Add negative integration tests for io_uring syscalls (EBADF)

Add two new scenarios and tests:
- iouring-enter-ebadf: io_uring_enter with invalid fd 99999
- iouring-register-ebadf: io_uring_register with invalid fd 99999

Both verify ior captures the tracepoint even when the syscall fails.

Task: 348
Amp-Thread-ID: https://ampcode.com/threads/T-019c81bb-a460-7298-a25a-fa33502272b9
Co-authored-by: Amp <amp@ampcode.com>

2 files changed, 60 insertions, 3 deletions

diff --git a/integrationtests/cmd/ioworkload/scenarios.go b/integrationtests/cmd/ioworkload/scenarios.go
index f25b8a4..0344999 100644
--- a/integrationtests/cmd/ioworkload/scenarios.go
+++ b/integrationtests/cmd/ioworkload/scenarios.go
@@ -90,9 +90,11 @@ var scenarios = map[string]func() error{
 	"truncate-ftruncate":      truncateFtruncate,
 	"truncate-enoent":         truncateEnoent,
 	"truncate-ftruncate-ebadf": truncateFtruncateEbadf,
-	"iouring-setup":       iouringSetup,
-	"iouring-enter":       iouringEnter,
-	"iouring-register":    iouringRegister,
+	"iouring-setup":          iouringSetup,
+	"iouring-enter":          iouringEnter,
+	"iouring-register":       iouringRegister,
+	"iouring-enter-ebadf":    iouringEnterEbadf,
+	"iouring-register-ebadf": iouringRegisterEbadf,
 }
 
 func makeTempDir(prefix string) (string, func(), error) {
@@ -2434,6 +2436,41 @@ func iouringRegister() error {
 	return nil
 }
 
+// iouringEnterEbadf calls io_uring_enter on an invalid fd.
+// The syscall fails with EBADF, but ior captures the enter_io_uring_enter tracepoint.
+func iouringEnterEbadf() error {
+	_, _, errno := syscall.Syscall6(
+		sysIoUringEnter,
+		99999, // invalid fd
+		0,     // to_submit
+		0,     // min_complete
+		0,     // flags
+		0,     // sig
+		0,     // sz
+	)
+	if errno == 0 {
+		return fmt.Errorf("expected EBADF, but io_uring_enter succeeded")
+	}
+	return nil
+}
+
+// iouringRegisterEbadf calls io_uring_register on an invalid fd.
+// The syscall fails with EBADF, but ior captures the enter_io_uring_register tracepoint.
+func iouringRegisterEbadf() error {
+	_, _, errno := syscall.Syscall6(
+		sysIoUringRegister,
+		99999,             // invalid fd
+		ioringRegisterProbe,
+		0,                 // arg (NULL)
+		0,                 // nr_args
+		0, 0,
+	)
+	if errno == 0 {
+		return fmt.Errorf("expected EBADF, but io_uring_register succeeded")
+	}
+	return nil
+}
+
 // ioUringSetupRing calls io_uring_setup(2) and returns the ring fd.
 func ioUringSetupRing(entries uint32) (int, error) {
 	var params [ioUringParamsSize]byte
diff --git a/integrationtests/iouring_test.go b/integrationtests/iouring_test.go
index 20c156c..02d7a16 100644
--- a/integrationtests/iouring_test.go
+++ b/integrationtests/iouring_test.go
@@ -31,3 +31,23 @@ func TestIouringRegister(t *testing.T) {
 		},
 	})
 }
+
+func TestIouringEnterEbadf(t *testing.T) {
+	runScenario(t, "iouring-enter-ebadf", []ExpectedEvent{
+		{
+			Tracepoint: "enter_io_uring_enter",
+			Comm:       "ioworkload",
+			MinCount:   1,
+		},
+	})
+}
+
+func TestIouringRegisterEbadf(t *testing.T) {
+	runScenario(t, "iouring-register-ebadf", []ExpectedEvent{
+		{
+			Tracepoint: "enter_io_uring_register",
+			Comm:       "ioworkload",
+			MinCount:   1,
+		},
+	})
+}