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

[Benno Schulenberg]

On Mon, Oct 17, 2016, at 12:35, Darren Austin wrote:
> On Sun, 16 Oct 2016, Benno Schulenberg wrote:
> > 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.

Okay.  So it is something very basic that triggers the panic
-- nothing fancy like locking or libmagic or anything.

> > If it panics, then run
> >   git bisect reset
> >   git bisect start
> >   git bisect bad
> >   git checkout 162d534f  &&  make
> > and try your recipe again.
> 
> 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.

Something you could also try: reduce the NFS options to the
absolute bare minimum that you need for the thing to be usable,
and then see if the panic still occurs.

> At this point I stopped per instructions.

Good.  If you're still at the 162d534f checkout, mark
it as bad with 'git bisect bad' and then run:
  git checkout 544c56c0  &&  make

(If the make fails, change "@sp4" to "@sp 4" in
doc/texinfo/nano.texi.  Newer makeinfos don't like
the unspaced version of that command.  Then run
make again.)

Then see if this version (essentially 2.2.5) also triggers
the panic.  If it does, stop.  If it doesn't, continue bisecting.

(If after some checkout and make, git refuses to move to
another checkout because some file has changed, run
'git reset --hard master' first.)

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

Why "poor Mac"?  Think of it as allowing your Mac some relief
from the everyday tedium of doing everything perfectly.  :)
A kernel panic is to a Mac what a bungee jump is to you.  :)

> Let me know if I can help further.

I would try stracing nano to try and find precisely what
action of nano triggers the panic.  But I don't know how
to force strace to write the log synchronically so everything
before the panic will be on disk.

Benno

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