Stack unwinding for green threads

[Botond Dénes]

On Mon, 2020-07-06 at 12:48 -0500, Christian Biesinger wrote:
> On Fri, Jul 3, 2020 at 4:51 AM Botond Dénes <bdenes@scylladb.com>
> wrote:
> > Hi,
> > 
> > I'm working on Scylla [1], an application which is built using the
> > seastar framework [2]. This framework provides green threads [3]
> > that
> > have their own stacks. These threads are created with
> > `setcontext()`
> > and later we switch in/out using `setjmp()`/`longjmp()`.
> > 
> > We have a collection of python scripts [4] to help debug Scylla,
> > among
> > these we have a utility command which allows switching in/out of
> > these
> > green threads in gdb. This command basically (tries) to emulate
> > `setjmp()`/`longjmp()` in python, saving and restoring registers.
> > There
> > are several problems with this method. For starters it crashes gdb
> > for
> > some time now
> 
> It may be worth filing a bug for that at
> https://sourceware.org/bugzilla/, crashing GDB sounds like a bug.


We see a lot of crashes of GDB at ScyllaDB. Yes, I should get into the
habit of reporting these.

> 
> Christian