2026-09-22 11:54 UTC+0900 ~ Hui Su <[email protected]> > Commit 4b82b181a26c ("bpf: Allow pre-ordering for bpf cgroup progs") > introduced BPF_F_PREORDER to request pre-order execution across the > cgroup hierarchy. Furthermore, attachments legitimately use combinations > such as BPF_F_ALLOW_MULTI | BPF_F_PREORDER or > BPF_F_ALLOW_OVERRIDE | BPF_F_PREORDER. > > With BPF_PROG_QUERY reporting the per-program BPF_F_PREORDER attribute, > bpftool's exact-match formatter falls back to "unknown(40)" when > BPF_F_PREORDER is present alone, or "unknown(41)" / "unknown(42)" when > combined with BPF_F_ALLOW_OVERRIDE or BPF_F_ALLOW_MULTI. Additionally, > do_attach() only accepts "multi" and "override", rejecting "preorder" > with "unknown option". > > Before: > $ bpftool cgroup show <cg> > 1234 cgroup_inet_ingress unknown(42) test_prog > $ bpftool cgroup attach <cg> cgroup_inet_ingress id 5678 multi preorder > Error: unknown option: preorder > > After: > $ bpftool cgroup show <cg> > 1234 cgroup_inet_ingress multi,preorder test_prog > $ bpftool cgroup attach <cg> cgroup_inet_ingress id 5678 multi preorder > (attaches successfully) > > Refactor the attach flags formatter into a bitmask formatter that outputs > comma-separated flag names for plain text while preserving unrecognized > bits as "unknown(...)". Render attach flags as an array of flag names in > JSON output. Accept "preorder" in do_attach(), update the cgroup > documentation and synopsis to express valid flag combinations, and teach > bash completion about them ("multi" or "override" optionally combined > with "preorder"). > > Signed-off-by: Hui Su <[email protected]>
Acked-by: Quentin Monnet <[email protected]> Thank you
