unikernel/duniverse/eqaf/attack/microtime.c

@@ -0,0 +1,41 @@
+/* Copyright (c) 2018 David Kaloper Meršinjak. All rights reserved.
+   See LICENSE.md */
+
+#include <caml/mlvalues.h>
+
+#if defined (__x86_64__)
+#define __x86__
+
+#elif defined (__i686__)
+#warning Unmark uses unboxed native ints for low-level counters. Proceed with extreme caution.
+/* We can still do short benchmarks, tho. */
+#define __x86__
+
+#endif
+
+#if defined (__x86__)
+#include <x86intrin.h>
+#endif
+
+#include <time.h>
+
+#define __unit value unit __attribute__((unused))
+#define nsec 1000000000
+
+CAMLprim value caml_rdtsc (__unit) {
+#if defined (__x86__)
+  return Val_long (__rdtsc ());
+#else
+#warning Disabling RDTSC.
+  return Val_long (0);
+#endif
+}
+
+/* This will break on some, or all, of: Windows, macOS, Mirage.
+ * Please fill in the missing definitions.
+ */
+CAMLprim value caml_microtime (__unit) {
+  struct timespec ts;
+  clock_gettime (CLOCK_MONOTONIC, &ts);
+  return Val_long ((intnat) ts.tv_sec * nsec + (intnat) ts.tv_nsec);
+}