kern/60882: KASAN/KUBSAN massively bloat the kernel

["nia%pkgsrc.org@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60882
>Category:       kern
>Synopsis:       KASAN/KUBSAN massively bloat the kernel
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Oct 15 13:35:00 +0000 2026
>Originator:     nia
>Release:        -current, -11, -10
>Organization:
The NetBSAN Foundation
>Environment:
NetBSD siphon 11.99.9 NetBSD 11.99.9 (SIPHON) #2: Sun Oct 11 21:09:47 CEST 2026  nia@siphon:/encrypt/obj/sys/arch/amd64/compile/SIPHON amd64
>Description:
KUBSAN/KASAN seem to be producing massive amounts of kernel bloat,
resulting in kernel sizes that approach 200MB.

This impedes debugging and finding bugs because a kernel that is 100MB+
is a struggle for the bootloader and in some cases doesn't even load.
>How-To-Repeat:
Build a kernel with the following configuration, e.g. for amd64:

# $NetBSD$

include "arch/amd64/conf/GENERIC"

options		KUBSAN

makeoptions	KASAN=1	
options		KASAN

no options	SVS


Observe file size of over 100MB.
>Fix: