From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965007AbXBLQyR (ORCPT ); Mon, 12 Feb 2007 11:54:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964977AbXBLQwJ (ORCPT ); Mon, 12 Feb 2007 11:52:09 -0500 Received: from ns2.suse.de ([195.135.220.15]:53655 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964968AbXBLQvt (ORCPT ); Mon, 12 Feb 2007 11:51:49 -0500 From: Andi Kleen References: <20070212551.664370000@suse.de> In-Reply-To: <20070212551.664370000@suse.de> To: Rusty Russell , patches@x86-64.org, linux-kernel@vger.kernel.org Subject: [PATCH x86 for review III] [25/29] i386: paravirt unhandled fallthrough Message-Id: <20070212165146.22BCC13E1B@wotan.suse.de> Date: Mon, 12 Feb 2007 17:51:46 +0100 (CET) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Rusty Russell The current code simply calls "start_kernel" directly if we're under a hypervisor and no paravirt_ops backend wants us, because paravirt.c registers that as a backend. This was always a vain hope; start_kernel won't get far without setup. It's also impossible for paravirt_ops backends which don't sit in the arch/i386/kernel directory: they can't link before paravirt.o anyway. Keep it simple: if we pass all the registered paravirt probes, BUG(). Signed-off-by: Rusty Russell Signed-off-by: Andi Kleen --- arch/i386/kernel/Makefile | 2 -- arch/i386/kernel/head.S | 7 ++++++- arch/i386/kernel/paravirt.c | 3 --- 3 files changed, 6 insertions(+), 6 deletions(-) Index: linux/arch/i386/kernel/Makefile =================================================================== --- linux.orig/arch/i386/kernel/Makefile +++ linux/arch/i386/kernel/Makefile @@ -41,8 +41,6 @@ obj-$(CONFIG_HPET_TIMER) += hpet.o obj-$(CONFIG_K8_NB) += k8.o obj-$(CONFIG_VMI) += vmi.o vmitime.o - -# Make sure this is linked after any other paravirt_ops structs: see head.S obj-$(CONFIG_PARAVIRT) += paravirt.o EXTRA_AFLAGS := -traditional Index: linux/arch/i386/kernel/head.S =================================================================== --- linux.orig/arch/i386/kernel/head.S +++ linux/arch/i386/kernel/head.S @@ -513,10 +513,11 @@ startup_paravirt: pushl %ecx pushl %eax - /* paravirt.o is last in link, and that probe fn never returns */ pushl $__start_paravirtprobe 1: movl 0(%esp), %eax + cmpl $__stop_paravirtprobe, %eax + je unhandled_paravirt pushl (%eax) movl 8(%esp), %eax call *(%esp) @@ -528,6 +529,10 @@ startup_paravirt: addl $4, (%esp) jmp 1b + +unhandled_paravirt: + /* Nothing wanted us: we're screwed. */ + ud2 #endif /* Index: linux/arch/i386/kernel/paravirt.c =================================================================== --- linux.orig/arch/i386/kernel/paravirt.c +++ linux/arch/i386/kernel/paravirt.c @@ -482,9 +482,6 @@ static int __init print_banner(void) } core_initcall(print_banner); -/* We simply declare start_kernel to be the paravirt probe of last resort. */ -paravirt_probe(start_kernel); - struct paravirt_ops paravirt_ops = { .name = "bare hardware", .paravirt_enabled = 0,