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Re: Problems with _Unwind_Backtrace() vs signal handlers
Bryce McKinlay wrote:
> I don't think Linux uses MD_FALLBACK_FRAME_STATE_FOR any more, at least
> on the i686/ppc/x86-64 targets which I checked. Instead, my
> understanding is that glibc now provides the unwind info for its signal
> handler frames.
>
> So, it could be a bug in glibc's unwind info, but from what I can tell,
> throwing exceptions through the signal frames appears to be working fine
> - this is why I suspect a problem with _Unwind_Backtrace().
I have a related general question. I'm trying to learn about the
situation with unwinding on GCC. Is there a general overview of the
entire process availible somewhere? How can I get up to speed so I know
all about the _Unwind_ functions and how Dwarf2 exceptions work, etc?
In particular, what mechanism GCC use to get information directly from
glibc rather than MD_FALLBACK_FRAME_STATE_FOR?
Who exactly is responsible for providing misc. unwind functions, and
where are they documented? I notice all of libgcc, glibc, and sometimes
libunwind are providing some sort of information, but I can't figure out
who is responsible for what.
Thanks for any hints or pointers,
Aaron W. LaFramboise