bpo-39877: Fix take_gil() for daemon threads (GH-19054)
bpo-39877, bpo-39984: If the thread must exit, don't access tstate to
prevent a potential crash: tstate memory has been freed.
diff --git a/Python/ceval_gil.h b/Python/ceval_gil.h
index 9c051ae..f8b06ac 100644
--- a/Python/ceval_gil.h
+++ b/Python/ceval_gil.h
@@ -281,13 +281,17 @@
if (_Py_atomic_load_relaxed(&ceval->gil_drop_request)) {
RESET_GIL_DROP_REQUEST(ceval);
}
- if (tstate->async_exc != NULL) {
+
+ int must_exit = tstate_must_exit(tstate);
+
+ /* Don't access tstate if the thread must exit */
+ if (!must_exit && tstate->async_exc != NULL) {
_PyEval_SignalAsyncExc(ceval);
}
MUTEX_UNLOCK(gil->mutex);
- if (tstate_must_exit(tstate)) {
+ if (must_exit) {
/* bpo-36475: If Py_Finalize() has been called and tstate is not
the thread which called Py_Finalize(), exit immediately the
thread.