From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752043AbdHHJ6V (ORCPT <rfc822;w@1wt.eu>);
        Tue, 8 Aug 2017 05:58:21 -0400
Received: from mx1.redhat.com ([209.132.183.28]:45996 "EHLO mx1.redhat.com"
        rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
        id S1751921AbdHHJ6U (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 8 Aug 2017 05:58:20 -0400
DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com E5B8A883B9
Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com
Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=fweimer@redhat.com
Subject: Re: [PATCH v2 0/2] mm,fork,security: introduce MADV_WIPEONFORK
To: Mike Kravetz <mike.kravetz@oracle.com>, riel@redhat.com,
        linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org, colm@allcosts.net, akpm@linux-foundation.org,
        keescook@chromium.org, luto@amacapital.net, wad@chromium.org,
        mingo@kernel.org, kirill@shutemov.name, dave.hansen@intel.com
References: <20170806140425.20937-1-riel@redhat.com>
 <a0d79f77-f916-d3d6-1d61-a052581dbd4a@oracle.com>
From: Florian Weimer <fweimer@redhat.com>
Message-ID: <bfdab709-e5b2-0d26-1c0f-31535eda1678@redhat.com>
Date: Tue, 8 Aug 2017 11:58:13 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.2.1
MIME-Version: 1.0
In-Reply-To: <a0d79f77-f916-d3d6-1d61-a052581dbd4a@oracle.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Tue, 08 Aug 2017 09:58:20 +0000 (UTC)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 08/07/2017 08:23 PM, Mike Kravetz wrote:
> If my thoughts above are correct, what about returning EINVAL if one
> attempts to set MADV_DONTFORK on mappings set up for sharing?

That's my preference as well.  If there is a use case for shared or
non-anonymous mappings, then we can implement MADV_DONTFORK with the
semantics for this use case.  If we pick some arbitrary semantics now,
without any use case, we might end up with something that's not actually
useful.

Thanks,
Florian