1 files changed, 43 insertions, 0 deletions
diff --git a/integrationtests/readwrite_test.go b/integrationtests/readwrite_test.go
index 8bfa539..636cc5c 100644
--- a/integrationtests/readwrite_test.go
+++ b/integrationtests/readwrite_test.go
@@ -302,6 +302,49 @@ func TestReadwriteReadaheadEbadf(t *testing.T) {
 	}, 0)
 }
 
+func TestReadwriteFadvise64(t *testing.T) {
+	// fadvise64(2) is KindFd / UNCLASSIFIED: it declares a page-cache access hint
+	// and returns 0/-1 (no byte count, transfers no bytes to userspace), so the
+	// tracer must attribute zero bytes (not misread the 0/-1 return or the
+	// offset/len hint parameters as a byte count) while still capturing the fd
+	// (args[0]) on enter and timing the syscall.
+	result, _ := runScenarioResult(t, "readwrite-fadvise64", []ExpectedEvent{
+		{
+			PathContains: "fadvise64file.txt",
+			Tracepoint:   "enter_fadvise64",
+			Comm:         "ioworkload",
+			MinCount:     1,
+		},
+	})
+	exp := ExpectedEvent{
+		PathContains: "fadvise64file.txt",
+		Tracepoint:   "enter_fadvise64",
+		Comm:         "ioworkload",
+	}
+	// UNCLASSIFIED: no byte count is attributed for a successful fadvise64.
+	assertEventBytesEqual(t, result, exp, 0)
+	// Timing is captured end-to-end (enter/exit paired into a duration).
+	assertEventDurationPositive(t, result, exp)
+}
+
+func TestReadwriteFadvise64Ebadf(t *testing.T) {
+	// fadvise64 on an invalid fd fails with EBADF, but ior still captures the
+	// enter_fadvise64 tracepoint because arguments are read on syscall entry
+	// before the kernel returns the error. The UNCLASSIFIED -1 return must not
+	// be attributed as bytes.
+	result, _ := runScenarioResult(t, "readwrite-fadvise64-ebadf", []ExpectedEvent{
+		{
+			Tracepoint: "enter_fadvise64",
+			Comm:       "ioworkload",
+			MinCount:   1,
+		},
+	})
+	assertEventBytesEqual(t, result, ExpectedEvent{
+		Tracepoint: "enter_fadvise64",
+		Comm:       "ioworkload",
+	}, 0)
+}
+
 func TestReadwriteCachestat(t *testing.T) {
 	// cachestat(2) is KindFd / UNCLASSIFIED: it queries page-cache residency for
 	// a file and returns 0/-1 (no byte count, no I/O bytes to userspace), so the