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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 E0ADCC433E7 for ; Fri, 16 Oct 2020 03:04:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 967E12087D for ; Fri, 16 Oct 2020 03:04:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602817476; bh=Or2CQpqLEow/lTsRBd/DMklcdBJcMe9YNSJWWD0WuiM=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=sIvr4kxK+6g7ztNxWq8VRWeUoIIQL/DkY/kuZuIWU/oXOcmgPT5v1RWE+JtZIUs1Q TC0k8ZKj66SLbf2Q4HrUlkj7/uc8YhE5Awif4dTG2jbRB6suyAeukeNX7NHusqiB9P by0oyFjrFFa2fccIFswdhwMSVs22UHxKgikiVKvI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732581AbgJPDEg (ORCPT ); Thu, 15 Oct 2020 23:04:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:43588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728261AbgJPDEg (ORCPT ); Thu, 15 Oct 2020 23:04:36 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C439F208E4; Fri, 16 Oct 2020 03:04:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602817474; bh=Or2CQpqLEow/lTsRBd/DMklcdBJcMe9YNSJWWD0WuiM=; h=Date:From:To:Subject:In-Reply-To:From; b=UKHLkdhGJANl6FxzLavEdW3GQ4apJ3m924MvlP+R0yAMzUFaZxyEBe8ofk7ZOz04j ZQwQEIm6sDvPBIDRmqAPD49HRo+sXJGceSmVKLOTWJtmzCmRjRlCYj/pAYMKhRTE0j SxhtzLe9GiCwe6bKyD/JKuSEczr02Z2FdhTe44nM= Date: Thu, 15 Oct 2020 20:04:33 -0700 From: Andrew Morton To: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, anshuman.khandual@arm.com, christophe.leroy@csgroup.eu, mm-commits@vger.kernel.org, mpe@ellerman.id.au, torvalds@linux-foundation.org Subject: [patch 004/156] mm/debug_vm_pgtable/ppc64: avoid setting top bits in radom value Message-ID: <20201016030433.MZtKsUVYK%akpm@linux-foundation.org> In-Reply-To: <20201015194043.84cda0c1d6ca2a6847f2384a@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: "Aneesh Kumar K.V" Subject: mm/debug_vm_pgtable/ppc64: avoid setting top bits in radom value ppc64 use bit 62 to indicate a pte entry (_PAGE_PTE). Avoid setting that bit in random value. Link: https://lkml.kernel.org/r/20200902114222.181353-4-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V Reviewed-by: Anshuman Khandual Cc: Christophe Leroy Cc: Michael Ellerman Signed-off-by: Andrew Morton --- mm/debug_vm_pgtable.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-ppc64-avoid-setting-top-bits-in-radom-value +++ a/mm/debug_vm_pgtable.c @@ -44,10 +44,17 @@ * entry type. But these bits might affect the ability to clear entries with * pxx_clear() because of how dynamic page table folding works on s390. So * while loading up the entries do not change the lower 4 bits. It does not - * have affect any other platform. + * have affect any other platform. Also avoid the 62nd bit on ppc64 that is + * used to mark a pte entry. */ -#define S390_MASK_BITS 4 -#define RANDOM_ORVALUE GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS) +#define S390_SKIP_MASK GENMASK(3, 0) +#if __BITS_PER_LONG == 64 +#define PPC64_SKIP_MASK GENMASK(62, 62) +#else +#define PPC64_SKIP_MASK 0x0 +#endif +#define ARCH_SKIP_MASK (S390_SKIP_MASK | PPC64_SKIP_MASK) +#define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK) #define RANDOM_NZVALUE GENMASK(7, 0) static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot) _