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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 6F8DAC04E53 for ; Wed, 15 May 2019 14:28:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4951220862 for ; Wed, 15 May 2019 14:28:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727849AbfEOO2d (ORCPT ); Wed, 15 May 2019 10:28:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53169 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726911AbfEOO2d (ORCPT ); Wed, 15 May 2019 10:28:33 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 139C88553A; Wed, 15 May 2019 14:28:33 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.43.17.159]) by smtp.corp.redhat.com (Postfix) with SMTP id 147181001DD7; Wed, 15 May 2019 14:28:31 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 15 May 2019 16:28:30 +0200 (CEST) Date: Wed, 15 May 2019 16:28:28 +0200 From: Oleg Nesterov To: Konstantin Khlebnikov Cc: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: use down_read_killable for locking mmap_sem in access_remote_vm Message-ID: <20190515142828.GA18892@redhat.com> References: <155790847881.2798.7160461383704600177.stgit@buzz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <155790847881.2798.7160461383704600177.stgit@buzz> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 15 May 2019 14:28:33 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > @@ -4348,7 +4348,9 @@ int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, > void *old_buf = buf; > int write = gup_flags & FOLL_WRITE; > > - down_read(&mm->mmap_sem); > + if (down_read_killable(&mm->mmap_sem)) > + return 0; > + I too think that "return 0" looks a bit strange even if correct, to me "return -EINTR" would look better. But I won't insist, this is cosmetic. Acked-by: Oleg Nesterov