Re: [LTP] [PATCH] ioctl_pidfd02-06: Add CONFIG_USER_NS and CONFIG_PID_NS to needs_kconfigs

Petr Vorel
2026-01-07T16:18:49Z

> Hi!
> > Thanks for your input. I understand that you're for replacing in ioctl_ns06.c:

> > int exists = access("/proc/self/ns/user", F_OK);

> > if (exists < 0)
> > tst_res(TCONF, "namespace not available");

> > with .needs_kconfigs:

> > .needs_kconfigs = (const char *[]) {
> > "CONFIG_USER_NS",
> > NULL
> > }

> > Because that was my question - really always prefer kconfig even there is a
> > simple runtime solution? I'd like to have some "rule" like conclusion we can
> > point during review.

> I think that from a long term view this is going to be simpler solution
> than having many different types of checks. The less diverse these
> checks are the easier they are to review and maintain. Hence I lean
> towards kernel config checks even though they are slower (mostly
> unmeasurable on today's harware) than the alternatives.

Great, thanks for a general resolution. Unless somebody objects I'm ok with the
conclusion (ideally we should formalise it in rules in docs).

Kind regards,
Petr