Issue #9185: On Solaris and OpenBSD, posix_getcwd() could loop indefinitely
if the path length exceeded PATH_MAX.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 8a23e65..17af508 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -1957,6 +1957,28 @@
 "getcwd() -> path\n\n\
 Return a string representing the current working directory.");
 
+#if (defined(__sun) && defined(__SVR4)) || defined(__OpenBSD__)
+/* Issue 9185: getcwd() returns NULL/ERANGE indefinitely. */
+static PyObject *
+posix_getcwd(PyObject *self, PyObject *noargs)
+{
+    char buf[PATH_MAX+2];
+    char *res;
+
+    Py_BEGIN_ALLOW_THREADS
+#if defined(PYOS_OS2) && defined(PYCC_GCC)
+        res = _getcwd2(buf, sizeof buf);
+#else
+        res = getcwd(buf, sizeof buf);
+#endif
+    Py_END_ALLOW_THREADS
+
+    if (res == NULL)
+        return posix_error();
+
+    return PyString_FromString(buf);
+}
+#else
 static PyObject *
 posix_getcwd(PyObject *self, PyObject *noargs)
 {
@@ -1993,6 +2015,7 @@
 
     return dynamic_return;
 }
+#endif /* getcwd() NULL/ERANGE workaround. */
 
 #ifdef Py_USING_UNICODE
 PyDoc_STRVAR(posix_getcwdu__doc__,