Boot error with OpenZFS

[Mark Johnston]

On Tue, Sep 08, 2020 at 07:24:38PM +0200, Guido Falsi wrote:
> On 08/09/20 10:01, Guido Falsi wrote:
> > Hi,
> > 
> > I'm trying to update to recent head, but I can't boot my system with the
> > compiled kernel.
> > 
> > The system has ZFS on root and was working with previous kernel (before
> > OpenZFS migration).
> > 
> > I'm trying to boot r365437.
> > 
> > I load zfs from loader with zfs_load="YES" as usual and get this error
> > message at the start of kernel output:
> > 
> > link_elf_obj: symbol lockstat_enabled undefined
> > KLD file zfs.ko - could not finalize loading
> > 
> > The zfs.ko file is aligned with the kernel and I did not observe errors
> > while compiling.
> > 
> > I am able to make the machine using the kernel from the most recent head
> > snapshot on ftp.freebsd.org [1]. I'm also going to try with a kernel
> > with debug symbols and one with GENERIC config.
> 
> A locally built GENERIC works fine, so this is my fault. I clearly have
> something wrong in my kernel config.
> 
> I'll report anyway as soon as I discover what it is.

Can you verify that adding "options KDTRACE_HOOKS" fixes the problem?  I
note that the zfs.ko Makefile has -DKTRACE_HOOKS in CFLAGS, among a few
other surprising things.