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=-9.8 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 4E876C433DF for ; Wed, 19 Aug 2020 12:24:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A4912075E for ; Wed, 19 Aug 2020 12:24:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597839880; bh=W+c/GEYWtncLo4nmK+MWEoBjz69gLkhF/PNfrnmlzk0=; h=Subject:To:Cc:From:Date:List-ID:From; b=M3qMyHOT5jgP/RPszybJ2+x/uc42XAFAGo2CGSHaRaFElPaqdKHbe7M31b8CsN4uq kBuLaUEpdGWg1bTaOFE5+WZG5XzLC9pWAqrm4d1oDIFcHqqWWdv+DH424oImhd7huc axGhHnEBtq2k7hOoUgFFn+c2kHbrZrc3MddWO75Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726794AbgHSMYj (ORCPT ); Wed, 19 Aug 2020 08:24:39 -0400 Received: from wforward3-smtp.messagingengine.com ([64.147.123.22]:41885 "EHLO wforward3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726710AbgHSMYi (ORCPT ); Wed, 19 Aug 2020 08:24:38 -0400 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailforward.west.internal (Postfix) with ESMTP id 47991A40; Wed, 19 Aug 2020 08:24:37 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Wed, 19 Aug 2020 08:24:37 -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=agfkqZ MY55UDy6fNznXQtkTF4zbmEoDBS5GHGcTBG90=; b=MgGbgqGIPH7AAd4ajLOqdG Lj9DOKWIIqKaXZeelDOMQ79k7jNszoK318jTBjcl+Etif3CqwKt05/9klNMf+Jyi yaPqmT08e2c9IKzlHG4VbQ8US7vtoNmzgWEa+nwDGOPorXZN26Rl9xhaL7cbghxL F4bpvNKSDxjqte+Y7edB7Dn8jfQBY6TjEPqalE6/c+gfZc201q41C687NAZZ4iSk KDfwUsAmFOT9K8JpIlCfoirJSZj/kt+/OB3lUW3BfiqxbOHLCcbUyxNFsK4KLpAZ 20In3bCs5QjfKBbg2hJ1dxTpA/O5b9LmWBW/klvWDvDB9H93w4CXQ7EfkLISKzqA == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduiedruddtkedgfeeiucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefuvffhfffkgggtgfesthekredttd dtlfenucfhrhhomhepoehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhr gheqnecuggftrfgrthhtvghrnhepleelledvgeefleeltdetgedugeffgffhudffudduke egfeelgeeigeekjefhleevnecuffhomhgrihhnpehkvghrnhgvlhdrohhrghenucfkphep keefrdekiedrkeelrddutdejnecuvehluhhsthgvrhfuihiivgepheenucfrrghrrghmpe hmrghilhhfrhhomhepghhrvghgsehkrhhorghhrdgtohhm X-ME-Proxy: Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id 84EB330600A9; Wed, 19 Aug 2020 08:24:36 -0400 (EDT) Subject: FAILED: patch "[PATCH] khugepaged: khugepaged_test_exit() check mmget_still_valid()" failed to apply to 4.4-stable tree To: hughd@google.com, aarcange@redhat.com, akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, mike.kravetz@oracle.com, songliubraving@fb.com, stable@vger.kernel.org, torvalds@linux-foundation.org Cc: From: Date: Wed, 19 Aug 2020 14:24:59 +0200 Message-ID: <159783989916985@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.4-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 bbe98f9cadff58cdd6a4acaeba0efa8565dabe65 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 6 Aug 2020 23:26:25 -0700 Subject: [PATCH] khugepaged: khugepaged_test_exit() check mmget_still_valid() Move collapse_huge_page()'s mmget_still_valid() check into khugepaged_test_exit() itself. collapse_huge_page() is used for anon THP only, and earned its mmget_still_valid() check because it inserts a huge pmd entry in place of the page table's pmd entry; whereas collapse_file()'s retract_page_tables() or collapse_pte_mapped_thp() merely clears the page table's pmd entry. But core dumping without mmap lock must have been as open to mistaking a racily cleared pmd entry for a page table at physical page 0, as exit_mmap() was. And we certainly have no interest in mapping as a THP once dumping core. Fixes: 59ea6d06cfa9 ("coredump: fix race condition between collapse_huge_page() and core dumping") Signed-off-by: Hugh Dickins Signed-off-by: Andrew Morton Cc: Andrea Arcangeli Cc: Song Liu Cc: Mike Kravetz Cc: Kirill A. Shutemov Cc: [4.8+] Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008021217020.27773@eggly.anvils Signed-off-by: Linus Torvalds diff --git a/mm/khugepaged.c b/mm/khugepaged.c index ac04b332a373..b52bd46ad146 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -431,7 +431,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm, static inline int khugepaged_test_exit(struct mm_struct *mm) { - return atomic_read(&mm->mm_users) == 0; + return atomic_read(&mm->mm_users) == 0 || !mmget_still_valid(mm); } static bool hugepage_vma_check(struct vm_area_struct *vma, @@ -1100,9 +1100,6 @@ static void collapse_huge_page(struct mm_struct *mm, * handled by the anon_vma lock + PG_lock. */ mmap_write_lock(mm); - result = SCAN_ANY_PROCESS; - if (!mmget_still_valid(mm)) - goto out; result = hugepage_vma_revalidate(mm, address, &vma); if (result) goto out;