From patchwork Sun May 8 09:36:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baolin Wang X-Patchwork-Id: 12842295 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C0EF0C433EF for ; Sun, 8 May 2022 09:38:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date:Subject:Cc:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=x2h+ZFf0X0AnkGvoFCvBF5+UVrVYO1GGZIfZKE6eH84=; b=fB7MjhY9IBnnOJ y2i9E5O5YvT4PRGKesk+QMHTopbNFM6SKa+XXpQYFAzARuLMCLbC4QbbnPNoOJj1zjm9aswDTm9o1 3n38Kb0/Ct+cb9ER9WRlNfAhMTBosF++RlU7IyTLr9//rzB+XT9so1sn0pPX5swHtWBQWvoNtz+kn 34s6/G/RidvbPVG9Z9Mt5ZfBdJUdxegrn+eZRBrigW3EqENfr7S5IOwUAU0bdd+LGbT3oKm+z2ISL OnwDM4mgvbjbxmmIfK3kfLo7i6XVh5hRW8Naxrzg6ZAciYC0BSpqSFWUlTLH5DEY86xC+RnFJ5xxs 0ml7wOKHotYx4rcE+eog==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nndLa-009fAI-3Q; Sun, 08 May 2022 09:37:02 +0000 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nndLV-009f8L-KB for linux-arm-kernel@lists.infradead.org; Sun, 08 May 2022 09:37:00 +0000 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R271e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04395; MF=baolin.wang@linux.alibaba.com; NM=1; PH=DS; RN=31; SR=0; TI=SMTPD_---0VCa0vRD_1652002610; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0VCa0vRD_1652002610) by smtp.aliyun-inc.com(127.0.0.1); Sun, 08 May 2022 17:36:51 +0800 From: Baolin Wang To: akpm@linux-foundation.org, mike.kravetz@oracle.com, catalin.marinas@arm.com, will@kernel.org Cc: tsbogend@alpha.franken.de, James.Bottomley@HansenPartnership.com, deller@gmx.de, mpe@ellerman.id.au, benh@kernel.crashing.org, paulus@samba.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, ysato@users.sourceforge.jp, dalias@libc.org, davem@davemloft.net, arnd@arndb.de, baolin.wang@linux.alibaba.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 0/3] Fix CONT-PTE/PMD size hugetlb issue when unmapping or migrating Date: Sun, 8 May 2022 17:36:38 +0800 Message-Id: X-Mailer: git-send-email 1.8.3.1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220508_023657_875674_F640607F X-CRM114-Status: GOOD ( 12.39 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, Now migrating a hugetlb page or unmapping a poisoned hugetlb page, we'll use ptep_clear_flush() and set_pte_at() to nuke the page table entry and remap it, and this is incorrect for CONT-PTE or CONT-PMD size hugetlb page, which will cause potential data consistent issue. This patch set will change to use hugetlb related APIs to fix this issue, please find details in each patch. Thanks. Note: Mike pointed out the huge_ptep_get() will only return the one specific value, and it would not take into account the dirty or young bits of CONT-PTE/PMDs like the huge_ptep_get_and_clear() [1]. This inconsistent issue is not introduced by this patch set, and will address this issue in another thread [2]. Meanwhile the uffd for hugetlb case [3] pointed by Gerald also need another patch to address. [1] https://lore.kernel.org/linux-mm/85bd80b4-b4fd-0d3f-a2e5-149559f2f387@oracle.com/ [2] https://lore.kernel.org/all/cover.1651998586.git.baolin.wang@linux.alibaba.com/ [3] https://lore.kernel.org/linux-mm/20220503120343.6264e126@thinkpad/ Changes from v1: - Add acked tag from Mike. - Update some commit message. - Add VM_BUG_ON in try_to_unmap() for hugetlb case. - Add an explict void casting for huge_ptep_clear_flush() in hugetlb.c. Baolin Wang (3): mm: change huge_ptep_clear_flush() to return the original pte mm: rmap: Fix CONT-PTE/PMD size hugetlb issue when migration mm: rmap: Fix CONT-PTE/PMD size hugetlb issue when unmapping arch/arm64/include/asm/hugetlb.h | 4 +-- arch/arm64/mm/hugetlbpage.c | 12 +++----- arch/ia64/include/asm/hugetlb.h | 4 +-- arch/mips/include/asm/hugetlb.h | 9 ++++-- arch/parisc/include/asm/hugetlb.h | 4 +-- arch/powerpc/include/asm/hugetlb.h | 9 ++++-- arch/s390/include/asm/hugetlb.h | 6 ++-- arch/sh/include/asm/hugetlb.h | 4 +-- arch/sparc/include/asm/hugetlb.h | 4 +-- include/asm-generic/hugetlb.h | 4 +-- mm/hugetlb.c | 2 +- mm/rmap.c | 63 ++++++++++++++++++++++++-------------- 12 files changed, 73 insertions(+), 52 deletions(-)