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,URIBL_BLOCKED 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 77825C3279B for ; Wed, 4 Jul 2018 19:40:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3BE6720878 for ; Wed, 4 Jul 2018 19:40:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3BE6720878 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.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 S1752946AbeGDTkH (ORCPT ); Wed, 4 Jul 2018 15:40:07 -0400 Received: from terminus.zytor.com ([198.137.202.136]:43893 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752568AbeGDTkF (ORCPT ); Wed, 4 Jul 2018 15:40:05 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w64JdrTU785220 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 4 Jul 2018 12:39:53 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w64JdqR1785215; Wed, 4 Jul 2018 12:39:52 -0700 Date: Wed, 4 Jul 2018 12:39:52 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Toshi Kani Message-ID: Cc: linux-kernel@vger.kernel.org, toshi.kani@hpe.com, mhocko@suse.com, stable@vger.kernel.org, akpm@linux-foundation.org, mingo@kernel.org, joro@8bytes.org, tglx@linutronix.de, hpa@zytor.com Reply-To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, toshi.kani@hpe.com, mhocko@suse.com, stable@vger.kernel.org, joro@8bytes.org, tglx@linutronix.de, hpa@zytor.com, mingo@kernel.org In-Reply-To: <20180627141348.21777-2-toshi.kani@hpe.com> References: <20180627141348.21777-2-toshi.kani@hpe.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86/mm: Disable ioremap free page handling on x86-PAE Git-Commit-ID: f967db0b9ed44ec3057a28f3b28efc51df51b835 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: f967db0b9ed44ec3057a28f3b28efc51df51b835 Gitweb: https://git.kernel.org/tip/f967db0b9ed44ec3057a28f3b28efc51df51b835 Author: Toshi Kani AuthorDate: Wed, 27 Jun 2018 08:13:46 -0600 Committer: Thomas Gleixner CommitDate: Wed, 4 Jul 2018 21:37:08 +0200 x86/mm: Disable ioremap free page handling on x86-PAE ioremap() supports pmd mappings on x86-PAE. However, kernel's pmd tables are not shared among processes on x86-PAE. Therefore, any update to sync'd pmd entries need re-syncing. Freeing a pte page also leads to a vmalloc fault and hits the BUG_ON in vmalloc_sync_one(). Disable free page handling on x86-PAE. pud_free_pmd_page() and pmd_free_pte_page() simply return 0 if a given pud/pmd entry is present. This assures that ioremap() does not update sync'd pmd entries at the cost of falling back to pte mappings. Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") Reported-by: Joerg Roedel Signed-off-by: Toshi Kani Signed-off-by: Thomas Gleixner Cc: mhocko@suse.com Cc: akpm@linux-foundation.org Cc: hpa@zytor.com Cc: cpandya@codeaurora.org Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: stable@vger.kernel.org Cc: Andrew Morton Cc: Michal Hocko Cc: "H. Peter Anvin" Cc: Link: https://lkml.kernel.org/r/20180627141348.21777-2-toshi.kani@hpe.com --- arch/x86/mm/pgtable.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 47b5951e592b..1aeb7a5dbce5 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -719,6 +719,7 @@ int pmd_clear_huge(pmd_t *pmd) return 0; } +#ifdef CONFIG_X86_64 /** * pud_free_pmd_page - Clear pud entry and free pmd page. * @pud: Pointer to a PUD. @@ -766,4 +767,22 @@ int pmd_free_pte_page(pmd_t *pmd) return 1; } + +#else /* !CONFIG_X86_64 */ + +int pud_free_pmd_page(pud_t *pud) +{ + return pud_none(*pud); +} + +/* + * Disable free page handling on x86-PAE. This assures that ioremap() + * does not update sync'd pmd entries. See vmalloc_sync_one(). + */ +int pmd_free_pte_page(pmd_t *pmd) +{ + return pmd_none(*pmd); +} + +#endif /* CONFIG_X86_64 */ #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */