Yes, those patches work, with a caveat.  While testing this, I found out why I had needed EINVAL earlier (and still do, for now): there is a bug in the Solaris implementation of getrandom(2).  If flags are 0 and the buffer size > 1024, then it fails with EINVAL.  That is only supposed to happen for a buffer that big if GNRD_RANDOM is set in flags but GNRD_NONBLOCK is not set.  So until that bug is fixed, I have to patch py_getrandom() to treat EINVAL like ENOSYS and fall back to using /dev/urandom as if getrandom(2) were not supported.