[fpc-pascal] Get all caller adresses of a given function/procedure before executing

Marco van de Voort marcov at stack.nl
Sat Aug 11 17:34:44 CEST 2012

In our previous episode, Rainer Stratmann said:
> > > There are not many different ways for a call.
> > >
> > > http://css.csail.mit.edu/6.858/2011/readings/i386/CALL.htm
> >
> > Yes, so the amount of effort may increase drastically. New CPU may bring
> > new ways too.
> But not the 80x86 CPU. It is still the same opcode for a call ($E8).

Maybe not the call, but changing or adding address encoding is quite

I assume you tested your code for PIC cases (which are quite common on


FPC supports PIC
And of course finding a perfect starting point so that you don't find false
positives when you find $E8 inside the address (change 1 in 256 obviously)

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