Skip scanning string and bytes data during garbage collection

py/objstr.c

@@ -2408,7 +2408,8 @@ mp_obj_t mp_obj_new_str_copy(const mp_obj_type_t *type, const byte *data, size_t
     o->len = len;
     if (data) {
         o->hash = qstr_compute_hash(data, len);
-        byte *p = m_new(byte, len + 1);
+        // CIRCUITPY-CHANGE: Don't scan string data for pointers.
+        byte *p = m_malloc_without_collect(sizeof(byte) * (len + 1));
         o->data = p;
         memcpy(p, data, len * sizeof(byte));
         p[len] = '\0'; // for now we add null for compatibility with C ASCIIZ strings

py/objstringio.c

@@ -83,7 +83,8 @@ static mp_uint_t stringio_read(mp_obj_t o_in, void *buf, mp_uint_t size, int *er
 
 static void stringio_copy_on_write(mp_obj_stringio_t *o) {
     const void *buf = o->vstr->buf;
-    o->vstr->buf = m_new(char, o->vstr->len);
+    // CIRCUITPY-CHANGE: Don't scan string data for pointers.
+    o->vstr->buf = m_malloc_without_collect(sizeof(char) * o->vstr->len);
     o->vstr->fixed_buf = false;
     o->ref_obj = MP_OBJ_NULL;
     memcpy(o->vstr->buf, buf, o->vstr->len);

py/vstr.c

@@ -44,7 +44,8 @@ void vstr_init(vstr_t *vstr, size_t alloc) {
     }
     vstr->alloc = alloc;
     vstr->len = 0;
-    vstr->buf = m_new(char, vstr->alloc);
+    // CIRCUITPY-CHANGE: Don't scan string data for pointers.
+    vstr->buf = m_malloc_without_collect(sizeof(char) * vstr->alloc);
     vstr->fixed_buf = false;
 }