT ); Tue, 31 Aug 2004 20:28:04 -0400 Date: Tue, 31 Aug 2004 17:27:54 -0700 Message-Id: <200409010027.i810RsWT001980@magilla.sf.frob.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Roland McGrath To: Andi Kleen X-Fcc: ~/Mail/linus Cc: linux-kernel@vger.kernel.org, torvalds@osdl.org, akpm@osdl.org Subject: Re: [PATCH] cleanup ptrace stops and remove notify_parent In-Reply-To: Andi Kleen's message of Tuesday, 31 August 2004 12:00:02 +0200 X-Shopping-List: (1) Circular condiments (2) Diagnostic ardent geese (3) Independent enemas Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Are you sure such a user visible semantic change is a good idea? Not if it's not too hard to avoid. I think I can make it not come up by converting TASK_STOPPED into TASK_TRACED when you use ptrace. It will just take some synchronization for that case. > I at least have written (not very important, but existing) user space > code in the past that assumed it can stop and single step without > SIGCONT. I wouldn't be surprised if other debuggers ran into > the same issue. I assume you mean stop with SIGSTOP, then attach with PTRACE_ATTACH, then step with PTRACE_SINGLESTEP. If you are already attached, then any stop will report to you first in TASK_TRACED and never end up TASK_STOPPED unless you explicitly pass a stop signal through with ptrace. Thanks, Roland