Re: [PATCH v9 2/4] linux-user/syscall: Add support for clock_gettime64/clock_settime64

[Philippe Mathieu-Daudé]

On 3/18/20 11:46 PM, Alistair Francis wrote:
> Add support for the clock_gettime64/clock_settime64 syscalls.
>
> If your host is 64-bit or is 32-bit with the *_time64 syscall then the
> timespec will correctly be a 64-bit time_t. Otherwise the host will
> return a 32-bit time_t which will be rounded to 64-bits. This will be
> incorrect after y2038.
>
> Signed-off-by: Alistair Francis <address@hidden>
> Reviewed-by: Laurent Vivier <address@hidden>
> ---
>   linux-user/syscall.c | 39 +++++++++++++++++++++++++++++++++++++++
>   1 file changed, 39 insertions(+)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 909bec94a5..60fd775d9c 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -1229,6 +1229,22 @@ static inline abi_long target_to_host_timespec(struct 
> timespec *host_ts,
>   }
>   #endif
>   
> +#if defined(TARGET_NR_clock_settime64)
> +static inline abi_long target_to_host_timespec64(struct timespec *host_ts,
> +                                                 abi_ulong target_addr)
> +{
> +    struct target__kernel_timespec *target_ts;
> +
> +    if (!lock_user_struct(VERIFY_READ, target_ts, target_addr, 1)) {
> +        return -TARGET_EFAULT;
> +    }
> +    __get_user(host_ts->tv_sec, &target_ts->tv_sec);
> +    __get_user(host_ts->tv_nsec, &target_ts->tv_nsec);
> +    unlock_user_struct(target_ts, target_addr, 0);
> +    return 0;
> +}
> +#endif
> +
>   static inline abi_long host_to_target_timespec(abi_ulong target_addr,
>                                                  struct timespec *host_ts)
>   {
> @@ -11458,6 +11474,18 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>           return ret;
>       }
>   #endif
> +#ifdef TARGET_NR_clock_settime64
> +    case TARGET_NR_clock_settime64:
> +    {
> +        struct timespec ts;
> +
> +        ret = target_to_host_timespec64(&ts, arg2);
> +        if (!is_error(ret)) {
> +            ret = get_errno(clock_settime(arg1, &ts));
> +        }
> +        return ret;
> +    }
> +#endif
>   #ifdef TARGET_NR_clock_gettime
>       case TARGET_NR_clock_gettime:
>       {
> @@ -11469,6 +11497,17 @@ static abi_long do_syscall1(void *cpu_env, int num, 
> abi_long arg1,
>           return ret;
>       }
>   #endif
> +#ifdef TARGET_NR_clock_gettime64
> +    case TARGET_NR_clock_gettime64:
> +    {
> +        struct timespec ts;
> +        ret = get_errno(clock_gettime(arg1, &ts));
> +        if (!is_error(ret)) {
> +            ret = host_to_target_timespec64(arg2, &ts);
> +        }
> +        return ret;
> +    }
> +#endif
>   #ifdef TARGET_NR_clock_getres
>       case TARGET_NR_clock_getres:
>       {

Reviewed-by: Philippe Mathieu-Daudé <address@hidden>