*: remove unused parameters and tautological conditions

These get flagged by gopls and always stick around in my editor,
so I decided to get rid of them. There's currently no way to run
the gopls linters in CI, so not modifying the linter config at this time.

Signed-off-by: Timo Beckers <[email protected]>

btf/ext_info.go

@@ -799,7 +799,7 @@ func parseCORERelos(r io.Reader, bo binary.ByteOrder, strings *stringTable) (map
 			return nil, err
 		}
 
-		records, err := parseCOREReloRecords(r, bo, recordSize, infoHeader.NumInfo)
+		records, err := parseCOREReloRecords(r, bo, infoHeader.NumInfo)
 		if err != nil {
 			return nil, fmt.Errorf("section %v: %w", secName, err)
 		}
@@ -811,7 +811,7 @@ func parseCORERelos(r io.Reader, bo binary.ByteOrder, strings *stringTable) (map
 // parseCOREReloRecords parses a stream of CO-RE relocation entries into a
 // coreRelos. These records appear after a btf_ext_info_sec header in the
 // core_relos sub-section of .BTF.ext.
-func parseCOREReloRecords(r io.Reader, bo binary.ByteOrder, recordSize uint32, recordNum uint32) ([]bpfCORERelo, error) {
+func parseCOREReloRecords(r io.Reader, bo binary.ByteOrder, recordNum uint32) ([]bpfCORERelo, error) {
 	var out []bpfCORERelo
 
 	var relo bpfCORERelo

btf/marshal_test.go

@@ -82,7 +82,7 @@ func TestRoundtripVMlinux(t *testing.T) {
 	visited := make(map[Type]struct{})
 limitTypes:
 	for i, typ := range types {
-		visitInPostorder(typ, visited, func(t Type) bool { return true })
+		visitInPostorder(typ, visited, func(_ Type) bool { return true })
 		if len(visited) >= math.MaxInt16 {
 			// IDs exceeding math.MaxUint16 can trigger a bug when loading BTF.
 			// This can be removed once the patch lands.

link/kprobe.go

@@ -177,7 +177,7 @@ func kprobe(symbol string, prog *ebpf.Program, opts *KprobeOptions, ret bool) (*
 	if err == nil {
 		return tp, nil
 	}
-	if err != nil && !errors.Is(err, ErrNotSupported) {
+	if !errors.Is(err, ErrNotSupported) {
 		return nil, fmt.Errorf("creating perf_kprobe PMU (arch-specific fallback for %q): %w", symbol, err)
 	}
 

link/kprobe_multi.go

@@ -126,7 +126,7 @@ type kprobeMultiLink struct {
 
 var _ Link = (*kprobeMultiLink)(nil)
 
-func (kml *kprobeMultiLink) Update(prog *ebpf.Program) error {
+func (kml *kprobeMultiLink) Update(_ *ebpf.Program) error {
 	return fmt.Errorf("update kprobe_multi: %w", ErrNotSupported)
 }
 

link/netfilter.go

@@ -63,7 +63,7 @@ func AttachNetfilter(opts NetfilterOptions) (Link, error) {
 	return &netfilterLink{RawLink{fd, ""}}, nil
 }
 
-func (*netfilterLink) Update(new *ebpf.Program) error {
+func (*netfilterLink) Update(_ *ebpf.Program) error {
 	return fmt.Errorf("netfilter update: %w", ErrNotSupported)
 }
 

link/perf_event.go

@@ -115,7 +115,7 @@ func (pl *perfEventLink) Close() error {
 	return nil
 }
 
-func (pl *perfEventLink) Update(prog *ebpf.Program) error {
+func (pl *perfEventLink) Update(_ *ebpf.Program) error {
 	return fmt.Errorf("perf event link update: %w", ErrNotSupported)
 }
 
@@ -185,7 +185,7 @@ func (pi *perfEventIoctl) isLink() {}
 //
 // Detaching a program from a perf event is currently not possible, so a
 // program replacement mechanism cannot be implemented for perf events.
-func (pi *perfEventIoctl) Update(prog *ebpf.Program) error {
+func (pi *perfEventIoctl) Update(_ *ebpf.Program) error {
 	return fmt.Errorf("perf event ioctl update: %w", ErrNotSupported)
 }
 

link/tracing.go

@@ -14,7 +14,7 @@ type tracing struct {
 	RawLink
 }
 
-func (f *tracing) Update(new *ebpf.Program) error {
+func (f *tracing) Update(_ *ebpf.Program) error {
 	return fmt.Errorf("tracing update: %w", ErrNotSupported)
 }
 

link/uprobe.go

@@ -321,7 +321,7 @@ func (ex *Executable) uprobe(symbol string, prog *ebpf.Program, opts *UprobeOpti
 	if err == nil {
 		return tp, nil
 	}
-	if err != nil && !errors.Is(err, ErrNotSupported) {
+	if !errors.Is(err, ErrNotSupported) {
 		return nil, fmt.Errorf("creating perf_uprobe PMU: %w", err)
 	}
 

link/uprobe_multi.go

@@ -168,7 +168,7 @@ type uprobeMultiLink struct {
 
 var _ Link = (*uprobeMultiLink)(nil)
 
-func (kml *uprobeMultiLink) Update(prog *ebpf.Program) error {
+func (kml *uprobeMultiLink) Update(_ *ebpf.Program) error {
 	return fmt.Errorf("update uprobe_multi: %w", ErrNotSupported)
 }
 

map.go

@@ -359,7 +359,7 @@ func newMapWithOptions(spec *MapSpec, opts MapOptions) (_ *Map, err error) {
 			return nil, errors.New("inner maps cannot be pinned")
 		}
 
-		template, err := spec.InnerMap.createMap(nil, opts)
+		template, err := spec.InnerMap.createMap(nil)
 		if err != nil {
 			return nil, fmt.Errorf("inner map: %w", err)
 		}
@@ -371,7 +371,7 @@ func newMapWithOptions(spec *MapSpec, opts MapOptions) (_ *Map, err error) {
 		innerFd = template.fd
 	}
 
-	m, err := spec.createMap(innerFd, opts)
+	m, err := spec.createMap(innerFd)
 	if err != nil {
 		return nil, err
 	}
@@ -389,7 +389,7 @@ func newMapWithOptions(spec *MapSpec, opts MapOptions) (_ *Map, err error) {
 
 // createMap validates the spec's properties and creates the map in the kernel
 // using the given opts. It does not populate or freeze the map.
-func (spec *MapSpec) createMap(inner *sys.FD, opts MapOptions) (_ *Map, err error) {
+func (spec *MapSpec) createMap(inner *sys.FD) (_ *Map, err error) {
 	closeOnError := func(closer io.Closer) {
 		if err != nil {
 			closer.Close()