Re: What's the point having GLIBC_ABI_DT_RELR?

[Florian Weimer <fweimer@redhat.com>]

* Bjørn Mork via Libc-help:

> [ dropped Peter's Cc as his email seems defunct ]
>
> Florian Weimer <fweimer@redhat.com> writes:
>> * Bjørn Mork via Libc-help:
>>
>>> Isn't the whole GLIBC_ABI_DT_RELR test just unnecessarily preventing
>>> glibc from loading libraries with DT_RELR?  Any glibc version testing
>>> for it will also support DT_RELR. So it would have worked fine if it
>>> weren't for the test.  Looks like unnecessary forced breakage - there
>>> must be something I'm missing. But what?
>>
>> The purpose of the check is to stop the proliferation of binaries that
>> crash when loaded by glibc versions that do not support DT_RELR.
>
> Thanks. Is this a crash on load, or will (some of) those binaries load
> successfully and then mysteriously crash later?

It's a mysterious crash.  Even with symbols and GDB, it's difficult to
figure out what is going on because the symptoms are quite unusual: some
pointers in global data are null because initialization has not been
performed.  These null pointers may end up at very distant places before
the crash.

Thanks,
Florian