kern/60877: t_signal_and_sp test failure with i386 userland on amd64 kernel

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

>Number:         60877
>Category:       kern
>Synopsis:       t_signal_and_sp test failure with i386 userland on amd64 kernel
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Oct 14 18:25:00 +0000 2026
>Originator:     Martin Husemann
>Release:        NetBSD 11.99.9
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD seven-days-to-the-wolves.aprisoft.de 11.99.9 NetBSD 11.99.9 (GENERIC) #903: Wed Oct 14 14:46:31 CEST 2026 martin%seven-days-to-the-wolves.aprisoft.de@localhost:/work/src/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:

When running the i386 tests on an amd64 machine (in a 32bit chroot)
the /usr/tests/kernel/t_signal_and_sp test program shows lots of 
failures, like:

tc-start: 1792001789.340810, getstack_vforkexec
tc-so:child
tc-se:h_getstack: ELF AT_STACKBASE: addr=0xffff4000
tc-se:h_getstack:       getcontext: addr=0xfffff000       used=2000
tc-se:h_getstack:     __ps_strings: addr=0xffff4000
tc-se:h_getstack:     pthread attr: addr=0xffff4000       size=400000
tc-se:h_getstack:     RLIMIT_STACK:                       size=400000 min, 4000000 max
tc-se:h_getstack:      sigaltstack: addr=0x0              size=0
tc-se:h_getstack: Stack disagreement!
tc-so:parent
tc-se:*** Check failed: /work/src/tests/kernel/t_signal_and_sp.c:779: child exited with code 255
tc-se:t_signal_and_sp: ELF AT_STACKBASE: addr=0xfff6d000
tc-se:t_signal_and_sp:       getcontext: addr=0xfffff000       used=3000
tc-se:t_signal_and_sp:     __ps_strings: addr=0xfff6d000
tc-se:t_signal_and_sp:     pthread attr: addr=0xfff6d000       size=400000
tc-se:t_signal_and_sp:     RLIMIT_STACK:                       size=400000 min, 4000000 max
tc-se:t_signal_and_sp:      sigaltstack: addr=0x0              size=0
tc-se:t_signal_and_sp: Stack disagreement!
tc-se:*** Check failed: /work/src/tests/kernel/t_signal_and_sp.c:786: checkgetstack() == 0 not met
tc-end: 1792001789.344804, getstack_vforkexec, failed, 2 checks failed; see output for more details

see also:
https://netbsd.org/~martin/amd64-compat32-atf/

>How-To-Repeat:
s/a

>Fix:
n/a