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=-2.1 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 48F6FC43603 for ; Sat, 14 Dec 2019 19:46:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 178A52073D for ; Sat, 14 Dec 2019 19:46:36 +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="HVurpgad" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726918AbfLNTqb (ORCPT ); Sat, 14 Dec 2019 14:46:31 -0500 Received: from mail-qk1-f193.google.com ([209.85.222.193]:46350 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726484AbfLNTqa (ORCPT ); Sat, 14 Dec 2019 14:46:30 -0500 Received: by mail-qk1-f193.google.com with SMTP id r14so1641608qke.13; Sat, 14 Dec 2019 11:46:30 -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=taLHS8JyLC+BenbNT7BxnrVrwoDPqQMtSy8lb0fixC0=; b=HVurpgad1QMZQN0+i58d659mAg2CARQfC7k6Yc2ns+gRiGEMv+w662w2XASNY+IBO0 obJd8LRJkqjqAenPYRGZZnrote5+1rpMa9nHxa5DQTQueo+82hxsRVo3D8ANaRk75+si 9G81TK6fBwZeIxbVZLaaDVMQFMw1OSEDE7VojohAI1kRpEMxwoAjJ/iZoijSrYueLjV/ xxSmyZlzThT5yo90i1oUBwhSjiCKrqZgRIbTU1By6IEKtkODA/IlqX0o3/ICRpPQY6we EqbRu5FKQiNHdG+48YSA0nFN9mnHx6O3sBHSO2ttCAbzSWjn2TFOtqBKkswukr8sF+zT N6mw== 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=taLHS8JyLC+BenbNT7BxnrVrwoDPqQMtSy8lb0fixC0=; b=TftmVZc4oWBcZsk62txCrodD1Ioqgiy6GF8wy4/BaPYUl1YqnMSmH1FMPuKQGU2/9/ sWtN+wPVrCMs9RKXhz85mj58tO+rNcMtssUMKZQNiZDVuwvE6zqs7iNjg2sehbVftAtz o2oNXuDM9kx+n7ZpPj2blPNjKkuL3JCIbWXJvgtYx7HPvbvGvLq4UB2+gD6Go7emD3zZ FdV+Vxxjt37L07R87K3ZsBedrVT3Dw4TxXXwiEOq/THmPds2OLHMyFkhLwWY9tNz1oDd 4828ZrDA983abCtY1xCtYVSNvCnSLRPuZ2zyhKEOdKyAUPv2u4rjWRim2swv4aDdGqKV 4RPQ== X-Gm-Message-State: APjAAAVtEkh0MWgsIQqW7O1ZkbA8MEo1GlyYMwb1kUlhBZ5aCBCW+O7/ 8oYDsQRVL8mg+2/EJhwQfzg= X-Google-Smtp-Source: APXvYqwQrs/JEOLTWQC8pQo+gOvB/pQ/X08MuDids0dmfojHeL4EZ/iAx1PIIZhPK+PosoSANVKCmw== X-Received: by 2002:a37:2e47:: with SMTP id u68mr19395733qkh.485.1576352789530; Sat, 14 Dec 2019 11:46:29 -0800 (PST) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id d25sm4837459qtm.67.2019.12.14.11.46.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Dec 2019 11:46:28 -0800 (PST) From: Arvind Sankar X-Google-Original-From: Arvind Sankar Date: Sat, 14 Dec 2019 14:46:27 -0500 To: Ard Biesheuvel Cc: linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, Hans de Goede , Matthew Garrett , Ingo Molnar , Andy Lutomirski , Thomas Gleixner , Arvind Sankar Subject: Re: [PATCH 05/10] efi/libstub: distinguish between native/mixed not 32/64 bit Message-ID: <20191214194626.GA140998@rani.riverdale.lan> References: <20191214175735.22518-1-ardb@kernel.org> <20191214175735.22518-6-ardb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20191214175735.22518-6-ardb@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 14, 2019 at 06:57:30PM +0100, Ard Biesheuvel wrote: > + > +#define efi_table_attr(table, attr, instance) ({ \ > + __typeof__(((table##_t *)0)->attr) __ret; \ > + if (efi_is_native()) { \ > + __ret = ((table##_t *)instance)->attr; \ > + } else { \ > + __typeof__(((table##_32_t *)0)->attr) at; \ > + at = (((table##_32_t *)(unsigned long)instance)->attr); \ > + __ret = (__typeof__(__ret))(unsigned long)at; \ > + } \ > + __ret; \ > +}) The casting of `at' is appropriate if the attr is a pointer type which needs to be zero-extended to 64-bit, but for other fields it is unnecessary at best and possibly dangerous. There are probably no instances currently where it is called for a non-pointer field, but is it possible to detect if the type is pointer and avoid the cast if not?