[libunwind] Re: multiple dynamic list-info addresses?

[Todd L Miller]

> To make this work, you only need to be able to check whether the
> unwind-list lock is taken.

        I guess I was thinking about restricting this functionality to
libunwind proper, but given that my implementation of
_U_dyn_register_remote() assumes the caller has the ability to do symbol
lookups already*, adding another parameter for the address of the lock
should not be problematic.  I'll try to look into this today.

> I don't know the context of your tool/application, so you're the best
> judge of that, but perhaps you could avoid linking in libunwind of you
> find that the target already has a dynamic unwind list?

        It's certainly possible.  I'll see how the above turns out.

- Todd Miller

*: Rather than try to ptrace() through /proc/pid/maps, which would have
been exceedingly painful to code and, I think, rather slow, I assume the
caller of _U_dyn_register_remote() has determined the address of
_U_dyn_info_list in the remote process on its own.