Expand objdump DLX ASLR delta coverage

objdump-dlx-calc-poc/tools/aslr_delta_coverage.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+from collections import Counter
+
+
+STDERR = 0x2044E0
+SYSTEM = 0x58750
+PAGE = 0x1000
+
+
+def be_from_le32(value):
+    return int.from_bytes((value & 0xFFFFFFFF).to_bytes(4, "little"), "big")
+
+
+def delta_for_base(base):
+    src = be_from_le32((base + STDERR) & 0xFFFFFFFF)
+    dst = be_from_le32((base + SYSTEM) & 0xFFFFFFFF)
+    return (dst - src) & 0xFFFFFFFF
+
+
+def main():
+    counts = Counter(delta_for_base(base) for base in range(0, 1 << 32, PAGE))
+    total = sum(counts.values())
+    covered = 0
+    for delta, count in counts.most_common():
+        covered += count
+        print(f"0x{delta:08x} pages={count} coverage={count / total:.6f} cumulative={covered / total:.6f}")
+    print(f"unique={len(counts)} total_pages={total}")
+
+
+if __name__ == "__main__":
+    main()