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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 5DDFCC33CB2 for ; Wed, 29 Jan 2020 05:17:52 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id A8A0E20CC7 for ; Wed, 29 Jan 2020 05:17:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A8A0E20CC7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ellerman.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-17635-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 16265 invoked by uid 550); 29 Jan 2020 05:17:44 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 16225 invoked from network); 29 Jan 2020 05:17:43 -0000 X-powerpc-patch-notification: thanks X-powerpc-patch-commit: 970d54f99ceac5bbf27929cb5ebfe18338ba1543 In-Reply-To: <20191224064126.183670-1-ruscur@russell.cc> To: Russell Currey , linuxppc-dev@lists.ozlabs.org From: Michael Ellerman Cc: ajd@linux.ibm.com, kernel-hardening@lists.openwall.com, npiggin@gmail.com, Russell Currey Subject: Re: [PATCH 1/2] powerpc/book3s64/hash: Disable 16M linear mapping size if not aligned Message-Id: <486sDm3Clwz9sRW@ozlabs.org> Date: Wed, 29 Jan 2020 16:17:28 +1100 (AEDT) On Tue, 2019-12-24 at 06:41:25 UTC, Russell Currey wrote: > With STRICT_KERNEL_RWX on in a relocatable kernel under the hash MMU, if > the position the kernel is loaded at is not 16M aligned, the kernel > miscalculates its ALIGN*()s and things go horribly wrong. > > We can easily avoid this when selecting the linear mapping size, so do > so and print a warning. I tested this for various alignments and as > long as the position is 64K aligned it's fine (the base requirement for > powerpc). > > Signed-off-by: Russell Currey Series applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/970d54f99ceac5bbf27929cb5ebfe18338ba1543 cheers