Subject: Re: [PATCH v12 06/13] seccomp: add system call filtering using BPF

From: "H. Peter Anvin" <[email-masked]>
Date: Thu, 01 Mar 2012 21:52:59 -0800

On 03/01/2012 09:45 PM, Indan Zupancic wrote:
> 
>> + * @nr: the system call number
>> + * @arch: indicates system call convention as an AUDIT_ARCH_* value
>> + *        as defined in <linux/audit.h>.
>> + * @instruction_pointer: at the time of the system call.
> 
> If the vDSO is used this will always be the same, so what good is this?
> I haven't gotten an answer to this yet.
> 

And if it isn't, or you're on an architecture which doesn't use the vdso
as the launching point, it's not. You seem to be unable to look outside
your own particular use cases, but it is very likely that the same
oddball cases which do mixed-mode programming are ones for which this
kind of filtering facility would be extremely useful -- Pin is a great
example.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.