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

From: Gavin Shan <[email-masked]>
Date: Fri, 12 Feb 2016 17:09:24 +1100

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 <[email-masked]>
>>Reported-by: Pradipta Ghosh <[email-masked]>
>>Signed-off-by: Gavin Shan <[email-masked]>
>>Tested-by: Andrew Donnellan <[email-masked]>
>
>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.

Thanks,
Gavin

>-- 
>Andrew Donnellan              Software Engineer, OzLabs
>[email-masked]  Australia Development Lab, Canberra
>+61 2 6201 8874 (work)        IBM Australia Limited