[Bug]: ParseCTraceContext may be not memory-safe

[longjiquan]

Is there an existing issue for this?

• I have searched the existing issues

Environment

- Milvus version:
- Deployment mode(standalone or cluster):
- MQ type(rocksmq, pulsar or kafka):    
- SDK version(e.g. pymilvus v2.0.0rc2):
- OS(Ubuntu or CentOS): 
- CPU/Memory: 
- GPU: 
- Others:

Current Behavior

milvus/internal/querynodev2/segments/trace.go

Lines 34 to 44 in 5bb672d

	func ParseCTraceContext(ctx context.Context) C.CTraceContext {
	span := trace.SpanFromContext(ctx)
	traceID := span.SpanContext().TraceID()
	spanID := span.SpanContext().SpanID()
	return C.CTraceContext{
	traceID: (*C.uint8_t)(unsafe.Pointer(&traceID[0])),
	spanID: (*C.uint8_t)(unsafe.Pointer(&spanID[0])),
	traceFlags: (C.uint8_t)(span.SpanContext().TraceFlags()),
	}
	}

Expected Behavior

spanID and traceID are local variables inner ParseCTraceContext, they may be garbage collected after return their address, so it's not safe to use them in cgo code.

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response

[longjiquan]

/unassign @yanliang567
/assign @czs007 @congqixia