From b2f5e19277a95e91b25b77ef51dbcba3cf1395c8 Mon Sep 17 00:00:00 2001
From: Tommy Reilly <gnurizen@gmail.com>
Date: Mon, 11 Nov 2024 22:59:09 -0500
Subject: [PATCH] Fix errors against parca-dev/opentelemetry-ebpf-profile HEAD

---
 main.go                    | 29 +++++++++++------------------
 reporter/parca_reporter.go | 11 +++++++++--
 2 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/main.go b/main.go
index 592ba08084..182f5f6dc1 100644
--- a/main.go
+++ b/main.go
@@ -23,14 +23,6 @@ import (
 	"github.com/apache/arrow/go/v16/arrow/memory"
 	"github.com/armon/circbuf"
 	"github.com/common-nighthawk/go-figure"
-	"go.opentelemetry.io/ebpf-profiler/host"
-	otelmetrics "go.opentelemetry.io/ebpf-profiler/metrics"
-	otelreporter "go.opentelemetry.io/ebpf-profiler/reporter"
-	"go.opentelemetry.io/ebpf-profiler/times"
-	"go.opentelemetry.io/ebpf-profiler/tracehandler"
-	"go.opentelemetry.io/ebpf-profiler/tracer"
-	tracertypes "go.opentelemetry.io/ebpf-profiler/tracer/types"
-	"go.opentelemetry.io/ebpf-profiler/util"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/collectors"
 	"github.com/prometheus/client_golang/prometheus/promauto"
@@ -41,6 +33,14 @@ import (
 	"github.com/tklauser/numcpus"
 	"github.com/zcalusic/sysinfo"
 	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+	"go.opentelemetry.io/ebpf-profiler/host"
+	otelmetrics "go.opentelemetry.io/ebpf-profiler/metrics"
+	otelreporter "go.opentelemetry.io/ebpf-profiler/reporter"
+	"go.opentelemetry.io/ebpf-profiler/times"
+	"go.opentelemetry.io/ebpf-profiler/tracehandler"
+	"go.opentelemetry.io/ebpf-profiler/tracer"
+	tracertypes "go.opentelemetry.io/ebpf-profiler/tracer/types"
+	"go.opentelemetry.io/ebpf-profiler/util"
 	"go.opentelemetry.io/otel/trace"
 	"go.opentelemetry.io/otel/trace/noop"
 	"golang.org/x/sys/unix"
@@ -249,10 +249,6 @@ func mainWithExitCode() flags.ExitCode {
 		return flags.Failure(fmt.Sprintf("Failed to probe eBPF syscall: %v", err))
 	}
 
-	if err = tracer.ProbeTracepoint(); err != nil {
-		log.Warnf("Failed to probe tracepoint: %v. Parca-agent may fail to run on some kernel versions.", err)
-	}
-
 	externalLabels := reporter.Labels{}
 	if len(f.Metadata.ExternalLabels) > 0 {
 		for name, value := range f.Metadata.ExternalLabels {
@@ -317,7 +313,7 @@ func mainWithExitCode() flags.ExitCode {
 		return flags.Failure("Failed to start reporting: %v", err)
 	}
 	otelmetrics.SetReporter(parcaReporter)
-	parcaReporter.Run(mainCtx)
+	parcaReporter.Start(mainCtx)
 	var rep otelreporter.Reporter = parcaReporter
 
 	// Load the eBPF code and map definitions
@@ -340,11 +336,8 @@ func mainWithExitCode() flags.ExitCode {
 	log.Printf("eBPF tracer loaded")
 	defer trc.Close()
 
-	// Initial scan of /proc filesystem to list currently-active PIDs and have them processed.
-	if err = trc.StartPIDEventProcessor(mainCtx); err != nil {
-		log.Errorf("Failed to list processes from /proc: %v", err)
-	}
-	log.Debug("Completed initial PID listing")
+	// Start watching for PID events.
+	trc.StartPIDEventProcessor(mainCtx)
 
 	// Attach our tracer to the perf event
 	if err := trc.AttachTracer(); err != nil {
diff --git a/reporter/parca_reporter.go b/reporter/parca_reporter.go
index ee6caeb1f3..58ec3d8255 100644
--- a/reporter/parca_reporter.go
+++ b/reporter/parca_reporter.go
@@ -235,6 +235,13 @@ func (r *ParcaReporter) ReportFramesForTrace(_ *libpf.Trace) {}
 func (r *ParcaReporter) ReportCountForTrace(_ libpf.TraceHash, _ uint16, _ *reporter.TraceEventMeta) {
 }
 
+// ExecutableKnown returns true if the metadata of the Executable specified by fileID is
+// cached in the reporter.
+func (r *ParcaReporter) ExecutableKnown(fileID libpf.FileID) bool {
+	_, known := r.executables.Get(fileID)
+	return known
+}
+
 // ExecutableMetadata accepts a fileID with the corresponding filename
 // and caches this information.
 func (r *ParcaReporter) ExecutableMetadata(args *reporter.ExecutableMetadataArgs) {
@@ -526,7 +533,7 @@ func New(
 	return r, nil
 }
 
-func (r *ParcaReporter) Run(mainCtx context.Context) (reporter.Reporter, error) {
+func (r *ParcaReporter) Start(mainCtx context.Context) error {
 	// Create a child context for reporting features
 	ctx, cancelReporting := context.WithCancel(mainCtx)
 
@@ -564,7 +571,7 @@ func (r *ParcaReporter) Run(mainCtx context.Context) (reporter.Reporter, error)
 		cancelReporting()
 	}()
 
-	return r, nil
+	return nil
 }
 
 // reportDataToBackend creates and sends out an arrow record for a Parca backend.