PCI: make duplicate devfn allocation fatal

Only two callers of pci_create_simple/pci_register_device bothered
to check the return value. Other cases were prone to crashing with
spurious NULL pointer dereferences.

Make QEMU exit with an error message when devfn is attempted to
be duplicated, also applies to case when the bus is full. Remove
checks.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

2 files changed, 3 insertions, 5 deletions

diff --git a/hw/openpic.c b/hw/openpic.c
index 68af9c1..42db59d 100644
--- a/hw/openpic.c
+++ b/hw/openpic.c
@@ -1202,8 +1202,6 @@ qemu_irq *openpic_init (PCIBus *bus, int *pmem_index, int nb_cpus,
     if (bus) {
         opp = (openpic_t *)pci_register_device(bus, "OpenPIC", sizeof(openpic_t),
                                                -1, NULL, NULL);
-        if (opp == NULL)
-            return NULL;
         pci_conf = opp->pci_dev.config;
         pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_IBM);
         pci_config_set_device_id(pci_conf, PCI_DEVICE_ID_IBM_OPENPIC2);
diff --git a/hw/pci.c b/hw/pci.c
index 6864339..5b3461c 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -499,10 +499,11 @@ static PCIDevice *do_pci_register_device(PCIDevice *pci_dev, PCIBus *bus,
             if (!bus->devices[devfn])
                 goto found;
         }
-        return NULL;
+        hw_error("PCI: no devfn available for %s, all in use\n", name);
     found: ;
     } else if (bus->devices[devfn]) {
-        return NULL;
+        hw_error("PCI: devfn %d not available for %s, in use by %s\n", devfn,
+                 name, bus->devices[devfn]->name);
     }
     pci_dev->bus = bus;
     pci_dev->devfn = devfn;
@@ -1273,7 +1274,6 @@ static int pci_qdev_init(DeviceState *qdev, DeviceInfo *base)
     pci_dev = do_pci_register_device(pci_dev, bus, base->name, devfn,
                                      info->config_read, info->config_write,
                                      info->header_type);
-    assert(pci_dev);
     rc = info->init(pci_dev);
     if (rc != 0)
         return rc;