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

From: Hengqi Chen
Date: Tue Oct 03 2023 - 04:44:11 EST


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