Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755749AbYJPA0s (ORCPT ); Wed, 15 Oct 2008 20:26:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754092AbYJPA0k (ORCPT ); Wed, 15 Oct 2008 20:26:40 -0400 Received: from mx1.redhat.com ([66.187.233.31]:60784 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753992AbYJPA0j (ORCPT ); Wed, 15 Oct 2008 20:26:39 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit From: Roland McGrath To: prasad@linux.vnet.ibm.com X-Fcc: ~/Mail/linus Cc: Linux Kernel Mailing List , Alan Stern , akpm@linux-foundation.org, mingo@elte.hu, jason.wessel@windriver.com, avi@qumranet.com, richardj_moore@uk.ibm.com Subject: Re: [RFC Patch 3/9] Modifying generic debug exception to use virtual debug registers In-Reply-To: K.Prasad's message of Thursday, 9 October 2008 00:54:20 +0530 <20081008192420.GC4989@in.ibm.com> References: <20081008192044.GA4510@in.ibm.com> <20081008192420.GC4989@in.ibm.com> X-Zippy-Says: Gee, I feel kind of LIGHT in the head now, knowing I can't make my satellite dish PAYMENTS! Message-Id: <20081016002555.808EF1544CB@magilla.localdomain> Date: Wed, 15 Oct 2008 17:25:55 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 939 Lines: 25 You need to redo this (and the whole set) for the post-2.6.27 tree. e.g. traps.c has been unified. + /* Store the virtualized DR6 value */ + tsk->thread.vdr6 = dr6; + + if (notify_die(DIE_DEBUG, "debug", regs, dr6, error_code, + SIGTRAP) == NOTIFY_STOP) return; I'm not sure you should change vdr6 when notify_die returns NOTIFY_STOP. Maybe Alan and I hashed out the logic of this before, I don't recall. If the notifier is eating the event, then it should not affect the thread-virtualized view of %db6. That would be consistent with the existing code, where ->thread.debugreg6 is only set later when all the intercepted or spurious exceptions have been filtered out. Thanks, Roland -- 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/