Fix TSan: use larger minimum stack size

Author: vstinner

Include/internal/pycore_pythonrun.h

@@ -54,6 +54,12 @@ extern const char* _Py_SourceAsString(
 #  define _PyOS_STACK_MARGIN_SHIFT (_PyOS_LOG2_STACK_MARGIN + 2)
 #endif
 
+#ifdef _Py_THREAD_SANITIZER
+#  define _PyOS_MIN_STACK_SIZE (_PyOS_STACK_MARGIN_BYTES * 6)
+#else
+#  define _PyOS_MIN_STACK_SIZE (_PyOS_STACK_MARGIN_BYTES * 3)
+#endif
+
 
 #ifdef __cplusplus
 }

Modules/_testinternalcapi.c

@@ -2425,9 +2425,8 @@ check_threadstate_set_stack(PyThreadState *tstate, void *start, size_t size)
     assert(!PyErr_Occurred());
 
     _PyThreadStateImpl *ts = (_PyThreadStateImpl *)tstate;
-    assert(ts->c_stack_hard_limit == (uintptr_t)start + _PyOS_STACK_MARGIN_BYTES);
     assert(ts->c_stack_top == (uintptr_t)start + size);
-    assert(ts->c_stack_soft_limit >= ts->c_stack_hard_limit);
+    assert(ts->c_stack_hard_limit <= ts->c_stack_soft_limit);
     assert(ts->c_stack_soft_limit < ts->c_stack_top);
 }
 
@@ -2443,12 +2442,13 @@ test_threadstate_set_stack(PyObject *self, PyObject *Py_UNUSED(args))
     size_t init_top = ts->c_stack_init_top;
 
     // Test the minimum stack size
-    size_t size = _PyOS_STACK_MARGIN_BYTES * 3;
+    size_t size = _PyOS_MIN_STACK_SIZE;
     void *start = (void*)(_Py_get_machine_stack_pointer() - size);
     check_threadstate_set_stack(tstate, start, size);
 
     // Test a larger size
     size = 7654321;
+    assert(size > _PyOS_MIN_STACK_SIZE);
     start = (void*)(_Py_get_machine_stack_pointer() - size);
     check_threadstate_set_stack(tstate, start, size);
 

Python/ceval.c

@@ -487,7 +487,7 @@ tstate_set_stack(PyThreadState *tstate,
                  uintptr_t base, uintptr_t top)
 {
     assert(base < top);
-    assert((top - base) >= (_PyOS_STACK_MARGIN_BYTES * 3));
+    assert((top - base) >= _PyOS_MIN_STACK_SIZE);
 
 #ifdef _Py_THREAD_SANITIZER
     // Thread sanitizer crashes if we use more than half the stack.
@@ -533,10 +533,10 @@ int
 PyUnstable_ThreadState_SetStack(PyThreadState *tstate,
                                 void *stack_start_addr, size_t stack_size)
 {
-    if (stack_size < (_PyOS_STACK_MARGIN_BYTES * 3)) {
+    if (stack_size < _PyOS_MIN_STACK_SIZE) {
         PyErr_Format(PyExc_ValueError,
                      "stack_size must be at least %zu bytes",
-                     _PyOS_STACK_MARGIN_BYTES * 3);
+                     _PyOS_MIN_STACK_SIZE);
         return -1;
     }