Issue #25498: Fix GC crash due to ctypes objects wrapping a memoryview
This was a regression caused by revision 1da9630e9b7f. Based on patch by
Eryksun.
diff --git a/Lib/ctypes/test/test_frombuffer.py b/Lib/ctypes/test/test_frombuffer.py
index 6aa2d1c..86954fe 100644
--- a/Lib/ctypes/test/test_frombuffer.py
+++ b/Lib/ctypes/test/test_frombuffer.py
@@ -38,11 +38,32 @@
del a; gc.collect(); gc.collect(); gc.collect()
self.assertEqual(x[:], expected)
- with self.assertRaises(TypeError):
+ with self.assertRaisesRegex(TypeError, "not writable"):
(c_char * 16).from_buffer(b"a" * 16)
- with self.assertRaises(TypeError):
+ with self.assertRaisesRegex(TypeError, "not writable"):
+ (c_char * 16).from_buffer(memoryview(b"a" * 16))
+ with self.assertRaisesRegex(TypeError, "not C contiguous"):
+ (c_char * 16).from_buffer(memoryview(bytearray(b"a" * 16))[::-1])
+ msg = "does not have the buffer interface"
+ with self.assertRaisesRegex(TypeError, msg):
(c_char * 16).from_buffer("a" * 16)
+ def test_fortran_contiguous(self):
+ try:
+ import _testbuffer
+ except ImportError as err:
+ self.skipTest(str(err))
+ flags = _testbuffer.ND_WRITABLE | _testbuffer.ND_FORTRAN
+ array = _testbuffer.ndarray(
+ [97] * 16, format="B", shape=[4, 4], flags=flags)
+ with self.assertRaisesRegex(TypeError, "not C contiguous"):
+ (c_char * 16).from_buffer(array)
+ array = memoryview(array)
+ self.assertTrue(array.f_contiguous)
+ self.assertFalse(array.c_contiguous)
+ with self.assertRaisesRegex(TypeError, "not C contiguous"):
+ (c_char * 16).from_buffer(array)
+
def test_from_buffer_with_offset(self):
a = array.array("i", range(16))
x = (c_int * 15).from_buffer(a, sizeof(c_int))
@@ -55,6 +76,12 @@
with self.assertRaises(ValueError):
(c_int * 1).from_buffer(a, 16 * sizeof(c_int))
+ def test_from_buffer_memoryview(self):
+ a = [c_char.from_buffer(memoryview(bytearray(b'a')))]
+ a.append(a)
+ del a
+ gc.collect() # Should not crash
+
def test_from_buffer_copy(self):
a = array.array("i", range(16))
x = (c_int * 16).from_buffer_copy(a)
diff --git a/Misc/ACKS b/Misc/ACKS
index abf7304..c9d69e2 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -391,6 +391,7 @@
Stoffel Erasmus
Jürgen A. Erhard
Michael Ernst
+Eryksun
Ben Escoto
Andy Eskilsson
André Espaze
diff --git a/Misc/NEWS b/Misc/NEWS
index 4e5ea19..aacd51e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -103,6 +103,10 @@
Library
-------
+- Issue #25498: Fix a crash when garbage-collecting ctypes objects created
+ by wrapping a memoryview. This was a regression made in 3.4.3. Based
+ on patch by Eryksun.
+
- Issue #18010: Fix the pydoc web server's module search function to handle
exceptions from importing packages.
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 2e5939c..2b27ed3 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -463,45 +463,65 @@
static PyObject *
CDataType_from_buffer(PyObject *type, PyObject *args)
{
- Py_buffer buffer;
+ PyObject *obj;
+ PyObject *mv;
+ PyObject *result;
+ Py_buffer *buffer;
Py_ssize_t offset = 0;
- PyObject *result, *mv;
+
StgDictObject *dict = PyType_stgdict(type);
assert (dict);
- if (!PyArg_ParseTuple(args, "w*|n:from_buffer", &buffer, &offset))
+ if (!PyArg_ParseTuple(args, "O|n:from_buffer", &obj, &offset))
return NULL;
+ mv = PyMemoryView_FromObject(obj);
+ if (mv == NULL)
+ return NULL;
+
+ buffer = PyMemoryView_GET_BUFFER(mv);
+
+ if (buffer->readonly) {
+ PyErr_SetString(PyExc_TypeError,
+ "underlying buffer is not writable");
+ Py_DECREF(mv);
+ return NULL;
+ }
+
+ if (!PyBuffer_IsContiguous(buffer, 'C')) {
+ PyErr_SetString(PyExc_TypeError,
+ "underlying buffer is not C contiguous");
+ Py_DECREF(mv);
+ return NULL;
+ }
+
if (offset < 0) {
PyErr_SetString(PyExc_ValueError,
"offset cannot be negative");
- PyBuffer_Release(&buffer);
+ Py_DECREF(mv);
return NULL;
}
- if (dict->size > buffer.len - offset) {
+
+ if (dict->size > buffer->len - offset) {
PyErr_Format(PyExc_ValueError,
- "Buffer size too small (%zd instead of at least %zd bytes)",
- buffer.len, dict->size + offset);
- PyBuffer_Release(&buffer);
+ "Buffer size too small "
+ "(%zd instead of at least %zd bytes)",
+ buffer->len, dict->size + offset);
+ Py_DECREF(mv);
return NULL;
}
- result = PyCData_AtAddress(type, (char *)buffer.buf + offset);
+ result = PyCData_AtAddress(type, (char *)buffer->buf + offset);
if (result == NULL) {
- PyBuffer_Release(&buffer);
+ Py_DECREF(mv);
return NULL;
}
- mv = PyMemoryView_FromBuffer(&buffer);
- if (mv == NULL) {
- PyBuffer_Release(&buffer);
+ if (-1 == KeepRef((CDataObject *)result, -1, mv)) {
+ Py_DECREF(result);
return NULL;
}
- /* Hack the memoryview so that it will release the buffer. */
- ((PyMemoryViewObject *)mv)->mbuf->master.obj = buffer.obj;
- ((PyMemoryViewObject *)mv)->view.obj = buffer.obj;
- if (-1 == KeepRef((CDataObject *)result, -1, mv))
- result = NULL;
+
return result;
}