2018-04-27 22:13+0200, Arnd Bergmann:
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.
diff --git 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/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 @@ -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.*/
(Modern TSC extensions stripped pvclock of all advantages, so we'll likely abandon pvclock by then.)
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)
kvmclock and pvclock changes
Acked-by: Radim Krčmář rkrcmar@redhat.com