Re: Compat 32-bit syscall entry from 64-bit task!?

[Linus Torvalds]

On Thu, Jan 19, 2012 at 11:37 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> I would suggest looking at 'rip/rsp' first, though, and just say that
> if it's >32-bit, it's flat mode. Only if both rsp and rip fit in 32
> bits should you even bother start guessing.

Oh, there's a few other hints you can look at. If 'ds' is zero, you
might technically be in 32-bit mode, but realistically nothing really
would work, so you might as well assume you're in long mode.

So you can have a lot of heuristics (including just looking at what
the disassembly itself looks like) if you really want to..

                    Linus
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