Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751153AbWHGIRr (ORCPT ); Mon, 7 Aug 2006 04:17:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751156AbWHGIRr (ORCPT ); Mon, 7 Aug 2006 04:17:47 -0400 Received: from public.id2-vpn.continvity.gns.novell.com ([195.33.99.129]:54734 "EHLO emea1-mh.id2.novell.com") by vger.kernel.org with ESMTP id S1751153AbWHGIRq (ORCPT ); Mon, 7 Aug 2006 04:17:46 -0400 Message-Id: <44D7136E.76E4.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 7.0.1 Date: Mon, 07 Aug 2006 09:18:22 +0100 From: "Jan Beulich" To: "Andi Kleen" , "Andrew Morton" Cc: "Michal Piotrowski" , , , Subject: Re: 2.6.18-rc3-g3b445eea BUG: warning at /usr/src/linux-git/kernel/cpu.c:51/unlock_cpu_hotplug() References: <6bffcb0e0608041204u4dad7cd6rab0abc3eca6747c0@mail.gmail.com> <20060804222400.GC18792@redhat.com> <20060805003142.GH18792@redhat.com> <20060805021051.GA13393@redhat.com> <20060805022356.GC13393@redhat.com> <20060805024947.GE13393@redhat.com> <20060805064727.GF13393@redhat.com> <6bffcb0e0608060959m164436baj9c4c602496e87f5d@mail.gmail.com> <20060806123243.826105fc.akpm@osdl.org> <20060807012638.GA42404@muc.de> In-Reply-To: <20060807012638.GA42404@muc.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1102 Lines: 24 >> It's a false-positive in this case - the backtrace was complete. It would >> be good if we could make the did-we-get-stuck detector a bit smarter. Even >> special-casing "sysenter_past_esp" would stop a lot of this.. > >Actually it's not completely false in this case -- it should >have reached user mode and stopped there, but for some reason >I didn't and already stopped still in the kernel. > >Most likely the CFI annotation for that sysenter path is not complete. Correct, the return point of sysexit (SYSENTER_RETURN) is still in kernel space, but its annotations are invisible to the unwinder. We should make the VDSO be treated as user-mode code despite living above PAGE_OFFSET. >It's on my todo list to investigate but I still hope Jan does it first ;-) I'll try to, once I've got through moving the Xen code from 2.6.16 to 2.6.18-rc3 Jan - 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/