[PATCH] PCI Hotplug: dereference null variable cleanup patches.

These were pointed out by "dan carpenter" <error27@email.com>
from his smatch tool.

drivers/hotplug/cpci_hotplug_pci.c

@@ -395,6 +395,8 @@ static int cpci_configure_bridge(struct pci_bus* bus, struct pci_dev* dev)
 	/* Scan behind bridge */
 	n = pci_scan_bridge(bus, dev, max, 2);
 	child = pci_find_bus(max + 1);
+	if (!child)
+		return -ENODEV;
 #ifdef CONFIG_PROC_FS
 	pci_proc_attach_bus(child);
 #endif

drivers/hotplug/cpqphp_core.c

@@ -488,6 +488,8 @@ static int get_slot_mapping (struct pci_bus *bus, u8 bus_num, u8 dev_num, u8 *sl
 	bridgeSlot = 0xFF;
 
 	PCIIRQRoutingInfoLength = pcibios_get_irq_routing_table();
+	if (!PCIIRQRoutingInfoLength)
+		return -1;
 
 	len = (PCIIRQRoutingInfoLength->size -
 	       sizeof(struct irq_routing_table)) / sizeof(struct irq_info);

drivers/hotplug/cpqphp_ctrl.c

@@ -188,6 +188,8 @@ static u8 handle_presence_change(u16 change, struct controller * ctrl)
 			rc++;
 
 			p_slot = find_slot(ctrl, hp_slot + (readb(ctrl->hpc_reg + SLOT_MASK) >> 4));
+			if (!p_slot)
+				return 0;
 
 			// If the switch closed, must be a button
 			// If not in button mode, nevermind
@@ -1799,8 +1801,12 @@ static void interrupt_event_handler(struct controller *ctrl)
 				hp_slot = ctrl->event_queue[loop].hp_slot;
 
 				func = cpqhp_slot_find(ctrl->bus, (hp_slot + ctrl->slot_device_offset), 0);
+				if (!func)
+					return;
 
 				p_slot = find_slot(ctrl, hp_slot + ctrl->slot_device_offset);
+				if (!p_slot)
+					return;
 
 				dbg("hp_slot %d, func %p, p_slot %p\n",
 				    hp_slot, func, p_slot);
@@ -2511,8 +2517,14 @@ static int configure_new_function (struct controller * ctrl, struct pci_func * f
 		// Setup the IO, memory, and prefetchable windows
 
 		io_node = get_max_resource(&(resources->io_head), 0x1000);
+		if (!io_node)
+			return -ENOMEM;
 		mem_node = get_max_resource(&(resources->mem_head), 0x100000);
+		if (!mem_node)
+			return -ENOMEM;
 		p_mem_node = get_max_resource(&(resources->p_mem_head), 0x100000);
+		if (!p_mem_node)
+			return -ENOMEM;
 		dbg("Setup the IO, memory, and prefetchable windows\n");
 		dbg("io_node\n");
 		dbg("(base, len, next) (%x, %x, %p)\n", io_node->base, io_node->length, io_node->next);

drivers/hotplug/cpqphp_pci.c

@@ -435,6 +435,8 @@ static int PCI_GetBusDevHelper(struct controller *ctrl, u8 *bus_num, u8 *dev_num
 	u8 tbus, tdevice, tslot;
 
 	PCIIRQRoutingInfoLength = pcibios_get_irq_routing_table();
+	if (!PCIIRQRoutingInfoLength)
+		return -1;
 
 	len = (PCIIRQRoutingInfoLength->size -
 	       sizeof(struct irq_routing_table)) / sizeof(struct irq_info);

drivers/hotplug/cpqphp_proc.c

@@ -113,6 +113,8 @@ static int read_dev (char *buf, char **start, off_t offset, int len, int *eof, v
 
 	while (slot) {
 		new_slot = cpqhp_slot_find(slot->bus, slot->device, 0);
+		if (!new_slot)
+			break;
 		out += sprintf(out, "assigned resources: memory\n");
 		index = 11;
 		res = new_slot->mem_head;

drivers/hotplug/ibmphp_core.c

@@ -1057,6 +1057,8 @@ static int ibm_configure_device (struct pci_func *func)
 
 	if (func->dev == NULL) {
 		dev0.bus = ibmphp_find_bus (func->busno);
+		if (!dev0.bus)
+			return 0;
 		dev0.devfn = ((func->device << 3) + (func->function & 0x7));
 		dev0.sysdata = dev0.bus->sysdata;
 
@@ -1097,6 +1099,8 @@ static int is_bus_empty (struct slot * slot_cur)
 			continue;
 		}
 		tmp_slot = ibmphp_get_slot_from_physical_num (i);
+		if (!tmp_slot)
+			return 0;
 		rc = slot_update (&tmp_slot);
 		if (rc)
 			return 0;
@@ -1219,6 +1223,8 @@ static int check_limitations (struct slot *slot_cur)
 
 	for (i = slot_cur->bus_on->slot_min; i <= slot_cur->bus_on->slot_max; i++) {
 		tmp_slot = ibmphp_get_slot_from_physical_num (i);
+		if (!tmp_slot)
+			return -ENODEV;
 		if ((SLOT_PWRGD (tmp_slot->status)) && !(SLOT_CONNECT (tmp_slot->status))) 
 			count++;
 	}