Re: [Y2038] [PATCH v2] crypto: Jitter RNG - use ktime_get_ns as fallback

[Arnd Bergmann]

On Wednesday, June 22, 2016 7:26:06 PM CEST Stephan Mueller wrote:
> As part of the Y2038 development, __getnstimeofday is not supposed to be
> used any more. It is now replaced with ktime_get_ns. The Jitter RNG uses
> the time stamp to measure the execution time of a given code path and
> tries to detect variations in the execution time. Therefore, the only
> requirement the Jitter RNG has, is a sufficient high resolution to
> detect these variations.
> 
> The change was tested on x86 to show an identical behavior as RDTSC. The
> used test code simply measures the execution time of the heart of the
> RNG:
> 
>         jent_get_nstime(&time);
>         jent_memaccess(ec, min);
>         jent_fold_time(NULL, time, &folded, min);
>         jent_get_nstime(&time2);
>         return ((time2 - time));
> 
> Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx>
> ---
> 

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>