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 B0BD8C3404E for ; Wed, 19 Feb 2020 01:44:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84D3C24655 for ; Wed, 19 Feb 2020 01:44:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582076698; bh=aVQwG9WbHNNYU4OqvOToBzjPL2hM+OZFJ3Hcvpg3sqs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ewLDTKoOz3M9Lnk0nvgDcAGG3GN4O2iaG20OCgxR+L+5AEoD/86NVSw1+DOGy1Ewj LmUOmKZ16ipriTDiXGqxbxXXbrh2X6NiDHwY4N+wRVnTfutOA2AbZpIh6sWlz9zUTn 47fozfJtUCgj2xlFtZqV06W8jJVy5yBlBy8gD03Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728025AbgBSBo5 (ORCPT ); Tue, 18 Feb 2020 20:44:57 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:46273 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728093AbgBSBos (ORCPT ); Tue, 18 Feb 2020 20:44:48 -0500 Received: by mail-pl1-f194.google.com with SMTP id y8so8842798pll.13; Tue, 18 Feb 2020 17:44:48 -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=/6BKpu6I9GWZilmKCDR/xIEf9kb10U/fQ/hS1RFxo/E=; b=AeiF/BUIODJ7Elpdb3GXCCzXBoQS9IDbCw9VSMC/jL+pPhcr/hr375CchvyTPhz7Pw 0UOfnIko0AblDWL/yTdmeiTlRoIfhMWdWFD3hNHRiqveweEiIFdLmzsDjyssGqVlyrTi febRwSW0h0+kaMkhfKy6efdR7uMe5zL+d+KmyIKLPs0rgr5VxIwjrVpWWZEPFxsMwZ23 J/8duxiMxzzsojGZ4V6XQhchtynRJdtbiMasGQl4+ZCJDiom8Qude7YarbGY5V0fKzVt AFoKRAVeNBBiW7zrGGHfvJ2A02+p1VpXuF6g0cnYJV37hKbKe7v2cv28gZItVOFqnAa3 aTPg== 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=/6BKpu6I9GWZilmKCDR/xIEf9kb10U/fQ/hS1RFxo/E=; b=X6bBqnh+Vay65Dt7+KWdz9qnZChyqpyeUDcRs7GFRhcmfLQAx2d7p4lEGWnGDNymss lv0zIO013ayjHzwaSbKZPtbQeTbclxZGqpOwDVepQp80JTv3/tHNdLx0gw0FdKEou29k qqgdy7uAsxaN0p+xjZwFfta+A5huVscI/LkyQqYg3aIivb+0P9xCLTuRRl2GzC05Ww52 X45s/K0kTz6CX7g0AW8uM0rcKQRxq5AavjKvqvj2AP8Uwsyf57Eq0Kr6zFA5tcyIFBt3 /JUhCXydd6fmqqSV6NoO/0iq9ubCSEBQVnp9xe88bxcwEmy27Ehix2Dp7Zk5+u7gEr5L oW3A== X-Gm-Message-State: APjAAAXIuviPlr27hGfTalXtCPJlW1GjgkcAdLgGXic2bXtoLmgarRma Liee8CgWhDjrefZ6idchxRQ= X-Google-Smtp-Source: APXvYqwwKle6VVN2am3/CWIym5vOlHdjzCyQZW3QPgCSqnuGkU97ImrWpOZRQFtL2HjvnrD66h8CEw== X-Received: by 2002:a17:902:8f8e:: with SMTP id z14mr24068362plo.195.1582076688168; Tue, 18 Feb 2020 17:44:48 -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 t186sm221192pgd.26.2020.02.18.17.44.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Feb 2020 17:44:46 -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 , sj38.park@gmail.com, alexander.h.duyck@linux.intel.com, Jann Horn , Minchan Kim Subject: [PATCH v6 6/7] mm/madvise: employ mmget_still_valid for write lock Date: Tue, 18 Feb 2020 17:44:32 -0800 Message-Id: <20200219014433.88424-7-minchan@kernel.org> X-Mailer: git-send-email 2.25.0.265.gbab2e86ba0-goog In-Reply-To: <20200219014433.88424-1-minchan@kernel.org> References: <20200219014433.88424-1-minchan@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@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 f6d9b9e66243..c55a18fe71f9 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1118,6 +1118,8 @@ int do_madvise(struct task_struct *target_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); } @@ -1169,6 +1171,7 @@ int do_madvise(struct task_struct *target_task, struct mm_struct *mm, } out: blk_finish_plug(&plug); +skip_mm: if (write) up_write(&mm->mmap_sem); else -- 2.25.0.265.gbab2e86ba0-goog