linux/pci_back: fix NULL pointer ref.

pcistub_device_release() can be called during
initialization. Thus pci_get_drvdata() can return NULL.
Fix it by inserting NULL check.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>

diff --git a/drivers/xen/pciback/conf_space.c b/drivers/xen/pciback/conf_space.c
index 0c4dd49067bf4f86c3862d91451481745750c2b6..0c76db1d5aed70530ff9010b97cc1593742d5b96 100644 (file)
--- a/drivers/xen/pciback/conf_space.c
+++ b/drivers/xen/pciback/conf_space.c
@@ -297,6 +297,8 @@ void pciback_config_free_dyn_fields(struct pci_dev *dev)
 
        dev_dbg(&dev->dev,
                "free-ing dynamically allocated virtual configuration space fields\n");
+       if (!dev_data)
+               return;
 
        list_for_each_entry_safe(cfg_entry, t, &dev_data->config_fields, list) {
                field = cfg_entry->field;
@@ -321,6 +323,8 @@ void pciback_config_reset_dev(struct pci_dev *dev)
        const struct config_field *field;
 
        dev_dbg(&dev->dev, "resetting virtual configuration space\n");
+       if (!dev_data)
+               return;
 
        list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
                field = cfg_entry->field;
@@ -337,6 +341,8 @@ void pciback_config_free_dev(struct pci_dev *dev)
        const struct config_field *field;
 
        dev_dbg(&dev->dev, "free-ing virtual configuration space fields\n");
+       if (!dev_data)
+               return;
 
        list_for_each_entry_safe(cfg_entry, t, &dev_data->config_fields, list) {
                list_del(&cfg_entry->list);