linux-kernel - Re: [RFC][PATCHSET] mremap/mmap mess

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20091208.130802.25121122.davem@davemloft.net>
Date:	Tue, 08 Dec 2009 13:08:02 -0800 (PST)
From:	David Miller <davem@...emloft.net>
To:	hugh.dickins@...cali.co.uk
Cc:	viro@...IV.linux.org.uk, viro@....linux.org.uk,
	linux-arch@...r.kernel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, linux-kernel@...r.kernel.org
Subject: Re: [RFC][PATCHSET] mremap/mmap mess

From: Hugh Dickins <hugh.dickins@...cali.co.uk>
Date: Tue, 8 Dec 2009 13:03:30 +0000 (GMT)

> That would impose some (unacceptable?) limits, and require some funny
> code to migrate the pages over to the new mm later (instead of
> relocating within the new mm as we do now).

I think this approach would create new failure cases that don't exist
now.  Whether that's acceptable or not is another issue.

The forced page table move, and TLB+cache flush that goes along with
that, for every single compat task we get now on the other hand is not
acceptable :-)

I also think this page table move overhead is worse than the
non-swapability added by Al's approach.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/