Re: What could cause this SEGV

[Paul Smith <paul at mad-scientist dot net>]

On Wed, 2018-06-13 at 12:11 +0100, Andrew Haley wrote:
> > Is there more I could do to track this down and understand it? 
> > Should I just proceed with the "working" _fastmath.so and call it
> > good? It seems like there's some hole in my encapsulation that I
> > can't see; I would prefer to find and patch it if possible...
> 
> It might be related to ordering.  There very probably is something
> really wrong, so I think it deserves more investigation.  However,
> I think you really have to debug it.  gdb is your friend.

I did make an effort to use GDB, but the code is compiled with a high
level of optimization and stripped and there were no useful debug
symbols.  Because of the nature of the object (python module, etc.) its
build options are buried under several layers and not easy to modify. 
I will make more of an effort (recompile by hand etc.) and see where I
get.

If it is an ordering problem that implies to me that it's a bug in the
_fastmath code, which is not properly accounting for ordering issues
during static initialization, no?  Or is your concern that it could be
an issue in the linker itself?

Thanks for the reply Andrew!