Re: Privilege Levels Below User

On 6/10/2024 2:04 AM, Anton Ertl wrote:

Terje Mathisen <terje.mathisen@tmsw.no> writes:

Modern Unix typically provides 64-bit time_t seconds and a (effectively) =
>
30-bit ns field, so you can store them in a 96-bit container but I don't =
>
think anyone does that?

 man time_t tells me:
 |time_t
|              ...
|              Used for time in seconds.  According to POSIX, it  shall  be  an
|              integer type.
 |timespec
|              ...
|              struct timespec {
|                  time_t  tv_sec;  /* Seconds */
|                  long    tv_nsec; /* Nanoseconds */
|              };
|
|              Describes times in seconds and nanoseconds.
|
|              Conforming to: C11 and later; POSIX.1-2001 and later.
 So if you have a 64-bit time_t, the C standard does that, and POSIX
does it earlier.  Typical ABIs pad struct timespec to 128 bits,
though.
 

Can note, that I was mostly doing 64-bit time in microseconds for internal use.
This doesn't change the interface for gettimeofday or clock_gettime().
But, I guess, if nanoseconds is relevant, a nanosecond timer could be provided; but would not be terribly useful on a CPU with a 20ns clock cycle (will be stale well before one can do anything with it).

- anton