Re: Regression for duplicate (?) console parameters on next-20220630

[Michael Walle]

Am 2022-06-30 21:35, schrieb Nathan Chancellor:
> On Thu, Jun 30, 2022 at 03:11:58PM +0200, Michael Walle wrote:
> > Hi,
> >
> > I'm not sure it these are the correct recipients, feel free to CC 
> > others.
> >
> > Since next-20220630 (or maybe also since next-20220629) I'm getting 
> > the
> >
> > [    3.707900] WARNING: CPU: 0 PID: 38 at fs/kernfs/dir.c:531
> > kernfs_put.part.0+0x1a0/0x1d4
> > [    3.716313] kernfs_put: console/active: released with incorrect
> > active_ref 0
> >
> > on both arm and arm64 boards. See for example:
> > https://linux.kernelci.org/test/case/id/62bd840b330c4851eaa39c16/
> >
> > I have the console set in the device tree as well as on the 
> > commandline.
> > Up until recently that wasn't a problem and I guess that should be a 
> > valid
> > configuration. That being said, the warn() will go away if I remove 
> > the
> > console= parameter on the commandline.
> >
> > I haven't had time to do a bisect yet. That will probably my next 
> > step;
> > or maybe kernelci will already do that for me, Guillaume? Unless 
> > someone
> > has some more insights/ideas.
>
> I noticed this as well when booting ARCH=um defconfig.
>
> I ended up doing a bisect against next-20220630 and I landed on the
> driver-core merge (5732b42edfd18ee888e127fa13d425ed3ed1bef3). I did two
> more bisects to figure out that there is some sort of contextual
> contlict between commit 5831788afb17 ("Revert "printk: add kthread
> console printers"") and commit b8f35fa1188b ("kernfs: Change
> kernfs_notify_list to llist."), as it is only when those two changes 
> are
> present that this issue occurs. I am happy to provide more information
> if necessary.

Thanks for the info.

I can confirm that reverting b8f35fa1188b will fix the error. I couldn't
revert 5831788afb17 though, didn't apply cleanly.

-michael