questions on struct sigcontext

["Chris Friesen" <cfriesen@nortel.com>]

Hi all,

First, I'm not subscribed to the list so I'd appreciate being cc'd on 
any replies.

We have a project getting started with MIPS, and one of the things that 
we're trying to bring in is some exception-handling code that logs 
various information about the ways that apps fail.

In particular, the guys working on this have asked for the STATUS, 
CAUSE, BADVADDR, and FPC_EIR registers to be made available as part of 
struct sigcontext so that they can determine exactly why the app is failing.

Looking at include/asm-mips/sigcontext.h I can see that these registers 
appear to be in the struct, but are either marked as "unused" or now 
have different names.

Am I correct that these registers are not currently exported to 
userspace on a fault?  If this is the case, why not?  Does anyone have a 
patch to enable this export?

It seems odd that mips app designers wouldn't want this information to 
be made available.

Any information you can provide would be useful.

Chris