From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FA8AC433E1 for ; Wed, 27 May 2020 11:55:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EEA3F207CB for ; Wed, 27 May 2020 11:55:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387972AbgE0Lzx (ORCPT ); Wed, 27 May 2020 07:55:53 -0400 Received: from elvis.franken.de ([193.175.24.41]:41116 "EHLO elvis.franken.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729415AbgE0LzJ (ORCPT ); Wed, 27 May 2020 07:55:09 -0400 Received: from uucp (helo=alpha) by elvis.franken.de with local-bsmtp (Exim 3.36 #1) id 1jdueJ-00019x-02; Wed, 27 May 2020 13:55:07 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id 646EDC059B; Wed, 27 May 2020 13:53:54 +0200 (CEST) Date: Wed, 27 May 2020 13:53:54 +0200 From: Thomas Bogendoerfer To: Jiaxun Yang Cc: linux-mips@vger.kernel.org, Kees Cook , Borislav Petkov , Heiko Carstens , Fangrui Song , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 2/3] MIPS: Move kernel head into a standalone section Message-ID: <20200527115354.GC13965@alpha.franken.de> References: <20200527063438.391949-1-jiaxun.yang@flygoat.com> <20200527063438.391949-3-jiaxun.yang@flygoat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200527063438.391949-3-jiaxun.yang@flygoat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 27, 2020 at 02:34:33PM +0800, Jiaxun Yang wrote: > That's what already done by Arm64 and other architectures. > That would allow us put more things like PE headers safely into > the header. > > Signed-off-by: Jiaxun Yang > --- > arch/mips/kernel/head.S | 4 ++-- > arch/mips/kernel/vmlinux.lds.S | 8 ++++++-- > 2 files changed, 8 insertions(+), 4 deletions(-) > > diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S > index c7c2795837e7..8081a905a71c 100644 > --- a/arch/mips/kernel/head.S > +++ b/arch/mips/kernel/head.S > @@ -59,6 +59,8 @@ > #endif > .endm > > + __HEAD > +_head: > #ifndef CONFIG_NO_EXCEPT_FILL > /* > * Reserved space for exception handlers. I'm adding the missing piece, why this change ist broken: * Necessary for machines which link their kernels at KSEG0. by putting something in front of that will probably break platforms making use of "feature". If we can make sure, we don't need it anymore, we should first remove this and then add __HEAD part. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]