chore: consider errno in NULL return

module-iterator.go

@@ -23,8 +23,9 @@ func (it *BPFObjectIterator) NextMap() *BPFMap {
 		startMapC = it.prevMap.bpfMap
 	}
 
-	bpfMapC := C.bpf_object__next_map(it.m.obj, startMapC)
+	bpfMapC, errno := C.bpf_object__next_map(it.m.obj, startMapC)
 	if bpfMapC == nil {
+		_ = errno // intentionally ignored
 		return nil
 	}
 
@@ -63,8 +64,9 @@ func (it *BPFObjectIterator) NextProgram() *BPFProg {
 		startProg = it.prevProg.prog
 	}
 
-	progC := C.bpf_object__next_program(it.m.obj, startProg)
+	progC, errno := C.bpf_object__next_program(it.m.obj, startProg)
 	if progC == nil {
+		_ = errno // intentionally ignored
 		return nil
 	}
 

module.go

@@ -330,9 +330,9 @@ func (m *Module) InitRingBuf(mapName string, eventsChan chan []byte) (*RingBuffe
 		return nil, fmt.Errorf("max ring buffers reached")
 	}
 
-	rbC := C.cgo_init_ring_buf(C.int(bpfMap.FileDescriptor()), C.uintptr_t(slot))
+	rbC, errno := C.cgo_init_ring_buf(C.int(bpfMap.FileDescriptor()), C.uintptr_t(slot))
 	if rbC == nil {
-		return nil, fmt.Errorf("failed to initialize ring buffer")
+		return nil, fmt.Errorf("failed to initialize ring buffer: %w", errno)
 	}
 
 	ringBuf := &RingBuffer{
@@ -365,10 +365,10 @@ func (m *Module) InitPerfBuf(mapName string, eventsChan chan []byte, lostChan ch
 		return nil, fmt.Errorf("max number of ring/perf buffers reached")
 	}
 
-	pbC := C.cgo_init_perf_buf(C.int(bpfMap.FileDescriptor()), C.int(pageCnt), C.uintptr_t(slot))
+	pbC, errno := C.cgo_init_perf_buf(C.int(bpfMap.FileDescriptor()), C.int(pageCnt), C.uintptr_t(slot))
 	if pbC == nil {
 		eventChannels.remove(uint(slot))
-		return nil, fmt.Errorf("failed to initialize perf buffer")
+		return nil, fmt.Errorf("failed to initialize perf buffer: %w", errno)
 	}
 
 	perfBuf.pb = pbC