From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: Re: [PATCH] x86, vmlinux.lds: Page-Align end of ..page_aligned sections Date: Tue, 21 Jul 2020 11:44:07 -0700 Message-ID: <202007211143.AC36D096@keescook> References: <20200721093448.10417-1-joro@8bytes.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727115AbgGUSoJ (ORCPT ); Tue, 21 Jul 2020 14:44:09 -0400 Received: from mail-pj1-x1043.google.com (mail-pj1-x1043.google.com [IPv6:2607:f8b0:4864:20::1043]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8AEDEC0619DA for ; Tue, 21 Jul 2020 11:44:09 -0700 (PDT) Received: by mail-pj1-x1043.google.com with SMTP id cv18so1755463pjb.1 for ; Tue, 21 Jul 2020 11:44:09 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20200721093448.10417-1-joro@8bytes.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Joerg Roedel Cc: x86@kernel.org, hpa@zytor.com, Arnd Bergmann , Heiko Carstens , Joerg Roedel , Bob Haarman , hjl.tools@gmail.com, Arvind Sankar , Dmitry Safonov <0x7f454c46@gmail.com>, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org On Tue, Jul 21, 2020 at 11:34:48AM +0200, Joerg Roedel wrote: > From: Joerg Roedel > > Align the end of the .bss..page_aligned and .data..page_aligned section > on page-size too. Otherwise the linker might place other objects on the > page of the last ..page_aligned object. This is inconsistent with other > objects in those sections, which all have their own page. What problem was actually encountered? (i.e. why is it a problem for the other data to be in the page of the page-aligned data? shouldn't those data have their own, separate, alignment hint?) -- Kees Cook