Re: Using time() leads to binary incompatibility of static executables

[Niels Thykier <niels@thykier.net>]

Peter Keller:
> Dear all,
> 

Hi Peter,

Thanks for your interest and for testing the issue.

> We have come across a binary compatibility problem involving
> Debian-testing: an executable built from the trivial test program at
> the end of this message segfaults on Debian-testing in the call to the
> time() function, when the executable was built on a CentOS 6 or CentOS
> 5 system. We have tested this (both compiling and running) on a
> variety of other distributions, and we have found that the following
> conditions must all be satisfied to trigger the segfault:
> 
>  * compilation/linking (with 'gcc -g --static test_time.c'):
>    - on CentOS 5 or CentOS 6
>    - the executable must be static
>    - the executable must be 64-bit
>  * running
>    - must be run on Debian-testing (kernel 4.11)
> 

We very recently got a kernel 4.12.2 in Debian testing:

 * Could you test if that fixes the problem?

 * FYI, there was a glibc migration today.  So both has been updated
   recently.

If not, let us move on to filing an actual bug.

> [...]
> 
> We would be grateful for any comments from someone with more expertise
> than us in this area. In particular:
> 
>   * have we found a bug in Debian-testing, or is binary compatibility
>     not to be expected under these circumstances?
> 

I suspect you have found a bug, but I am not entirely sure.  At first
glance, I believe it should work/be compatible.  However, I would prefer
to let people, who understand the technical aspect of the problem,
answer this part if it has not been fixed by the recent changes. :)

>   * if it is a bug, which package should we report it under? (glibc?
>     linux? some other package?)
> 

Good question.  When you tested in debian testing with linux 4.9 and
linux 4.11, was the only different the kernel?  If so, I would go for
the linux kernel.

If you want/need to retest it, please remember that we have the
snapshot.debian.org service, which can provide you with versions of the
archive as they looked on a given day.

>   * have upcoming changes in unstable or experimental already
>     addressed this issue?
> 

Not that I know of, but I have not tried. To be honest, I think you
might be a better judge of that if you are willing to test unstable. :)

Anyway, if the recent updates have not fixed the issue, please let us
look into filing a bug. :)

Hope it was helpful. :)

Thanks,
Niels