port-amd64/56560: execsnoop test now fails

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         56560
>Category:       port-amd64
>Synopsis:       execsnoop test now fails
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-amd64-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Dec 20 11:50:00 +0000 2021
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current, source date 2021.12.19.16.01.29
>Organization:

>Environment:
System: NetBSD
Architecture: x86_64
Machine: amd64
>Description:

Since yesteday's DRM update, the usr.sbin/execsnoop/t_execsnoop:basic
test case is failing on amd64, both under qemu and on real hardware:

  http://releng.netbsd.org/b5reports/amd64/2021/2021.12.19.12.45.50/test.html#usr.sbin_execsnoop_t_execsnoop_basic

  https://www.gson.org/netbsd/bugs/build/amd64-baremetal/2021/2021.12.19.16.01.29/test.html#usr.sbin_execsnoop_t_execsnoop_basic

The 51-line long error message ends with:

  "/usr/lib/dtrace/psinfo.d", line 46: failed to copy type of 'pr_arglen': Type information is in parent and unavailable

I don't see any obvious connection between DRM and DTrace, but perhaps
this is another case of the total number of symbols, types, or similar
in the kernel growing past some fixed limit in DTrace.

>How-To-Repeat:

>Fix: