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 CF8E6C33CB3 for ; Fri, 17 Jan 2020 00:00:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4AD92081E for ; Fri, 17 Jan 2020 00:00:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579219215; bh=G0283Q8hMHKKF9racdanh0IQ0iAR8ib1BlB2aq6qRVA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pEIO6tCLlYpQJiOeAVqXjdliuOHxtH+HGOyc4trZ7HlwcaKgiA8MaMz+gbOjxcBfk w9TJ4fMWCQbnttwc4q/+bFl9Vq8ZrjVynC09M6sUzNpJkHtFf7PebtgGV4rEgyzjSJ /CqOZner2Nx9Xka5bzNQZ7/91DWqJyFZzcDycWB4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387894AbgAQAAO (ORCPT ); Thu, 16 Jan 2020 19:00:14 -0500 Received: from mail-pg1-f193.google.com ([209.85.215.193]:45917 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726189AbgAQAAK (ORCPT ); Thu, 16 Jan 2020 19:00:10 -0500 Received: by mail-pg1-f193.google.com with SMTP id b9so10708471pgk.12; Thu, 16 Jan 2020 16:00:09 -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=H1DNUZeta8kOxobeAib3DAPo7bHpJ+/lYiSVOVvzyGQ=; b=WJ92vaxECeagQOoGBDEDdM7YktShjAd3nesXf6/7YuFwM6gwIC9ZFcYHpMBycQy7jx OUb6ZmuMxApgyI70xP3UPmBYhUswrWydKD2x2V87vtcno4GaGsDWfeYRUlk/N5fgDIbI Zpm4x36fZlEVZWG12IdYFGTH0OLNz/OfQ3SWxDGyROi46G2CMokgMt4TVXtHGhSu2a7y lPGaSXSNCIfzqj1NK3+8UKA2pg00tSRYeWh7byCutkbIiE46Q6cY6a3euF71NbDf4DSQ d5h/tvIqpEZB647toINcAtPUuBQBxyxOhSKaowiq4YWzqkb1MEwB/HMFrjPvrazpX9FZ q7Qg== 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=H1DNUZeta8kOxobeAib3DAPo7bHpJ+/lYiSVOVvzyGQ=; b=YB3vamL2SwdLc9txdNCPuc7ojLm53EgVmKwGUviOxlfMwUmBl6JT3vl1G7M4eimeyk t/k27WsVD2ydru9mBjXO4v9njulm6UcXsXCHijgQp4hQM5yxHZ2aZ0wKq10Ir//cu5FO 6rjDFPA+oCPIGH3pIfTfy5LeYUadz8UKmF7RHkt9nSZtSnjfzHSX9iVI/QDrrwqY8hNJ y8vjOBdwAk8Cf0lnbA6uBVKqj/19l48wuDJwIjhNGlUV0e2FALfjaD0IUjqxZ/b23GiG lk7VwE3rYxf4lBvC6t4ERZoBe76c7iI2bKw/FpFUy+KhjFGrKK/NcsEKSM9FUj8jsdeT MSmw== X-Gm-Message-State: APjAAAXGrzz58nUKA1UWT9CCxJ5wkxKhDKtTPhFnUfBzQ+G7K+aE7B6m LFiPbBJCannZSkUgkoiIF8Y= X-Google-Smtp-Source: APXvYqyPinp8CvGNRE9v8A54LMeUYeFi996WEC2tsK78EEm8vsNaHuPQ0nYWHFxnY7x2K4aNEz4mKQ== X-Received: by 2002:a63:1447:: with SMTP id 7mr41679802pgu.22.1579219209212; Thu, 16 Jan 2020 16:00:09 -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 z4sm26584885pfn.42.2020.01.16.16.00.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Jan 2020 16:00:07 -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 , ktkhai@virtuozzo.com, christian.brauner@ubuntu.com, sjpark@amazon.de, Minchan Kim , Minchan Kim Subject: [PATCH v2 3/5] mm/madvise: employ mmget_still_valid for write lock Date: Thu, 16 Jan 2020 15:59:51 -0800 Message-Id: <20200116235953.163318-4-minchan@kernel.org> X-Mailer: git-send-email 2.25.0.rc1.283.g88dfdc4193-goog In-Reply-To: <20200116235953.163318-1-minchan@kernel.org> References: <20200116235953.163318-1-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 59b5cc99ef61..84cffd0900f1 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1059,6 +1059,8 @@ static int madvise_common(struct task_struct *task, struct mm_struct *mm, 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); } @@ -1109,6 +1111,7 @@ static int madvise_common(struct task_struct *task, struct mm_struct *mm, } out: blk_finish_plug(&plug); +skip_mm: if (write) up_write(&mm->mmap_sem); else -- 2.25.0.rc1.283.g88dfdc4193-goog