On 19/10/2017 12:57, Arnd Bergmann wrote:
> The x86 platform operations are fairly isolated, so we can
> change them from using timespec to timespec64. I checked that
> All the users and callers are safe, and there is only one
> critical function that is broken beyond 2106:
>
> pvclock_read_wallclock() uses a 32-bit number of seconds since
> the epoch to communicate the boot time between host and guest
> in a virtual environment. This will work until 2106, but we
> should ideally find a replacement anyway. I've added a comment
> about it there.
>
> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> v2 changes:
> - move comment block (Boris)
> - remove unnecessary type cast (Boris)
> - fix format string (0day bot)
> - fix include order (0day bot)
> ---
> arch/x86/include/asm/intel_mid_vrtc.h | 4 ++--
> arch/x86/include/asm/mc146818rtc.h | 4 ++--
> arch/x86/include/asm/pvclock.h | 2 +-
> arch/x86/include/asm/x86_init.h | 7 +++----
> arch/x86/kernel/kvmclock.c | 4 ++--
> arch/x86/kernel/pvclock.c | 15 +++++++++++----
> arch/x86/kernel/rtc.c | 16 ++++++++--------
> arch/x86/platform/intel-mid/intel_mid_vrtc.c | 12 ++++++------
> arch/x86/xen/time.c | 10 +++++-----
> 9 files changed, 40 insertions(+), 34 deletions(-)
>
> diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
> index d88967659098..01c76e8cd4be 100644
> --- a/arch/x86/kernel/kvmclock.c
> +++ b/arch/x86/kernel/kvmclock.c
> @@ -58,7 +58,7 @@ EXPORT_SYMBOL_GPL(pvclock_pvti_cpu0_va);
> * have elapsed since the hypervisor wrote the data. So we try to account for
> * that with system time
> */
> -static void kvm_get_wallclock(struct timespec *now)
> +static void kvm_get_wallclock(struct timespec64 *now)
> {
> struct pvclock_vcpu_time_info *vcpu_time;
> int low, high;
> @@ -77,7 +77,7 @@ static void kvm_get_wallclock(struct timespec *now)
> put_cpu();
> }
>
> -static int kvm_set_wallclock(const struct timespec *now)
> +static int kvm_set_wallclock(const struct timespec64 *now)
> {
> return -1;
> }
> diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
> index 5c3f6d6a5078..013bef851664 100644
> --- a/arch/x86/kernel/pvclock.c
> +++ b/arch/x86/kernel/pvclock.c
> @@ -121,26 +121,33 @@ u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src)
>
> void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock,
> struct pvclock_vcpu_time_info *vcpu_time,
> - struct timespec *ts)
> + struct timespec64 *ts)
> {
> u32 version;
> u64 delta;
> - struct timespec now;
> + struct timespec64 now;
>
> /* get wallclock at system boot */
> do {
> version = wall_clock->version;
> rmb(); /* fetch version before time */
> + /*
> + * Note: wall_clock->sec is a u32 value, so it can
> + * only store dates between 1970 and 2106. To allow
> + * times beyond that, we need to create a new hypercall
> + * interface with an extended pvclock_wall_clock structure
> + * like ARM has.
> + */
> now.tv_sec = wall_clock->sec;
> now.tv_nsec = wall_clock->nsec;
> rmb(); /* fetch time before checking version */
> } while ((wall_clock->version & 1) || (version != wall_clock->version));
>
> delta = pvclock_clocksource_read(vcpu_time); /* time since system boot */
> - delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec;
> + delta += now.tv_sec * NSEC_PER_SEC + now.tv_nsec;
>
> now.tv_nsec = do_div(delta, NSEC_PER_SEC);
> now.tv_sec = delta;
>
> - set_normalized_timespec(ts, now.tv_sec, now.tv_nsec);
> + set_normalized_timespec64(ts, now.tv_sec, now.tv_nsec);
> }
For kvmclock.c and pvclock.c,
Acked-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
