Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932176Ab3HGR1s (ORCPT ); Wed, 7 Aug 2013 13:27:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:30882 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756870Ab3HGR1r (ORCPT ); Wed, 7 Aug 2013 13:27:47 -0400 Date: Wed, 7 Aug 2013 19:22:08 +0200 From: Oleg Nesterov To: Grazvydas Ignotas Cc: Linus Torvalds , Felipe Contreras , Linux Kernel Mailing List , Frederic Weisbecker , Ingo Molnar , Denys Vlasenko Subject: Re: [PATCH 0/1] (Was: Linux 3.11-rc4) Message-ID: <20130807172208.GA2122@redhat.com> References: <20130806154314.GA398@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1294 Lines: 35 On 08/07, Grazvydas Ignotas wrote: > > It's not that wine needs all this, it's the Windows games that use > debug registers to store random values to them for their copy > protection stuff. Thanks. > My wine commits try to sidestep these > kernel restrictions/sanity checking. My point was, it seems that starting from 3.11 you can remove both extra PTRACE_POKEUSER's. Unless, of course, the initial state of dr7 doesn't match dr0 - dr6 set_thread_context() is going to update. Anyway I agree this interface is very confusing and inconvenient. And just in case, it is not that I think set_thread_context() should be changed, I am just wondering whether the kernel still has the bugs which should be fixed. > Personally I'd say the kernel should not limit what's written to debug > registers. Why can't I write insane values to registers in _my_ > hardware? It's not like it's going to break the hardware or anything. Even if this is safe (and btw I have no idea if this is always true or not ;), how a user can notice the error then? Oleg. -- 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/