Commit-ID: a51e996d48ac9fa0a1260a3822a14f3d570d3be7 Gitweb: https://git.kernel.org/tip/a51e996d48ac9fa0a1260a3822a14f3d570d3be7 Author: Thomas Gleixner <[email protected]> AuthorDate: Mon, 17 Sep 2018 14:45:36 +0200 Committer: Thomas Gleixner <[email protected]> CommitDate: Thu, 4 Oct 2018 23:00:25 +0200
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 <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Matt Rickard <[email protected]> Cc: Stephen Boyd <[email protected]> Cc: John Stultz <[email protected]> Cc: Florian Weimer <[email protected]> Cc: "K. Y. Srinivasan" <[email protected]> Cc: Vitaly Kuznetsov <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Paolo Bonzini <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Juergen Gross <[email protected]> Link: https://lkml.kernel.org/r/[email protected] --- arch/x86/entry/vdso/vclock_gettime.c | 2 +- arch/x86/kernel/time.c | 6 ++++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index e48ca3afa091..6a950854034f 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -201,7 +201,7 @@ notrace static inline u64 vgetsns(int *mode) #endif else return 0; - v = (cycles - gtod->cycle_last) & gtod->mask; + v = cycles - gtod->cycle_last; return v * gtod->mult; } diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c index 1fa632e0829f..b23f5420b26a 100644 --- a/arch/x86/kernel/time.c +++ b/arch/x86/kernel/time.c @@ -120,4 +120,10 @@ void clocksource_arch_init(struct clocksource *cs) 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; + } }
