Re: RESEND [PATCH v6 11/12] lib: vdso: Add support for CLOCK_BOOTTIME

[Thomas Gleixner]

On Mon, 1 Oct 2018, Mark Salyzyn wrote:
>  
> +static notrace int do_boottime(const struct vdso_data *vd, struct timespec *ts)
> +{
> +	u32 seq, mult, shift;
> +	u64 nsec, cycle_last;
> +	vdso_wtm_clock_nsec_t wtm_nsec;
> +
> +	/* open coding timespec_add_ns to save a ts->tv_nsec = 0 */
> +	ts->tv_sec = sec + __iter_div_u64_rem(nsec, NSEC_PER_SEC, &nsec);
> +	ts->tv_nsec = nsec;
> +
> +	return 0;
> +}
> +

Instead of adding yet another copy of the same code you might want to look
at the rework I did for the x86 vdso in order to support CLOCK_TAI w/o
running into the issue of the clock switch case being compiled into a jump
table and then the compile asking for retpoline.

  http://lkml.kernel.org/r/20180917124533.329334911@xxxxxxxxxxxxx

Thanks,

	tglx