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Since this addressing scheme is <object, offset>, and as these pairs need to fit in 64 bits, I am curious, is the numjer of bits for each part is fixed and what are those fixed widths. In other words what is the maximum possible offset within one object and the max number of objects?

Probably segment registers in x86 can be thought as object identifiers, thus allowing the same non-linear approach?(Isn't that the purpose of segments even?)

Update: BTW, another term for what the author calls "linear" is "flat".




Yeah, x86 segments in the protected modes were intended to be used as a hardware object capability system like the author is getting at.

And yeah, it's probably a fixed 64bit lookup into an object descriptor table.


Wouldn't it be hilarious if the 21st century brought about the re-adoption of the security design features introduced in the 80286 (1982)?


I came this close to ordering custom "Make the LDT Great Again" hats after spectre was released, lol.




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