Check attributes under /sys can be read without stucking the system

Author: xanthein

providers/base/bin/check_hardware_attributes.py

@@ -0,0 +1,53 @@
+#!/bin/env python3
+import os
+import multiprocessing
+import sys
+
+
+def try_read_node(path):
+    """
+    Attempts to read a single sysfs attribute.
+    Isolated in a subprocess to protect against D-state hangs.
+    """
+    try:
+        with open(path, "r") as f:
+            # We only need the first byte to trigger the kernel 'show' function
+            f.read(1)
+    except Exception:
+        pass
+
+
+def walk_devices(base_path="/sys/devices", timeout=10.0):
+
+    # We use os.walk but skip non-device directories if necessary
+    failed = 0
+    for root, dirs, files in os.walk(base_path):
+        for name in files:
+            full_path = os.path.join(root, name)
+
+            # Skip known 'noisy' or non-hardware files to be efficient
+            if name in ["uevent", "modalias", "resource"]:
+                continue
+
+            if os.access(full_path, os.R_OK):
+                p = multiprocessing.Process(
+                    target=try_read_node, args=(full_path,)
+                )
+                p.start()
+
+                p.join(timeout)
+
+                if p.is_alive():
+                    failed = 1
+                    print(f"{full_path}")
+                    p.terminate()
+                    p.join()
+                # We stay silent on success to highlight the problem areas
+    return failed
+
+
+if __name__ == "__main__":
+    print(
+        "Scanning /sys/devices for unresponsive attributes (Timeout: 10s)..."
+    )
+    sys.exit(walk_devices())

providers/base/units/miscellanea/jobs.pxu

@@ -632,3 +632,10 @@ _steps:
     3. Boot into the recovered system without errors
 _verification:
     1. The system boots into the factory recovery system successfully.
+
+plugin: shell
+category_id: com.canonical.plainbox::miscellanea
+estimated_duration: 120.0
+id: miscellanea/check-hardware-attributes
+command: check_hardware_attributes.py
+_summary: Check that all the attributes are able to read