Re: [Libunwind-devel] use_prev_instr breaking unwind - how to stop it?

[Dave Watson]

On 03/27/17 05:36 PM, Doug Moore wrote:
> It looks like the call to tdep_fetch_frame in fetch_proc_info would determine 
> whether or not this was a signal frame, and thus whether or not we needed to 
> use the previous instruction for the lookup.
> 
> Of course, we call tdep_fetch_frame only after we’ve already tried that 
> lookup.  But perhaps some of the work done to identify signal frames could be 
> moved up a bit, so that a better decision could be made about whether or not 
> to use the previous instruction.
> 
> Does that make any sense?

But I think we need to know the IP to detect signal frames? 

My thought was that if IP-1 lookup failed, we could try IP lookup, and
if it was a signal frame, use that instead (probably with verify=1)