Re: [PATCH] PCI: rcar-gen2: Fix crash in resource_list_first_type()

[Rob Herring <robh@kernel.org>]

On Tue, Aug 4, 2020 at 10:22 AM Bjorn Helgaas <helgaas@kernel.org> wrote:
>
> On Tue, Aug 04, 2020 at 05:13:25PM +0100, Lorenzo Pieralisi wrote:
> > On Tue, Aug 04, 2020 at 02:04:30PM +0200, Geert Uytterhoeven wrote:
> > > The conversion to modern host bridge probing made the driver allocate
> > > its private data using devm_pci_alloc_host_bridge(), but forgot to
> > > remove the old allocation.  Hence part of the driver initialization is
> > > done using the new instance, while another part is done using the old
> > > instance, leading to a crash due to uninitialized bridge DMA ranges:
> > >
> > >     Unable to handle kernel NULL pointer dereference at virtual address 00000008
> > >     pgd = (ptrval)
> > >     [00000008] *pgd=00000000
> > >     Internal error: Oops: 5 [#1] SMP ARM
> > >     CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.8.0-rc1-shmobile-00035-g92d69cc6275845a7 #645
> > >     Hardware name: Generic R-Car Gen2 (Flattened Device Tree)
> > >     PC is at rcar_pci_probe+0x154/0x340
> > >     LR is at _raw_spin_unlock_irqrestore+0x18/0x20
> > >
> > > Fix this by dropping the old allocation.
> > >
> > > Fixes: 92d69cc6275845a7 ("PCI: rcar-gen2: Convert to use modern host bridge probe functions")
> > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > > ---
> > >  drivers/pci/controller/pci-rcar-gen2.c | 4 ----
> > >  1 file changed, 4 deletions(-)
> >
> > Squashed in the initial commit, pushed out on pci/misc.
>
> I updated my 'next' branch with this.
>
> Rob, are there any similar issues in other drivers that we should fix
> before asking Linus to pull this?

I'd expect only different issues. :)

This commit is unique as it was using the old arm32 PCI functions and
the most complicated change of the lot.

Rob