Don't use .debug_frame info for Go binaries (#2782)

### Why?
It doesn't work, and we need more time to debug why.

### What?
<!-- Please explain to us what does it do? Or let the copilot handle it.
-->

### How?
<!-- Please explain to us how should it work? Or let the copilot handle
it. -->

### Test Plan
<!-- How did you test it? How can we test it? -->

pkg/stack/unwind/compact_unwind_table.go

@@ -310,6 +310,15 @@ func NewCompactUnwindTableGenerator(logger log.Logger, reg prometheus.Registerer
  }
 }
 
+func isGoBinary(file *objectfile.ObjectFile) (bool, error) {
+ elf, err := file.ELF()
+ if err != nil {
+ return false, err
+ }
+ isGo := elf.Section(".gopclntab") != nil
+ return isGo, nil
+}
+
 // GenerateCompactUnwindTable produces the compact unwind table for a given
 // executable.
 func (g *CompactUnwindTableGenerator) Gen(file *objectfile.ObjectFile) (CompactUnwindTable, elf.Machine, frame.FrameDescriptionEntries, error) {
@@ -323,27 +332,41 @@ func (g *CompactUnwindTableGenerator) Gen(file *objectfile.ObjectFile) (CompactU
  if isUnexpected(err) {
  return nil, 0, nil, err
  }
- debugFrameFdes, arch2, err := ReadFDEs(file, false)
- if isUnexpected(err) {
- // don't bail here, just fall back to using only .eh_frame.
- // The reason is because .debug_frame parsing is a somewhat
- // untested feature, and if it's buggy we don't want to break unwinding for the
- // .eh_frame-based cases where it worked before.
- //
- // If real users run this for a while and it turns out these errors aren't seen in real life,
- // we can be more conservative here.
-
- level.Warn(g.logger).Log("msg", "failed to parse .debug_frame", "err", err)
- g.debugFrameErrors.Inc()
- debugFrameFdes = nil
- arch2 = arch
+ var debugFrameFdes frame.FrameDescriptionEntries
+ var arch2 elf.Machine
+ isGo, err := isGoBinary(file)
+ if err != nil {
+ level.Warn(g.logger).Log("msg", "failed to detect whether file is a Go binary, defaulting to not use .debug_frame", "path", file.Path, "err", err)
+ isGo = true
  }
- if arch != arch2 {
- // see above, we should ultimately bail here,
- // but for now just ignore .debug_frame
- level.Warn(g.logger).Log("msg", "failed to parse .debug_frame: mismatched arch", "ehFrameArch", arch, "debugFrameArch", arch2)
- g.debugFrameErrors.Inc()
+ if isGo {
+ // TODO[btv] - Figure out how to make DWARF unwinding work with Go binaries.
+ // It seems some functions in the Go runtime (e.g. `runtime.mcall`) switch stacks
+ // in a way that we don't know how to deal with.
  debugFrameFdes = nil
+ } else {
+ debugFrameFdes, arch2, err = ReadFDEs(file, false)
+ if isUnexpected(err) {
+ // don't bail here, just fall back to using only .eh_frame.
+ // The reason is because .debug_frame parsing is a somewhat
+ // untested feature, and if it's buggy we don't want to break unwinding for the
+ // .eh_frame-based cases where it worked before.
+ //
+ // If real users run this for a while and it turns out these errors aren't seen in real life,
+ // we can be more conservative here.
+
+ level.Warn(g.logger).Log("msg", "failed to parse .debug_frame", "err", err)
+ g.debugFrameErrors.Inc()
+ debugFrameFdes = nil
+ arch2 = arch
+ }
+ if arch != arch2 {
+ // see above, we should ultimately bail here,
+ // but for now just ignore .debug_frame
+ level.Warn(g.logger).Log("msg", "failed to parse .debug_frame: mismatched arch", "ehFrameArch", arch, "debugFrameArch", arch2)
+ g.debugFrameErrors.Inc()
+ debugFrameFdes = nil
+ }
  }
  if len(ehFrameFdes) == 0 && len(debugFrameFdes) == 0 {
  return nil, 0, nil, ErrNoFDEsFound