crash on priviledged instruction

[Ove Kaaven]

On 9 Oct 2001, Andreas Mohr Usenet 10/01 wrote:

> Stefan Leichter <Stefan.Leichter at camline.com> wrote:
> > --nextPart2958321.T8p0MMh6RI
> > Content-Type: text/plain; charset=iso-8859-15
> > Content-Transfer-Encoding: 8Bit
> 
> > Hello,
> 
> > is it possible to make a work around for the crash ? The crashing program 
> > is the installer of the T-Online software (CD from 29.04.1999).
> 
> > 080689b8:08243b48: exception code=c0000096
> > Unhandled exception: priviledged instruction in 16-bit code (050f:1006).
> > In 16-bit mode.
> > 0x050f:0x1006: lesw	%es:0x0(%si),%si
> > Wine-dbg>quit
> 
> Huh ??
> les si is in no way a privileged instruction !!

Well, it happens to be "privileged" under circumstances such as:

- es is zero
- the selector that's being loaded into es (by lesw) points to an invalid
or privileged segment (i.e. a segment that is marked accessible only to
ring 0, or has an invalid descriptor, or otherwise does not exist), or
the requested privilege level (the two least-significant bits of the
selector value) is higher than the current privilege level (ring 3)

If es:si is a bad pointer, then this usually happens, since there's
usually no permitted (to ring 3) selector at the destination.