x86-64: support Constant objects (apply relocations) in ExecutableFun…

…ction
Maratyszcza · Sep 21, 2015 · 584ec3d · 584ec3d
1 parent 4799cc9
commit 584ec3d
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Showing 2 changed files with 31 additions and 2 deletions.
diff --git a/peachpy/loader.py b/peachpy/loader.py
@@ -135,6 +135,12 @@ def _nacl_copy_code(self, code_segment):
         code_offset = 0
         self.allocation.dyncode_create(code_segment, code_offset)
 
+    def copy_data(self, data_segment):
+        import ctypes
+        ctypes.memmove(self.data_address,
+                       ctypes.c_char_p(bytes(data_segment)),
+                       len(data_segment))
+
     def __del__(self):
         if self._release_memory is not None:
             if self.code_address is not None:

diff --git a/peachpy/x86_64/function.py b/peachpy/x86_64/function.py
@@ -1852,11 +1852,34 @@ def __init__(self, function):
             raise ValueError("Function ABI (%s) does not match process ABI (%s)" %
                              (str(function.abi), str(process_abi)))
 
-        self.code_segment = function.code_section.content
+        self.code_segment = bytearray(function.code_section.content)
+        self.const_segment = bytearray(function.const_section.content)
 
         import peachpy.loader
-        self.loader = peachpy.loader.Loader(len(self.code_segment))
+        self.loader = peachpy.loader.Loader(len(self.code_segment), len(self.const_segment))
+
+        # Apply relocations
+        from peachpy.x86_64.meta import RelocationType
+        from peachpy.util import is_sint32
+        for relocation in function.code_section.relocations:
+            assert relocation.type == RelocationType.rip_disp32
+            assert relocation.symbol in function.const_section.symbols
+            old_value = self.code_segment[relocation.offset] | \
+                (self.code_segment[relocation.offset + 1] << 8) | \
+                (self.code_segment[relocation.offset + 2] << 16) | \
+                (self.code_segment[relocation.offset + 3] << 24)
+            new_value = old_value + \
+                (self.loader.data_address + relocation.symbol.offset) - \
+                (self.loader.code_address + relocation.offset + 4)
+            assert is_sint32(new_value)
+            self.code_segment[relocation.offset] = new_value & 0xFF
+            self.code_segment[relocation.offset + 1] = (new_value >> 8) & 0xFF
+            self.code_segment[relocation.offset + 2] = (new_value >> 16) & 0xFF
+            self.code_segment[relocation.offset + 3] = (new_value >> 24) & 0xFF
+        assert not function.const_section.relocations
+
         self.loader.copy_code(self.code_segment)
+        self.loader.copy_data(self.const_segment)
 
         import ctypes
         result_type = None if function.result_type is None else function.result_type.as_ctypes_type