From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932569AbXBLDcr (ORCPT ); Sun, 11 Feb 2007 22:32:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932941AbXBLDcr (ORCPT ); Sun, 11 Feb 2007 22:32:47 -0500 Received: from ozlabs.org ([203.10.76.45]:50808 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932569AbXBLDcr (ORCPT ); Sun, 11 Feb 2007 22:32:47 -0500 Subject: [PATCH 1/7] cleanup: paravirt unhandled fallthrough From: Rusty Russell To: Andrew Morton Cc: lkml - Kernel Mailing List , virtualization , Andi Kleen Content-Type: text/plain Date: Mon, 12 Feb 2007 14:32:00 +1100 Message-Id: <1171251120.10409.2.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.8.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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 diff -r 4fb7fc327801 arch/i386/kernel/Makefile --- a/arch/i386/kernel/Makefile Mon Feb 12 12:37:01 2007 +1100 +++ b/arch/i386/kernel/Makefile Mon Feb 12 12:55:00 2007 +1100 @@ -41,8 +41,6 @@ obj-$(CONFIG_KWATCH) += debugreg.o kwat obj-$(CONFIG_KWATCH) += debugreg.o kwatch.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 diff -r 4fb7fc327801 arch/i386/kernel/head.S --- a/arch/i386/kernel/head.S Mon Feb 12 12:37:01 2007 +1100 +++ b/arch/i386/kernel/head.S Mon Feb 12 12:54:19 2007 +1100 @@ -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 @@ 1: addl $4, (%esp) jmp 1b + +unhandled_paravirt: + /* Nothing wanted us: we're screwed. */ + ud2 #endif /* diff -r 4fb7fc327801 arch/i386/kernel/paravirt.c --- a/arch/i386/kernel/paravirt.c Mon Feb 12 12:37:01 2007 +1100 +++ b/arch/i386/kernel/paravirt.c Mon Feb 12 12:54:19 2007 +1100 @@ -481,9 +481,6 @@ static int __init print_banner(void) return 0; } 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",