[PATCH bpf-next 0/4] Introduce bpf_kernfs_read_xattr

[Christian Brauner]

On Wed, Jun 18, 2025 at 02:43:34PM -1000, Tejun Heo wrote:
> 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

cgroup specific, please. That's what I suggested to Daan.