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=-11.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 57A2DC43463 for ; Mon, 21 Sep 2020 12:26:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1589920EDD for ; Mon, 21 Sep 2020 12:26:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600691178; bh=B9m47IuE1+copBHi/pgUAHD+SLwWrVMGkMJMqhle0Bk=; h=Subject:To:Cc:From:Date:List-ID:From; b=z7yDWbhrZhwy3ZtwZlcKoes5CVjSSZhyhNQoRqKWnBg4CO/ItLmKx7P3C9F1fvdEV yFUTYjtFr0GJufkJJJM/BNl7WSw4TC7vLGakusNguRkLtixF2KIUxEGHCtyQe8KPJ8 Y0A+YE9opypULeAjM93iQt1ZCEGIv7xKO0+/onWQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726625AbgIUM0R (ORCPT ); Mon, 21 Sep 2020 08:26:17 -0400 Received: from forward3-smtp.messagingengine.com ([66.111.4.237]:44135 "EHLO forward3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726510AbgIUM0R (ORCPT ); Mon, 21 Sep 2020 08:26:17 -0400 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailforward.nyi.internal (Postfix) with ESMTP id CC31C1940EC8; Mon, 21 Sep 2020 08:26:16 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Mon, 21 Sep 2020 08:26:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=fPEwm3 5ZVE3UXt3h5h6NVqg77Ua+nr4iB2NSM3o6cmc=; b=MI4+kdd9GAFAT7EQ5fD/4M NzUEFa4gB4Z+fIppIP0ahh0czVrDbLLaEnjaZ0gKrxYchEJoTtKkhujMUI13IJln NT4aNfXcuVcn8JRsiXE/PDhElQKnW8o8Fui96DNnBzAU7ex526TyTn9M+fQhIW6t g4lTLEBw8NUb+BVQgOMlsTq7GoQXuclPpn9LLRzTYM2LwMemUZJRyfgtRXVacRRi LsNG56sJtETXziNjj0rDX8/PjK0aNhLHP1ekoSFOazzuotfVaYY9/dOM7d6vUbdL 0olUTgRZhld8nEfn6xc/I23V4kd7ZIHaktdxSLgk0eNgwYodDo12ekr/PIKI8Yjg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedujedruddvgdehgecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecunecujfgurhepuffvhfffkfggtgfgsehtkeertddttd flnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdhorhhg qeenucggtffrrghtthgvrhhnpeelleelvdegfeelledtteegudegfffghfduffduudekge efleegieegkeejhfelveenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecukfhppeek fedrkeeirdejgedrieegnecuvehluhhsthgvrhfuihiivgepudenucfrrghrrghmpehmrg hilhhfrhhomhepghhrvghgsehkrhhorghhrdgtohhm X-ME-Proxy: Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) by mail.messagingengine.com (Postfix) with ESMTPA id 4D69A3064674; Mon, 21 Sep 2020 08:26:16 -0400 (EDT) Subject: FAILED: patch "[PATCH] mm/thp: fix __split_huge_pmd_locked() for migration PMD" failed to apply to 4.19-stable tree To: rcampbell@nvidia.com, akpm@linux-foundation.org, apopple@nvidia.com, bharata@linux.ibm.com, bskeggs@redhat.com, hch@lst.de, jgg@nvidia.com, jglisse@redhat.com, jhubbard@nvidia.com, shuah@kernel.org, shy828301@gmail.com, stable@vger.kernel.org, torvalds@linux-foundation.org, ziy@nvidia.com Cc: From: Date: Mon, 21 Sep 2020 14:26:40 +0200 Message-ID: <160069120043152@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ec0abae6dcdf7ef88607c869bf35a4b63ce1b370 Mon Sep 17 00:00:00 2001 From: Ralph Campbell Date: Fri, 18 Sep 2020 21:20:24 -0700 Subject: [PATCH] mm/thp: fix __split_huge_pmd_locked() for migration PMD A migrating transparent huge page has to already be unmapped. Otherwise, the page could be modified while it is being copied to a new page and data could be lost. The function __split_huge_pmd() checks for a PMD migration entry before calling __split_huge_pmd_locked() leading one to think that __split_huge_pmd_locked() can handle splitting a migrating PMD. However, the code always increments the page->_mapcount and adjusts the memory control group accounting assuming the page is mapped. Also, if the PMD entry is a migration PMD entry, the call to is_huge_zero_pmd(*pmd) is incorrect because it calls pmd_pfn(pmd) instead of migration_entry_to_pfn(pmd_to_swp_entry(pmd)). Fix these problems by checking for a PMD migration entry. Fixes: 84c3fc4e9c56 ("mm: thp: check pmd migration entry in common path") Signed-off-by: Ralph Campbell Signed-off-by: Andrew Morton Reviewed-by: Yang Shi Reviewed-by: Zi Yan Cc: Jerome Glisse Cc: John Hubbard Cc: Alistair Popple Cc: Christoph Hellwig Cc: Jason Gunthorpe Cc: Bharata B Rao Cc: Ben Skeggs Cc: Shuah Khan Cc: [4.14+] Link: https://lkml.kernel.org/r/20200903183140.19055-1-rcampbell@nvidia.com Signed-off-by: Linus Torvalds diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 7ff29cc3d55c..faadc449cca5 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2022,7 +2022,7 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, put_page(page); add_mm_counter(mm, mm_counter_file(page), -HPAGE_PMD_NR); return; - } else if (is_huge_zero_pmd(*pmd)) { + } else if (pmd_trans_huge(*pmd) && is_huge_zero_pmd(*pmd)) { /* * FIXME: Do we want to invalidate secondary mmu by calling * mmu_notifier_invalidate_range() see comments below inside @@ -2116,30 +2116,34 @@ static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, pte = pte_offset_map(&_pmd, addr); BUG_ON(!pte_none(*pte)); set_pte_at(mm, addr, pte, entry); - atomic_inc(&page[i]._mapcount); - pte_unmap(pte); - } - - /* - * Set PG_double_map before dropping compound_mapcount to avoid - * false-negative page_mapped(). - */ - if (compound_mapcount(page) > 1 && !TestSetPageDoubleMap(page)) { - for (i = 0; i < HPAGE_PMD_NR; i++) + if (!pmd_migration) atomic_inc(&page[i]._mapcount); + pte_unmap(pte); } - lock_page_memcg(page); - if (atomic_add_negative(-1, compound_mapcount_ptr(page))) { - /* Last compound_mapcount is gone. */ - __dec_lruvec_page_state(page, NR_ANON_THPS); - if (TestClearPageDoubleMap(page)) { - /* No need in mapcount reference anymore */ + if (!pmd_migration) { + /* + * Set PG_double_map before dropping compound_mapcount to avoid + * false-negative page_mapped(). + */ + if (compound_mapcount(page) > 1 && + !TestSetPageDoubleMap(page)) { for (i = 0; i < HPAGE_PMD_NR; i++) - atomic_dec(&page[i]._mapcount); + atomic_inc(&page[i]._mapcount); + } + + lock_page_memcg(page); + if (atomic_add_negative(-1, compound_mapcount_ptr(page))) { + /* Last compound_mapcount is gone. */ + __dec_lruvec_page_state(page, NR_ANON_THPS); + if (TestClearPageDoubleMap(page)) { + /* No need in mapcount reference anymore */ + for (i = 0; i < HPAGE_PMD_NR; i++) + atomic_dec(&page[i]._mapcount); + } } + unlock_page_memcg(page); } - unlock_page_memcg(page); smp_wmb(); /* make pte visible before pmd */ pmd_populate(mm, pmd, pgtable);