Question about EI_ABIVERSION handling

[Florian Weimer]

* Dragan Mladjenovic:

> It seems that ld.so does not validate EI_ABIVERSION of main executable
> when the said executable is loaded directly by the kernel.

Hmm.  I think this may be an oversight.  I can confirm this behavior on
x86-64.

> Is this behavior intended? If I would wish to ensure that executable
> with newer ABI version get rejected by the old loaders, am I expected
> to add some other incompatible change like new dynamic tag?

Unknown dynamic tags are ignored (like unknown program headers).  Only
unknown relocation types result in errors.

Thanks,
Florian