fix: return errors for invalid event filters (task 382)

9 files changed, 78 insertions, 29 deletions

diff --git a/internal/bench_components_test.go b/internal/bench_components_test.go
index 1f9ccb5..54c6f2e 100644
--- a/internal/bench_components_test.go
+++ b/internal/bench_components_test.go
@@ -71,7 +71,7 @@ func BenchmarkDeserializeDup3Event(b *testing.B) {
 func BenchmarkRawHandlerLookup(b *testing.B) {
 	b.ReportAllocs()
 
-	el := newEventLoop(eventLoopConfig{})
+	el := mustNewEventLoop(b, eventLoopConfig{})
 	eventTypes := []types.EventType{
 		types.ENTER_OPEN_EVENT,
 		types.EXIT_OPEN_EVENT,
@@ -97,7 +97,7 @@ func BenchmarkTracepointEntered(b *testing.B) {
 
 	gen := benchutil.NewEventGenerator()
 	_, raw := gen.EnterOpenEvent(1, componentBenchPID, componentBenchTID)
-	el := newComponentBenchEventLoop(componentBenchTID)
+	el := newComponentBenchEventLoop(b, componentBenchTID)
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -118,7 +118,7 @@ func BenchmarkTracepointExited(b *testing.B) {
 	gen := benchutil.NewEventGenerator()
 	_, enterRaw := gen.EnterNullEvent(1, componentBenchPID, componentBenchTID, types.SYS_ENTER_SYNC)
 	_, exitRaw := gen.ExitNullEvent(2, componentBenchPID, componentBenchTID, types.SYS_EXIT_SYNC)
-	el := newComponentBenchEventLoop(componentBenchTID)
+	el := newComponentBenchEventLoop(b, componentBenchTID)
 	out := make(chan *event.Pair, 1)
 
 	b.ResetTimer()
@@ -137,7 +137,7 @@ func BenchmarkHandleOpenExit(b *testing.B) {
 	gen := benchutil.NewEventGenerator()
 	enterTemplate, _ := gen.EnterOpenEvent(1, componentBenchPID, componentBenchTID)
 	exitTemplate, _ := gen.ExitOpenEvent(2, componentBenchPID, componentBenchTID)
-	el := newComponentBenchEventLoop(componentBenchTID)
+	el := newComponentBenchEventLoop(b, componentBenchTID)
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -160,7 +160,7 @@ func BenchmarkHandleFdExit(b *testing.B) {
 	gen := benchutil.NewEventGenerator()
 	enterTemplate, _ := gen.EnterFdEvent(1, componentBenchPID, componentBenchTID, 99, types.SYS_ENTER_READ)
 	exitTemplate, _ := gen.ExitRetEvent(2, componentBenchPID, componentBenchTID, types.SYS_EXIT_READ, 128)
-	el := newComponentBenchEventLoop(componentBenchTID)
+	el := newComponentBenchEventLoop(b, componentBenchTID)
 	el.fdState().set(99, file.NewFd(99, "/tmp/fd", syscall.O_RDONLY))
 
 	b.ResetTimer()
@@ -184,7 +184,7 @@ func BenchmarkHandlePathExit(b *testing.B) {
 	gen := benchutil.NewEventGenerator()
 	enterTemplate, _ := gen.EnterPathEvent(1, componentBenchPID, componentBenchTID, "/tmp/path", types.SYS_ENTER_MKDIR)
 	exitTemplate, _ := gen.ExitRetEvent(2, componentBenchPID, componentBenchTID, types.SYS_EXIT_MKDIR, 0)
-	el := newComponentBenchEventLoop(componentBenchTID)
+	el := newComponentBenchEventLoop(b, componentBenchTID)
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -207,7 +207,7 @@ func BenchmarkHandleNameExit(b *testing.B) {
 	gen := benchutil.NewEventGenerator()
 	enterTemplate, _ := gen.EnterNameEvent(1, componentBenchPID, componentBenchTID, "/tmp/a", "/tmp/b", types.SYS_ENTER_RENAME)
 	exitTemplate, _ := gen.ExitRetEvent(2, componentBenchPID, componentBenchTID, types.SYS_EXIT_RENAME, 0)
-	el := newComponentBenchEventLoop(componentBenchTID)
+	el := newComponentBenchEventLoop(b, componentBenchTID)
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -230,7 +230,7 @@ func BenchmarkHandleNullExit(b *testing.B) {
 	gen := benchutil.NewEventGenerator()
 	enterTemplate, _ := gen.EnterNullEvent(1, componentBenchPID, componentBenchTID, types.SYS_ENTER_SYNC)
 	exitTemplate, _ := gen.ExitNullEvent(2, componentBenchPID, componentBenchTID, types.SYS_EXIT_SYNC)
-	el := newComponentBenchEventLoop(componentBenchTID)
+	el := newComponentBenchEventLoop(b, componentBenchTID)
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
@@ -253,7 +253,7 @@ func BenchmarkHandleFcntlExit(b *testing.B) {
 	gen := benchutil.NewEventGenerator()
 	enterTemplate, _ := gen.EnterFcntlEvent(1, componentBenchPID, componentBenchTID, 7, syscall.F_SETFL, syscall.O_NONBLOCK)
 	exitTemplate, _ := gen.ExitRetEvent(2, componentBenchPID, componentBenchTID, types.SYS_EXIT_FCNTL, 0)
-	el := newComponentBenchEventLoop(componentBenchTID)
+	el := newComponentBenchEventLoop(b, componentBenchTID)
 	el.fdState().set(7, file.NewFd(7, "/tmp/fcntl", syscall.O_RDONLY))
 
 	b.ResetTimer()
@@ -277,7 +277,7 @@ func BenchmarkHandleDup3Exit(b *testing.B) {
 	gen := benchutil.NewEventGenerator()
 	enterTemplate, _ := gen.EnterDup3Event(1, componentBenchPID, componentBenchTID, 9, syscall.O_CLOEXEC)
 	exitTemplate, _ := gen.ExitRetEvent(2, componentBenchPID, componentBenchTID, types.SYS_EXIT_DUP3, 10)
-	el := newComponentBenchEventLoop(componentBenchTID)
+	el := newComponentBenchEventLoop(b, componentBenchTID)
 	el.fdState().set(9, file.NewFd(9, "/tmp/dup3", syscall.O_RDONLY))
 
 	b.ResetTimer()
@@ -354,8 +354,9 @@ func benchmarkDeserialize[T recyclable](b *testing.B, raw []byte, decode func([]
 	}
 }
 
-func newComponentBenchEventLoop(tids ...uint32) *eventLoop {
-	el := newEventLoop(eventLoopConfig{})
+func newComponentBenchEventLoop(tb testing.TB, tids ...uint32) *eventLoop {
+	tb.Helper()
+	el := mustNewEventLoop(tb, eventLoopConfig{})
 	for _, tid := range tids {
 		el.setCachedComm(tid, fmt.Sprintf("bench-%d", tid))
 	}
diff --git a/internal/bench_pipeline_test.go b/internal/bench_pipeline_test.go
index 822e5a2..aa48302 100644
--- a/internal/bench_pipeline_test.go
+++ b/internal/bench_pipeline_test.go
@@ -70,7 +70,7 @@ func benchmarkPipelineMix(b *testing.B, mix benchutil.EventMix, events, numThrea
 		close(rawCh)
 
 		var pairCount int64
-		el := newEventLoop(eventLoopConfig{})
+		el := mustNewEventLoop(b, eventLoopConfig{})
 		preseedBenchComms(el, numThreads)
 		el.printCb = func(ep *event.Pair) {
 			pairCount++
diff --git a/internal/eventfilter.go b/internal/eventfilter.go
index 1e87fea..d49e612 100644
--- a/internal/eventfilter.go
+++ b/internal/eventfilter.go
@@ -15,12 +15,12 @@ type eventFilter struct {
 	pathFilter       string
 }
 
-func newEventFilter(commFilter, pathFilter string) *eventFilter {
+func newEventFilter(commFilter, pathFilter string) (*eventFilter, error) {
 	var ef eventFilter
 
 	if commFilter != "" {
-		if len(commFilter) > types.MAX_FILENAME_LENGTH {
-			panic(fmt.Sprintf("Comm filter's max size is %d", types.MAX_PROGNAME_LENGTH))
+		if len(commFilter) > types.MAX_PROGNAME_LENGTH {
+			return nil, fmt.Errorf("comm filter max size is %d (got %d)", types.MAX_PROGNAME_LENGTH, len(commFilter))
 		}
 		ef.commFilterEnable = true
 		ef.commFilter = commFilter
@@ -28,13 +28,13 @@ func newEventFilter(commFilter, pathFilter string) *eventFilter {
 
 	if pathFilter != "" {
 		if len(pathFilter) > types.MAX_FILENAME_LENGTH {
-			panic(fmt.Sprintf("Path filter's max size is %d", types.MAX_FILENAME_LENGTH))
+			return nil, fmt.Errorf("path filter max size is %d (got %d)", types.MAX_FILENAME_LENGTH, len(pathFilter))
 		}
 		ef.pathFilterEnable = true
 		ef.pathFilter = pathFilter
 	}
 
-	return &ef
+	return &ef, nil
 }
 
 func (ef *eventFilter) eventPair(ev *event.Pair) bool {
diff --git a/internal/eventloop.go b/internal/eventloop.go
index 6f14325..d95a441 100644
--- a/internal/eventloop.go
+++ b/internal/eventloop.go
@@ -181,12 +181,16 @@ type eventLoop struct {
 	done                    chan struct{}
 }
 
-func newEventLoop(cfg eventLoopConfig) *eventLoop {
+func newEventLoop(cfg eventLoopConfig) (*eventLoop, error) {
 	filesByFD := make(map[int32]file.File)
 	commsByTID := make(map[uint32]string)
+	filter, err := newEventFilter(cfg.commFilter, cfg.pathFilter)
+	if err != nil {
+		return nil, fmt.Errorf("create event filter: %w", err)
+	}
 
 	el := &eventLoop{
-		filter:         newEventFilter(cfg.commFilter, cfg.pathFilter),
+		filter:         filter,
 		enterEvs:       make(map[uint32]*event.Pair),
 		pendingHandles: make(map[uint32]string),
 		files:          filesByFD,
@@ -203,7 +207,7 @@ func newEventLoop(cfg eventLoopConfig) *eventLoop {
 	el.initRawHandlers()
 	el.configureOutputCallback()
 	el.seedTrackedPidComm()
-	return el
+	return el, nil
 }
 
 func (e *eventLoop) seedTrackedPidComm() {
diff --git a/internal/eventloop_constructor_test.go b/internal/eventloop_constructor_test.go
new file mode 100644
index 0000000..52ca570
--- /dev/null
+++ b/internal/eventloop_constructor_test.go
@@ -0,0 +1,41 @@
+package internal
+
+import (
+	"strings"
+	"testing"
+
+	"ior/internal/types"
+)
+
+func mustNewEventLoop(tb testing.TB, cfg eventLoopConfig) *eventLoop {
+	tb.Helper()
+	el, err := newEventLoop(cfg)
+	if err != nil {
+		tb.Fatalf("newEventLoop() error = %v", err)
+	}
+	return el
+}
+
+func TestNewEventFilterRejectsTooLongCommFilter(t *testing.T) {
+	tooLong := strings.Repeat("a", types.MAX_PROGNAME_LENGTH+1)
+	_, err := newEventFilter(tooLong, "")
+	if err == nil {
+		t.Fatalf("expected error for comm filter longer than %d", types.MAX_PROGNAME_LENGTH)
+	}
+}
+
+func TestNewEventFilterRejectsTooLongPathFilter(t *testing.T) {
+	tooLong := strings.Repeat("a", types.MAX_FILENAME_LENGTH+1)
+	_, err := newEventFilter("", tooLong)
+	if err == nil {
+		t.Fatalf("expected error for path filter longer than %d", types.MAX_FILENAME_LENGTH)
+	}
+}
+
+func TestNewEventLoopPropagatesFilterError(t *testing.T) {
+	tooLong := strings.Repeat("a", types.MAX_PROGNAME_LENGTH+1)
+	_, err := newEventLoop(eventLoopConfig{commFilter: tooLong})
+	if err == nil {
+		t.Fatalf("expected newEventLoop to propagate invalid filter error")
+	}
+}
diff --git a/internal/eventloop_error_handling_test.go b/internal/eventloop_error_handling_test.go
index 12f9b2f..8361dea 100644
--- a/internal/eventloop_error_handling_test.go
+++ b/internal/eventloop_error_handling_test.go
@@ -8,7 +8,7 @@ import (
 )
 
 func TestTracepointExitedMalformedOpenExitDoesNotPanicAndNotifies(t *testing.T) {
-	el := newEventLoop(eventLoopConfig{})
+	el := mustNewEventLoop(t, eventLoopConfig{})
 	warnings := make(chan string, 1)
 	el.warningCb = func(message string) { warnings <- message }
 
@@ -48,7 +48,7 @@ func TestTracepointExitedMalformedOpenExitDoesNotPanicAndNotifies(t *testing.T)
 }
 
 func TestTracepointExitedMalformedOpenByHandleAtExitDoesNotPanicAndNotifies(t *testing.T) {
-	el := newEventLoop(eventLoopConfig{})
+	el := mustNewEventLoop(t, eventLoopConfig{})
 	warnings := make(chan string, 1)
 	el.warningCb = func(message string) { warnings <- message }
 
@@ -84,7 +84,7 @@ func TestTracepointExitedMalformedOpenByHandleAtExitDoesNotPanicAndNotifies(t *t
 }
 
 func TestProcessRawEventUnknownTypeDoesNotPanicAndNotifies(t *testing.T) {
-	el := newEventLoop(eventLoopConfig{})
+	el := mustNewEventLoop(t, eventLoopConfig{})
 	warnings := make(chan string, 1)
 	el.warningCb = func(message string) { warnings <- message }
 
diff --git a/internal/eventloop_filter_test.go b/internal/eventloop_filter_test.go
index ddd6451..e9fa91b 100644
--- a/internal/eventloop_filter_test.go
+++ b/internal/eventloop_filter_test.go
@@ -21,7 +21,7 @@ func TestCommPropagation(t *testing.T) {
 	inCh := make(chan []byte)
 	outCh := make(chan *event.Pair)
 
-	el := newEventLoop(eventLoopConfig{})
+	el := mustNewEventLoop(t, eventLoopConfig{})
 	el.printCb = func(ev *event.Pair) { outCh <- ev }
 	go el.run(ctx, inCh)
 
diff --git a/internal/eventloop_test.go b/internal/eventloop_test.go
index 4ae8597..d1bcc16 100644
--- a/internal/eventloop_test.go
+++ b/internal/eventloop_test.go
@@ -96,7 +96,7 @@ func TestEventloop(t *testing.T) {
 			inCh := make(chan []byte)
 			outCh := make(chan *event.Pair)
 
-			el := newEventLoop(eventLoopConfig{})
+			el := mustNewEventLoop(t, eventLoopConfig{})
 			el.printCb = func(ev *event.Pair) { outCh <- ev }
 			go el.run(ctx, inCh)
 
@@ -142,7 +142,7 @@ func TestEventloop(t *testing.T) {
 }
 
 func TestHandleFdExitCloseClearsProcFdCache(t *testing.T) {
-	el := newEventLoop(eventLoopConfig{})
+	el := mustNewEventLoop(t, eventLoopConfig{})
 	pid := uint32(1001)
 	fd := int32(55)
 
@@ -170,7 +170,7 @@ func TestHandleFdExitCloseClearsProcFdCache(t *testing.T) {
 }
 
 func TestHandleFdExitCloseRangeClearsProcFdCacheRange(t *testing.T) {
-	el := newEventLoop(eventLoopConfig{})
+	el := mustNewEventLoop(t, eventLoopConfig{})
 	pid := uint32(2002)
 
 	el.setProcFdCache(10, pid, file.NewFd(10, "keep", syscall.O_RDONLY))
diff --git a/internal/ior.go b/internal/ior.go
index 7c1368a..b5f9091 100644
--- a/internal/ior.go
+++ b/internal/ior.go
@@ -432,7 +432,10 @@ func runTraceWithContext(parentCtx context.Context, started chan<- struct{}, con
 
 	signalTraceStarted(started)
 
-	el := newEventLoop(newEventLoopConfig(cfg))
+	el, err := newEventLoop(newEventLoopConfig(cfg))
+	if err != nil {
+		return err
+	}
 	if configure != nil {
 		configure(el)
 	}