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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 9240FC2D0C8 for ; Sat, 28 Dec 2019 06:35:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CA0321582 for ; Sat, 28 Dec 2019 06:35:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AXm6o1X4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726018AbfL1Gff (ORCPT ); Sat, 28 Dec 2019 01:35:35 -0500 Received: from mail-qk1-f194.google.com ([209.85.222.194]:43837 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725999AbfL1Gff (ORCPT ); Sat, 28 Dec 2019 01:35:35 -0500 Received: by mail-qk1-f194.google.com with SMTP id t129so22939292qke.10 for ; Fri, 27 Dec 2019 22:35:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=nZ8onEKn9qBmgxCL/WHku5+COjxuEn7Ue0xL0gB/QBY=; b=AXm6o1X4jpJx+brRhqbRlRkZr1+yBDX0Ytt3kslwg2kpIg+CfZyYoAAmUOE+NGP1mE abrFyzIInp3vZMK87icfab+l0sXo2cljmZ0dybeSe+IfHaMrEDqqHoms+D/57UVFhoYf FLSkv91e7vCS2jbmrQdlgJi3z7XQi5X9Kz0v9RXIuWhXQ8jhQJ8b/Htfnxaeg31cQIYt DL8+RuIUAwondhWLq+Yp6RJ0YBzzYR1qkoU8ScuTF3i+oxOb6NiJ/matjwy60E93Wjr8 y+YiFw6jinQXFQtX+xMW9HMauJuVnzKbb84Ge/v/wwe2d9leQg/IKNgezJ8iIlXP3+hM cqMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:date:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=nZ8onEKn9qBmgxCL/WHku5+COjxuEn7Ue0xL0gB/QBY=; b=roHkE13cRp9492JaBtX5WN+dgptoYk5y4V8pLyEgTYFu/Y9Af5sXmIMpcZN4/rartI r8fmBT8chaW3CbAXpbdjdF61LHAyc6HhFQKtbUxwKIJpNcgrhXjSOgmFW5a8TXBTuZjg RyyQPVEuA0QBTzGe5yS9nPFC+ygnBcBZwgiVzFfISva2toVl2NukluZzp7dSrnlKM4Tm h+SYaXb/kKoOf2INTCsnRO/TcU7gWdw5MyFZ74jkY8X2LvKh6yX7xPMpd8hJDEp1h/ev JEoXfSqLuM2neM3rTN4yMAdmWknrsNqW6Z5YhIIx+mMUWB+8EOR76L9T9qn0qbsVCcJZ tJCg== X-Gm-Message-State: APjAAAWKAJiaA6HjunXt6+Km53lKOOyz5E6W/Iv+vLVcr29Av4qyvLbi 52YUHvlW6/xVsdazRNjb+Ctr9f1f X-Google-Smtp-Source: APXvYqw0Rpm+eiVwT5LTyl4lZtF4EVAAuDZ31zvdwui4ihWOsfe4nEAuvtNAbsBmSxGstddJdkMJEA== X-Received: by 2002:a37:5841:: with SMTP id m62mr45624488qkb.256.1577514934454; Fri, 27 Dec 2019 22:35:34 -0800 (PST) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id l62sm10467880qke.12.2019.12.27.22.35.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Dec 2019 22:35:33 -0800 (PST) From: Arvind Sankar X-Google-Original-From: Arvind Sankar Date: Sat, 28 Dec 2019 01:35:32 -0500 To: Andy Lutomirski Cc: Arvind Sankar , Ard Biesheuvel , Andy Lutomirski , Ingo Molnar , Ard Biesheuvel , linux-efi , Hans de Goede Subject: Re: [PATCH 1/3] efi/x86: simplify 64-bit EFI firmware call wrapper Message-ID: <20191228063531.GB1194635@rani.riverdale.lan> References: <20191228044357.GA1194635@rani.riverdale.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-efi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org On Sat, Dec 28, 2019 at 01:29:00PM +0800, Andy Lutomirski wrote: > > > * The stack must be 16-byte aligned > > Nope. The asm needs to do this for runtime services. The kernel runs with 8-byte stack alignment. > 32-bit code is actually only 4-byte aligned in the kernel proper, right? Currently, only native 64-bit calls always respect the 16-byte alignment requirement, by aligning explicitly in the asm stubs, or after the cleanup patches, via the efi bootloader running with 16-byte stack alignment. I think mixed mode might actually be aligned via the asm stub in the kernel proper, though it doesn't look like it is in the bootloader portion.