pyudev: explicitly specify all return value and argument types (#559394)

We were relying on the ctypes behavior to default to int as return type for
all functions. But most of the functions in question are not returning int's
but pointers, which are 64 bit on s390x (and ppc64 and x86_64).

Due to the fact that we were getting virtual addresses below 4G + the C
calling conventions on x86_64 making it not matter when passing in an 32 bit
int instead of a 64 bit one, as long as the 32 bit one represent the correct
number, we got away with this on x86_64 (unfortunately really).

This patch very likely also fixes #560035.

Note I also threw in a traceback fix in the same codepath, baseudev assumes
that devices always have a DEVLINKS property, which is not true for for
example network devices.

1 files changed, 45 insertions, 16 deletions

diff --git a/pyudev.py b/pyudev.py
index 58ea074d8..1b9b6061a 100644
--- a/pyudev.py
+++ b/pyudev.py
@@ -42,30 +42,68 @@ libudev = CDLL(libudev)
 
 # create aliases for needed functions and set the return types where needed
 libudev_udev_new = libudev.udev_new
+libudev_udev_new.argtypes = []
+libudev_udev_new.restype = c_void_p
 libudev_udev_unref = libudev.udev_unref
+libudev_udev_unref.argtypes = [ c_void_p ]
 
 libudev_udev_device_new_from_syspath = libudev.udev_device_new_from_syspath
+libudev_udev_device_new_from_syspath.restype = c_void_p
+libudev_udev_device_new_from_syspath.argtypes = [ c_void_p, c_char_p ]
 libudev_udev_device_unref = libudev.udev_device_unref
+libudev_udev_device_unref.argtypes = [ c_void_p ]
 
 libudev_udev_device_get_syspath = libudev.udev_device_get_syspath
-libudev_udev_device_get_sysname = libudev.udev_device_get_sysname
 libudev_udev_device_get_syspath.restype = c_char_p
+libudev_udev_device_get_syspath.argtypes = [ c_void_p ]
+libudev_udev_device_get_sysname = libudev.udev_device_get_sysname
 libudev_udev_device_get_sysname.restype = c_char_p
+libudev_udev_device_get_sysname.argtypes = [ c_void_p ]
+libudev_udev_device_get_devpath = libudev.udev_device_get_devpath
+libudev_udev_device_get_devpath.restype = c_char_p
+libudev_udev_device_get_devpath.argtypes = [ c_void_p ]
+libudev_udev_device_get_devtype = libudev.udev_device_get_devtype
+libudev_udev_device_get_devtype.restype = c_char_p
+libudev_udev_device_get_devtype.argtypes = [ c_void_p ]
+libudev_udev_device_get_devnode = libudev.udev_device_get_devnode
+libudev_udev_device_get_devnode.restype = c_char_p
+libudev_udev_device_get_devnode.argtypes = [ c_void_p ]
+libudev_udev_device_get_subsystem = libudev.udev_device_get_subsystem
+libudev_udev_device_get_subsystem.restype = c_char_p
+libudev_udev_device_get_subsystem.argtypes = [ c_void_p ]
+libudev_udev_device_get_sysnum = libudev.udev_device_get_sysnum
+libudev_udev_device_get_sysnum.restype = c_char_p
+libudev_udev_device_get_sysnum.argtypes = [ c_void_p ]
 
 libudev_udev_device_get_properties_list_entry = libudev.udev_device_get_properties_list_entry
+libudev_udev_device_get_properties_list_entry.restype = c_void_p
+libudev_udev_device_get_properties_list_entry.argtypes = [ c_void_p ]
 libudev_udev_list_entry_get_next = libudev.udev_list_entry_get_next
+libudev_udev_list_entry_get_next.restype = c_void_p
+libudev_udev_list_entry_get_next.argtypes = [ c_void_p ]
 
 libudev_udev_list_entry_get_name = libudev.udev_list_entry_get_name
-libudev_udev_list_entry_get_value = libudev.udev_list_entry_get_value
 libudev_udev_list_entry_get_name.restype = c_char_p
+libudev_udev_list_entry_get_name.argtypes = [ c_void_p ]
+libudev_udev_list_entry_get_value = libudev.udev_list_entry_get_value
 libudev_udev_list_entry_get_value.restype = c_char_p
+libudev_udev_list_entry_get_value.argtypes = [ c_void_p ]
 
 libudev_udev_enumerate_new = libudev.udev_enumerate_new
+libudev_udev_enumerate_new.restype = c_void_p
+libudev_udev_enumerate_new.argtypes = [ c_void_p ]
 libudev_udev_enumerate_unref = libudev.udev_enumerate_unref
+libudev_udev_enumerate_unref.argtypes = [ c_void_p ]
 
 libudev_udev_enumerate_add_match_subsystem = libudev.udev_enumerate_add_match_subsystem
+libudev_udev_enumerate_add_match_subsystem.restype = c_int
+libudev_udev_enumerate_add_match_subsystem.argtypes = [ c_void_p, c_char_p ]
 libudev_udev_enumerate_scan_devices = libudev.udev_enumerate_scan_devices
+libudev_udev_enumerate_scan_devices.restype = c_int
+libudev_udev_enumerate_scan_devices.argtypes = [ c_void_p ]
 libudev_udev_enumerate_get_list_entry = libudev.udev_enumerate_get_list_entry
+libudev_udev_enumerate_get_list_entry.restype = c_void_p
+libudev_udev_enumerate_get_list_entry.argtypes = [ c_void_p ]
 
 
 class UdevDevice(dict):
@@ -113,20 +151,11 @@ class UdevDevice(dict):
             property_entry = libudev_udev_list_entry_get_next(property_entry)
 
         # set additional properties
-        libudev.udev_device_get_devpath.restype = c_char_p
-        self.devpath = libudev.udev_device_get_devpath(udev_device)
-
-        libudev.udev_device_get_subsystem.restype = c_char_p
-        self.subsystem = libudev.udev_device_get_subsystem(udev_device)
-
-        libudev.udev_device_get_devtype.restype = c_char_p
-        self.devtype = libudev.udev_device_get_devtype(udev_device)
-
-        libudev.udev_device_get_sysnum.restype = c_char_p
-        self.sysnum = libudev.udev_device_get_sysnum(udev_device)
-
-        libudev.udev_device_get_devnode.restype = c_char_p
-        self.devnode = libudev.udev_device_get_devnode(udev_device)
+        self.devpath = libudev_udev_device_get_devpath(udev_device)
+        self.subsystem = libudev_udev_device_get_subsystem(udev_device)
+        self.devtype = libudev_udev_device_get_devtype(udev_device)
+        self.sysnum = libudev_udev_device_get_sysnum(udev_device)
+        self.devnode = libudev_udev_device_get_devnode(udev_device)
 
         # cleanup
         libudev_udev_device_unref(udev_device)