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 DF389C3F2DB for ; Mon, 2 Mar 2020 19:36:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B9DED2080C for ; Mon, 2 Mar 2020 19:36:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583177814; bh=1eBQvH/3HF8KwpmzdPtqPqik1R+9KP4gzVHTx2vv0/w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kbsnwStaxV9cDhiyAaDHDLWXr3pqf6YTwcbVNtOdhKMRGNNYkrFV5bwiaKXIeCqyq A9Zd71U2cMEOYle2+I1VvuVeJYN6uOGQ4cLuQp1/erLlt+xbHsOPev349QloS5q8yl JSNF5eSdqmmvwkq0ylcfaLmFXTEld2tH0sEC5s4Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727775AbgCBTgx (ORCPT ); Mon, 2 Mar 2020 14:36:53 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:34795 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727767AbgCBTgx (ORCPT ); Mon, 2 Mar 2020 14:36:53 -0500 Received: by mail-pf1-f195.google.com with SMTP id y21so216488pfp.1; Mon, 02 Mar 2020 11:36:52 -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=xPq4MnSfZ5jWfAsPssUVfjNY8ScP1mqw+MypBd7iP+U=; b=oVv7S+P/QEC4IU0JDW3R6+pH/HZQedvJgo/p6dLtJbajwRcJqo63ZjdjfP6Ha5zzeg Yek9HPH1rVrC7+TbFuveVjZTlryEeEiAPzr/4j7HtUFDgWG36Da9obumxjlnsZrMCWSK OFxnXBCRtKPcKIFR9QDy+A6XD9Q/V7rFLGekAwxJb0/JVc7zqPyrU3zJfpWHPEG7kN0o xkoLZz3J/qCLjy8ARct6biDDVe9Le9+F1G/M9RGeDd6MmxIoeZfGDLPRH+YFha0gFu9e A8zPcDCOEBZYuCZ58v4eoa1lTSg+/Q0nLNDXSKylf246Yv42793BURa8ErWOkeaq+ufh RvXQ== 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=xPq4MnSfZ5jWfAsPssUVfjNY8ScP1mqw+MypBd7iP+U=; b=eisYK+yE/21SjBkdKxawulYdob4q/qc6ojKClH2GNyyk/8gVKdaGTHi0yGWnELUWao ZE1ng5YZySXklFQpnUyt+GEZAm8RAZrtNHgmiKZB71lFj3PCaT4Ew7VM7cESFZETwkW5 i5V/cksAwqUNE9JOyNZZ4z8DyhxYw3SF77DZETHPwyNYkUZPJ4n3eOBL5XF1DiqKAXbC JjLs/p2fn5WgbVUXX/EujV9xHdvyslWk0bd6yJjgyP07zUTzjTS/5cQgV+UROSi/dd6x pSHjnmApPkpdTOk0uJbgX2Ceyxa4nuE+hggRFNGISCdoZC04SNVooOZDoDUujD6V9X9K /dKA== X-Gm-Message-State: ANhLgQ174m7RimzwpPgUpVkIG4acLnjesA1uo8rY9mpqHjc+OkBBSiYz 6AgSfznndRjQd24X0hDNnFM= X-Google-Smtp-Source: ADFU+vv9CLHD6sVa3fBRa6pzZ4SBhCdu9PYfQpsoPVh3OiiLUei4gNaaBkWGAAN2cXCdFxrDXM+9Yw== X-Received: by 2002:aa7:9497:: with SMTP id z23mr526938pfk.229.1583177811915; Mon, 02 Mar 2020 11:36:51 -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 hg6sm35441pjb.22.2020.03.02.11.36.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 02 Mar 2020 11:36:50 -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 , Jann Horn , alexander.h.duyck@linux.intel.com, sj38.park@gmail.com, Minchan Kim Subject: [PATCH v7 6/7] mm/madvise: employ mmget_still_valid for write lock Date: Mon, 2 Mar 2020 11:36:29 -0800 Message-Id: <20200302193630.68771-7-minchan@kernel.org> X-Mailer: git-send-email 2.25.0.265.gbab2e86ba0-goog In-Reply-To: <20200302193630.68771-1-minchan@kernel.org> References: <20200302193630.68771-1-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. Reviewed-by: Suren Baghdasaryan 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 e794367f681e..e77c6c1fad34 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