From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11990 invoked by alias); 14 Aug 2012 15:57:26 -0000 Received: (qmail 11972 invoked by uid 22791); 14 Aug 2012 15:57:23 -0000 X-SWARE-Spam-Status: No, hits=-7.4 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,KHOP_THREADED,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mga14.intel.com (HELO mga14.intel.com) (143.182.124.37) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 14 Aug 2012 15:57:03 +0000 Received: from azsmga002.ch.intel.com ([10.2.17.35]) by azsmga102.ch.intel.com with ESMTP; 14 Aug 2012 08:57:02 -0700 X-ExtLoop1: 1 Received: from irsmsx103.ger.corp.intel.com ([163.33.3.157]) by AZSMGA002.ch.intel.com with ESMTP; 14 Aug 2012 08:57:01 -0700 Received: from irsmsx102.ger.corp.intel.com ([169.254.2.176]) by IRSMSX103.ger.corp.intel.com ([169.254.3.87]) with mapi id 14.01.0355.002; Tue, 14 Aug 2012 16:56:47 +0100 From: "Metzger, Markus T" To: Mark Kettenis CC: "gdb-patches@sourceware.org" , "markus.t.metzger@gmail.com" , "jan.kratochvil@redhat.com" , "palves@redhat.com" , "tromey@redhat.com" Subject: FW: [patch v3 16/16] btrace, x86: restrict to Atom Date: Tue, 14 Aug 2012 15:57:00 -0000 Message-ID: References: <1344949171-9545-1-git-send-email-markus.t.metzger@intel.com> <1344949171-9545-17-git-send-email-markus.t.metzger@intel.com> <201208141327.q7EDR7TC017727@glazunov.sibelius.xs4all.nl> In-Reply-To: Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-IsSubscribed: yes 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: 2012-08/txt/msg00406.txt.bz2 Resend. The original reply bounced. Apologies for the spam to those who received multiple copies of this email. -----Original Message----- From: Metzger, Markus T Sent: Tuesday, August 14, 2012 3:42 PM To: Mark Kettenis Cc: gdb-patches@sourceware.org; markus.t.metzger@gmail.com; jan.kratochvil@= redhat.com; palves@redhat.com; tromey@redhat.com Subject: RE: [patch v3 16/16] btrace, x86: restrict to Atom > -----Original Message----- > From: Mark Kettenis [mailto:mark.kettenis@xs4all.nl] > Sent: Tuesday, August 14, 2012 3:27 PM Thanks for your feedback! > > +int > > +i386_linux_supports_btrace (void) > > +{ > > + unsigned int cpuid, model, family; > > + > > + if (!linux_supports_btrace ()) > > + return 0; > > + > > + __asm__ __volatile__ ("movl $1, %%eax;" > > + "cpuid;" > > + : "=3Da" (cpuid) > > + :: "%ebx", "%ecx", "%edx"); > > + [...] > You can't have this function in a -tdep.c, since this file needs to be > compilable everywhere (not just on i386/amd64). But even in a -nat.c > file you shouldn't use inline assembly, since it isn't a standardized > C feature. I can only guess why you want to restrict this feature to > Atom only, but I suspect that the proper solution is to query the > target whether branch tracing is supported. That means the -nat.c > code should have code to query for support in the Linux kernel. I agree that it would be better to have this check done in the kernel. The = problem is that such a patch will take very long before it becomes available in distributions. And even then, we would need to hand= le kernels without the patch, so we would need something similar to this in gdb, as well. I took the cpuid bits from gdb/go32-nat.c. I have not seen any compilation = guard around it. I thought that the i386-tdep files are meant to contain i386 specific code,= that's why I put the code there. Where would be the right place to put such code? Thanks, Markus. Intel GmbH Dornacher Strasse 1 85622 Feldkirchen/Muenchen, Deutschland Sitz der Gesellschaft: Feldkirchen bei Muenchen Geschaeftsfuehrer: Douglas Lusk, Peter Gleissner, Hannes Schwaderer, Christ= ian Lamprechter Registergericht: Muenchen HRB 47456 Ust.-IdNr./VAT Registration No.: DE129385895 Citibank Frankfurt a.M. (BLZ 502 109 00) 600119052