Re: [PATCH v4 seccomp 5/5] seccomp/cache: Report cache data through /proc/pid/seccomp_cache

From: YiFei Zhu
Date: Thu Oct 22 2020 - 19:42:13 EST


On Thu, Oct 22, 2020 at 5:32 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> I've been going back and forth on this, and I think what I've settled
> on is I'd like to avoid new CONFIG dependencies just for this feature.
> Instead, how about we just fill in SECCOMP_NATIVE and SECCOMP_COMPAT
> for all the HAVE_ARCH_SECCOMP_FILTER architectures, and then the
> cache reporting can be cleanly tied to CONFIG_SECCOMP_FILTER? It
> should be relatively simple to extract those details and make
> SECCOMP_ARCH_{NATIVE,COMPAT}_NAME part of the per-arch enabling patches?

Hmm. So I could enable the cache logic to every architecture (one
patch per arch) that does not have the sparse syscall numbers, and
then have the proc reporting after the arch patches? I could do that.
I don't have test machines to run anything other than x86_64 or ia32,
so they will need a closer look by people more familiar with those
arches.

> I'd still like to get more specific workload performance numbers too.
> The microbenchmark is nice, but getting things like build times under
> docker's default seccomp filter, etc would be lovely. I've almost gotten
> there, but my benchmarks are still really noisy and CPU isolation
> continues to frustrate me. :)

Ok, let me know if I can help.

YiFei Zhu