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=-7.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 06586C04E53 for ; Wed, 15 May 2019 08:41:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CAD5E2082E for ; Wed, 15 May 2019 08:41:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yandex-team.ru header.i=@yandex-team.ru header.b="aNjr5SR1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726521AbfEOIl3 (ORCPT ); Wed, 15 May 2019 04:41:29 -0400 Received: from forwardcorp1p.mail.yandex.net ([77.88.29.217]:54100 "EHLO forwardcorp1p.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726410AbfEOIlZ (ORCPT ); Wed, 15 May 2019 04:41:25 -0400 Received: from mxbackcorp2j.mail.yandex.net (mxbackcorp2j.mail.yandex.net [IPv6:2a02:6b8:0:1619::119]) by forwardcorp1p.mail.yandex.net (Yandex) with ESMTP id 658F52E146D; Wed, 15 May 2019 11:41:22 +0300 (MSK) Received: from smtpcorp1o.mail.yandex.net (smtpcorp1o.mail.yandex.net [2a02:6b8:0:1a2d::30]) by mxbackcorp2j.mail.yandex.net (nwsmtp/Yandex) with ESMTP id 9zoT92Owie-fL0uKV6u; Wed, 15 May 2019 11:41:22 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1557909682; bh=DXKTyv1Zt0cbjxS03oPn1lBJLs878fkqtHSHT6TGUvY=; h=In-Reply-To:Message-ID:References:Date:To:From:Subject:Cc; b=aNjr5SR1VzkHw+xEMkDZjfNamwaILWaRolaTmyWU5+xXDFs9RbvV8LmC1+fXO4YCP dm2PkDwHYBgEKcdaXOl1syN8qZ/el2BXO6s9Bno/cJUjP8agzdxS8NqjpxZqkvdF5P GFMlg9fUgmB31B3VVcLdRfMkfsf1X2zY9luH43kk= Authentication-Results: mxbackcorp2j.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-red.dhcp.yndx.net (dynamic-red.dhcp.yndx.net [2a02:6b8:0:40c:ed19:3833:7ce1:2324]) by smtpcorp1o.mail.yandex.net (nwsmtp/Yandex) with ESMTPSA id wNdlQeZj5Y-fLl0uD8T; Wed, 15 May 2019 11:41:21 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) Subject: [PATCH 4/5] proc: use down_read_killable for /proc/pid/clear_refs From: Konstantin Khlebnikov To: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Cc: Cyrill Gorcunov , Kirill Tkhai , Al Viro Date: Wed, 15 May 2019 11:41:21 +0300 Message-ID: <155790968147.1319.10247444846354273332.stgit@buzz> In-Reply-To: <155790967258.1319.11531787078240675602.stgit@buzz> References: <155790967258.1319.11531787078240675602.stgit@buzz> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Replace the only unkillable mmap_sem lock in clear_refs_write. Signed-off-by: Konstantin Khlebnikov --- fs/proc/task_mmu.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 78bed6adc62d..7f84d1477b5b 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1140,7 +1140,10 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, goto out_mm; } - down_read(&mm->mmap_sem); + if (down_read_killable(&mm->mmap_sem)) { + count = -EINTR; + goto out_mm; + } tlb_gather_mmu(&tlb, mm, 0, -1); if (type == CLEAR_REFS_SOFT_DIRTY) { for (vma = mm->mmap; vma; vma = vma->vm_next) {