x86: read_tsc sync

make native_read_tsc() always non-speculative. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
git-mirror · Jan 30, 2008 · f06e4ec · f06e4ec
1 parent e402644
commit f06e4ec
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
@@ -200,7 +200,10 @@ unsigned long long __vsyscall_fn native_read_tsc(void)
 {
 	DECLARE_ARGS(val, low, high);
 
+	rdtsc_barrier();
 	asm volatile("rdtsc" : EAX_EDX_RET(val, low, high));
+	rdtsc_barrier();
+
 	return EAX_EDX_VAL(val, low, high);
 }
 EXPORT_SYMBOL_GPL(native_read_tsc);