Re: [Libunwind-devel] Question about memory references

[Arun Sharma]

On Wed, Oct 10, 2012 at 9:21 AM, Harald Servat <address@hidden> wrote:
> Hello list,
>
>   I was wondering whether in the recent development of libunwind if the
> library gives the possibility to know which is the effective address
> that is being accessed in a sighandler (not the Program Counter itself,
> but the memory referenced, if the PC pointed to a Load/Store op). Or if
> this functionality is out of the scope of libunwind and must be done
> through other libraries/tools (and if any, do you have any clue?).

I'd say this is out of the scope of libunwind. A couple of suggestions:

* SA_SIGINFO can provide the faulting address for some signals
* PEBS/IBS on x86 CPUs have this capability (as a profiling tool).
Relevant patches have been posted multiple times on linux-kernel, but
haven't made it to mainline yet.
* If nothing else works, you could try to use a x86 instruction
decoder and compute the effective address by interpreting the
instruction.

 -Arun