When CONFIG_NETKIT=y,
bpftool-cgroup shows error even if the cgroup's path is correct:
$ bpftool cgroup tree /sys/fs/cgroup
CgroupPath
ID AttachType AttachFlags Name
Error: can't query bpf programs attached to /sys/fs/cgroup: No such device or address
>From strace and kernel tracing, I found netkit returned ENXIO and this command failed.
I think this AttachType(BPF_NETKIT_PRIMARY) is not relevant to cgroup.
bpftool-cgroup should query just only cgroup-related attach types.
v2->v3:
- removed an unnecessary check
v1->v2:
- used an array of cgroup attach types
Signed-off-by: Kenta Tada <tadakentaso@gmail.com>
Reviewed-by: Quentin Monnet <qmo@kernel.org>
Link: https://lore.kernel.org/r/20240607111704.6716-1-tadakentaso@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>