Michael S (already5chosen.delete@this.yahoo.com) on January 12, 2020 1:43 am wrote:
> Adrian (a.delete@this.acm.org) on January 11, 2020 11:18 pm wrote:
> >
> > The worst method, but which is guaranteed to always succeed, is to move some memory from time to time.
> >
>
> I don't understand how it is guaranteed to succeed in a common case.
> Even when all pointers are tagged there are difficulties (due to creative use of indexes).
> And without tagged pointers ... well, I simply don't see how it's possible.
>


It would take too much time to explain now and I might change a lot, but yes, because of the unpredictable use of pointers and of the lack of cooperation from the applications in the early Windows style, for this to work with standard Linux applications, one variant is to recompile them from the source. An old binary would not work due to unknown pointer locations. Another tested variant simulates the effect of a few segment registers used just for relocation and not-accessible by the user program (by shifted identity mappings in the page tables, since the x86 segment register bases do not work in 64-bit mode).