Re: Nuking unexec
Malcolm Purvis <malcolmp(a)xemacs.org> writes:
>>>>> "Ben" == Ben Wing <ben(a)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(a)suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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