Re: [Nano-devel] Kernel panic on Ubuntu 1610 with NFS - nano specific

[Darren Austin]

On Sun, 16 Oct 2016, Benno Schulenberg wrote:
> Okay.  During further testing keep using --ignore.

Gotchya.  But just to be sure, I mv'd .nanorc and /etc/nanorc out of the 
way.

> But to be clear: you have found a bug in the kernel, not in
> nano.  No matter what nano does, it should be *impossible*
> for it to bring down the kernel.  The kernel may kill nano
> (if nano does something entirely stupid), but the other way
> around is a capital fault in the kernel.

I figured it might be a bug in the kernel, but wanted to report it here as 
it was nano that triggered it.  And, as you say, a userspace application 
shouldn't be able to bring down the kernel.

> Before bisecting, and after ./autogen.sh, first run
>   ./configure && make
> and then run 'src/nano --ignore ...' and follow your
> reproduction recipe.  If that causes a panic, then run
>   ./configure --enable-tiny && make
> and try your recipe again.

Both of these tests caused the panic.

> If it does cause a panic, then run
>   git checkout 8edb0968
>   ./configure  &&  make
> and try your recipe (always using src/nano --ignore).

It bombed out again.

> If it panics, then run
>   git bisect reset
>   git bisect start
>   git bisect bad
>   git checkout 162d534f  &&  make
> and try your recipe again.
> This checkout should not panic, as it equals the 2.5.3 version
> of nano that runs on Ubuntu 16.04.  If, however, it /does/
> panic, you can stop here.

It paniced again - even on the 1604 version.  But it definiately wasn't 
doing this on 1604 when I was running it under exactly the same NFS 
export/mount situation.

At this point I stopped per instructions.

My poor Mac has taken quite a few panics over this bug now!

Let me know if I can help further.

Darren.