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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 49053C04E53 for ; Wed, 15 May 2019 09:16:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2620A2084A for ; Wed, 15 May 2019 09:16:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726338AbfEOJQT (ORCPT ); Wed, 15 May 2019 05:16:19 -0400 Received: from relay.sw.ru ([185.231.240.75]:49850 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725933AbfEOJQT (ORCPT ); Wed, 15 May 2019 05:16:19 -0400 Received: from [172.16.25.169] by relay.sw.ru with esmtp (Exim 4.91) (envelope-from ) id 1hQq1H-00071z-GC; Wed, 15 May 2019 12:16:15 +0300 Subject: Re: [PATCH 1/5] proc: use down_read_killable for /proc/pid/maps To: Konstantin Khlebnikov , linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Cc: Cyrill Gorcunov , Al Viro References: <155790967258.1319.11531787078240675602.stgit@buzz> From: Kirill Tkhai Message-ID: <77650cec-70cc-149a-74e9-2256c6138032@virtuozzo.com> Date: Wed, 15 May 2019 12:16:14 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <155790967258.1319.11531787078240675602.stgit@buzz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15.05.2019 11:41, Konstantin Khlebnikov wrote: > Do not stuck forever if something wrong. > This function also used for /proc/pid/smaps. > > Signed-off-by: Konstantin Khlebnikov For the series: Reviewed-by: Kirill Tkhai > --- > fs/proc/task_mmu.c | 6 +++++- > fs/proc/task_nommu.c | 6 +++++- > 2 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c > index 01d4eb0e6bd1..2bf210229daf 100644 > --- a/fs/proc/task_mmu.c > +++ b/fs/proc/task_mmu.c > @@ -166,7 +166,11 @@ static void *m_start(struct seq_file *m, loff_t *ppos) > if (!mm || !mmget_not_zero(mm)) > return NULL; > > - down_read(&mm->mmap_sem); > + if (down_read_killable(&mm->mmap_sem)) { > + mmput(mm); > + return ERR_PTR(-EINTR); > + } > + > hold_task_mempolicy(priv); > priv->tail_vma = get_gate_vma(mm); > > diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c > index 36bf0f2e102e..7907e6419e57 100644 > --- a/fs/proc/task_nommu.c > +++ b/fs/proc/task_nommu.c > @@ -211,7 +211,11 @@ static void *m_start(struct seq_file *m, loff_t *pos) > if (!mm || !mmget_not_zero(mm)) > return NULL; > > - down_read(&mm->mmap_sem); > + if (down_read_killable(&mm->mmap_sem)) { > + mmput(mm); > + return ERR_PTR(-EINTR); > + } > + > /* start from the Nth VMA */ > for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) > if (n-- == 0)