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=-3.8 required=3.0 tests=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 11962C43331 for ; Thu, 2 Apr 2020 04:08:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C88B22074D for ; Thu, 2 Apr 2020 04:08:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Hqj4Mp/W" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C88B22074D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7C1468E0057; Thu, 2 Apr 2020 00:08:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 799288E000D; Thu, 2 Apr 2020 00:08:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6AEC68E0057; Thu, 2 Apr 2020 00:08:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0184.hostedemail.com [216.40.44.184]) by kanga.kvack.org (Postfix) with ESMTP id 52D3B8E000D for ; Thu, 2 Apr 2020 00:08:05 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 186C98248047 for ; Thu, 2 Apr 2020 04:08:05 +0000 (UTC) X-FDA: 76661582130.15.bomb12_468c06899c749 X-HE-Tag: bomb12_468c06899c749 X-Filterd-Recvd-Size: 3634 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf23.hostedemail.com (Postfix) with ESMTP for ; Thu, 2 Apr 2020 04:08:04 +0000 (UTC) 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 37534208FE; Thu, 2 Apr 2020 04:08:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585800484; bh=W903QNY55BuNdmTjoM3wNjhHp3qPPEo3P/wYJ9buPgs=; h=Date:From:To:Subject:In-Reply-To:From; b=Hqj4Mp/WRHo/teKKWxq3rV56HV/c8Nary9dnCcZO7QWHaUm7YbOEfDmWh2aoMXb9g ZNPkRDDXNm2r3ZTTOS83a565wTFVXRpDX4O5LZ4WH+t3XqmNhYJBr5Q5jN1IjQ2gzY K5jNyDNyVWD8pHIRPOAjLVY66Q3EIia4i0v4paLU= Date: Wed, 01 Apr 2020 21:08:02 -0700 From: Andrew Morton To: aarcange@redhat.com, akpm@linux-foundation.org, bgeffon@google.com, bobbypowers@gmail.com, cracauer@cons.org, david@redhat.com, dgilbert@redhat.com, dplotnikov@virtuozzo.com, gokhale2@llnl.gov, hannes@cmpxchg.org, hughd@google.com, jglisse@redhat.com, kirill@shutemov.name, linux-mm@kvack.org, mcfadden8@llnl.gov, mgorman@suse.de, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, peterx@redhat.com, rppt@linux.vnet.ibm.com, torvalds@linux-foundation.org, willy@infradead.org, xemul@openvz.org Subject: [patch 087/155] mm/gup: fix __get_user_pages() on fault retry of hugetlb Message-ID: <20200402040802.XNDU2drzz%akpm@linux-foundation.org> In-Reply-To: <20200401210155.09e3b9742e1c6e732f5a7250@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Peter Xu Subject: mm/gup: fix __get_user_pages() on fault retry of hugetlb When follow_hugetlb_page() returns with *locked==0, it means we've got a VM_FAULT_RETRY within the fauling process and we've released the mmap_sem. When that happens, we should stop and bail out. Link: http://lkml.kernel.org/r/20200220155353.8676-3-peterx@redhat.com Signed-off-by: Peter Xu Tested-by: Brian Geffon Cc: Andrea Arcangeli Cc: Bobby Powers Cc: David Hildenbrand Cc: Denis Plotnikov Cc: "Dr . David Alan Gilbert" Cc: Hugh Dickins Cc: Jerome Glisse Cc: Johannes Weiner Cc: "Kirill A . Shutemov" Cc: Linus Torvalds Cc: Martin Cracauer Cc: Marty McFadden Cc: Matthew Wilcox Cc: Maya Gokhale Cc: Mel Gorman Cc: Mike Kravetz Cc: Mike Rapoport Cc: Pavel Emelyanov Signed-off-by: Andrew Morton --- mm/gup.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/mm/gup.c~mm-gup-fix-__get_user_pages-on-fault-retry-of-hugetlb +++ a/mm/gup.c @@ -1065,6 +1065,16 @@ static long __get_user_pages(struct task i = follow_hugetlb_page(mm, vma, pages, vmas, &start, &nr_pages, i, gup_flags, locked); + if (locked && *locked == 0) { + /* + * We've got a VM_FAULT_RETRY + * and we've lost mmap_sem. + * We must stop here. + */ + BUG_ON(gup_flags & FOLL_NOWAIT); + BUG_ON(ret != 0); + goto out; + } continue; } } _