[RFC PATCH 0/2] seccomp: Split set filter into two steps

From: Hengqi Chen <hengqi.chen@gmail.com>
To: linux-kernel@vger.kernel.org, bpf@vger.kernel.org
Cc: keescook@chromium.org, luto@amacapital.net, wad@chromium.org,
	alexyonghe@tencent.com, hengqi.chen@gmail.com
Subject: [RFC PATCH 0/2] seccomp: Split set filter into two steps
Date: Tue,  3 Oct 2023 08:38:34 +0000	[thread overview]
Message-ID: <20231003083836.100706-1-hengqi.chen@gmail.com> (raw)

This patchset introduces two new operations which essentially
splits the SECCOMP_SET_MODE_FILTER process into two steps:
SECCOMP_LOAD_FILTER and SECCOMP_ATTACH_FILTER.

The SECCOMP_LOAD_FILTER loads the filter and returns a fd
which can be pinned to bpffs. This extends the lifetime of the
filter and thus can be reused by different processes.
With this new operation, we can eliminate a hot path of JITing
BPF program (the filter) where we apply the same seccomp filter
to thousands of micro VMs on a bare metal instance.

The SECCOMP_ATTACH_FILTER is used to attach a loaded filter.
The filter is represented by a fd which is either returned
from SECCOMP_LOAD_FILTER or obtained from bpffs using bpf syscall.

Hengqi Chen (2):
  seccomp: Introduce SECCOMP_LOAD_FILTER operation
  seccomp: Introduce SECCOMP_ATTACH_FILTER operation

 include/uapi/linux/seccomp.h |   2 +
 kernel/seccomp.c             | 138 ++++++++++++++++++++++++++++++++++-
 2 files changed, 136 insertions(+), 4 deletions(-)

-- 
2.34.1