Re: Kernel panic : Unable to handle kernel paging request at virtual address - dead address between user and kernel address ranges

From: Naresh Kamboju
Date: Fri Aug 28 2020 - 05:23:02 EST


On Thu, 27 Aug 2020 at 17:06, Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> wrote:
>
> On Thu, 27 Aug 2020 at 15:42, Viresh Kumar <viresh.kumar@xxxxxxxxxx> wrote:
> >
> > On 27-08-20, 11:48, Arnd Bergmann wrote:
> > > > > [ 3.680477] dev_pm_opp_put_clkname+0x30/0x58
> > > > > [ 3.683431] sdhci_msm_probe+0x284/0x9a0
> > >
> > > dev_pm_opp_put_clkname() is part of the error handling in the
> > > probe function, so I would deduct there are two problems:
> > >
> > > - something failed during the probe and the driver is trying
> > > to unwind
> > > - the error handling it self is buggy and tries to undo something
> > > again that has already been undone.
> >
> > Right.
> >
> > > This points to Viresh's
> > > d05a7238fe1c mmc: sdhci-msm: Unconditionally call dev_pm_opp_of_remove_table()
> >
> > I completely forgot that Ulf already pushed this patch and I was
> > wondering on which of the OPP core changes I wrote have done this :(
> >
> > > Most likely this is not the entire problem but it uncovered a preexisting
> > > bug.
> >
> > I think this is.
> >
> > Naresh: Can you please test with this diff ?
>
> I have applied your patch and tested but still see the reported problem.

The git bisect shows that the first bad commit is,
d05a7238fe1c mmc: sdhci-msm: Unconditionally call dev_pm_opp_of_remove_table()

Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx>
Reported-by: Anders Roxell <anders.roxell@xxxxxxxxxx>

>
> - Naresh