Re: [PATCH v2 0/2] mm,fork,security: introduce MADV_WIPEONFORK

From: Florian Weimer <fweimer@redhat.com>
To: "Michal Hocko" <mhocko@kernel.org>,
	"Colm MacCárthaigh" <colm@allcosts.net>
Cc: Kees Cook <keescook@chromium.org>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	Rik van Riel <riel@redhat.com>, Will Drewry <wad@chromium.org>,
	akpm@linux-foundation.org, dave.hansen@intel.com,
	kirill@shutemov.name, linux-api@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	luto@amacapital.net, mingo@kernel.org
Subject: Re: [PATCH v2 0/2] mm,fork,security: introduce MADV_WIPEONFORK
Date: Fri, 11 Aug 2017 16:11:44 +0200	[thread overview]
Message-ID: <c8cda773-b28d-f35f-7f18-6735584cb173@redhat.com> (raw)
In-Reply-To: <20170811140653.GO30811@dhcp22.suse.cz>

On 08/11/2017 04:06 PM, Michal Hocko wrote:

> I am sorry to look too insisting here (I have still hard time to reconcile
> myself with the madvise (ab)use) but if we in fact want minherit like
> interface why don't we simply add minherit and make the code which wants
> to use that interface easier to port? Is the only reason that hooking
> into madvise is less code? If yes is that a sufficient reason to justify
> the (ab)use of madvise? If there is a general consensus on that part I
> will shut up and won't object anymore. Arguably MADV_DONTFORK would fit
> into minherit API better as well.

It does, OpenBSD calls it MAP_INHERIT_NONE.

Could you implement MAP_INHERIT_COPY and MAP_INHERIT_SHARE as well?  Or
is changing from MAP_SHARED to MAP_PRIVATE and back impossible?

Thanks,
Florian