Date: Fri, 5 Mar 1999 00:13:22 +0100 (MET)
From: Wojciech Piechowski <voyt AT ds2 DOT pg DOT gda DOT pl>
To: DJGPP mailing list <djgpp AT delorie DOT com>
Subject: Re: C++ exceptions and stack messing
In-Reply-To: <Pine.UW2.3.95.990304214951.3657A-100000@bryggen.bgnett.no>
Message-ID: <Pine.GSO.3.96.990305000712.15084A-100000@delta.ds2.pg.gda.pl>
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Reply-To: djgpp AT delorie DOT com

On Thu, 4 Mar 1999, Gisle Vanem wrote:

> On Thu, 4 Mar 1999, Wojciech Piechowski wrote:
> 
> > I'm writing a program that uses some privilege levels using call gates.
> > Calling the gate changes the privilege and switches to another stack
> > specific to the new privilege. The old stack comes back when the
> > privileged routine does 'RET'. I wonder if the privileged function can
> > throw exceptions which will be caught by the non-privileged caller?
> 
> The protected mode architecture prohibits a transfer to a lower
> PL when interrupts/exceptions occur. So, the solution must include
> exception handlers at the privileged level (RPL 0) also.

Ah... these ambiguous words... When I said 'exception' I thought about C++
exceptions (try, throw, catch) instead of Intel exceptions/interrupts :-)

--------------------\  Wojciech  Piechowski  /----------------------------
Student informatyki  \  voyt AT ds2 DOT pg DOT gda DOT pl  /  Student of computer science
Politechnika Gdanska  \____________________/   Gdansk Technical University