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=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 A7D1DC3B1A1 for ; Fri, 14 Feb 2020 17:06:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 81EEB206CC for ; Fri, 14 Feb 2020 17:06:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581699996; bh=R8IPHafpk6mNTTytsOKn27aAC+igEInjANGrd3cam60=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=njZbeoRuQAidneA3VbrDFjmM/VQpZ17A9NZW3ElYTEW1zVHAcPQlF9ZkxJ1+lahWi S7XJA7h0J+Sxe/my/czY2/X3TU1/oZPdmPv+mWg00iGWFPmLpuOozMTNtmRpytNcTF 7UJ700dl0dujuQ5f8VEQDs6XyyPioSfh+znKc/HU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394505AbgBNRGf (ORCPT ); Fri, 14 Feb 2020 12:06:35 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:33405 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2394142AbgBNRGd (ORCPT ); Fri, 14 Feb 2020 12:06:33 -0500 Received: by mail-pl1-f193.google.com with SMTP id ay11so3962464plb.0; Fri, 14 Feb 2020 09:06:33 -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=V7GUkh8wE1dRQiutiAZwQygV0oqWtMLGFWC+ZDS/JnU=; b=RQvOq32m45tdZVuQ4eP1UET1YZUzdiMgqS7sSPeokFVt7jEldPUoBqPTKGstnRngbF 75+1ncGimpxQlYmLre/iK7NDvLq5nH9Hi2GOxUwGhbRCZJZt2puGtJKk1yDtaNxdvTOa H/HYX/Zmw9vTr3fPSoY7uBY66RtNlMV/AMAWXeRe+em474RVFHaMWlLU35ynOr5o0Aln 3w27QgjvOu2G2AsRfDdNSepSUB0fIO/aFIzpGmYcuoM5LFW+01oXGF0iKP2e7kzay49e Mv30kROuXKTJkKiBAtSpcvfYw77pEgG193ErM30jobYpwJHikPO41vYt6EZFzgMttboN PzsA== 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=V7GUkh8wE1dRQiutiAZwQygV0oqWtMLGFWC+ZDS/JnU=; b=ZSmsquOoGvWnzQGKYysxZcpEsUnO/fK6GzLXlgAKioyWgq3pQuqCpH8jJp4e2Ag4rC /fu3soyR1pA3vUIUxCzcNMSAW52Q9tAUdjd99lZ9pgeg/eAE6EI1cXTHddD5ncahXB02 FGLK6il+3yoW5OCrCZsnpisARiPxAvwUovJGil3XkgSi9+7/CYJ2lysC6nE3HHdujx+r 8kZXVK5rH9lAS3jvsFt/nXo9l9oWlW170Z8F6ztF5+ZAI6yZTTnbdrO4hcMf4hELkof4 yaKPHTsayET7lSdmtjotm+yFN8bRFLdTQq1T+7Qr1ELQjNd5PFM2JVrXcnIAUyGqCSMS ItKQ== X-Gm-Message-State: APjAAAXKHRhZJbD695PZ17sXiObCZIFkddj+Feu1dMts3/y8V+2VYJq9 2HJHt9edm0Atc1p018uVwOU= X-Google-Smtp-Source: APXvYqxGn47fJ2zoDaJU+qvDPEHLfhiapXpwP4YiNrmS4xOrwHPdDO5MUL/VY69qyCv30aJDRferSg== X-Received: by 2002:a17:90b:46cf:: with SMTP id jx15mr4967429pjb.2.1581699993075; Fri, 14 Feb 2020 09:06:33 -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 a13sm7662924pfg.65.2020.02.14.09.06.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Feb 2020 09:06:30 -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 v5 6/7] mm/madvise: employ mmget_still_valid for write lock Date: Fri, 14 Feb 2020 09:05:19 -0800 Message-Id: <20200214170520.160271-7-minchan@kernel.org> X-Mailer: git-send-email 2.25.0.265.gbab2e86ba0-goog In-Reply-To: <20200214170520.160271-1-minchan@kernel.org> References: <20200214170520.160271-1-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 bbbfea93396a..762a68205e65 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1117,6 +1117,8 @@ int do_madvise(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); } @@ -1167,6 +1169,7 @@ int do_madvise(struct task_struct *task, struct mm_struct *mm, } out: blk_finish_plug(&plug); +skip_mm: if (write) up_write(&mm->mmap_sem); else -- 2.25.0.265.gbab2e86ba0-goog