[rfc] Fix broken i386 signal unwinding (Re: graceful unwind termination when we'd need unavailable/uncollect memory or regis

[Ulrich Weigand]

Pedro Alves wrote:
> On Thursday 31 March 2011 14:57:51, Ulrich Weigand wrote:
> > It seems this change broke unwinding out of signal trampoline
> > frames on i386 for me.  In this case, neither SAVED_SP nor
> > SAVED_SP_REG is set; instead, SP is supposed to be unwound
> > from memory (the trampoline stack frame) via SAVED_REGS.
> > 
> > However, after your change, we now fall into the _got_constant
> > case and SP is always unwound as 0.
> > 
> > The following patch fixes this for me, and gets about 50 test
> > cases back to PASS.
> > 
> > Does this look right to you?
> 
> Yes it does.  Thanks much for tracking and fixing it.

OK, I've checked this in now.

Thanks,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com