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 89CC2C282DD for ; Fri, 10 Jan 2020 21:34:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E51520842 for ; Fri, 10 Jan 2020 21:34:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578692091; bh=gkLFik+WxVLsQTQ867WL308s2sGg5bI8rb+tp7rkpsk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HuvXbqzIVAc2Fi+rPE1d7IFDEI0KQgy2G3dgZ45Mvs3H2PIFb2evcMxT0EHptKf7x DxkkqF2WXRJlw43b/Bi/po/jScTrF5BfG6brwFo/BWT+khkMacOOkklxDllzhE0+2h YuS3LLl/fh5Y2+z7/XGshnmXT0LxxjQpSakN7O8c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727378AbgAJVeu (ORCPT ); Fri, 10 Jan 2020 16:34:50 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:35147 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726912AbgAJVeo (ORCPT ); Fri, 10 Jan 2020 16:34:44 -0500 Received: by mail-pg1-f196.google.com with SMTP id l24so1589606pgk.2; Fri, 10 Jan 2020 13:34:43 -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=89Kh03xU7w1BbnZNyOorUIvmlI1tvq4/L3B5YcvwpqQ=; b=CN5DkxBOYcoZgoiH2Jg3EQwKATglnYi/wVLvJpLQHlzdJyFu/8fl8QjLSRY+E089Dv UBb1RvbJ7SWnmO8UDEIvtF3nSSLvDitBa+gvxVGttXpwCiS7xqI5oDIBRq/7tzUJLVGa bbTykYCi84W6ZUPr9/Otr5aamOfMUSZeM0mKCemPrw0+VLcm/ifCMQVmN54xb4XWUQ3Q qgMB+KMUKiYOnyXMzJnOdXcwW6JSms1sYN3mcPyf9Q1p5NQIg8PbUfrddxPob5rSSht2 WsOgwCVDy/Sv604e3Sl3xT3h+USBKk1WH2Y9+mR76qdS/AYSjae1hGw51oxcFZeYOBAt PICw== 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=89Kh03xU7w1BbnZNyOorUIvmlI1tvq4/L3B5YcvwpqQ=; b=eAYUEhN57UCHNXB3iN6W+Ys6mDFOGcyGergm4Hp9oyYiEOfSjhlCzsOA6knBNlCzGu Z+exof2peOo94+OMf39o4AsADLO9qqIGkEOHYZFEJ/m+UK64W4t+NWR1J9Z4LHmQgOJq SQqWvyNSxa6lNTDsVfx6VRx3bFg4wDStAp195VaMlaHziM9TB/clxC2w1AeS+V/SJnxy blTawTOEeUv0NwSET+gTXwYZcnUS2SNnlIirZ59R12c3aw2QtCxpqSguESULpb++hOMK vuWlsBagJW5TjpSA9B8A8gBhNnT6P9r84/WJGPv9NqJsXF78X3DrRmr+M9cPBS1Az4Ca T4gA== X-Gm-Message-State: APjAAAWYEK51uxKsF9rmh+1lVH9SdvfvV9oKBhL6NeM3lkdzep6BiF8i MqEOd8Upv+nCSHJqbtKDvo8= X-Google-Smtp-Source: APXvYqz7Q5MwkbpSHvKG6GzBJj5sOFfZsoHRNrjc1+Ap4AxBr5ADxxl2rO10KMu4ykwTZzwAJ7B1cw== X-Received: by 2002:a63:5920:: with SMTP id n32mr6683623pgb.443.1578692083372; Fri, 10 Jan 2020 13:34:43 -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 t137sm3692307pgb.40.2020.01.10.13.34.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jan 2020 13:34:42 -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 , Minchan Kim Subject: [PATCH 3/4] mm/madvise: employ mmget_still_valid for write lock Date: Fri, 10 Jan 2020 13:34:32 -0800 Message-Id: <20200110213433.94739-4-minchan@kernel.org> X-Mailer: git-send-email 2.25.0.rc1.283.g88dfdc4193-goog In-Reply-To: <20200110213433.94739-1-minchan@kernel.org> References: <20200110213433.94739-1-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 e15dfb4df7bf..eb42b2b7f49b 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