Add smoke test ensuring we can attach to /proc/vmcore

Signed-off-by: Kevin Svetlitski <[email protected]>

Author: Svetlitski

setup.py

@@ -196,9 +196,11 @@ def _run_vm(self, kernel_dir):
 else
     DRGN_RUN_LINUX_HELPER_TESTS=1 "$PYTHON" -Bm \
         unittest discover -t . -s tests/helpers/linux {"-v" if self.verbose else ""}
-    "$PYTHON" vmtest/enter_kdump.py
-    # We should crash and not reach this.
-    exit 1
+    if "$BUSYBOX" [ -n "$crashkernel" ]; then
+        "$PYTHON" vmtest/enter_kdump.py
+        # We should crash and not reach this.
+        exit 1
+    fi
 fi
 """
         try:

tests/linux_kernel/vmcore/test_dummy.py

@@ -0,0 +1,14 @@
+from pathlib import Path
+import unittest
+
+from drgn import Program
+
+VMCORE_PATH = Path("/proc/vmcore")
+
+
+@unittest.skipUnless(VMCORE_PATH.exists(), "not running in kdump")
+class TestAttachToVMCore(unittest.TestCase):
+    def test_attach_to_vmcore(self):
+        prog = Program()
+        prog.set_core_dump("/proc/vmcore")
+        prog.load_debug_info("", default=True, main=True)

tests/linux_kernel/vmcore/test_vmcore.py

@@ -19,6 +19,9 @@
 with open("/proc/cmdline", "rb") as f:
     cmdline = f.read().rstrip(b"\n")
     cmdline = re.sub(rb"(^|\s)crashkernel=\S+", b"", cmdline)
+    # `nosmp` is required to avoid QEMU sporadically failing an internal assertion
+    # `nokaslr` is required to avoid sporadically failing to reserve space for the
+    # capture kernel
     cmdline += b" nosmp nokaslr"
 
 with open(f"/lib/modules/{os.uname().release}/vmlinuz", "rb") as kernel: