Fail if PyMem_Malloc() is called without holding the GIL
Issue #26563: Debug hooks on Python memory allocators now raise a fatal error
if functions of the PyMem_Malloc() family are called without holding the GIL.
diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index 8e6245b..8f4836a 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -602,15 +602,24 @@
regex = regex.format(ptr=self.PTR_REGEX)
self.assertRegex(out, regex)
- def test_pyobject_malloc_without_gil(self):
- # Calling PyObject_Malloc() without holding the GIL must raise an
- # error in debug mode.
- code = 'import _testcapi; _testcapi.pyobject_malloc_without_gil()'
+ def check_malloc_without_gil(self, code):
out = self.check(code)
expected = ('Fatal Python error: Python memory allocator called '
'without holding the GIL')
self.assertIn(expected, out)
+ def test_pymem_malloc_without_gil(self):
+ # Debug hooks must raise an error if PyMem_Malloc() is called
+ # without holding the GIL
+ code = 'import _testcapi; _testcapi.pymem_malloc_without_gil()'
+ self.check_malloc_without_gil(code)
+
+ def test_pyobject_malloc_without_gil(self):
+ # Debug hooks must raise an error if PyObject_Malloc() is called
+ # without holding the GIL
+ code = 'import _testcapi; _testcapi.pyobject_malloc_without_gil()'
+ self.check_malloc_without_gil(code)
+
class PyMemMallocDebugTests(PyMemDebugTests):
PYTHONMALLOC = 'malloc_debug'
diff --git a/Misc/NEWS b/Misc/NEWS
index 7f93b2b..adfa04b 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,10 @@
Core and Builtins
-----------------
+- Issue #26563: Debug hooks on Python memory allocators now raise a fatal
+ error if functions of the :c:func:`PyMem_Malloc` family are called without
+ holding the GIL.
+
- Issue #26564: On error, the debug hooks on Python memory allocators now use
the :mod:`tracemalloc` module to get the traceback where a memory block was
allocated.
diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index b3d8818..0fc7cbc 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -3644,10 +3644,28 @@
}
static PyObject*
+pymem_malloc_without_gil(PyObject *self, PyObject *args)
+{
+ char *buffer;
+
+ /* Deliberate bug to test debug hooks on Python memory allocators:
+ call PyMem_Malloc() without holding the GIL */
+ Py_BEGIN_ALLOW_THREADS
+ buffer = PyMem_Malloc(10);
+ Py_END_ALLOW_THREADS
+
+ PyMem_Free(buffer);
+
+ Py_RETURN_NONE;
+}
+
+static PyObject*
pyobject_malloc_without_gil(PyObject *self, PyObject *args)
{
char *buffer;
+ /* Deliberate bug to test debug hooks on Python memory allocators:
+ call PyObject_Malloc() without holding the GIL */
Py_BEGIN_ALLOW_THREADS
buffer = PyObject_Malloc(10);
Py_END_ALLOW_THREADS
@@ -3841,6 +3859,7 @@
{"get_recursion_depth", get_recursion_depth, METH_NOARGS},
{"pymem_buffer_overflow", pymem_buffer_overflow, METH_NOARGS},
{"pymem_api_misuse", pymem_api_misuse, METH_NOARGS},
+ {"pymem_malloc_without_gil", pymem_malloc_without_gil, METH_NOARGS},
{"pyobject_malloc_without_gil", pyobject_malloc_without_gil, METH_NOARGS},
{NULL, NULL} /* sentinel */
};
diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c
index 8812f59..503fcdf 100644
--- a/Objects/obmalloc.c
+++ b/Objects/obmalloc.c
@@ -198,7 +198,7 @@
static PyMemAllocatorEx _PyMem = {
#ifdef Py_DEBUG
- &_PyMem_Debug.mem, PYRAWDBG_FUNCS
+ &_PyMem_Debug.mem, PYDBG_FUNCS
#else
NULL, PYMEM_FUNCS
#endif
@@ -321,17 +321,17 @@
PyMem_SetAllocator(PYMEM_DOMAIN_RAW, &alloc);
}
- if (_PyMem.malloc != _PyMem_DebugRawMalloc) {
- alloc.ctx = &_PyMem_Debug.mem;
- PyMem_GetAllocator(PYMEM_DOMAIN_MEM, &_PyMem_Debug.mem.alloc);
- PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &alloc);
- }
-
alloc.malloc = _PyMem_DebugMalloc;
alloc.calloc = _PyMem_DebugCalloc;
alloc.realloc = _PyMem_DebugRealloc;
alloc.free = _PyMem_DebugFree;
+ if (_PyMem.malloc != _PyMem_DebugMalloc) {
+ alloc.ctx = &_PyMem_Debug.mem;
+ PyMem_GetAllocator(PYMEM_DOMAIN_MEM, &_PyMem_Debug.mem.alloc);
+ PyMem_SetAllocator(PYMEM_DOMAIN_MEM, &alloc);
+ }
+
if (_PyObject.malloc != _PyMem_DebugMalloc) {
alloc.ctx = &_PyMem_Debug.obj;
PyMem_GetAllocator(PYMEM_DOMAIN_OBJ, &_PyMem_Debug.obj.alloc);