diff mbox series

Fix PyDict_Next contiguous assumption and pypy

Message ID 20241130201516.18034-1-george@george-graphics.co.uk
State Superseded
Headers show
Series Fix PyDict_Next contiguous assumption and pypy | expand

Commit Message

George Harker Nov. 30, 2024, 8:15 p.m. UTC 
pos is not guaranteed contiguous, and pypy increments
past the end of the dict size
---
 bindings/python/gpiod/ext/request.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/bindings/python/gpiod/ext/request.c b/bindings/python/gpiod/ext/request.c
index e1a2a42..4e49289 100644
--- a/bindings/python/gpiod/ext/request.c
+++ b/bindings/python/gpiod/ext/request.c
@@ -206,6 +206,7 @@  static PyObject *request_set_values(request_object *self, PyObject *args)
 {
 	PyObject *values, *key, *val, *val_stripped;
 	Py_ssize_t pos = 0;
+	Py_ssize_t index = 0;
 	int ret;
 
 	ret = PyArg_ParseTuple(args, "O", &values);
@@ -214,8 +215,10 @@  static PyObject *request_set_values(request_object *self, PyObject *args)
 
 	clear_buffers(self);
 
+	// Note: pos may not be contiguous and in pypy, is incremented
+	// past the end of the dict size.
 	while (PyDict_Next(values, &pos, &key, &val)) {
-		self->offsets[pos - 1] = Py_gpiod_PyLongAsUnsignedInt(key);
+		self->offsets[index] = Py_gpiod_PyLongAsUnsignedInt(key);
 		if (PyErr_Occurred())
 			return NULL;
 
@@ -223,15 +226,17 @@  static PyObject *request_set_values(request_object *self, PyObject *args)
 		if (!val_stripped)
 			return NULL;
 
-		self->values[pos - 1] = PyLong_AsLong(val_stripped);
+		self->values[index] = PyLong_AsLong(val_stripped);
 		Py_DECREF(val_stripped);
 		if (PyErr_Occurred())
 			return NULL;
+
+		index += 1;
 	}
 
 	Py_BEGIN_ALLOW_THREADS;
 	ret = gpiod_line_request_set_values_subset(self->request,
-						   pos,
+						   index,
 						   self->offsets,
 						   self->values);
 	Py_END_ALLOW_THREADS;