TUN-9467: bump coredns to solve CVE

* TUN-9467: bump coredns to solve CVE

vendor/go.opentelemetry.io/otel/sdk/trace/batch_span_processor.go

@@ -201,10 +201,9 @@ func (bsp *batchSpanProcessor) ForceFlush(ctx context.Context) error {
 			}
 		}
 
-		wait := make(chan error)
+		wait := make(chan error, 1)
 		go func() {
 			wait <- bsp.exportSpans(ctx)
-			close(wait)
 		}()
 		// Wait until the export is finished or the context is cancelled/timed out
 		select {
@@ -280,6 +279,7 @@ func (bsp *batchSpanProcessor) exportSpans(ctx context.Context) error {
 		//
 		// It is up to the exporter to implement any type of retry logic if a batch is failing
 		// to be exported, since it is specific to the protocol and backend being sent to.
+		clear(bsp.batch) // Erase elements to let GC collect objects
 		bsp.batch = bsp.batch[:0]
 
 		if err != nil {
@@ -316,7 +316,11 @@ func (bsp *batchSpanProcessor) processQueue() {
 			bsp.batchMutex.Unlock()
 			if shouldExport {
 				if !bsp.timer.Stop() {
-					<-bsp.timer.C
+					// Handle both GODEBUG=asynctimerchan=[0|1] properly.
+					select {
+					case <-bsp.timer.C:
+					default:
+					}
 				}
 				if err := bsp.exportSpans(ctx); err != nil {
 					otel.Handle(err)
@@ -381,7 +385,7 @@ func (bsp *batchSpanProcessor) enqueueBlockOnQueueFull(ctx context.Context, sd R
 	}
 }
 
-func (bsp *batchSpanProcessor) enqueueDrop(ctx context.Context, sd ReadOnlySpan) bool {
+func (bsp *batchSpanProcessor) enqueueDrop(_ context.Context, sd ReadOnlySpan) bool {
 	if !sd.SpanContext().IsSampled() {
 		return false
 	}

vendor/go.opentelemetry.io/otel/sdk/trace/evictedqueue.go

@@ -3,23 +3,44 @@
 
 package trace // import "go.opentelemetry.io/otel/sdk/trace"
 
+import (
+	"slices"
+	"sync"
+
+	"go.opentelemetry.io/otel/internal/global"
+)
+
 // evictedQueue is a FIFO queue with a configurable capacity.
-type evictedQueue struct {
-	queue        []interface{}
-	capacity     int
-	droppedCount int
+type evictedQueue[T any] struct {
+	queue          []T
+	capacity       int
+	droppedCount   int
+	logDroppedMsg  string
+	logDroppedOnce sync.Once
 }
 
-func newEvictedQueue(capacity int) evictedQueue {
+func newEvictedQueueEvent(capacity int) evictedQueue[Event] {
 	// Do not pre-allocate queue, do this lazily.
-	return evictedQueue{capacity: capacity}
+	return evictedQueue[Event]{
+		capacity:      capacity,
+		logDroppedMsg: "limit reached: dropping trace trace.Event",
+	}
+}
+
+func newEvictedQueueLink(capacity int) evictedQueue[Link] {
+	// Do not pre-allocate queue, do this lazily.
+	return evictedQueue[Link]{
+		capacity:      capacity,
+		logDroppedMsg: "limit reached: dropping trace trace.Link",
+	}
 }
 
 // add adds value to the evictedQueue eq. If eq is at capacity, the oldest
 // queued value will be discarded and the drop count incremented.
-func (eq *evictedQueue) add(value interface{}) {
+func (eq *evictedQueue[T]) add(value T) {
 	if eq.capacity == 0 {
 		eq.droppedCount++
+		eq.logDropped()
 		return
 	}
 
@@ -28,6 +49,16 @@ func (eq *evictedQueue) add(value interface{}) {
 		copy(eq.queue[:eq.capacity-1], eq.queue[1:])
 		eq.queue = eq.queue[:eq.capacity-1]
 		eq.droppedCount++
+		eq.logDropped()
 	}
 	eq.queue = append(eq.queue, value)
 }
+
+func (eq *evictedQueue[T]) logDropped() {
+	eq.logDroppedOnce.Do(func() { global.Warn(eq.logDroppedMsg) })
+}
+
+// copy returns a copy of the evictedQueue.
+func (eq *evictedQueue[T]) copy() []T {
+	return slices.Clone(eq.queue)
+}

vendor/go.opentelemetry.io/otel/sdk/trace/id_generator.go

@@ -41,7 +41,12 @@ func (gen *randomIDGenerator) NewSpanID(ctx context.Context, traceID trace.Trace
 	gen.Lock()
 	defer gen.Unlock()
 	sid := trace.SpanID{}
-	_, _ = gen.randSource.Read(sid[:])
+	for {
+		_, _ = gen.randSource.Read(sid[:])
+		if sid.IsValid() {
+			break
+		}
+	}
 	return sid
 }
 
@@ -51,9 +56,19 @@ func (gen *randomIDGenerator) NewIDs(ctx context.Context) (trace.TraceID, trace.
 	gen.Lock()
 	defer gen.Unlock()
 	tid := trace.TraceID{}
-	_, _ = gen.randSource.Read(tid[:])
 	sid := trace.SpanID{}
-	_, _ = gen.randSource.Read(sid[:])
+	for {
+		_, _ = gen.randSource.Read(tid[:])
+		if tid.IsValid() {
+			break
+		}
+	}
+	for {
+		_, _ = gen.randSource.Read(sid[:])
+		if sid.IsValid() {
+			break
+		}
+	}
 	return tid, sid
 }
 

vendor/go.opentelemetry.io/otel/sdk/trace/provider.go

@@ -139,9 +139,10 @@ func (p *TracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.T
 		name = defaultTracerName
 	}
 	is := instrumentation.Scope{
-		Name:      name,
-		Version:   c.InstrumentationVersion(),
-		SchemaURL: c.SchemaURL(),
+		Name:       name,
+		Version:    c.InstrumentationVersion(),
+		SchemaURL:  c.SchemaURL(),
+		Attributes: c.InstrumentationAttributes(),
 	}
 
 	t, ok := func() (trace.Tracer, bool) {
@@ -168,7 +169,7 @@ func (p *TracerProvider) Tracer(name string, opts ...trace.TracerOption) trace.T
 		//   slowing down all tracing consumers.
 		// - Logging code may be instrumented with tracing and deadlock because it could try
 		//   acquiring the same non-reentrant mutex.
-		global.Info("Tracer created", "name", name, "version", is.Version, "schemaURL", is.SchemaURL)
+		global.Info("Tracer created", "name", name, "version", is.Version, "schemaURL", is.SchemaURL, "attributes", is.Attributes)
 	}
 	return t
 }
@@ -291,7 +292,7 @@ func (p *TracerProvider) Shutdown(ctx context.Context) error {
 				retErr = err
 			} else {
 				// Poor man's list of errors
-				retErr = fmt.Errorf("%v; %v", retErr, err)
+				retErr = fmt.Errorf("%w; %w", retErr, err)
 			}
 		}
 	}

vendor/go.opentelemetry.io/otel/sdk/trace/sampler_env.go

@@ -5,7 +5,6 @@ package trace // import "go.opentelemetry.io/otel/sdk/trace"
 
 import (
 	"errors"
-	"fmt"
 	"os"
 	"strconv"
 	"strings"
@@ -26,7 +25,7 @@ const (
 type errUnsupportedSampler string
 
 func (e errUnsupportedSampler) Error() string {
-	return fmt.Sprintf("unsupported sampler: %s", string(e))
+	return "unsupported sampler: " + string(e)
 }
 
 var (
@@ -39,7 +38,7 @@ type samplerArgParseError struct {
 }
 
 func (e samplerArgParseError) Error() string {
-	return fmt.Sprintf("parsing sampler argument: %s", e.parseErr.Error())
+	return "parsing sampler argument: " + e.parseErr.Error()
 }
 
 func (e samplerArgParseError) Unwrap() error {

vendor/go.opentelemetry.io/otel/sdk/trace/sampling.go

@@ -47,12 +47,12 @@ const (
 	// Drop will not record the span and all attributes/events will be dropped.
 	Drop SamplingDecision = iota
 
-	// Record indicates the span's `IsRecording() == true`, but `Sampled` flag
-	// *must not* be set.
+	// RecordOnly indicates the span's IsRecording method returns true, but trace.FlagsSampled flag
+	// must not be set.
 	RecordOnly
 
-	// RecordAndSample has span's `IsRecording() == true` and `Sampled` flag
-	// *must* be set.
+	// RecordAndSample indicates the span's IsRecording method returns true and trace.FlagsSampled flag
+	// must be set.
 	RecordAndSample
 )
 

vendor/go.opentelemetry.io/otel/sdk/trace/simple_span_processor.go

@@ -58,7 +58,7 @@ func (ssp *simpleSpanProcessor) Shutdown(ctx context.Context) error {
 	var err error
 	ssp.stopOnce.Do(func() {
 		stopFunc := func(exp SpanExporter) (<-chan error, func()) {
-			done := make(chan error)
+			done := make(chan error, 1)
 			return done, func() { done <- exp.Shutdown(ctx) }
 		}
 

vendor/go.opentelemetry.io/otel/sdk/trace/snapshot.go

@@ -99,7 +99,7 @@ func (s snapshot) InstrumentationScope() instrumentation.Scope {
 
 // InstrumentationLibrary returns information about the instrumentation
 // library that created the span.
-func (s snapshot) InstrumentationLibrary() instrumentation.Library {
+func (s snapshot) InstrumentationLibrary() instrumentation.Library { //nolint:staticcheck // This method needs to be define for backwards compatibility
 	return s.instrumentationScope
 }
 

vendor/go.opentelemetry.io/otel/sdk/trace/span.go

@@ -17,10 +17,10 @@ import (
 
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/internal/global"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
-	"go.opentelemetry.io/otel/sdk/internal"
 	"go.opentelemetry.io/otel/sdk/resource"
-	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 	"go.opentelemetry.io/otel/trace"
 	"go.opentelemetry.io/otel/trace/embedded"
 )
@@ -62,7 +62,7 @@ type ReadOnlySpan interface {
 	// InstrumentationLibrary returns information about the instrumentation
 	// library that created the span.
 	// Deprecated: please use InstrumentationScope instead.
-	InstrumentationLibrary() instrumentation.Library
+	InstrumentationLibrary() instrumentation.Library //nolint:staticcheck // This method needs to be define for backwards compatibility
 	// Resource returns information about the entity that produced the span.
 	Resource() *resource.Resource
 	// DroppedAttributes returns the number of attributes dropped by the span
@@ -137,12 +137,13 @@ type recordingSpan struct {
 	// ReadOnlySpan exported when the span ends.
 	attributes        []attribute.KeyValue
 	droppedAttributes int
+	logDropAttrsOnce  sync.Once
 
 	// events are stored in FIFO queue capped by configured limit.
-	events evictedQueue
+	events evictedQueue[Event]
 
 	// links are stored in FIFO queue capped by configured limit.
-	links evictedQueue
+	links evictedQueue[Link]
 
 	// executionTracerTaskEnd ends the execution tracer span.
 	executionTracerTaskEnd func()
@@ -173,6 +174,17 @@ func (s *recordingSpan) IsRecording() bool {
 	s.mu.Lock()
 	defer s.mu.Unlock()
 
+	return s.isRecording()
+}
+
+// isRecording returns if this span is being recorded. If this span has ended
+// this will return false.
+//
+// This method assumes s.mu.Lock is held by the caller.
+func (s *recordingSpan) isRecording() bool {
+	if s == nil {
+		return false
+	}
 	return s.endTime.IsZero()
 }
 
@@ -181,11 +193,15 @@ func (s *recordingSpan) IsRecording() bool {
 // included in the set status when the code is for an error. If this span is
 // not being recorded than this method does nothing.
 func (s *recordingSpan) SetStatus(code codes.Code, description string) {
-	if !s.IsRecording() {
+	if s == nil {
 		return
 	}
+
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	if !s.isRecording() {
+		return
+	}
 	if s.status.Code > code {
 		return
 	}
@@ -209,17 +225,20 @@ func (s *recordingSpan) SetStatus(code codes.Code, description string) {
 // attributes the span is configured to have, the last added attributes will
 // be dropped.
 func (s *recordingSpan) SetAttributes(attributes ...attribute.KeyValue) {
-	if !s.IsRecording() {
+	if s == nil || len(attributes) == 0 {
 		return
 	}
 
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	if !s.isRecording() {
+		return
+	}
 
 	limit := s.tracer.provider.spanLimits.AttributeCountLimit
 	if limit == 0 {
 		// No attributes allowed.
-		s.droppedAttributes += len(attributes)
+		s.addDroppedAttr(len(attributes))
 		return
 	}
 
@@ -232,11 +251,11 @@ func (s *recordingSpan) SetAttributes(attributes ...attribute.KeyValue) {
 
 	// Otherwise, add without deduplication. When attributes are read they
 	// will be deduplicated, optimizing the operation.
-	s.attributes = slices.Grow(s.attributes, len(s.attributes)+len(attributes))
+	s.attributes = slices.Grow(s.attributes, len(attributes))
 	for _, a := range attributes {
 		if !a.Valid() {
 			// Drop all invalid attributes.
-			s.droppedAttributes++
+			s.addDroppedAttr(1)
 			continue
 		}
 		a = truncateAttr(s.tracer.provider.spanLimits.AttributeValueLengthLimit, a)
@@ -244,6 +263,22 @@ func (s *recordingSpan) SetAttributes(attributes ...attribute.KeyValue) {
 	}
 }
 
+// Declared as a var so tests can override.
+var logDropAttrs = func() {
+	global.Warn("limit reached: dropping trace Span attributes")
+}
+
+// addDroppedAttr adds incr to the count of dropped attributes.
+//
+// The first, and only the first, time this method is called a warning will be
+// logged.
+//
+// This method assumes s.mu.Lock is held by the caller.
+func (s *recordingSpan) addDroppedAttr(incr int) {
+	s.droppedAttributes += incr
+	s.logDropAttrsOnce.Do(logDropAttrs)
+}
+
 // addOverCapAttrs adds the attributes attrs to the span s while
 // de-duplicating the attributes of s and attrs and dropping attributes that
 // exceed the limit.
@@ -263,22 +298,27 @@ func (s *recordingSpan) addOverCapAttrs(limit int, attrs []attribute.KeyValue) {
 
 	// Do not set a capacity when creating this map. Benchmark testing has
 	// showed this to only add unused memory allocations in general use.
-	exists := make(map[attribute.Key]int)
-	s.dedupeAttrsFromRecord(&exists)
+	exists := make(map[attribute.Key]int, len(s.attributes))
+	s.dedupeAttrsFromRecord(exists)
 
 	// Now that s.attributes is deduplicated, adding unique attributes up to
 	// the capacity of s will not over allocate s.attributes.
-	sum := len(attrs) + len(s.attributes)
-	s.attributes = slices.Grow(s.attributes, min(sum, limit))
+
+	// max size = limit
+	maxCap := min(len(attrs)+len(s.attributes), limit)
+	if cap(s.attributes) < maxCap {
+		s.attributes = slices.Grow(s.attributes, maxCap-cap(s.attributes))
+	}
 	for _, a := range attrs {
 		if !a.Valid() {
 			// Drop all invalid attributes.
-			s.droppedAttributes++
+			s.addDroppedAttr(1)
 			continue
 		}
 
 		if idx, ok := exists[a.Key]; ok {
 			// Perform all updates before dropping, even when at capacity.
+			a = truncateAttr(s.tracer.provider.spanLimits.AttributeValueLengthLimit, a)
 			s.attributes[idx] = a
 			continue
 		}
@@ -286,7 +326,7 @@ func (s *recordingSpan) addOverCapAttrs(limit int, attrs []attribute.KeyValue) {
 		if len(s.attributes) >= limit {
 			// Do not just drop all of the remaining attributes, make sure
 			// updates are checked and performed.
-			s.droppedAttributes++
+			s.addDroppedAttr(1)
 		} else {
 			a = truncateAttr(s.tracer.provider.spanLimits.AttributeValueLengthLimit, a)
 			s.attributes = append(s.attributes, a)
@@ -307,54 +347,99 @@ func truncateAttr(limit int, attr attribute.KeyValue) attribute.KeyValue {
 	}
 	switch attr.Value.Type() {
 	case attribute.STRING:
-		if v := attr.Value.AsString(); len(v) > limit {
-			return attr.Key.String(safeTruncate(v, limit))
-		}
+		v := attr.Value.AsString()
+		return attr.Key.String(truncate(limit, v))
 	case attribute.STRINGSLICE:
 		v := attr.Value.AsStringSlice()
 		for i := range v {
-			if len(v[i]) > limit {
-				v[i] = safeTruncate(v[i], limit)
-			}
+			v[i] = truncate(limit, v[i])
 		}
 		return attr.Key.StringSlice(v)
 	}
 	return attr
 }
 
-// safeTruncate truncates the string and guarantees valid UTF-8 is returned.
-func safeTruncate(input string, limit int) string {
-	if trunc, ok := safeTruncateValidUTF8(input, limit); ok {
-		return trunc
+// truncate returns a truncated version of s such that it contains less than
+// the limit number of characters. Truncation is applied by returning the limit
+// number of valid characters contained in s.
+//
+// If limit is negative, it returns the original string.
+//
+// UTF-8 is supported. When truncating, all invalid characters are dropped
+// before applying truncation.
+//
+// If s already contains less than the limit number of bytes, it is returned
+// unchanged. No invalid characters are removed.
+func truncate(limit int, s string) string {
+	// This prioritize performance in the following order based on the most
+	// common expected use-cases.
+	//
+	//  - Short values less than the default limit (128).
+	//  - Strings with valid encodings that exceed the limit.
+	//  - No limit.
+	//  - Strings with invalid encodings that exceed the limit.
+	if limit < 0 || len(s) <= limit {
+		return s
 	}
-	trunc, _ := safeTruncateValidUTF8(strings.ToValidUTF8(input, ""), limit)
-	return trunc
-}
 
-// safeTruncateValidUTF8 returns a copy of the input string safely truncated to
-// limit. The truncation is ensured to occur at the bounds of complete UTF-8
-// characters. If invalid encoding of UTF-8 is encountered, input is returned
-// with false, otherwise, the truncated input will be returned with true.
-func safeTruncateValidUTF8(input string, limit int) (string, bool) {
-	for cnt := 0; cnt <= limit; {
-		r, size := utf8.DecodeRuneInString(input[cnt:])
-		if r == utf8.RuneError {
-			return input, false
+	// Optimistically, assume all valid UTF-8.
+	var b strings.Builder
+	count := 0
+	for i, c := range s {
+		if c != utf8.RuneError {
+			count++
+			if count > limit {
+				return s[:i]
+			}
+			continue
 		}
 
-		if cnt+size > limit {
-			return input[:cnt], true
+		_, size := utf8.DecodeRuneInString(s[i:])
+		if size == 1 {
+			// Invalid encoding.
+			b.Grow(len(s) - 1)
+			_, _ = b.WriteString(s[:i])
+			s = s[i:]
+			break
 		}
-		cnt += size
 	}
-	return input, true
+
+	// Fast-path, no invalid input.
+	if b.Cap() == 0 {
+		return s
+	}
+
+	// Truncate while validating UTF-8.
+	for i := 0; i < len(s) && count < limit; {
+		c := s[i]
+		if c < utf8.RuneSelf {
+			// Optimization for single byte runes (common case).
+			_ = b.WriteByte(c)
+			i++
+			count++
+			continue
+		}
+
+		_, size := utf8.DecodeRuneInString(s[i:])
+		if size == 1 {
+			// We checked for all 1-byte runes above, this is a RuneError.
+			i++
+			continue
+		}
+
+		_, _ = b.WriteString(s[i : i+size])
+		i += size
+		count++
+	}
+
+	return b.String()
 }
 
 // End ends the span. This method does nothing if the span is already ended or
 // is not being recorded.
 //
-// The only SpanOption currently supported is WithTimestamp which will set the
-// end time for a Span's life-cycle.
+// The only SpanEndOption currently supported are [trace.WithTimestamp], and
+// [trace.WithStackTrace].
 //
 // If this method is called while panicking an error event is added to the
 // Span before ending it and the panic is continued.
@@ -367,11 +452,12 @@ func (s *recordingSpan) End(options ...trace.SpanEndOption) {
 
 	// Store the end time as soon as possible to avoid artificially increasing
 	// the span's duration in case some operation below takes a while.
-	et := internal.MonotonicEndTime(s.startTime)
+	et := monotonicEndTime(s.startTime)
 
-	// Do relative expensive check now that we have an end time and see if we
-	// need to do any more processing.
-	if !s.IsRecording() {
+	// Lock the span now that we have an end time and see if we need to do any more processing.
+	s.mu.Lock()
+	if !s.isRecording() {
+		s.mu.Unlock()
 		return
 	}
 
@@ -396,10 +482,11 @@ func (s *recordingSpan) End(options ...trace.SpanEndOption) {
 	}
 
 	if s.executionTracerTaskEnd != nil {
+		s.mu.Unlock()
 		s.executionTracerTaskEnd()
+		s.mu.Lock()
 	}
 
-	s.mu.Lock()
 	// Setting endTime to non-zero marks the span as ended and not recording.
 	if config.Timestamp().IsZero() {
 		s.endTime = et
@@ -418,12 +505,28 @@ func (s *recordingSpan) End(options ...trace.SpanEndOption) {
 	}
 }
 
+// monotonicEndTime returns the end time at present but offset from start,
+// monotonically.
+//
+// The monotonic clock is used in subtractions hence the duration since start
+// added back to start gives end as a monotonic time. See
+// https://golang.org/pkg/time/#hdr-Monotonic_Clocks
+func monotonicEndTime(start time.Time) time.Time {
+	return start.Add(time.Since(start))
+}
+
 // RecordError will record err as a span event for this span. An additional call to
 // SetStatus is required if the Status of the Span should be set to Error, this method
 // does not change the Span status. If this span is not being recorded or err is nil
 // than this method does nothing.
 func (s *recordingSpan) RecordError(err error, opts ...trace.EventOption) {
-	if s == nil || err == nil || !s.IsRecording() {
+	if s == nil || err == nil {
+		return
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if !s.isRecording() {
 		return
 	}
 
@@ -459,14 +562,23 @@ func recordStackTrace() string {
 }
 
 // AddEvent adds an event with the provided name and options. If this span is
-// not being recorded than this method does nothing.
+// not being recorded then this method does nothing.
 func (s *recordingSpan) AddEvent(name string, o ...trace.EventOption) {
-	if !s.IsRecording() {
+	if s == nil {
+		return
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if !s.isRecording() {
 		return
 	}
 	s.addEvent(name, o...)
 }
 
+// addEvent adds an event with the provided name and options.
+//
+// This method assumes s.mu.Lock is held by the caller.
 func (s *recordingSpan) addEvent(name string, o ...trace.EventOption) {
 	c := trace.NewEventConfig(o...)
 	e := Event{Name: name, Attributes: c.Attributes(), Time: c.Timestamp()}
@@ -483,20 +595,21 @@ func (s *recordingSpan) addEvent(name string, o ...trace.EventOption) {
 		e.Attributes = e.Attributes[:limit]
 	}
 
-	s.mu.Lock()
 	s.events.add(e)
-	s.mu.Unlock()
 }
 
 // SetName sets the name of this span. If this span is not being recorded than
 // this method does nothing.
 func (s *recordingSpan) SetName(name string) {
-	if !s.IsRecording() {
+	if s == nil {
 		return
 	}
 
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	if !s.isRecording() {
+		return
+	}
 	s.name = name
 }
 
@@ -552,29 +665,26 @@ func (s *recordingSpan) Attributes() []attribute.KeyValue {
 func (s *recordingSpan) dedupeAttrs() {
 	// Do not set a capacity when creating this map. Benchmark testing has
 	// showed this to only add unused memory allocations in general use.
-	exists := make(map[attribute.Key]int)
-	s.dedupeAttrsFromRecord(&exists)
+	exists := make(map[attribute.Key]int, len(s.attributes))
+	s.dedupeAttrsFromRecord(exists)
 }
 
 // dedupeAttrsFromRecord deduplicates the attributes of s to fit capacity
 // using record as the record of unique attribute keys to their index.
 //
 // This method assumes s.mu.Lock is held by the caller.
-func (s *recordingSpan) dedupeAttrsFromRecord(record *map[attribute.Key]int) {
+func (s *recordingSpan) dedupeAttrsFromRecord(record map[attribute.Key]int) {
 	// Use the fact that slices share the same backing array.
 	unique := s.attributes[:0]
 	for _, a := range s.attributes {
-		if idx, ok := (*record)[a.Key]; ok {
+		if idx, ok := record[a.Key]; ok {
 			unique[idx] = a
 		} else {
 			unique = append(unique, a)
-			(*record)[a.Key] = len(unique) - 1
+			record[a.Key] = len(unique) - 1
 		}
 	}
-	// s.attributes have element types of attribute.KeyValue. These types are
-	// not pointers and they themselves do not contain pointer fields,
-	// therefore the duplicate values do not need to be zeroed for them to be
-	// garbage collected.
+	clear(s.attributes[len(unique):]) // Erase unneeded elements to let GC collect objects.
 	s.attributes = unique
 }
 
@@ -585,7 +695,7 @@ func (s *recordingSpan) Links() []Link {
 	if len(s.links.queue) == 0 {
 		return []Link{}
 	}
-	return s.interfaceArrayToLinksArray()
+	return s.links.copy()
 }
 
 // Events returns the events of this span.
@@ -595,7 +705,7 @@ func (s *recordingSpan) Events() []Event {
 	if len(s.events.queue) == 0 {
 		return []Event{}
 	}
-	return s.interfaceArrayToEventArray()
+	return s.events.copy()
 }
 
 // Status returns the status of this span.
@@ -615,7 +725,7 @@ func (s *recordingSpan) InstrumentationScope() instrumentation.Scope {
 
 // InstrumentationLibrary returns the instrumentation.Library associated with
 // the Tracer that created this span.
-func (s *recordingSpan) InstrumentationLibrary() instrumentation.Library {
+func (s *recordingSpan) InstrumentationLibrary() instrumentation.Library { //nolint:staticcheck // This method needs to be define for backwards compatibility
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	return s.tracer.instrumentationScope
@@ -630,7 +740,17 @@ func (s *recordingSpan) Resource() *resource.Resource {
 }
 
 func (s *recordingSpan) AddLink(link trace.Link) {
-	if !s.IsRecording() || !link.SpanContext.IsValid() {
+	if s == nil {
+		return
+	}
+	if !link.SpanContext.IsValid() && len(link.Attributes) == 0 &&
+		link.SpanContext.TraceState().Len() == 0 {
+		return
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if !s.isRecording() {
 		return
 	}
 
@@ -647,9 +767,7 @@ func (s *recordingSpan) AddLink(link trace.Link) {
 		l.Attributes = l.Attributes[:limit]
 	}
 
-	s.mu.Lock()
 	s.links.add(l)
-	s.mu.Unlock()
 }
 
 // DroppedAttributes returns the number of attributes dropped by the span
@@ -713,39 +831,27 @@ func (s *recordingSpan) snapshot() ReadOnlySpan {
 	}
 	sd.droppedAttributeCount = s.droppedAttributes
 	if len(s.events.queue) > 0 {
-		sd.events = s.interfaceArrayToEventArray()
+		sd.events = s.events.copy()
 		sd.droppedEventCount = s.events.droppedCount
 	}
 	if len(s.links.queue) > 0 {
-		sd.links = s.interfaceArrayToLinksArray()
+		sd.links = s.links.copy()
 		sd.droppedLinkCount = s.links.droppedCount
 	}
 	return &sd
 }
 
-func (s *recordingSpan) interfaceArrayToLinksArray() []Link {
-	linkArr := make([]Link, 0)
-	for _, value := range s.links.queue {
-		linkArr = append(linkArr, value.(Link))
-	}
-	return linkArr
-}
-
-func (s *recordingSpan) interfaceArrayToEventArray() []Event {
-	eventArr := make([]Event, 0)
-	for _, value := range s.events.queue {
-		eventArr = append(eventArr, value.(Event))
-	}
-	return eventArr
-}
-
 func (s *recordingSpan) addChild() {
-	if !s.IsRecording() {
+	if s == nil {
 		return
 	}
+
 	s.mu.Lock()
+	defer s.mu.Unlock()
+	if !s.isRecording() {
+		return
+	}
 	s.childSpanCount++
-	s.mu.Unlock()
 }
 
 func (*recordingSpan) private() {}

vendor/go.opentelemetry.io/otel/sdk/trace/tracer.go

@@ -132,8 +132,8 @@ func (tr *tracer) newRecordingSpan(psc, sc trace.SpanContext, name string, sr Sa
 		spanKind:    trace.ValidateSpanKind(config.SpanKind()),
 		name:        name,
 		startTime:   startTime,
-		events:      newEvictedQueue(tr.provider.spanLimits.EventCountLimit),
-		links:       newEvictedQueue(tr.provider.spanLimits.LinkCountLimit),
+		events:      newEvictedQueueEvent(tr.provider.spanLimits.EventCountLimit),
+		links:       newEvictedQueueLink(tr.provider.spanLimits.LinkCountLimit),
 		tracer:      tr,
 	}