Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750936AbWCNUAT (ORCPT ); Tue, 14 Mar 2006 15:00:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751402AbWCNUAT (ORCPT ); Tue, 14 Mar 2006 15:00:19 -0500 Received: from saraswathi.solana.com ([198.99.130.12]:37277 "EHLO saraswathi.solana.com") by vger.kernel.org with ESMTP id S1750936AbWCNUAS (ORCPT ); Tue, 14 Mar 2006 15:00:18 -0500 Date: Tue, 14 Mar 2006 15:00:55 -0500 From: Jeff Dike To: Chuck Ebbert <76306.1226@compuserve.com> Cc: linux-kernel , Roland McGrath , Linus Torvalds Subject: Re: What is ptrace flag PT_TRACESYSGOOD for? Message-ID: <20060314200055.GA22286@ccure.user-mode-linux.org> References: <200603140531_MC3-1-BAA0-B3C3@compuserve.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200603140531_MC3-1-BAA0-B3C3@compuserve.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 767 Lines: 16 On Tue, Mar 14, 2006 at 05:26:52AM -0500, Chuck Ebbert wrote: > I am trying to document PTRACE_SETOPTIONS and I can't figure out what > the option PTRACE_O_TRACESYSGOOD is used for. It makes it easier to distinguish between the child receiving a SIGTRAP and making a system call. On x86, without TRACESYSGOOD, you can see if orig_eax == -1 to check for a real SIGTRAP. I'm not sure about the other arches, but it's nice to have an arch-independent way of doing it, even if there are equivalents in every arch. Jeff - 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/