kmstest: Fix exception handling in CRCReader constructor and destructor

If an exception occurs in the CRCReader constructor, the self.dir,
self.ctrl and self.data members may not be set. This causes another
exception to be thrown by the destructor when it tries to access those
members. Fix it by initializing all the members first, and only closing
the dir and ctrl file descriptors if they have been successfully opened.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/tests/kmstest.py b/tests/kmstest.py
index 177110e..960c27f 100755
--- a/tests/kmstest.py
+++ b/tests/kmstest.py
@@ -168,17 +168,21 @@ class CRCReader(object):
 
     def __init__(self, crtc):
         self.pipe = crtc.idx
+        self.ctrl = -1
+        self.dir = -1
+        self.data = -1
 
         # Hardcode the device minor to 0 as the KMSTest constructor opens the
         # default card object.
         self.dir = os.open(f'/sys/kernel/debug/dri/0/crtc-{self.pipe}/crc', 0)
         self.ctrl = os.open('control', os.O_WRONLY, dir_fd = self.dir)
-        self.data = -1
 
     def __del__(self):
         self.stop()
-        os.close(self.ctrl)
-        os.close(self.dir)
+        if self.ctrl != -1:
+            os.close(self.ctrl)
+        if self.dir != -1:
+            os.close(self.dir)
 
     def start(self, source):
         os.write(self.ctrl, source.encode('ascii'))