[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 22 Feb 2012 11:53:42 -0800
From: "H. Peter Anvin" <hpa@...or.com>
To: Will Drewry <wad@...omium.org>
CC: Indan Zupancic <indan@....nu>, linux-kernel@...r.kernel.org,
linux-arch@...r.kernel.org, linux-doc@...r.kernel.org,
kernel-hardening@...ts.openwall.com, netdev@...r.kernel.org,
x86@...nel.org, arnd@...db.de, davem@...emloft.net, mingo@...hat.com,
oleg@...hat.com, peterz@...radead.org, rdunlap@...otime.net,
mcgrathr@...omium.org, tglx@...utronix.de, luto@....edu,
eparis@...hat.com, serge.hallyn@...onical.com, djm@...drot.org,
scarybeasts@...il.com, pmoore@...hat.com, akpm@...ux-foundation.org,
corbet@....net, eric.dumazet@...il.com, markus@...omium.org,
keescook@...omium.org
Subject: Re: [PATCH v10 05/11] seccomp: add system call filtering using BPF
On 02/22/2012 11:47 AM, Will Drewry wrote:
>>
>> I highly disagree with every filter having to check the mode: Filters that
>> don't check the arch on e.g. x86 are buggy, so they have to check it, even
>> if it's a 32-bit or 64-bit only system, the filters can't know that and
>> needs to check the arch at every syscall entry. All other info in the data
>> depends on the arch, because of this there isn't much code to share between
>> the two archs, so you can as well have one filter for each arch.
>>
>> Alternative approach: Tell the arch at filter install time and only run the
>> filters with the same arch as the current system call. If no filters are run,
>> deny the systemcall.
>
> This was roughly how I first implemented compat and non-compat
> support. It causes some implicit behavior across inheritance that is
> not nice though.
>
This is trivially doable at the BPF level, right? Just make this the
first instruction in the program (either deny or jump to a separate
program branch)... and then there is still "one program" without any
weird inheritance issues?
-hpa
--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
