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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 A4824C282C4 for ; Mon, 4 Feb 2019 10:53:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A998218A1 for ; Mon, 4 Feb 2019 10:53:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549277615; bh=l2WektBcJyBZejXsMFxm0AU68hN/47LqgaNyFXkcG4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Muvfps+WeHnhqNGHPVv+ZzEZ5TXIQuFindnew5rRx2WcT207SJO6QC3hh4GZqqBBN +fUQz9QGqjniSVkmn56PKoo3LH5akM8enoCdVgRthzqGW8ql3vYKYHiDmO2NTk0C1b ya8A1gv+ZacG3vhXZjdre7OoaglfXL3DmaHenAqw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732797AbfBDKxe (ORCPT ); Mon, 4 Feb 2019 05:53:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:51146 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732763AbfBDKxb (ORCPT ); Mon, 4 Feb 2019 05:53:31 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 11D0A2184B; Mon, 4 Feb 2019 10:53:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549277610; bh=l2WektBcJyBZejXsMFxm0AU68hN/47LqgaNyFXkcG4g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GphzHmXTKNBIA+UyfLnl7rrNvvYt7bhFUPA2+fkYyozxSgi1JFHk10L65Ba5QnFLj 9XnQiieKXNMooO0mb0ZqRi6o0m6vT2kNjPgwR4QFloJ1EiDbidxEMoyxny0syNrXGI FnQwx8pJzrty2GK4HUSzIUt4w3WwVrFui11W9Z4A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andrea Arcangeli , "Dr. David Alan Gilbert" , Mike Kravetz , Peter Xu , Mike Rapoport , Andrew Morton , Linus Torvalds Subject: [PATCH 4.20 69/80] mm/hugetlb.c: teach follow_hugetlb_page() to handle FOLL_NOWAIT Date: Mon, 4 Feb 2019 11:37:29 +0100 Message-Id: <20190204103629.622186172@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190204103620.287366543@linuxfoundation.org> References: <20190204103620.287366543@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrea Arcangeli commit 1ac25013fb9e4ed595cd608a406191e93520881e upstream. hugetlb needs the same fix as faultin_nopage (which was applied in commit 96312e61282a ("mm/gup.c: teach get_user_pages_unlocked to handle FOLL_NOWAIT")) or KVM hangs because it thinks the mmap_sem was already released by hugetlb_fault() if it returned VM_FAULT_RETRY, but it wasn't in the FOLL_NOWAIT case. Link: http://lkml.kernel.org/r/20190109020203.26669-2-aarcange@redhat.com Fixes: ce53053ce378 ("kvm: switch get_user_page_nowait() to get_user_pages_unlocked()") Signed-off-by: Andrea Arcangeli Tested-by: "Dr. David Alan Gilbert" Reported-by: "Dr. David Alan Gilbert" Reviewed-by: Mike Kravetz Reviewed-by: Peter Xu Cc: Mike Rapoport Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -4270,7 +4270,8 @@ long follow_hugetlb_page(struct mm_struc break; } if (ret & VM_FAULT_RETRY) { - if (nonblocking) + if (nonblocking && + !(fault_flags & FAULT_FLAG_RETRY_NOWAIT)) *nonblocking = 0; *nr_pages = 0; /*