Re: [RFC PATCH 5/8] READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses

[Arnd Bergmann]

On Fri, Jan 10, 2020 at 5:56 PM Will Deacon <will@xxxxxxxxxx> wrote:

> +/*
> + * Use __READ_ONCE() instead of READ_ONCE() if you do not require any
> + * atomicity or dependency ordering guarantees. Note that this may result
> + * in tears!
> + */
> +#define __READ_ONCE(x) (*(volatile typeof(x) *)&(x))
> +

This probably allows writing

       extern int i;
       __READ_ONCE(i) = 1;

and not get a warning for it. How about also casting to 'const'?

        Arnd