Re: [PATCH] [v3] x86: Convert x86_platform_ops to timespec64

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2018-04-27 22:13, 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@oracle.com>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> v2 changes:
> - move comment block (Boris)
> - remove unnecessary type cast (Boris)
> - fix format string (0day bot)
> - fix include order (0day bot)
> 
> v3 changes:
> - add jailhouse specific change
> - avoid include file header by relying on another
>   patch ("timekeeping: Remove timespec64 hack")
> 
> Not sure how we want to merge this (assuming the last modification
> worked, this has seen little testing). The "timekeeping: Remove
> timespec64 hack" patch should go through the timekeeping branch
> in tip, while this one is for x86. I assume the linux-tip maintainers
> can come up with a plan.
> ---
>  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              |  6 +++---
>  arch/x86/kernel/jailhouse.c                  |  2 +-
>  arch/x86/kernel/kvmclock.c                   |  4 ++--
>  arch/x86/kernel/pvclock.c                    | 15 +++++++++++----
>  arch/x86/kernel/rtc.c                        | 10 +++++-----
>  arch/x86/platform/intel-mid/intel_mid_vrtc.c | 12 ++++++------
>  arch/x86/xen/time.c                          | 10 +++++-----
>  10 files changed, 38 insertions(+), 31 deletions(-)
> 
> diff --git a/arch/x86/include/asm/intel_mid_vrtc.h b/arch/x86/include/asm/intel_mid_vrtc.h
> index 35555016b1be..0b44b1abe4d9 100644
> --- a/arch/x86/include/asm/intel_mid_vrtc.h
> +++ b/arch/x86/include/asm/intel_mid_vrtc.h
> @@ -4,7 +4,7 @@
>  
>  extern unsigned char vrtc_cmos_read(unsigned char reg);
>  extern void vrtc_cmos_write(unsigned char val, unsigned char reg);
> -extern void vrtc_get_time(struct timespec *now);
> -extern int vrtc_set_mmss(const struct timespec *now);
> +extern void vrtc_get_time(struct timespec64 *now);
> +extern int vrtc_set_mmss(const struct timespec64 *now);
>  
>  #endif
> diff --git a/arch/x86/include/asm/mc146818rtc.h b/arch/x86/include/asm/mc146818rtc.h
> index 1775a32f7ea6..97198001e567 100644
> --- a/arch/x86/include/asm/mc146818rtc.h
> +++ b/arch/x86/include/asm/mc146818rtc.h
> @@ -95,8 +95,8 @@ static inline unsigned char current_lock_cmos_reg(void)
>  unsigned char rtc_cmos_read(unsigned char addr);
>  void rtc_cmos_write(unsigned char val, unsigned char addr);
>  
> -extern int mach_set_rtc_mmss(const struct timespec *now);
> -extern void mach_get_cmos_time(struct timespec *now);
> +extern int mach_set_rtc_mmss(const struct timespec64 *now);
> +extern void mach_get_cmos_time(struct timespec64 *now);
>  
>  #define RTC_IRQ 8
>  
> diff --git a/arch/x86/include/asm/pvclock.h b/arch/x86/include/asm/pvclock.h
> index a7471dcd2205..b6033680d458 100644
> --- a/arch/x86/include/asm/pvclock.h
> +++ b/arch/x86/include/asm/pvclock.h
> @@ -12,7 +12,7 @@ void pvclock_set_flags(u8 flags);
>  unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
>  void pvclock_read_wallclock(struct pvclock_wall_clock *wall,
>  			    struct pvclock_vcpu_time_info *vcpu,
> -			    struct timespec *ts);
> +			    struct timespec64 *ts);
>  void pvclock_resume(void);
>  
>  void pvclock_touch_watchdogs(void);
> diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
> index ce8b4da07e35..2d27236c16a3 100644
> --- a/arch/x86/include/asm/x86_init.h
> +++ b/arch/x86/include/asm/x86_init.h
> @@ -170,7 +170,7 @@ struct x86_cpuinit_ops {
>  	void (*fixup_cpu_id)(struct cpuinfo_x86 *c, int node);
>  };
>  
> -struct timespec;
> +struct timespec64;
>  
>  /**
>   * struct x86_legacy_devices - legacy x86 devices
> @@ -264,8 +264,8 @@ struct x86_hyper_runtime {
>  struct x86_platform_ops {
>  	unsigned long (*calibrate_cpu)(void);
>  	unsigned long (*calibrate_tsc)(void);
> -	void (*get_wallclock)(struct timespec *ts);
> -	int (*set_wallclock)(const struct timespec *ts);
> +	void (*get_wallclock)(struct timespec64 *ts);
> +	int (*set_wallclock)(const struct timespec64 *ts);
>  	void (*iommu_shutdown)(void);
>  	bool (*is_untracked_pat_range)(u64 start, u64 end);
>  	void (*nmi_init)(void);
> diff --git a/arch/x86/kernel/jailhouse.c b/arch/x86/kernel/jailhouse.c
> index fa183a131edc..a0b05bf185ac 100644
> --- a/arch/x86/kernel/jailhouse.c
> +++ b/arch/x86/kernel/jailhouse.c
> @@ -37,7 +37,7 @@ static uint32_t __init jailhouse_detect(void)
>  	return jailhouse_cpuid_base();
>  }
>  
> -static void jailhouse_get_wallclock(struct timespec *now)
> +static void jailhouse_get_wallclock(struct timespec64 *now)
>  {
>  	memset(now, 0, sizeof(*now));
>  }
> diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
> index 8b26c9e01cc4..bf8d1eb7fca3 100644
> --- a/arch/x86/kernel/kvmclock.c
> +++ b/arch/x86/kernel/kvmclock.c
> @@ -53,7 +53,7 @@ static struct pvclock_wall_clock *wall_clock;
>   * 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;
> @@ -72,7 +72,7 @@ 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 -ENODEV;
>  }
> diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
> index 761f6af6efa5..637982efecd8 100644
> --- a/arch/x86/kernel/pvclock.c
> +++ b/arch/x86/kernel/pvclock.c
> @@ -123,28 +123,35 @@ 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);
>  }
>  
>  void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti)
> diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
> index f7b82ed7b5b5..586f718b8e95 100644
> --- a/arch/x86/kernel/rtc.c
> +++ b/arch/x86/kernel/rtc.c
> @@ -39,7 +39,7 @@ EXPORT_SYMBOL(rtc_lock);
>   * jump to the next second precisely 500 ms later. Check the Motorola
>   * MC146818A or Dallas DS12887 data sheet for details.
>   */
> -int mach_set_rtc_mmss(const struct timespec *now)
> +int mach_set_rtc_mmss(const struct timespec64 *now)
>  {
>  	unsigned long long nowtime = now->tv_sec;
>  	struct rtc_time tm;
> @@ -60,7 +60,7 @@ int mach_set_rtc_mmss(const struct timespec *now)
>  	return retval;
>  }
>  
> -void mach_get_cmos_time(struct timespec *now)
> +void mach_get_cmos_time(struct timespec64 *now)
>  {
>  	unsigned int status, year, mon, day, hour, min, sec, century = 0;
>  	unsigned long flags;
> @@ -118,7 +118,7 @@ void mach_get_cmos_time(struct timespec *now)
>  	} else
>  		year += CMOS_YEARS_OFFS;
>  
> -	now->tv_sec = mktime(year, mon, day, hour, min, sec);
> +	now->tv_sec = mktime64(year, mon, day, hour, min, sec);
>  	now->tv_nsec = 0;
>  }
>  
> @@ -145,13 +145,13 @@ void rtc_cmos_write(unsigned char val, unsigned char addr)
>  }
>  EXPORT_SYMBOL(rtc_cmos_write);
>  
> -int update_persistent_clock(struct timespec now)
> +int update_persistent_clock64(struct timespec64 now)
>  {
>  	return x86_platform.set_wallclock(&now);
>  }
>  
>  /* not static: needed by APM */
> -void read_persistent_clock(struct timespec *ts)
> +void read_persistent_clock64(struct timespec64 *ts)
>  {
>  	x86_platform.get_wallclock(ts);
>  }
> diff --git a/arch/x86/platform/intel-mid/intel_mid_vrtc.c b/arch/x86/platform/intel-mid/intel_mid_vrtc.c
> index 58024862a7eb..a52914aa3b6c 100644
> --- a/arch/x86/platform/intel-mid/intel_mid_vrtc.c
> +++ b/arch/x86/platform/intel-mid/intel_mid_vrtc.c
> @@ -57,7 +57,7 @@ void vrtc_cmos_write(unsigned char val, unsigned char reg)
>  }
>  EXPORT_SYMBOL_GPL(vrtc_cmos_write);
>  
> -void vrtc_get_time(struct timespec *now)
> +void vrtc_get_time(struct timespec64 *now)
>  {
>  	u8 sec, min, hour, mday, mon;
>  	unsigned long flags;
> @@ -83,18 +83,18 @@ void vrtc_get_time(struct timespec *now)
>  	pr_info("vRTC: sec: %d min: %d hour: %d day: %d "
>  		"mon: %d year: %d\n", sec, min, hour, mday, mon, year);
>  
> -	now->tv_sec = mktime(year, mon, mday, hour, min, sec);
> +	now->tv_sec = mktime64(year, mon, mday, hour, min, sec);
>  	now->tv_nsec = 0;
>  }
>  
> -int vrtc_set_mmss(const struct timespec *now)
> +int vrtc_set_mmss(const struct timespec64 *now)
>  {
>  	unsigned long flags;
>  	struct rtc_time tm;
>  	int year;
>  	int retval = 0;
>  
> -	rtc_time_to_tm(now->tv_sec, &tm);
> +	rtc_time64_to_tm(now->tv_sec, &tm);
>  	if (!rtc_valid_tm(&tm) && tm.tm_year >= 72) {
>  		/*
>  		 * tm.year is the number of years since 1900, and the
> @@ -110,8 +110,8 @@ int vrtc_set_mmss(const struct timespec *now)
>  		vrtc_cmos_write(tm.tm_sec, RTC_SECONDS);
>  		spin_unlock_irqrestore(&rtc_lock, flags);
>  	} else {
> -		pr_err("%s: Invalid vRTC value: write of %lx to vRTC failed\n",
> -			__func__, now->tv_sec);
> +		pr_err("%s: Invalid vRTC value: write of %llx to vRTC failed\n",
> +			__func__, (s64)now->tv_sec);
>  		retval = -EINVAL;
>  	}
>  	return retval;
> diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
> index 29163c43ebbd..e0f1bcf01d63 100644
> --- a/arch/x86/xen/time.c
> +++ b/arch/x86/xen/time.c
> @@ -57,7 +57,7 @@ static u64 xen_clocksource_get_cycles(struct clocksource *cs)
>  	return xen_clocksource_read();
>  }
>  
> -static void xen_read_wallclock(struct timespec *ts)
> +static void xen_read_wallclock(struct timespec64 *ts)
>  {
>  	struct shared_info *s = HYPERVISOR_shared_info;
>  	struct pvclock_wall_clock *wall_clock = &(s->wc);
> @@ -68,12 +68,12 @@ static void xen_read_wallclock(struct timespec *ts)
>  	put_cpu_var(xen_vcpu);
>  }
>  
> -static void xen_get_wallclock(struct timespec *now)
> +static void xen_get_wallclock(struct timespec64 *now)
>  {
>  	xen_read_wallclock(now);
>  }
>  
> -static int xen_set_wallclock(const struct timespec *now)
> +static int xen_set_wallclock(const struct timespec64 *now)
>  {
>  	return -ENODEV;
>  }
> @@ -461,7 +461,7 @@ static void __init xen_time_init(void)
>  {
>  	struct pvclock_vcpu_time_info *pvti;
>  	int cpu = smp_processor_id();
> -	struct timespec tp;
> +	struct timespec64 tp;
>  
>  	/* As Dom0 is never moved, no penalty on using TSC there */
>  	if (xen_initial_domain())
> @@ -479,7 +479,7 @@ static void __init xen_time_init(void)
>  
>  	/* Set initial system time with full resolution */
>  	xen_read_wallclock(&tp);
> -	do_settimeofday(&tp);
> +	do_settimeofday64(&tp);
>  
>  	setup_force_cpu_cap(X86_FEATURE_TSC);
>  
> 

For the few Jailhouse bits.

Acked-by: Jan Kiszka <jan.kiszka@siemens.com>