powerpc/pseries: Fix oops with MSIs when missing EEH PEs

aik · ozbenh · commit bb4618823a33 · 2012-11-23T13:26:05.000+11:00
The new EEH code introduced a small regression, if the EEH PEs
are missin (which happens currently in qemu for example), it
will deref a NULL pointer in the MSI code.

Signed-off-by: Alexey Kardashevskiy &lt;aik@ozlabs.ru&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
@@ -220,7 +220,8 @@ static struct device_node *find_pe_dn(struct pci_dev *dev, int *total)
 
 	/* Get the top level device in the PE */
 	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;
