PAPR_SYSPARM_MAX_OUTPUT
u8 val[PAPR_SYSPARM_MAX_OUTPUT];
__u8 data[PAPR_SYSPARM_MAX_OUTPUT];
static_assert(sizeof(user_iob->data) >= PAPR_SYSPARM_MAX_OUTPUT);
static_assert(sizeof(kern_spbuf->val) >= PAPR_SYSPARM_MAX_OUTPUT);
if (copy_to_user(user_iob->data, kern_spbuf->val, PAPR_SYSPARM_MAX_OUTPUT))