kern/60455: Module auto-load appears to be totally useless

["thorpej%me.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60455
>Category:       kern
>Synopsis:       Module auto-load appears to be totally useless
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 17 15:50:00 +0000 2026
>Originator:     Jason Thorpe
>Release:        11.99.7
>Organization:
Retrogrouches R Us
>Environment:
NetBSD icarus 11.99.7 NetBSD 11.99.7 (PHAETHON1) #136: Fri Jul 17 07:47:48 PDT 2026  thorpej@dhcp-105.ktnet:/Users/thorpej/NetBSD/current/src/sys/arch/hb68k/compile/PHAETHON1 hb68k
>Description:
While working on a new NetBSD port, I am striving to make the standard kernel as small as is reasonably feasible given that it is a resource-constrained machine (68010 CPU, 8MB base RAM).

I decided to fully embrace the MODULAR idea, trimming the kernel config down to the bare minimum of pseudo-devices and only the FFS file system.

I was successfully able to load the "if_sl" module at boot (the system does not yet have a working Ethernet interface).

But auto-loading the "ptyfs" module then file systems were being mounted totally blew up in my face, for two reasons:

- auto-loading is apparent configured off-by-default.  No matter, that can be changed easily enough, even at run-time.

- securelevel appears to be blocking auto-load.  This is the real problem, rending auto-loading totally useless.

>How-To-Repeat:
Attempt to auto-load an FS module during boot without the INSECURE option.
>Fix:
There is a kauth listener that grants auto-load, but secmodel_securelevel seems to be overriding it?  Maybe it shouldn't do that.  At the very least, the modules documentation should mention that auto-load is totally useless unless running INSECURE.