diff options
Diffstat (limited to 'lib/libc/amd64/sys/__vdso_gettc.c')
| -rw-r--r-- | lib/libc/amd64/sys/__vdso_gettc.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/lib/libc/amd64/sys/__vdso_gettc.c b/lib/libc/amd64/sys/__vdso_gettc.c index c6f2dfb3556a..1899b213e2f6 100644 --- a/lib/libc/amd64/sys/__vdso_gettc.c +++ b/lib/libc/amd64/sys/__vdso_gettc.c @@ -36,19 +36,29 @@ __FBSDID("$FreeBSD$"); static u_int __vdso_gettc_low(const struct vdso_timehands *th) { - uint32_t rv; + u_int rv; - __asm __volatile("rdtsc; shrd %%cl, %%edx, %0" + __asm __volatile("lfence; rdtsc; shrd %%cl, %%edx, %0" : "=a" (rv) : "c" (th->th_x86_shift) : "edx"); return (rv); } +static u_int +__vdso_rdtsc32(void) +{ + u_int rv; + + __asm __volatile("lfence;rdtsc" : "=a" (rv) : : "edx"); + return (rv); +} + #pragma weak __vdso_gettc u_int __vdso_gettc(const struct vdso_timehands *th) { - return (th->th_x86_shift > 0 ? __vdso_gettc_low(th) : rdtsc32()); + return (th->th_x86_shift > 0 ? __vdso_gettc_low(th) : + __vdso_rdtsc32()); } #pragma weak __vdso_gettimekeep |