Re: [PATCH v3 32/51] x86/dumpstack: simplify in_exception_stack()

From: Josh Poimboeuf
Date: Mon Aug 15 2016 - 11:35:10 EST


On Sun, Aug 14, 2016 at 12:48:15AM -0700, Andy Lutomirski wrote:
> On Fri, Aug 12, 2016 at 7:28 AM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> > in_exception_stack() does some bad, bad things just so the unwinder can
> > print different values for different areas of the debug exception stack.
> >
> > There's no need to clarify where exactly on the stack it is. Just print
> > "#DB" and be done with it.
>
> I'm okay with the printing part, but you're also using this to prevent
> infinite looping. Will this cause the unwind to fail if we go debug
> -> page fault -> debug or similar?

Yes, but that behavior already existed. This patch doesn't change that;
it just makes it clearer what's going on.

--
Josh