bug#64937: "who" reports funny dates

[Sven Joachim]

On 2023-07-29 17:30 -0700, Paul Eggert wrote:

> On 2023-07-29 12:44, Pádraig Brady wrote:
>> I tried a quick build with -D__WORDSIZE_TIME64_COMPAT32=1
>> which is what glibc uses to force the smaller time types.
>> However that didn't fix the issue, so I'll need to look a bit more,
>> and how to get only utmp access restricted to 32 bit types.

I guess -D__WORDSIZE_TIME64_COMPAT32=1 does not cut it because
bits/wordsize.h #defines __WORDSIZE_TIME64_COMPAT32 as 0, overriding the
commandline definition.

> What's Debian's and/or Fedora's plan for fixing <utmp.h>/<utmpx.h>'s
> Y2038 bugs? (Or is the idea to remove the <utmp.h></utmpx.h> API
> before 2038? :-)

I don't really know.  In the near future Debian plans to enable
-D_TIME_BITS=64 by default on most 32-bit architectures[1] though, and
then the utmp interface is going to break.  I have notified the Debian
glibc maintainers[2], but the problem needs to be addressed by glibc
upstream.

> See:
>
> https://lwn.net/Articles/925068/
>
> https://sourceware.org/glibc/wiki/Y2038ProofnessDesign#utmp_types_and_APIs

Thanks for the links.  And for fixing the bug. :-)

Cheers,
       Sven


1. https://lists.debian.org/debian-devel/2023/05/msg00168.html
2. https://bugs.debian.org/1042562