linters: add go-simple and fix corresponding alerts

Gosimple is beneficial since it makes the code more readable and
proposes simplification of things which can make things more efficient
if not already optimized by the compiler.

Signed-off-by: Mahe Tardy <[email protected]>

.golangci.yml

@@ -18,6 +18,7 @@ linters:
     - revive
     - staticcheck
     - unused
+    - gosimple
 
 linters-settings:
   goheader:

cmd/protoc-gen-go-tetragon/common/common.go

@@ -134,11 +134,7 @@ func FmtSprintf(g *protogen.GeneratedFile, fmt_ string, args ...string) string {
 
 // EventFieldCheck returns true if the event has the field
 func EventFieldCheck(msg *protogen.Message, field string) bool {
-	if msg.Desc.Fields().ByName(protoreflect.Name(field)) != nil {
-		return true
-	}
-
-	return false
+	return msg.Desc.Fields().ByName(protoreflect.Name(field)) != nil
 }
 
 // IsProcessEvent returns true if the message is an Tetragon event that has a process field

cmd/tetragon-vmtests-run/qemu.go

@@ -55,7 +55,7 @@ func buildQemuArgs(log *logrus.Logger, rcnf *RunConf) ([]string, error) {
 		}
 		qemuArgs = append(qemuArgs,
 			"-kernel", rcnf.kernelFname,
-			"-append", fmt.Sprintf("%s", strings.Join(appendArgs, " ")),
+			"-append", strings.Join(appendArgs, " "),
 		)
 	}
 

cmd/tetragon/main.go

@@ -154,7 +154,7 @@ func tetragonExecute() error {
 		log.Fatal(err)
 	}
 
-	if filepath.IsAbs(option.Config.TracingPolicyDir) == false {
+	if !filepath.IsAbs(option.Config.TracingPolicyDir) {
 		log.Fatalf("Failed path specified by --tracing-policy-dir '%q' is not absolute", option.Config.TracingPolicyDir)
 	}
 	option.Config.TracingPolicyDir = filepath.Clean(option.Config.TracingPolicyDir)
@@ -488,7 +488,7 @@ func tetragonExecute() error {
 	}
 
 	// k8s should have metrics, so periodically log only in a non k8s
-	if option.Config.EnableK8s == false {
+	if !option.Config.EnableK8s {
 		go logStatus(ctx, obs)
 	}
 
@@ -526,7 +526,7 @@ func loadTpFromDir(ctx context.Context, dir string) error {
 			return err
 		}
 
-		if st.Mode().IsRegular() == false {
+		if !st.Mode().IsRegular() {
 			return nil
 		}
 

pkg/btf/validation_test.go

@@ -5,7 +5,6 @@ package btf
 
 import (
 	"errors"
-	"fmt"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -55,7 +54,7 @@ func TestSpecs(t *testing.T) {
 	// NB: for now we check against a single BTF file.
 	btfFname := filepath.Join(testdataPath, "btf", "vmlinux-5.4.104+")
 	if _, err := os.Stat(btfFname); err != nil {
-		t.Skip(fmt.Sprintf("%s not found", btfFname))
+		t.Skipf("%s not found", btfFname)
 	}
 	btf, err := btf.LoadSpec(btfFname)
 	if err != nil {

pkg/cgroups/cgroups.go

@@ -238,7 +238,7 @@ func parseCgroupSubSysIds(filePath string) error {
 	}).Debugf("Cgroup available controllers")
 
 	// Could not find 'memory', 'pids' nor 'cpuset' controllers, are they compiled in?
-	if fixed == false {
+	if !fixed {
 		err = fmt.Errorf("detect cgroup controllers IDs from '%s' failed", filePath)
 		logger.GetLogger().WithFields(logrus.Fields{
 			"cgroup.fs": cgroupFSPath,
@@ -278,7 +278,7 @@ func setDeploymentMode(cgroupPath string) error {
 		return nil
 	}
 
-	if option.Config.EnableK8s == true {
+	if option.Config.EnableK8s {
 		deploymentMode = DEPLOY_K8S
 		return nil
 	}
@@ -354,7 +354,7 @@ func GetCgrpControllerName() string {
 func getValidCgroupv1Path(cgroupPaths []string) (string, error) {
 	for _, controller := range CgroupControllers {
 		// First lets go again over list of active controllers
-		if controller.Active == false {
+		if !controller.Active {
 			logger.GetLogger().WithField("cgroup.fs", cgroupFSPath).Debugf("Cgroup controller '%s' is not active", controller.Name)
 			continue
 		}

pkg/encoder/encoder.go

@@ -162,7 +162,7 @@ const (
 
 func CapTrailorPrinter(str string, caps string) string {
 	if len(caps) == 0 {
-		return fmt.Sprintf("%s", str)
+		return str
 	}
 	padding := 0
 	if len(str) < capsPad {

pkg/eventcheckertests/yamlhelpers/yamlhelpers.go

@@ -42,17 +42,11 @@ func AssertUnmarshalRoundTrip(t *testing.T, b []byte, o interface{}) bool {
 // AssertUnmarshal unmarshals an object and makes sure that it unmarshals
 func AssertUnmarshal(t *testing.T, b []byte, o interface{}) bool {
 	err := yaml.Unmarshal(b, o)
-	if !assert.NoError(t, err, "`%v` should unmarshal", o) {
-		return false
-	}
-	return true
+	return assert.NoError(t, err, "`%v` should unmarshal", o)
 }
 
 // AssertMarshal unmarshals an object and makes sure that it unmarshals
 func AssertMarshal(t *testing.T, b []byte, o interface{}) bool {
 	_, err := yaml.Marshal(o)
-	if !assert.NoError(t, err, "`%s` should marshal", string(b)) {
-		return false
-	}
-	return true
+	return assert.NoError(t, err, "`%s` should marshal", string(b))
 }

pkg/fieldfilters/fields.go

@@ -68,7 +68,7 @@ func fixupFieldFilterString(s string) string {
 	dec := json.NewDecoder(strings.NewReader(s))
 	enc := json.NewEncoder(builder)
 
-	for true {
+	for {
 		var dat map[string]interface{}
 		err := dec.Decode(&dat)
 		if err != nil {

pkg/idtable/idtable.go

@@ -72,7 +72,6 @@ func (t *Table) AddEntry(entry Entry) {
 	idx := t.findEmpty()
 	t.arr[idx] = entry
 	entry.SetID(EntryID{idx})
-	return
 }
 
 func (t *Table) getValidEntryIndex(id EntryID) (int, error) {

pkg/kernels/kernels.go

@@ -119,10 +119,7 @@ func MinKernelVersion(kernel string) bool {
 	runningVersion := int(KernelStringToNumeric(release))
 	minVersion := int(KernelStringToNumeric(kernel))
 
-	if minVersion <= runningVersion {
-		return true
-	}
-	return false
+	return minVersion <= runningVersion
 }
 
 func EnableV61Progs() bool {

pkg/observer/observer.go

@@ -429,7 +429,7 @@ func (k *Observer) LogPinnedBpf(observerDir string) {
 		return
 	}
 
-	if finfo.IsDir() == false {
+	if !finfo.IsDir() {
 		err := fmt.Errorf("is not a directory")
 		k.log.WithField("bpf-dir", observerDir).WithError(err).Warn("BPF: checking BPF resources failed")
 		// Do not fail, let bpf part handle it

pkg/option/config.go

@@ -161,7 +161,7 @@ func ReadConfigFile(path string, file string) error {
 	if err != nil {
 		return err
 	}
-	if st.Mode().IsRegular() == false {
+	if !st.Mode().IsRegular() {
 		return fmt.Errorf("failed to read config file '%s' not a regular file", file)
 	}
 
@@ -179,7 +179,7 @@ func ReadConfigDir(path string) error {
 	if err != nil {
 		return err
 	}
-	if st.IsDir() == false {
+	if !st.IsDir() {
 		return fmt.Errorf("'%s' is not a directory", path)
 	}
 

pkg/pidfile/pidfile.go

@@ -57,9 +57,7 @@ func Create() (uint64, error) {
 		return pid, ErrPidIsStillAlive
 	}
 
-	if err != nil &&
-		errors.Is(err, ErrPidFileAccess) == false &&
-		errors.Is(err, ErrPidIsNotAlive) == false {
+	if err != nil && !errors.Is(err, ErrPidFileAccess) && !errors.Is(err, ErrPidIsNotAlive) {
 		return 0, err
 	}
 

pkg/policyfilter/k8s_test.go

@@ -565,7 +565,7 @@ func TestK8s(t *testing.T) {
 	ts := newTestState(client)
 	st, err := newState(log, ts)
 	if err != nil {
-		t.Skip(fmt.Sprintf("failed to initialize policy filter state: %s", err))
+		t.Skipf("failed to initialize policy filter state: %s", err)
 	}
 	defer st.Close()
 

pkg/policyfilter/state_test.go

@@ -4,7 +4,6 @@
 package policyfilter
 
 import (
-	"fmt"
 	"testing"
 
 	"github.com/google/uuid"
@@ -14,7 +13,7 @@ import (
 func TestState(t *testing.T) {
 	s, err := New()
 	if err != nil {
-		t.Skip(fmt.Sprintf("failed to inialize policy filter state: %s", err))
+		t.Skipf("failed to inialize policy filter state: %s", err)
 	}
 	defer s.Close()
 

pkg/process/args.go

@@ -11,10 +11,7 @@ import (
 )
 
 func argsDecoderTrim(r rune) bool {
-	if r == 0x00 {
-		return true
-	}
-	return false
+	return r == 0x00
 }
 
 func ArgsDecoder(s string, flags uint32) (string, string) {

pkg/process/process.go

@@ -183,7 +183,7 @@ func (pi *ProcessInternal) UpdateExecOutsideCache(cred bool) (*tetragon.Process,
 
 	// Take a copy of the process, add the necessary fields to the
 	// final ProcessExec event
-	if update == true {
+	if update {
 		process = pi.GetProcessCopy()
 		process.BinaryProperties = prop
 	}

pkg/reader/namespace/namespace.go

@@ -61,7 +61,7 @@ func GetMyPidG() uint32 {
 	if procfs := os.Getenv("TETRAGON_PROCFS"); procfs != "" {
 		procFS, _ := os.ReadDir(procfs)
 		for _, d := range procFS {
-			if d.IsDir() == false {
+			if !d.IsDir() {
 				continue
 			}
 			cmdline, err := os.ReadFile(filepath.Join(procfs, d.Name(), "/cmdline"))
@@ -228,7 +228,7 @@ func initHostNamespace() (*tetragon.Namespaces, error) {
 	for _, n := range listNamespaces {
 		ino, err := GetPidNsInode(1, n)
 		if err != nil {
-			if (n == "time" || n == "time_for_children") && TimeNsSupport == false {
+			if (n == "time" || n == "time_for_children") && !TimeNsSupport {
 				// Explicitly initialize host time namespace to zero which indicates
 				// kernel does not support it.
 				knownNamespaces[n] = &tetragon.Namespace{Inum: 0, IsHost: false}

pkg/selectors/kernel.go

@@ -1100,7 +1100,7 @@ func ParseMatchNamespaceChanges(k *KernelSelectorState, actions []v1alpha1.Names
 	if len(actions) > 1 {
 		return fmt.Errorf("matchNamespaceChanges supports only a single filter (current number of filters is %d)", len(actions))
 	}
-	if (len(actions) == 1) && (kernels.EnableLargeProgs() == false) {
+	if (len(actions) == 1) && !kernels.EnableLargeProgs() {
 		return fmt.Errorf("matchNamespaceChanges is only supported in kernels >= 5.3")
 	}
 	loff := AdvanceSelectorLength(&k.data)
@@ -1333,7 +1333,7 @@ func InitKernelSelectorState(selectors []v1alpha1.KProbeSelector, args []v1alpha
 func HasOverride(spec *v1alpha1.KProbeSpec) bool {
 	for _, s := range spec.Selectors {
 		for _, action := range s.MatchActions {
-			act, _ := actionTypeTable[strings.ToLower(action.Action)]
+			act := actionTypeTable[strings.ToLower(action.Action)]
 			if act == ActionTypeOverride {
 				return true
 			}

pkg/selectors/kernel_test.go

@@ -819,7 +819,7 @@ func TestInitKernelSelectors(t *testing.T) {
 	var actionArgTable idtable.Table
 
 	b, _ := InitKernelSelectors(selectors, args, &actionArgTable)
-	if bytes.Equal(expected[0:len(expected)], b[0:len(expected)]) == false {
+	if bytes.Equal(expected[0:], b[0:len(expected)]) == false {
 		t.Errorf("InitKernelSelectors:\nexpected %v\nbytes    %v\n", expected, b[0:len(expected)])
 	}
 }

pkg/sensors/exec/exit_test.go

@@ -44,9 +44,7 @@ func TestExit(t *testing.T) {
 	execChecker := ec.NewProcessExecChecker("exec").WithProcess(procChecker)
 	exitChecker := ec.NewProcessExitChecker("exit").WithProcess(procChecker)
 
-	var checker *ec.UnorderedEventChecker
-
-	checker = ec.NewUnorderedEventChecker(execChecker, exitChecker)
+	checker := ec.NewUnorderedEventChecker(execChecker, exitChecker)
 
 	if err := exec.Command(testNop).Run(); err != nil {
 		t.Fatalf("Failed to execute test binary: %s\n", err)

pkg/sensors/exec/procevents/proc.go

@@ -72,7 +72,7 @@ func LookupContainerId(cgroup string, bpfSource bool, walkParent bool) (string,
 	// We trust BPF part that it will always return null terminated
 	// DOCKER_ID_LENGTH. For other cases where we read through /proc/
 	// strings are not truncated.
-	if bpfSource == true && len(subdir) >= processapi.DOCKER_ID_LENGTH-1 {
+	if bpfSource && len(subdir) >= processapi.DOCKER_ID_LENGTH-1 {
 		idTruncated = true
 	}
 
@@ -86,7 +86,7 @@ func LookupContainerId(cgroup string, bpfSource bool, walkParent bool) (string,
 	// walkParent argument set and get its parent cgroup
 	if !strings.HasSuffix(container, "service") &&
 		((len(container) >= ContainerIdLength) ||
-			(idTruncated == true && len(container) >= BpfContainerIdLength)) {
+			(idTruncated && len(container) >= BpfContainerIdLength)) {
 		// Return first 31 chars. If the string is less than 31 chars
 		// it's not a docker ID so skip it. For example docker.server
 		// will get here.

pkg/sensors/exec/procevents/proc_reader.go

@@ -346,7 +346,7 @@ func listRunningProcs(procPath string) ([]procs, error) {
 		var pexecPath string
 		var pnspid uint32
 
-		if d.IsDir() == false {
+		if !d.IsDir() {
 			continue
 		}
 
@@ -436,7 +436,7 @@ func listRunningProcs(procPath string) ([]procs, error) {
 		}
 		time_ns := uint32(0)
 		time_for_children_ns := uint32(0)
-		if namespace.TimeNsSupport == true {
+		if namespace.TimeNsSupport {
 			time_ns, err = namespace.GetPidNsInode(uint32(pid), "time")
 			if err != nil {
 				logger.GetLogger().WithError(err).Warnf("Reading time namespace failed")

pkg/sensors/exec/threads_test.go

@@ -127,20 +127,18 @@ func TestMatchCloneThreadsIDs(t *testing.T) {
 	clonePID, cloneTID := uint32(0), uint32(0)
 	events := perfring.RunTestEvents(t, ctx, ops)
 	for _, ev := range events {
-		switch ev.(type) {
+		switch ev := ev.(type) {
 		case *grpcexec.MsgExecveEventUnix:
-			exec := ev.(*grpcexec.MsgExecveEventUnix)
-			if exec.Process.Filename == testBin {
-				execPID = exec.Process.PID
-				execTID = exec.Process.TID
+			if ev.Process.Filename == testBin {
+				execPID = ev.Process.PID
+				execTID = ev.Process.TID
 			}
 		case *grpcexec.MsgCloneEventUnix:
-			msg := ev.(*grpcexec.MsgCloneEventUnix)
 			// We found the exec parent then catch the single per thread
 			// clone event
 			if execPID != 0 && clonePID == 0 {
-				clonePID = msg.PID
-				cloneTID = msg.TID
+				clonePID = ev.PID
+				cloneTID = ev.TID
 			}
 		}
 	}

pkg/sensors/program/loader.go

@@ -751,7 +751,7 @@ func doLoadProgram(
 					if verbose < 2 {
 						fmt.Println(slimVerifierError(fmt.Sprintf("%+v", ve)))
 					} else {
-						fmt.Println(fmt.Sprintf("%+v", ve))
+						fmt.Printf("%+v\n", ve)
 					}
 				}
 			}

pkg/sensors/tracing/generickprobe.go

@@ -446,7 +446,7 @@ func preValidateKprobes(name string, kprobes []v1alpha1.KProbeSpec, lists []v1al
 			}
 			if !f.Syscall {
 				for idx := range calls {
-					if strings.HasPrefix(calls[idx], "security_") == false {
+					if !strings.HasPrefix(calls[idx], "security_") {
 						return fmt.Errorf("Error override action can be used only with syscalls and security_ hooks")
 					}
 				}
@@ -756,7 +756,7 @@ func addKprobe(funcName string, f *v1alpha1.KProbeSpec, in *addKprobeIn) (id idt
 	// Mark remaining arguments as 'nops' the kernel side will skip
 	// copying 'nop' args.
 	for j, a := range argsBTFSet {
-		if a == false {
+		if !a {
 			if j != api.ReturnArgIndex {
 				config.Arg[j] = gt.GenericNopType
 				config.ArgM[j] = 0