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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 05EDBC43142 for ; Wed, 27 Jun 2018 11:23:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9ABF622BC4 for ; Wed, 27 Jun 2018 11:23:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9ABF622BC4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753585AbeF0LXG (ORCPT ); Wed, 27 Jun 2018 07:23:06 -0400 Received: from foss.arm.com ([217.140.101.70]:58360 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752144AbeF0LXF (ORCPT ); Wed, 27 Jun 2018 07:23:05 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4C3D67A9; Wed, 27 Jun 2018 04:23:05 -0700 (PDT) Received: from [10.1.206.34] (melchizedek.cambridge.arm.com [10.1.206.34]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E4C023F5C0; Wed, 27 Jun 2018 04:23:03 -0700 (PDT) Subject: Re: [PATCH v2 2/2] arm64/mm: Move {tramp_pg_dir, swapper_pg_dir} to .rodata section To: Suzuki K Poulose , Jun Yao Cc: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com, will.deacon@arm.com, ard.biesheuvel@linaro.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com References: <20180625113921.21854-1-yaojun8558363@gmail.com> <20180625113921.21854-3-yaojun8558363@gmail.com> <82f3bf16-cf3a-9b2d-a7d2-789a4abb0bf2@arm.com> From: James Morse Message-ID: Date: Wed, 27 Jun 2018 12:23:02 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <82f3bf16-cf3a-9b2d-a7d2-789a4abb0bf2@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Suzuki, Jun, On 27/06/18 12:07, Suzuki K Poulose wrote: > On 25/06/18 12:39, Jun Yao wrote: >> When CONFIG_ARM64_VA_BITS_36/CONFIG_ARM64_VA_BITS_39/ >> CONFIG_ARM64_VA_BITS_42 are selected, a block-mapping can be >> written to swapper_pg_dir. To defend 'KSMA', we move swapper_pg_dir >> to .rodata section when these configurations are selected. At the >> same time, we update swapper_pg_dir by fixmap. >> diff --git a/arch/arm64/include/asm/pgalloc.h b/arch/arm64/include/asm/pgalloc.h >> index 2e05bcd944c8..62512ad9c310 100644 >> --- a/arch/arm64/include/asm/pgalloc.h >> +++ b/arch/arm64/include/asm/pgalloc.h >> @@ -49,6 +49,22 @@ static inline void __pud_populate(pud_t *pudp, phys_addr_t >> pmdp, pudval_t prot) >>     static inline void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t >> *pmdp) >>   { >> +#ifdef CONFIG_ARM64_VA_BITS_39 > > Could we please use > > #ifdef __PAGETABLE_PUD_FOLDED ^^ >> @@ -142,6 +158,23 @@ pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, >> pte_t *ptep) >>       /* >>        * The pmd must be loaded with the physical address of the PTE table >>        */ >> +#if defined(CONFIG_ARM64_VA_BITS_42) || \ >> +    defined(CONFIG_ARM64_VA_BITS_36) > > and > > #ifdef __PGTABLE_PMD_FOLDED here ^^ > > >> +#if defined(CONFIG_ARM64_VA_BITS_39) || \ >> +    defined(CONFIG_ARM64_VA_BITS_36) || \ >> +    defined(CONFIG_ARM64_VA_BITS_42) > > and > > #ifdef __PGTABLE_PMD_FOLDED ^^ (as it implies > __PGTABLE_PUD_FOLDED ) > > instead ? Aha, I didn't know these existed. As we are only interested in matching one level for now, this is even clearer. Thanks, James