From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4222 invoked by alias); 28 Sep 2009 17:12:54 -0000 Received: (qmail 4209 invoked by uid 22791); 28 Sep 2009 17:12:53 -0000 X-SWARE-Spam-Status: No, hits=-1.6 required=5.0 tests=AWL,BAYES_00,MSGID_FROM_MTA_HEADER,SPF_PASS X-Spam-Check-By: sourceware.org Received: from mtagate7.de.ibm.com (HELO mtagate7.de.ibm.com) (195.212.17.167) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 28 Sep 2009 17:12:49 +0000 Received: from d12nrmr1607.megacenter.de.ibm.com (d12nrmr1607.megacenter.de.ibm.com [9.149.167.49]) by mtagate7.de.ibm.com (8.13.1/8.13.1) with ESMTP id n8SHCkWB009094 for ; Mon, 28 Sep 2009 17:12:46 GMT Received: from d12av02.megacenter.de.ibm.com (d12av02.megacenter.de.ibm.com [9.149.165.228]) by d12nrmr1607.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n8SHCkOH3551256 for ; Mon, 28 Sep 2009 19:12:46 +0200 Received: from d12av02.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av02.megacenter.de.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n8SHCjqU006326 for ; Mon, 28 Sep 2009 19:12:46 +0200 Received: from tuxmaker.boeblingen.de.ibm.com (tuxmaker.boeblingen.de.ibm.com [9.152.85.9]) by d12av02.megacenter.de.ibm.com (8.12.11.20060308/8.12.11) with SMTP id n8SHCidf006302; Mon, 28 Sep 2009 19:12:44 +0200 Message-Id: <200909281712.n8SHCidf006302@d12av02.megacenter.de.ibm.com> Received: by tuxmaker.boeblingen.de.ibm.com (sSMTP sendmail emulation); Mon, 28 Sep 2009 19:12:44 +0200 Subject: Re: [rfc] Fix PowerPC displaced stepping regression To: pedro@codesourcery.com (Pedro Alves) Date: Mon, 28 Sep 2009 17:12:00 -0000 From: "Ulrich Weigand" Cc: gdb-patches@sourceware.org, julian@codesourcery.com (Julian Brown), drow@false.org (Daniel Jacobowitz) In-Reply-To: <200909281757.49385.pedro@codesourcery.com> from "Pedro Alves" at Sep 28, 2009 05:57:48 PM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2009-09/txt/msg00869.txt.bz2 Pedro Alves wrote: > On Sunday 27 September 2009 22:47:13, Ulrich Weigand wrote: > > - In non-stop mode, we never want to use software single-step as > > common code does not support this in multiple threads at once. > > Right. Shouldn't we switch this particular predicate to > check the non_stop global instead? I'm not sure which "particular predicate" you're referring to, sorry ... The check currently reads: if (use_displaced_stepping (gdbarch) && (tp->trap_expected || (step && gdbarch_software_single_step_p (gdbarch))) && sig == TARGET_SIGNAL_0) that is, if we'd otherwise be about to issue a single step (potentially) treat it like stepping over a breakpoint. At what point would you suggest to check for non_stop? > Did you consider making the gdbarch_displaced_step_copy_insn > callback itself return that it expects the target to be > continued instead of stepped? Yes, but this would have required changes to the existing gdbarch interface that would have meant updating all existing users; and I wanted to produce a patch that doesn't touch any platform I cannot test at this point ... In any case, the two interfaces should be pretty much identical: a target can simply set a flag in its "closure" and return this flag from the displaced_step_hw_singlestep routine. That's why I'm passing the closure in, even though PPC doesn't need it ... Bye, Ulrich -- Dr. Ulrich Weigand GNU Toolchain for Linux on System z and Cell BE Ulrich.Weigand@de.ibm.com