[PATCH v2 2/4] powerpc/powernv: Fix stale PE primary bus

[Gavin Shan]

On Mon, Feb 15, 2016 at 09:38:35PM +1100, Michael Ellerman wrote:
>On Fri, 2016-02-12 at 17:09 +1100, Gavin Shan wrote:
>
>> On Fri, Feb 12, 2016 at 05:02:46PM +1100, Andrew Donnellan wrote:
>
>> > On 09/02/16 15:50, Gavin Shan wrote:
>
>> > > When PCI bus is unplugged during full hotplug for EEH recovery,
>> > > the platform PE instance (struct pnv_ioda_pe) isn't released and
>> > > it dereferences the stale PCI bus that has been released. It leads
>> > > to kernel crash when referring to the stale PCI bus.
>> > > 
>> > > This fixes the issue by correcting the PE's primary bus when it's
>> > > oneline at plugging time, in pnv_pci_dma_bus_setup() which is to
>> > > be called by pcibios_fixup_bus().
>> > > 
>> > > Reported-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
>> > > Reported-by: Pradipta Ghosh <pradghos at in.ibm.com>
>> > > Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
>> > > Tested-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
>> > 
>> > I realise this has already been merged, but the following was found by
>> > Coverity:
>> > 
>
>> > > +void pnv_pci_dma_bus_setup(struct pci_bus *bus)
>> > > +{
>> > > +	struct pci_controller *hose = bus->sysdata;
>> > > +	struct pnv_phb *phb = hose->private_data;
>> > > +	struct pnv_ioda_pe *pe;
>> > > +
>> > > +	list_for_each_entry(pe, &phb->ioda.pe_list, list) {
>> > > +		if (!(pe->flags | (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL)))
>> > > +			continue;
>> > 
>> > This condition is always false. I think the first "|" is supposed to be "&".
>> > 
>> 
>> Yeah, that should be "&". I think the problem isn't found when doing
>> testing in non-SRIOV environment. Thanks for pointing it out.
>> 
>> Michael, please let me know if I need send a follow-up revision to
>> correct this one? I found the first two patches have been put into
>> linux-next branch. I think we probably just need repost the correct
>> version for this one only.
>
>As it happens I needed to rebase my fixes branch anyway, so I've updated it and
>rebased. No further action required :)
>

Thanks Michael. Sorry for the rebase :-)

Thanks,
Gavin