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Re: [PATCH v2 2/6] time: Add a timeval with a long tv_sec and tv_usec


On Mon, 10 Feb 2020 09:43:21 -0800
Alistair Francis <alistair.francis@wdc.com> wrote:

> On y2038 safe 32-bit systems the Linux kernel expects itimerval to
> use a 32-bit time_t, even though the other time_t's are 64-bit. To
> address this let's add a __timeval32 struct to be used internally.
> ---
>  include/time.h | 41 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 41 insertions(+)
> 
> diff --git a/include/time.h b/include/time.h
> index 73f66277ac..f22abc13f4 100644
> --- a/include/time.h
> +++ b/include/time.h
> @@ -400,6 +400,47 @@ timespec64_to_timeval64 (const struct
> __timespec64 ts64) return tv64;
>  }
>  
> +/* A version of 'struct timeval' with `long` time_t
> +   and suseconds_t.  */
> +struct __timeval32
> +{
> +  long tv_sec;         /* Seconds.  */
> +  long tv_usec;        /* Microseconds.  */
> +};
> +
> +/* Conversion functions for converting to/from __timeval32
> +.  If the seconds field of a __timeval32 would
> +   overflow, they write { INT32_MAX, 999999 } to the output.  */

Please update the above comment.

> +static inline struct __timeval64
> +valid_timeval32_to_timeval64 (const struct __timeval32 tv)
> +{
> +  return (struct __timeval64) { tv.tv_sec, tv.tv_usec };
> +}
> +
> +static inline struct __timeval32
> +valid_timeval64_to_timeval32 (const struct __timeval64 tv64)
> +{
> +  return (struct __timeval32) { tv64.tv_sec, tv64.tv_usec };
> +}
> +
> +static inline struct timeval
> +valid_timeval32_to_timeval (const struct __timeval32 tv)
> +{
> +  return (struct timeval) { tv.tv_sec, tv.tv_usec };
> +}
> +
> +static inline struct timespec
> +valid_timeval32_to_timespec (const struct __timeval32 tv)
> +{
> +  return (struct timespec) { tv.tv_sec, tv.tv_usec * 1000 };
> +}
> +
> +static inline struct __timeval32
> +valid_timespec_to_timeval32 (const struct timespec ts)
> +{
> +  return (struct __timeval32) { (time_t) ts.tv_sec, ts.tv_nsec /
> 1000 }; +}
> +
>  /* Check if a value is in the valid nanoseconds range. Return true if
>     it is, false otherwise.  */
>  static inline bool




Best regards,

Lukasz Majewski

--

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