feat: generic probe support

Rename uprobe-specific code to generic probe terminology and add
support for kprobes alongside uprobes. Update probe-ctrl tool to
handle both probe types.

Author: manuelfelipe

cli_flags.go

@@ -71,7 +71,7 @@ var (
 	envVarsHelp = "Comma separated list of environment variables that will be reported with the" +
 		"captured profiling samples."
 	probeLinkHelper = "Attach a probe to a symbol of an executable. " +
-		"Expected format: /path/to/executable:symbol"
+		"Expected format: probe_type:target[:symbol]. probe_type can be kprobe, kretprobe, uprobe, or uretprobe."
 	loadProbeHelper = "Load generic eBPF program that can be attached externally to " +
 		"various user or kernel space hooks."
 )
@@ -133,8 +133,8 @@ func parseArgs() (*controller.Config, error) {
 
 	fs.StringVar(&args.IncludeEnvVars, "env-vars", defaultEnvVarsValue, envVarsHelp)
 
-	fs.Func("uprobe-link", probeLinkHelper, func(link string) error {
-		args.UProbeLinks = append(args.UProbeLinks, link)
+	fs.Func("probe-link", probeLinkHelper, func(link string) error {
+		args.ProbeLinks = append(args.ProbeLinks, link)
 		return nil
 	})
 

collector/config/config.go

@@ -19,7 +19,7 @@ type Config struct {
 	VerboseMode            bool          `mapstructure:"verbose_mode"`
 	OffCPUThreshold        float64       `mapstructure:"off_cpu_threshold"`
 	IncludeEnvVars         string        `mapstructure:"include_env_vars"`
-	UProbeLinks            []string      `mapstructure:"u_probe_links"`
+	ProbeLinks             []string      `mapstructure:"probe_links"`
 	LoadProbe              bool          `mapstructure:"load_probe"`
 	MapScaleFactor         uint          `mapstructure:"map_scale_factor"`
 	BPFVerifierLogLevel    uint          `mapstructure:"bpf_verifier_log_level"`

internal/controller/controller.go

@@ -88,7 +88,7 @@ func (c *Controller) Start(ctx context.Context) error {
 		ProbabilisticThreshold: c.config.ProbabilisticThreshold,
 		OffCPUThreshold:        uint32(c.config.OffCPUThreshold * float64(math.MaxUint32)),
 		IncludeEnvVars:         envVars,
-		UProbeLinks:            c.config.UProbeLinks,
+		ProbeLinks:             c.config.ProbeLinks,
 		LoadProbe:              c.config.LoadProbe,
 		ExecutableReporter:     c.config.ExecutableReporter,
 	})
@@ -118,11 +118,11 @@ func (c *Controller) Start(ctx context.Context) error {
 		log.Infof("Enabled off-cpu profiling with p=%f", c.config.OffCPUThreshold)
 	}
 
-	if len(c.config.UProbeLinks) > 0 {
-		if err := trc.AttachUProbes(c.config.UProbeLinks); err != nil {
-			return fmt.Errorf("failed to attach uprobes: %v", err)
+	if len(c.config.ProbeLinks) > 0 {
+		if err := trc.AttachProbes(c.config.ProbeLinks); err != nil {
+			return fmt.Errorf("failed to attach probes: %v", err)
 		}
-		log.Info("Attached uprobes")
+		log.Info("Attached probes")
 	}
 
 	if c.config.ProbabilisticThreshold < tracer.ProbabilisticThresholdMax {

reporter/base_reporter.go

@@ -45,7 +45,7 @@ func (b *baseReporter) ReportTraceEvent(trace *libpf.Trace, meta *samples.TraceE
 	switch meta.Origin {
 	case support.TraceOriginSampling:
 	case support.TraceOriginOffCPU:
-	case support.TraceOriginUProbe:
+	case support.TraceOriginProbe:
 	default:
 		return fmt.Errorf("skip reporting trace for %d origin: %w", meta.Origin,
 			errUnknownOrigin)

reporter/internal/pdata/generate.go

@@ -82,7 +82,7 @@ func (p *Pdata) Generate(tree samples.TraceEventsTree,
 		for _, origin := range []libpf.Origin{
 			support.TraceOriginSampling,
 			support.TraceOriginOffCPU,
-			support.TraceOriginUProbe,
+			support.TraceOriginProbe,
 		} {
 			if len(originToEvents[origin]) == 0 {
 				// Do not append empty profiles.
@@ -146,7 +146,7 @@ func (p *Pdata) setProfile(
 	case support.TraceOriginOffCPU:
 		st.SetTypeStrindex(stringSet.Add("off_cpu"))
 		st.SetUnitStrindex(stringSet.Add("nanoseconds"))
-	case support.TraceOriginUProbe:
+	case support.TraceOriginProbe:
 		st.SetTypeStrindex(stringSet.Add("events"))
 		st.SetUnitStrindex(stringSet.Add("count"))
 	default:

support/ebpf/uprobe.ebpf.c support/ebpf/generic_probe.ebpf.csupport/ebpf/uprobe.ebpf.c renamed to support/ebpf/generic_probe.ebpf.c

@@ -2,9 +2,7 @@
 #include "tracemgmt.h"
 #include "types.h"
 
-// uprobe__generic serves as entry point for uprobe based profiling.
-SEC("uprobe/generic")
-int uprobe__generic(void *ctx)
+static EBPF_INLINE int probe__generic(struct pt_regs *ctx)
 {
   u64 pid_tgid = bpf_get_current_pid_tgid();
   u32 pid      = pid_tgid >> 32;
@@ -16,5 +14,19 @@ int uprobe__generic(void *ctx)
 
   u64 ts = bpf_ktime_get_ns();
 
-  return collect_trace(ctx, TRACE_UPROBE, pid, tid, ts, 0);
+  return collect_trace(ctx, TRACE_PROBE, pid, tid, ts, 0);
+}
+
+// uprobe__generic serves as entry point for uprobe based profiling.
+SEC("uprobe/generic")
+int uprobe__generic(void *ctx)
+{
+  return probe__generic((struct pt_regs *)ctx);
+}
+
+// kprobe__generic serves as entry point for kprobe based profiling.
+SEC("kprobe/generic")
+int kprobe__generic(struct pt_regs *ctx)
+{
+  return probe__generic(ctx);
 }

support/ebpf/tracer.ebpf.amd64

@@ -362,7 +362,7 @@ typedef enum TraceOrigin {
   TRACE_UNKNOWN,
   TRACE_SAMPLING,
   TRACE_OFF_CPU,
-  TRACE_UPROBE,
+  TRACE_PROBE,
 } TraceOrigin;
 
 // MAX_FRAME_UNWINDS defines the maximum number of frames per