Merge pull request #42 from cupy/avoid-invalid-pointer-arithmetic

Avoid adding non-zero offset to zero-pointer
cupy · May 23, 2017 · bd2e0d7 · bd2e0d7
2 parents 8d7546c + bf1fe44
commit bd2e0d7
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Showing 3 changed files with 16 additions and 3 deletions.
diff --git a/cupy/core/core.pyx b/cupy/core/core.pyx
@@ -1222,10 +1222,16 @@ cdef class ndarray:
                 else:
                     dim = (s_stop - s_start + 1) // s_step + 1
 
+                if dim == 0:
+                    strides.push_back(self._strides[j])
+                else:
+                    strides.push_back(self._strides[j] * s_step)
+
+                if self.size > 0:
+                    offset += self._strides[j] * max(0, s_start)
+
                 shape.push_back(dim)
-                strides.push_back(self._strides[j] * s_step)
 
-                offset += max(0, s_start) * self._strides[j]
                 j += 1
             elif numpy.isscalar(s):
                 ind = int(s)
@@ -1235,7 +1241,8 @@ cdef class ndarray:
                     msg = ('Index %s is out of bounds for axis %s with '
                            'size %s' % (s, j, self._shape[j]))
                     raise IndexError(msg)
-                offset += ind * self._strides[j]
+                if self.size > 0:
+                    offset += ind * self._strides[j]
                 j += 1
             else:
                 raise TypeError('Invalid index type: %s' % type(slices[i]))

diff --git a/cupy/cuda/memory.pyx b/cupy/cuda/memory.pyx
@@ -83,6 +83,7 @@ cdef class MemoryPointer:
     """
 
     def __init__(self, mem, Py_ssize_t offset):
+        assert mem.ptr > 0 or offset == 0
         self.mem = mem
         self.device = mem.device
         self.ptr = mem.ptr + offset
@@ -101,11 +102,13 @@ cdef class MemoryPointer:
         else:
             self = <MemoryPointer?>y
             offset = <Py_ssize_t?>x
+        assert self.ptr > 0 or offset == 0
         return MemoryPointer(self.mem,
                              self.ptr - self.mem.ptr + offset)
 
     def __iadd__(self, Py_ssize_t offset):
         """Adds an offset to the pointer in place."""
+        assert self.ptr > 0 or offset == 0
         self.ptr += offset
         return self
 

diff --git a/tests/cupy_tests/core_tests/test_ndarray_indexing.py b/tests/cupy_tests/core_tests/test_ndarray_indexing.py
@@ -66,6 +66,9 @@
      'indexes': (None, slice(None, None, -1))},
     {'shape': (1, 0, 1), 'transpose': None,
      'indexes': (None, slice(None, None, -1), None)},
+    #
+    {'shape': (2, 0), 'transpose': None,
+     'indexes': (1, slice(None, None, None))},
 )
 @testing.gpu
 class TestArrayIndexingParameterized(unittest.TestCase):