lib/56768: lib/libc/regex/t_exhaust test crashes

[martin%NetBSD.org@localhost]

>Number:         56768
>Category:       lib
>Synopsis:       lib/libc/regex/t_exhaust test crashes
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Mar 26 16:00:01 +0000 2022
>Originator:     Martin Husemann
>Release:        NetBSD 9.99.95
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD thirdstage.duskware.de 9.99.95 NetBSD 9.99.95 (MODULAR) #536: Sat Mar 26 09:19:27 CET 2022 martin%thirdstage.duskware.de@localhost:/usr/src/sys/arch/sparc64/compile/MODULAR sparc64
Architecture: sparc64
Machine: sparc64
>Description:

The lib/libc/regex/t_exhaust test crashes reproducably on sparc64.

>How-To-Repeat:

cd /usr/tests/lib/libc/regex
gdb ./t_exhaust
(gdb) run regcomp_too_big
[..]
Program received signal SIGSEGV, Segmentation fault.
nstime_get (time=0x98)
    at /usr/src/external/bsd/jemalloc/lib/../dist/src/nstime.c:129
129             nstime_init2(time, ts.tv_sec, ts.tv_nsec);
(gdb) bt
#0  nstime_get (time=0x98)
    at /usr/src/external/bsd/jemalloc/lib/../dist/src/nstime.c:129
#1  nstime_update_impl (time=0x98)
    at /usr/src/external/bsd/jemalloc/lib/../dist/src/nstime.c:160
#2  0x00000000000000a0 in ?? ()

Something has smashed the stack here, in this case with 0x98 words
(I have seen a few other repeating values, like 0x10000000).

>Fix:
n/a