ACPI: fix single linked list manipulation

Fix single linked list manipulation for sub_driver.  If the remving entry
is not on the head of the sub_driver list, it goes into infinate loop.

Though that infinite loop doesn't happen.  Because the only user of
acpi_pci_register_dirver() is acpiphp.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 0984a1ee24ed..c92c144d6c58 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -98,11 +98,12 @@ void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
 
         struct acpi_pci_driver **pptr = &sub_driver;
         while (*pptr) {
-                if (*pptr != driver)
-                        continue;
-                *pptr = (*pptr)->next;
-                break;
+                if (*pptr == driver)
+                        break;
+                pptr = &(*pptr)->next;
         }
+        BUG_ON(!*pptr);
+        *pptr = (*pptr)->next;
 
         if (!driver->remove)
                 return;