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Subject[patch V2 03/11] x86/vdso: Enforce 64bit clocksource
All VDSO clock sources are TSC based and use CLOCKSOURCE_MASK(64). There is
no point in masking with all FF. Get rid of it and enforce the mask in the
sanity checker.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/entry/vdso/vclock_gettime.c | 2 +-
arch/x86/kernel/time.c | 6 ++++++
2 files changed, 7 insertions(+), 1 deletion(-)

--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -199,7 +199,7 @@ notrace static inline u64 vgetsns(int *m
#endif
else
return 0;
- v = (cycles - gtod->cycle_last) & gtod->mask;
+ v = cycles - gtod->cycle_last;
return v * gtod->mult;
}

--- a/arch/x86/kernel/time.c
+++ b/arch/x86/kernel/time.c
@@ -120,4 +120,10 @@ void clocksource_arch_init(struct clocks
cs->name, cs->archdata.vclock_mode);
cs->archdata.vclock_mode = VCLOCK_NONE;
}
+
+ if (cs->mask != CLOCKSOURCE_MASK(64)) {
+ pr_warn("clocksource %s registered with invalid mask %016llx. Disabling vclock.\n",
+ cs->name, cs->mask);
+ cs->archdata.vclock_mode = VCLOCK_NONE;
+ }
}

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