From patchwork Fri Nov 23 02:50:04 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: powerpc/pseries: Fix kernel crash caused by NULL PE Date: Thu, 22 Nov 2012 16:50:04 -0000 From: Alexey Kardashevskiy X-Patchwork-Id: 201235 Message-Id: <50AEE45C.80603@ozlabs.ru> To: Benjamin Herrenschmidt Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, David Gibson While hooking MSI interrupts, the corresponding device tree node of the PE that the PCI device has been put into should be checked. However, those PCI devices (e.g. VirtIO based PCI devices) that don't have EEH capability shouldn't have the associated PE. So we shouldn't try to get the PE's device tree node. Otherwise, it would cause kernel crash. Actually, it was introduced by commit 66523d9f ("powerpc/eeh: Trace error based on PE from beginning"). Signed-off-by: Alexey Kardashevskiy Signed-off-by: Gavin Shan --- arch/powerpc/platforms/pseries/msi.c | 11 +++++++++-- 1 files changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c index d19f497..9284e42 100644 --- a/arch/powerpc/platforms/pseries/msi.c +++ b/arch/powerpc/platforms/pseries/msi.c @@ -218,9 +218,16 @@ static struct device_node *find_pe_dn(struct pci_dev *dev, int *total) if (!dn) return NULL; - /* Get the top level device in the PE */ + /* + * Get the top level device in the PE, but some PCI devices + * without EEH capability (e.g. VirtIO based PCI devices) + * don't have the associated PE. So we should not get the + * top level device from PE for those PCI devices. + */ edev = of_node_to_eeh_dev(dn); - edev = list_first_entry(&edev->pe->edevs, struct eeh_dev, list); + if (edev->pe) + edev = list_first_entry(&edev->pe->edevs, + struct eeh_dev, list); dn = eeh_dev_to_of_node(edev); if (!dn) return NULL;