golang/go · warning

unknown load address

Error message

unknown load address

What it means

When analyzing a Mach-O binary, `machoFile.loadAddress()` looks for the `__TEXT` segment to determine the base load address. If no `__TEXT` segment exists, this error is returned. The `__TEXT` segment is standard in all macOS executables and shared libraries; its absence indicates a non-standard or corrupt Mach-O file.

Source

Thrown at src/cmd/internal/objfile/macho.go:124

	case macho.Cpu386:
		return "386"
	case macho.CpuAmd64:
		return "amd64"
	case macho.CpuArm:
		return "arm"
	case macho.CpuArm64:
		return "arm64"
	case macho.CpuPpc64:
		return "ppc64"
	}
	return ""
}

func (f *machoFile) loadAddress() (uint64, error) {
	if seg := f.macho.Segment("__TEXT"); seg != nil {
		return seg.Addr, nil
	}
	return 0, fmt.Errorf("unknown load address")
}

func (f *machoFile) dwarf() (*dwarf.Data, error) {
	return f.macho.DWARF()
}

View on GitHub (pinned to b6b368adc5)

Solutions

1. Verify the `__TEXT` segment exists: `otool -l <file> | grep __TEXT`.
2. Rebuild the binary with standard macOS linking.
3. Ensure the file is a genuine Mach-O executable: `file <path>`.
4. If the binary is corrupt, re-download or rebuild it.

Example fix

// before — Mach-O with no __TEXT segment
f, err := objfile.Open("weird_bin")
addr, err := f.LoadAddress()  // fails

// after — use a properly linked macOS binary
f, err := objfile.Open("go_binary")
addr, err := f.LoadAddress()  // succeeds

// Check for __TEXT segment in Mach-O
func hasTextSegment(path string) bool {
    f, err := macho.Open(path)
    if err != nil { return false }
    defer f.Close()
    return f.Segment("__TEXT") != nil
}

addr, err := f.LoadAddress()
if err != nil && strings.Contains(err.Error(), "unknown load address") {
    // Non-standard Mach-O; use 0 as fallback
    addr = 0
}

When it happens

Trigger: Calling `File.LoadAddress()` on a Mach-O file whose segment list does not include `__TEXT`. Occurs with non-standard Mach-O files, corrupted binaries, or Mach-O files generated by tools that use non-standard segment naming.

Common situations: Analyzing a stripped or post-processed macOS binary. Pointing pprof at a Mach-O file that is not a normal executable (e.g., a symbol stub, a kernel extension with non-standard layout). Corrupt Mach-O headers from incomplete downloads or filesystem issues.

Related errors

• text section not found
• text section not found
• unknown load address
• unknown load address
• text section not found

AI-assisted analysis of golang/go@b6b368adc5 (2026-08-12). Data as JSON: /api/errors/b0463c6909c7734e. Report an issue: GitHub.