gdb in CURRENT cannot debug userland cores, when is kernel lldb coming?

[Craig Rodrigues]

Ed,

Can we enable WITH_LLDB=yes by default in
CURRENT only?  It took me a while to figure out that I needed
to build/install lldb to debug some of my coredumps in CURRENT.

I realize that things are in motion with respect to the toolchain,
but it is annoying that in CURRENT, we have a debugger in the base system
that cannot
debug userland cores properly.  I realize that things are in motion with
respect to the
toolchain, but this will help.

I really hope that the Summer of Code project to implement kernel debugging
support
for lldb reaches completion and we can finally remove our ancient gdb from
base (at least in CURRENT).

Thanks.
--
Craig



On Wed, Jun 11, 2014 at 11:53 AM, Craig Rodrigues <rodrigc at freebsd.org>
wrote:

> Hi,
>
> Recently when trying to debug some coredumps in CURRENT from
> a userland process in the devel/libvirt port, I found that the gdb in
> base could not get a backtrace from the core file:
>
>
> http://lists.freebsd.org/pipermail/freebsd-virtualization/2014-June/002606.html
>
> I needed to add to my /etc/src.conf WITH_LLDB=yes
> and compile and install lldb, which *could* analyze the coredump.
>
> I realize that gdb in base is on its way out the door, and that
> clang and lldb are the new world order.  However, one of the
> main blockers for removing gdb from base is that
> there is no equivalent to kgdb in the lldb world.
>
> Is anyone working on a kernel lldb?  When is it expected to be ready?
> Will something like it be ready by end of 2014?
>
> Even though this may not be an issue in the stable/10 branch,
> it would be nice to have a kernel lldb debugger ready by
> the next 10.1R if possible.
>
> --
> Craig
>