Received: by 2002:a05:6358:3188:b0:123:57c1:9b43 with SMTP id q8csp31965990rwd; Fri, 7 Jul 2023 07:00:59 -0700 (PDT) X-Google-Smtp-Source: APBJJlHGoiI4qurgG1+CZf4VJjkB6UkmgeR5pccA825DyNgFAk0xGi7eACN9i6Abm0R+W9Urc42X X-Received: by 2002:a54:4507:0:b0:3a3:99ea:7770 with SMTP id l7-20020a544507000000b003a399ea7770mr5550363oil.30.1688738459271; Fri, 07 Jul 2023 07:00:59 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1688738459; cv=none; d=google.com; s=arc-20160816; b=EYMZ06+pV6vAzUJNXJpo8qapQa6ANpOJe4lgJ0933cIEDs/QM25uaYbXjbVV63XQDr Fzi0bkvHjHoVQi59wbO2LJ7k/8li3cKaI4QzkdLvS13HJWM3XUtX7RQWgoyep+367FYe o1TYzRegnhQ82tONyY5pDD4tXRct4Q33veEFC5SR8XPo9oNq47ZaBKigQbFr9I19b0Mu MwMuNDiwMUngCAKEUyjv40du2GvDCdwxiiMwUtGqbyfNFlHjpoOjUVc7xZd3IRN+JVwQ /uOqaGwhoBFucSsIs6N8/qT6PJDF0HhhP62b1XG3ev8pX5ViAaHp6io0xComafaGLWSB xycQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:dkim-signature :dkim-signature; bh=iNn8Lobuwq8oGyKnx/IrJ5I2KhzyBS1z7FSQ9+iwXAw=; fh=smwlySTEPN7NbtuvxBDR0YLYw0n8sfL/zSNxRQmJRvQ=; b=AZaRccqvbGY4NlA/zY5wyaYThNU+Os6isebpONr6cXrlk1xtcrV42wKalJg9NhCoel GROrfde/+4uk89sgRLvQmJ98XEsIRLkdgihJfmqc3BSWil967BP/TlTn163HD3PJYfpZ DRBoWbAmSeNMHfuh6YURcea28zmCwtz/mqEU8yQSDTeWr7qpeKXZOZYDQNQnxvkWm8OO QnSzDUZaJXKZYHhkHlb6148mkpEQUwou/9YBaOh3Yo0tFzAYEGd+JfvL0oKFEj1ZDuSH b42L3DekATQtDH9Dz+TpB9fi3qngIRfH2n6phh5qLXVZsT0FDcDAtkKplofHeJl3I57x hiaQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=eRR9ZBaJ; dkim=pass header.i=@alien8.de header.s=alien8 header.b=NnchMBN7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id c29-20020a630d1d000000b0055bc1aaa7d9si4037844pgl.413.2023.07.07.07.00.38; Fri, 07 Jul 2023 07:00:59 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@alien8.de header.s=dkim header.b=eRR9ZBaJ; dkim=pass header.i=@alien8.de header.s=alien8 header.b=NnchMBN7; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=alien8.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231745AbjGGN45 (ORCPT + 99 others); Fri, 7 Jul 2023 09:56:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35252 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229743AbjGGN44 (ORCPT ); Fri, 7 Jul 2023 09:56:56 -0400 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3AA721FC7; Fri, 7 Jul 2023 06:56:55 -0700 (PDT) Received: from mail.alien8.de (mail.alien8.de [IPv6:2a01:4f9:3051:3f93::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 87A131EC0773; Fri, 7 Jul 2023 15:56:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1688738213; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=iNn8Lobuwq8oGyKnx/IrJ5I2KhzyBS1z7FSQ9+iwXAw=; b=eRR9ZBaJGfBlMs+WLlyj2EELekTQY3VLN25t86xinriciYkfqKGtav3JpbkaUp7gP5jiM6 w4Mwi42Hx7dlP0djiUcKW1UYFu6UTxwBCpQhmaToWHZOWIZMzH/r7yF2E9ejYiDo6wmjg+ gmLDXQ/9+ofDiFE0d9D+cxZT1gXvTxQ= X-Virus-Scanned: Debian amavisd-new at mail.alien8.de Authentication-Results: mail.alien8.de (amavisd-new); dkim=pass (4096-bit key) header.d=alien8.de Received: from mail.alien8.de ([127.0.0.1]) by localhost (mail.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id Td-cmWnxeZ-a; Fri, 7 Jul 2023 13:56:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=alien8; t=1688738210; bh=iNn8Lobuwq8oGyKnx/IrJ5I2KhzyBS1z7FSQ9+iwXAw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NnchMBN7vx1cZyjXa/nEErc3VaRGeJVSvPTmkee4HYTv4Kwg44wRr0dEg1gjU92fJ N9tmvhchhtzR9ACfCEiOUDiZeRVYPHV8rFFxJeiMtmVLzuLMjxMXNZvToRV9Fqka0w GA1kN29bgwOVkLKWd+XftyWFa/K9vDiLTNvtXYZbD7HDEbZ/5ANDLpyIWilf/mkEBl uvxk+Z+IVn2SwyDDHoIQ63Nqclbzu6kp3vsoby/+S9BtfP6+s26IGPHn+HVqJQq9Ez J+/NDo4fbmM6D6vdatjDLyK9yG8n2vcXK11fykyBncBUV4Y0AXoBQFifJKCRqjvh/a HIPG52ObPed1kQwductDSeMY3Hv3Xeubvc5U4lYZBwaji++krp4/QE7OGvqEF7GLki 9e0GOWEq0TkAurCd4fJamvGpNJwWnyU2d8LCV+P6IlT0f+iwaYk9iAGyh7e9JieRzw WN9DPPF8JwTQh+IC6+1Fgb1+/OIGp6XAMh0fIe2RbtPm1fe9wOu6IWYsD0GmIwk5ey 3RyFx8HMw7AqUb85wRFJXYMBmuM9a8R0n1O3fPWA4hUhdjxBDaY0AfDSRSy7bPnD07 y8KcN5lC05sKqfO5HI8t/r/HMchEzktEdsDF3ecs6qpq+axvVlfDTPkkYQCIFtt+8/ GkgkN1+KIXkvE+lXjnRKvG6Q= Received: from zn.tnic (pd9530d32.dip0.t-ipconnect.de [217.83.13.50]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature ECDSA (P-256) server-digest SHA256) (No client certificate requested) by mail.alien8.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 927F440E0187; Fri, 7 Jul 2023 13:56:31 +0000 (UTC) Date: Fri, 7 Jul 2023 15:56:27 +0200 From: Borislav Petkov To: Ard Biesheuvel Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, Evgeniy Baskov , Andy Lutomirski , Dave Hansen , Ingo Molnar , Peter Zijlstra , Thomas Gleixner , Alexey Khoroshilov , Peter Jones , Gerd Hoffmann , Dave Young , Mario Limonciello , Kees Cook , Tom Lendacky , "Kirill A . Shutemov" , Linus Torvalds , Joerg Roedel Subject: Re: [PATCH v5 05/20] x86/decompressor: Use proper sequence to take the address of the GOT Message-ID: <20230707135627.GEZKgZizdtbMokdz2u@fat_crate.local> References: <20230607072342.4054036-1-ardb@kernel.org> <20230607072342.4054036-6-ardb@kernel.org> <20230621110852.GAZJLaRAuGBCc5R4yb@fat_crate.local> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jun 23, 2023 at 04:00:30PM +0200, Ard Biesheuvel wrote: > if you assemble this > > movl $_GLOBAL_OFFSET_TABLE_, %eax > movl $_GLOBAL_OFFSET_TABLE, %eax > > you'll end up with > > 0: b8 01 00 00 00 mov $0x1,%eax > 1: R_386_GOTPC _GLOBAL_OFFSET_TABLE_ > 5: b8 00 00 00 00 mov $0x0,%eax > 6: R_386_32 _GLOBAL_OFFSET_TABLE > > So it is not possible to take the absolute address of > _GLOBAL_OFFSET_TABLE_ via an absolute relocation, you will always get > the relative offset instead. Right. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette