[PATCH bpf-next 0/4] Introduce bpf_kernfs_read_xattr

[Tejun Heo]

Hello,

On Wed, Jun 18, 2025 at 04:37:35PM -0700, Song Liu wrote:
> Introduce a new kfunc bpf_kernfs_read_xattr, which can read xattr from
> kernfs nodes (cgroupfs, for example). The primary users are LSMs, for
> example, from systemd. sched_ext could also use xattrs on cgroupfs nodes.
> However, this is not allowed yet, because bpf_kernfs_read_xattr is only
> allowed from LSM hooks. The plan is to address sched_ext later (or in a
> later revision of this set).

I don't think kernfs is the name we should be exposing to BPF users. This is
an implementation detail which may change in the future. I'd rather make it
a generic interface or a cgroup specific one. The name "kernfs" doesn't
really mean much outside kernel code that's using them.

Thanks.

-- 
tejun