Track io_uring setup fds in event loop

Amp-Thread-ID: https://ampcode.com/threads/T-019c7fd9-5870-77b7-9909-3eb7550d17bb
Co-authored-by: Amp <amp@ampcode.com>

2 files changed, 45 insertions, 1 deletions

diff --git a/internal/eventloop.go b/internal/eventloop.go
index 91af7c9..c5467ec 100644
--- a/internal/eventloop.go
+++ b/internal/eventloop.go
@@ -345,6 +345,17 @@ func (e *eventLoop) tracepointExited(exitEv event.Event, ch chan<- *event.Pair)
 		}
 
 	case *NullEvent:
+		if ep.Is(SYS_ENTER_IO_URING_SETUP) {
+			retEvent, ok := exitEv.(*types.RetEvent)
+			if !ok {
+				panic("expected *types.RetEvent")
+			}
+			if fd := int32(retEvent.Ret); fd >= 0 {
+				fdFile := file.NewFdWithPid(fd, v.Pid)
+				e.files[fd] = fdFile
+				ep.File = fdFile
+			}
+		}
 		ep.Comm = e.comm(ep.EnterEv.GetTid())
 		if !e.filter.eventPair(ep) {
 			ep.Recycle()
@@ -404,7 +415,7 @@ func (e *eventLoop) tracepointExited(exitEv event.Event, ch chan<- *event.Pair)
 	// TODO: mmap, msync...
 	// TODO: getcwd?
 	// TODO: sync_file_range
-	// TODO: https://man7.org/linux/man-pages/man2/io_uring_enter.2.html (already captured but without FDs)
+	// TODO: io_uring_enter/io_uring_register are captured without fd arguments.
 
 	prevPairTime, _ := e.prevPairTimes[ep.EnterEv.GetTid()]
 	ep.CalculateDurations(prevPairTime)
diff --git a/internal/eventloop_test.go b/internal/eventloop_test.go
index f608eab..f53e6f3 100644
--- a/internal/eventloop_test.go
+++ b/internal/eventloop_test.go
@@ -50,6 +50,7 @@ func TestEventloop(t *testing.T) {
 		// NullEvent tests
 		"SyncEventTest":         makeSyncEventTestData(t),
 		"IoUringSetupEventTest": makeIoUringSetupEventTestData(t),
+		"IoUringSetupFailureTest": makeIoUringSetupFailureTestData(t),
 		// Dup3Event tests
 		"Dup3EventTest":       makeDup3EventTestData(t),
 		"Dup3WithCloexecTest": makeDup3WithCloexecTestData(t),
@@ -901,6 +902,38 @@ func makeIoUringSetupEventTestData(t *testing.T) (td testData) {
 		if !exitEv.Equals(ep.ExitEv) {
 			t.Errorf("Expected '%v' but got '%v'", exitEv, ep.ExitEv)
 		}
+		if ep.File == nil {
+			t.Errorf("Expected io_uring fd to be tracked")
+		}
+		if _, ok := el.files[48]; !ok {
+			t.Errorf("Expected io_uring fd 48 to be tracked")
+		}
+	})
+
+	return td
+}
+
+func makeIoUringSetupFailureTestData(t *testing.T) (td testData) {
+	enterEv, enterEvBytes := makeEnterNullEvent(t, defaulTime, defaultPid, defaultTid, types.SYS_ENTER_IO_URING_SETUP)
+	td.rawTracepoints = append(td.rawTracepoints, enterEvBytes)
+
+	// io_uring_setup returns -1 on failure
+	exitEv, exitEvBytes := makeExitRetEvent(t, defaulTime+100, defaultPid, defaultTid, types.SYS_EXIT_IO_URING_SETUP, -1)
+	td.rawTracepoints = append(td.rawTracepoints, exitEvBytes)
+
+	td.validates = append(td.validates, func(t *testing.T, el *eventLoop, ep *event.Pair) {
+		if !enterEv.Equals(ep.EnterEv) {
+			t.Errorf("Expected '%v' but got '%v'", enterEv, ep.EnterEv)
+		}
+		if !exitEv.Equals(ep.ExitEv) {
+			t.Errorf("Expected '%v' but got '%v'", exitEv, ep.ExitEv)
+		}
+		if ep.File != nil {
+			t.Errorf("Expected io_uring_setup failure to have no file tracked")
+		}
+		if len(el.files) != 0 {
+			t.Errorf("Expected no fds to be tracked after io_uring_setup failure")
+		}
 	})
 
 	return td