syz-fuzzer: use of monotonic time for latency measurement

time.Now/Since may reject to use monotonic time if the fuzzer
messes with system time badly enough. Enforce use of monotonic time.

1 files changed, 10 insertions, 0 deletions

diff --git a/pkg/osutil/osutil_test.go b/pkg/osutil/osutil_test.go
index 713a62c14..7d5913b4a 100644
--- a/pkg/osutil/osutil_test.go
+++ b/pkg/osutil/osutil_test.go
@@ -9,6 +9,7 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 )
 
 func TestIsExist(t *testing.T) {
@@ -119,3 +120,12 @@ func TestCopyFiles(t *testing.T) {
 		})
 	}
 }
+
+func TestMonotonicNano(t *testing.T) {
+	start := MonotonicNano()
+	time.Sleep(100 * time.Millisecond)
+	diff := MonotonicNano() - start
+	if diff <= 0 || diff > 10*time.Second {
+		t.Fatalf("diff %v", diff)
+	}
+}