Re: [Libunwind-devel] [RFC][patch] Fix crash in _ULx86_64_tdep_trace when sigaltstack is too far away

[Paul Pluzhnikov]

On Fri, Nov 11, 2011 at 9:46 AM, Lassi Tuura <address@hidden> wrote:
> Hi,
>
>>> I don't see any major disadvantages for fix 3.
>
> On second thought... The frame info recorded needs to be cacheable by %rip,
> and will be reused purely by %rip regardless of stack layout.
>
> If we are recording the real sigcontext_t address, will that still work?
> The original format hoped to be cacheable by recording only a delta from
> the current CFA so it's not dependent on actual stack location - not so
> good an idea with alt stacks as you noticed.

Ah, I see. But we could record delta here as well; just use 62 bits for it.

I'll update the patch shortly.

Thanks!
-- 
Paul Pluzhnikov