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 <t...@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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