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=-6.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH 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 E1864C43218 for ; Mon, 10 Jun 2019 21:33:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B70D12082E for ; Mon, 10 Jun 2019 21:33:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="JZs+5Deu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390113AbfFJVdH (ORCPT ); Mon, 10 Jun 2019 17:33:07 -0400 Received: from mail-pl1-f196.google.com ([209.85.214.196]:36416 "EHLO mail-pl1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389760AbfFJVdH (ORCPT ); Mon, 10 Jun 2019 17:33:07 -0400 Received: by mail-pl1-f196.google.com with SMTP id d21so4157867plr.3 for ; Mon, 10 Jun 2019 14:33:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=825Is8NE7RT8Jz0RpT7VVuP0UsDVOSwHLm6oF1wC/YU=; b=JZs+5DeutR1B/D3BdPr4D+n3NH1somXSgr0zmI6lWGlLMSblkHtowdJJ8SnJ/EyEaT vrFjXglj30BU2fmFW/XhemfiYhbvsDJD7e8e/bLPI/HCHW4EsSv7G1jT0FZqaMF0NSuS Gx4kpEr/qt1k8y3/DrU7IYsObBsYTcttNkmos= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=825Is8NE7RT8Jz0RpT7VVuP0UsDVOSwHLm6oF1wC/YU=; b=duh027KUmg7GRPP3MAac51LR13hU/juIX7jTY0G6DWNSeVT4+H6Ef1w4k/0IxUHCOK /JuNvyzMDybAshVhSqZEWXFmoEVKNGsrZsH8ayMFZqjs8tI3S6Es9aJak9UX4aOl6G9k oI135na2SSOJ8SgQ23+3rVYu4VnCAmsqu1vsUbg8H0gJkgLa+jI2ZjRhbCNfUrLNjryz E9vza5IteISErJLgfEUbb/HCJAzhFUKEd0iIP2e7nx5R/tOv1Da94oJnEARuJwfUY7ju mDohtFJw3Lce4+Bb+IkBIcZ6aRJWr/NphEN+XMSAWgMHtN8CGhH/iBWYYKnQCM16TPUW 95ZA== X-Gm-Message-State: APjAAAW5hFA0SZXKbLGhV6rilDllaNvlmoNMBO0PYcgEUJbnPTNQgai/ ZDvasyW51GNhyGJR0UbcA/+WLA== X-Google-Smtp-Source: APXvYqw9TXY3olY6Pl/0Z1nz7YqPCYtLr1ZiA+NtCVd1DLzmoU/1gP95w+gvw/fnAiD4DrEKysAVHA== X-Received: by 2002:a17:902:102c:: with SMTP id b41mr22976465pla.204.1560202386832; Mon, 10 Jun 2019 14:33:06 -0700 (PDT) Received: from www.outflux.net (173-164-112-133-Oregon.hfc.comcastbusiness.net. [173.164.112.133]) by smtp.gmail.com with ESMTPSA id x14sm14944984pfq.158.2019.06.10.14.33.05 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 10 Jun 2019 14:33:06 -0700 (PDT) Date: Mon, 10 Jun 2019 14:33:05 -0700 From: Kees Cook To: Thomas Garnier Cc: kernel-hardening@lists.openwall.com, kristen@linux.intel.com, Thomas Garnier , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 04/12] x86: relocate_kernel - Adapt assembly for PIE support Message-ID: <201906101433.0A1A27960@keescook> References: <20190520231948.49693-1-thgarnie@chromium.org> <20190520231948.49693-5-thgarnie@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190520231948.49693-5-thgarnie@chromium.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 20, 2019 at 04:19:29PM -0700, Thomas Garnier wrote: > From: Thomas Garnier > > Change the assembly code to use only absolute references of symbols for the > kernel to be PIE compatible. > > Position Independent Executable (PIE) support will allow to extend the > KASLR randomization range below 0xffffffff80000000. > > Signed-off-by: Thomas Garnier Reviewed-by: Kees Cook -Kees > --- > arch/x86/kernel/relocate_kernel_64.S | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S > index 11eda21eb697..3320368b6ec9 100644 > --- a/arch/x86/kernel/relocate_kernel_64.S > +++ b/arch/x86/kernel/relocate_kernel_64.S > @@ -208,7 +208,7 @@ identity_mapped: > movq %rax, %cr3 > lea PAGE_SIZE(%r8), %rsp > call swap_pages > - movq $virtual_mapped, %rax > + movabsq $virtual_mapped, %rax > pushq %rax > ret > > -- > 2.21.0.1020.gf2820cf01a-goog > -- Kees Cook