Re: [Linux-ia64] Unwind can load wrong data from pt_regs

[Keith Owens <kaos@sgi.com>]

On Mon, 9 Dec 2002 13:21:07 -0800, 
David Mosberger <davidm@napali.hpl.hp.com> wrote:
>>>>>> On Mon, 09 Dec 2002 19:35:03 +1100, Keith Owens <kaos@sgi.com> said:
>
>  Keith> This implicitly assumes that when a fr or br register is
>  Keith> required from pt_regs, info->sp is pointing to pt_regs.  But
>  Keith> info->sp is modified as the code unwinds through each
>  Keith> function.  The above code only gives correct results for
>  Keith> register lookups from the failing function.  Unwinding and
>  Keith> accessing a fr or br register from earlier functions loads
>  Keith> incorrect values for those registers.
>
>Yes, this is something that has been fixed already in the user-level
>libunwind.  It's not hard to fix, just someone needs to get around to
>do it.  I don't think it's a critical issue, since it only happens for
>nested traps.  I assume you saw this with kdb?

How did you guess :).  I will look at libunwind and do a kernel fix.