On 2023-03-28, Petr Mladek <pmladek@xxxxxxxx> wrote: >> A compilation check would be nice. Is that possible? > > I think the following might do the trick: > > static_assert(sizeof(struct cons_state) == sizeof(atomic_long_t)); I never realized the kernel code was allowed to have that. But it is everywhere! :-) Thanks. I've added and tested the following: /* * The nbcon_state struct is used to easily create and interpret values that * are stored in the console.nbcon_state variable. Make sure this struct stays * within the size boundaries of that atomic variable's underlying type in * order to avoid any accidental truncation. */ static_assert(sizeof(struct nbcon_state) <= sizeof(long)); Note that I am checking against sizeof(long), the underlying variable type. We probably shouldn't assume sizeof(atomic_long_t) is always sizeof(long). John
