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SubjectRe: [patch] 2.4.0-test2: %cr4 in a register dump

How about just checking the feature flags to see if debugging extensions
are present (IO breakpoints) which always means that a valid CR4
register is present (since the bit to enable IO breakpoints in located
in CR4). Then the patch will work accross all Pentium class processors
and you won't need the trap .....

:-)

Jeff

Brian Gerst wrote:
>
> Linus Torvalds wrote:
> > If I remember correctly, there are CPU's out there that will bomb out
> > horribly when you access %cr4 if the register doesn't exist.
> >
> > Do I remember wrong?
> >
> > I'd certainly agree with printing out cr4 even if it would be zero, I just
> > disagree very much with adding a register read to the dump output that may
> > cause an infinite regression of traps..
> >
> > Linus
>
> How about just trapping the illegal opcode exception then? (patch
> untested)
>
> --
>
> Brian Gerst
>
> ------------------------------------------------------------------------
> Name: cr4.diff
> cr4.diff Type: application/x-unknown-content-type-diff_auto_file
> Encoding: base64

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