Re: [PATCH v6 01/19] kernel: Standardize vdso_datapage

Arnd Bergmann
2019-05-31T08:16:51Z

On Thu, May 30, 2019 at 4:15 PM Vincenzo Frascino
<vincenzo.frascino@arm.com> wrote:

> + * vdso_data will be accessed by 64 bit and compat code at the same time
> + * so we should be careful before modifying this structure.
> + */
> +struct vdso_data {
> + u32 seq;
> +
> + s32 clock_mode;
> + u64 cycle_last;
> + u64 mask;
> + u32 mult;
> + u32 shift;
> +
> + struct vdso_timestamp basetime[VDSO_BASES];
> +
> + s32 tz_minuteswest;
> + s32 tz_dsttime;
> + u32 hrtimer_res;
> +};

The structure contains four padding bytes at the end, which is
something we try to avoid, at least if this ends up being used as
an ABI. Maybe add "u32 __unused" at the end?

Arnd