Nuking unexec

[Andreas Schwab]

Malcolm Purvis <malcolmp at xemacs.org> writes:

>>>>>> "Ben" == Ben Wing <ben at 666.com> writes:
>
> Ben> I find that hard to believe; I wonder what his reasons are ...
>
> Some of the objects that get dumped contain function pointers.  In the IA64
> ABI, these point to a descriptor containing { &code, &data_context }.  At the
> very least data_context varies between machines and across reboots (I'm not
> sure about per process).  Data_context is so machine dependant that there is
> no useful way that we can get access to it in XEmacs.

Note that only dynamic assignments are a problem, because their function
descriptors are allocated at runtime (during initial relocation), thus
their address differ before and after dumping.  (This is unlike powerpc64
where every function has a descriptor preallocated.)  For static
initialisations the corresponding descriptors are also statically
allocated and won't change.  Thus for example C++ vtables would not pose a
problem.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab at suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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"And now for something completely different."