diff options
Diffstat (limited to 'lib/vdso')
| -rw-r--r-- | lib/vdso/gettimeofday.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c index 9fa90e0794c9..9c3a8d2440c9 100644 --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c @@ -13,6 +13,18 @@ # define VDSO_DELTA_MASK(vd) (vd->mask) #endif +#ifdef CONFIG_GENERIC_VDSO_OVERFLOW_PROTECT +static __always_inline bool vdso_delta_ok(const struct vdso_data *vd, u64 delta) +{ + return delta < vd->max_cycles; +} +#else +static __always_inline bool vdso_delta_ok(const struct vdso_data *vd, u64 delta) +{ + return true; +} +#endif + #ifndef vdso_shift_ns static __always_inline u64 vdso_shift_ns(u64 ns, u32 shift) { @@ -28,7 +40,10 @@ static __always_inline u64 vdso_calc_ns(const struct vdso_data *vd, u64 cycles, { u64 delta = (cycles - vd->cycle_last) & VDSO_DELTA_MASK(vd); - return vdso_shift_ns((delta * vd->mult) + base, vd->shift); + if (likely(vdso_delta_ok(vd, delta))) + return vdso_shift_ns((delta * vd->mult) + base, vd->shift); + + return mul_u64_u32_add_u64_shr(delta, vd->mult, base, vd->shift); } #endif /* vdso_calc_ns */ |