Re: NVidia glx stuff dies in sysarch(I386_SET_LDT, ...)

From: Julian Elischer <julian_at_elischer.org>
Date: Fri, 1 Aug 2003 16:20:05 -0700 (PDT)
On Fri, 1 Aug 2003, Daniel Eischen wrote:

> On Fri, 1 Aug 2003, Marcel Moolenaar wrote:
> 
> > On Fri, Aug 01, 2003 at 06:51:33PM -0400, Daniel Eischen wrote:
> > 
> > > > LUCODE_SEL is used by kernel to load _ucodesel to user %cs
> > > > LUDATA_SEL is used by kernel to load _udatasel to user %ds, %es, %fs, %gs.
> > > > I didn't check other ABIs, but setting to a fixed location of LDT in userland
> > > > is also a bad idea, I think it will conflict with thread library soon,
> > > > it is better to use dynamic allocating facility newly added in i386_set_ldt.
> > > 
> > > Perhaps we need to rethink the interface and disallow
> > > specification of any ldt; only allow dynamic.  We would
> > > need a different method of setting an array of them, though.
> > 
> > Why not allow setting a specific entry when it's currently unused
> > and not reserved by us?
> > We can simply fail if the process is trying to set a LDT entry that's
> > currently being used or is reserved by us. The only case that causes
> > problems is when an existing LDT entry is overwritten by another
> > consumer.
> 
> That's what I was worried about.  Once an application or
> library is written to use specific LDTs, you never know
> how it will be affected by the use of threading libraries
> (or other libraries using threads).
> 
> I can see the need to keep the old behavoir for compatibility's
> sake.

How about we complain loudly on the console when it's done..
(for the first few times) 
(with info on how to do it right)

> 
> -- 
> Dan Eischen
> 
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Received on Fri Aug 01 2003 - 14:20:27 UTC

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