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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 89DDBC3B187 for ; Wed, 12 Feb 2020 23:40:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61A172168B for ; Wed, 12 Feb 2020 23:40:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581550807; bh=3qrEz0QV6RfItfHwYqewbnPIQ2HOr6xLn43ltyfPhXA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lJ5TEHMnBHGE1XMQFV13gdKkjqbp7JUy4WBCSfmzq4gSl79S6/xQOK3yrZXnxYNd8 7j8IOI+MPx69Hku8L9FJ6niV4+fJO7bblZssn+GMBqjYhCyNi+gd9P5FYik2BcIKWE 12lMZjvMeU0DT2iQ3cWiLWAuqcJu6RWrR/4Rtnd0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729383AbgBLXkG (ORCPT ); Wed, 12 Feb 2020 18:40:06 -0500 Received: from mail-pf1-f193.google.com ([209.85.210.193]:43535 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729356AbgBLXkC (ORCPT ); Wed, 12 Feb 2020 18:40:02 -0500 Received: by mail-pf1-f193.google.com with SMTP id s1so2007421pfh.10; Wed, 12 Feb 2020 15:40:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=ZMr8LhEVC9oO5IOdT1EAti6B5+7g8NKkMYB8pLjiUts=; b=FZrxKnddlcDw5zyfExhzpFB7yNfAtSGotiVUgDx7kQeEtRk96KD2mjuJAwspjEWZEN 8KQGuw5rgbMTjblF/1hERi1coEcedKQRj0A3ZDpTh/rLPLJ01OSf3UbmgfW6utovZI3H qKbek4ZUVtEesWnc8Jz1oh3eReFVrokHuT8LrXYSlGbQs0tKXLnC7cKdOT9I8H90mNP/ 6LeqDCmJSqRfYdC0SBilvY0LlpVtSqLG7Oof/zDRge1nTZaZh3bSa2QLWuT7PpN2E/V8 MufG1jDdEtKBDxSNXo3mv7bob5OGe9IF3J0ofzL96vWBtLLs9Lykq6WoQHJCnrmHn7sj g+/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; bh=ZMr8LhEVC9oO5IOdT1EAti6B5+7g8NKkMYB8pLjiUts=; b=P3y+bgE0nFKK9IKIISHhoWHBaSJ+xqXZmCXROVPjQ9kJgRTQ3laqlIz+nTs8pL3jUL 5eyD4zP0ClsyBJUTI6em3Usnng1JNLXv/bx6P/Nm8YwR7SIAVd5qO/B0F6wgt9yGuJRF OyPBJMA2/XaeEt/ucGLJ3gsFcP1ilIDb6xD9slyVk187iqHJD+T0V6u7r7bUz7CqS0Hi A0se8XJQa4XgjhKJkIvx4mVhJ6Y2gMmAi5fFWkeC7kv3g3jv0Ylx8bELQ+fxeb5J6yWk h65L2TD6URaKbk9xDVSsAXzw/uaGpvOgl4y5nQG6HoAuODGjIbk3uArvWNJFh8bd4gvE MsWw== X-Gm-Message-State: APjAAAW7b04lUdboo1PH1kQ37ofbFkFuadwgesCeJoxynW3heIfSFpie v1vOBoLhsH0fT4uqxU7TlTVSsh0R X-Google-Smtp-Source: APXvYqyTYiXBm1zUHh7AFeoGz7OUaVklPnIUFSpjd2o7FpUwNPngIaBgYKUhERpn7MoMtdc1mZ47HA== X-Received: by 2002:a65:645a:: with SMTP id s26mr10828696pgv.135.1581550801457; Wed, 12 Feb 2020 15:40:01 -0800 (PST) Received: from bbox-1.mtv.corp.google.com ([2620:15c:211:1:3e01:2939:5992:52da]) by smtp.gmail.com with ESMTPSA id k5sm296664pju.29.2020.02.12.15.39.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 12 Feb 2020 15:40:00 -0800 (PST) From: Minchan Kim To: Andrew Morton Cc: LKML , linux-mm , linux-api@vger.kernel.org, oleksandr@redhat.com, Suren Baghdasaryan , Tim Murray , Daniel Colascione , Sandeep Patil , Sonny Rao , Brian Geffon , Michal Hocko , Johannes Weiner , Shakeel Butt , John Dias , Joel Fernandes , Alexander Duyck , Minchan Kim Subject: [PATCH v4 5/8] mm/madvise: employ mmget_still_valid for write lock Date: Wed, 12 Feb 2020 15:39:43 -0800 Message-Id: <20200212233946.246210-6-minchan@kernel.org> X-Mailer: git-send-email 2.25.0.225.g125e21ebc7-goog In-Reply-To: <20200212233946.246210-1-minchan@kernel.org> References: <20200212233946.246210-1-minchan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Oleksandr Natalenko Do the very same trick as we already do since 04f5866e41fb. KSM hints will require locking mmap_sem for write since they modify vm_flags, so for remote KSM hinting this additional check is needed. Signed-off-by: Oleksandr Natalenko Signed-off-by: Minchan Kim --- mm/madvise.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/madvise.c b/mm/madvise.c index 276b9d81c1dd..71f0ba199ae8 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1120,6 +1120,8 @@ int do_madvise(struct task_struct *task, unsigned long start, if (write) { if (down_write_killable(&mm->mmap_sem)) return -EINTR; + if (current->mm != mm && !mmget_still_valid(mm)) + goto skip_mm; } else { down_read(&mm->mmap_sem); } @@ -1170,6 +1172,7 @@ int do_madvise(struct task_struct *task, unsigned long start, } out: blk_finish_plug(&plug); +skip_mm: if (write) up_write(&mm->mmap_sem); else -- 2.25.0.225.g125e21ebc7-goog