Make the paged exceptions more useful at knowing how big an area is unavailable.

volatility/framework/exceptions.py

@@ -22,6 +22,17 @@ class InvalidAddressException(VolatilityException):
         self.layer_name = layer_name
 
 
+class PagedInvalidAddressException(InvalidAddressException):
+    """Thrown when an address is not valid in the paged space in which it was request
+
+    Includes the invalid address and the number of bits of the address that are invalid
+    """
+
+    def __init__(self, layer_name, invalid_address, invalid_bits, *args, **kwargs):
+        super().__init__(layer_name, invalid_address, *args, **kwargs)
+        self.invalid_bits = invalid_bits
+
+
 class SymbolSpaceError(VolatilityException):
     """Thrown when an error occurs dealing with Symbols and Symbolspaces"""
 

volatility/framework/layers/intel.py

@@ -72,8 +72,8 @@ class Intel(interfaces.layers.TranslationLayerInterface):
         for (name, size, large_page) in self._structure:
             # Check we're valid
             if not self._page_is_valid(entry):
-                raise exceptions.InvalidAddressException(self.name, offset,
-                                                         "Page Fault at entry " + hex(entry) + " in table " + name)
+                raise exceptions.PagedInvalidAddressException(self.name, offset, position + 1,
+                                                              "Page Fault at entry " + hex(entry) + " in table " + name)
             # Check if we're a large page
             if large_page and (entry & (1 << 7)):
                 # We're a large page, the rest is finished below
@@ -94,8 +94,8 @@ class Intel(interfaces.layers.TranslationLayerInterface):
 
         # Now we're done
         if not self._page_is_valid(entry):
-            raise exceptions.InvalidAddressException(self.name, offset,
-                                                     "Page Fault at entry " + hex(entry) + " in page entry")
+            raise exceptions.PagedInvalidAddressException(self.name, offset, position + 1,
+                                                          "Page Fault at entry {} in page entry".format(hex(entry)))
         page = self._mask(entry, self._maxphyaddr - 1, position + 1) | self._mask(offset, position, 0)
         return page, 1 << (position + 1)