RFR(XXS): 8224793: os::die() does not honor CreateCoredumpOnCrash option

[Kim Barrett]

> On May 28, 2019, at 8:27 PM, Kim Barrett <kim.barrett at oracle.com> wrote:
> Calling os::exit here seems wrong.  We may have already tried calling
> os::exit and gotten here because of problems therein.  And the doc
> comment for os::die says "no exit hook, no abort hook, no cleanup."
> 
> SIGABRT (signaled by ::abort) has a default action of Core, which is
> the reason for the current behavior.  (And ::abort will invoke that
> action if the installed action returns rather than terminating the
> process.)  If no core is wanted, SIGKILL has a default action of
> Terminate, and that behavior can't be replaced.  So issuing a SIGKILL
> when -CreateCoredumpOnCrash seems like it should get the desired
> behavior.
> 
> These various implementations of os::die() look like they could be
> merged into os_posix.cpp.
> 

And looking at this some more, I think I agree with David's comment in
the CR, that os::die *should* always dump core.  It gets called when
things have gone horribly wrong, and a core dump might be the only way
to understand what went wrong.

Maybe there are paths to os::die that ought to be calling os::abort
instead?

I think os::abort probably should not be calling ::exit either, but
should be raising SIGKILL if no core dump is requested.  os::exit is
the path to exit functions and the like.

It's unfortunate that the Linux version of os::abort needs to do
something special for DumpPrivateMappingsInCore; without that, we
could have a merged posix version of os::abort.