// other threads, so mp is usually not getg().m.
	// In fact mp may not even be stopped.
	// See golang.org/issue/17165.
	getg().m.mallocing++

	var u unwinder
	var stk [maxCPUProfStack]uintptr
	n := 0
	if mp.ncgo > 0 && mp.curg != nil && mp.curg.syscallpc != 0 && mp.curg.syscallsp != 0 {
		cgoOff := 0
		// Check cgoCallersUse to make sure that we are not

	// (any write other than adding or subtracting a constant amount).
	// The traceback routines cannot encode such changes into the
	// pcsp tables, so the function traceback cannot safely unwind past
	// SPWrite functions. Stopping at an SPWrite function is considered
	// to be an incomplete unwinding of the stack. In certain contexts
	// (in particular garbage collector stack scans) that is a fatal error.

#endif
	CALLNORESUME runtime·osinit(SB)
	CALLNORESUME runtime·schedinit(SB)
	MOVD $runtime·mainPC(SB), 0(SP)
	CALLNORESUME runtime·newproc(SB)
	CALL runtime·mstart(SB) // WebAssembly stack will unwind when switching to another goroutine
	UNDEF

TEXT runtime·mstart(SB),NOSPLIT|TOPFRAME,$0
	CALL	runtime·mstart0(SB)
	RET // not reached

DATA  runtime·mainPC+0(SB)/8,$runtime·main(SB)

		t.Fatalf("child process did not produce a crash report")
	}

	// Parse the PCs out of the child's crash report.
	pcs, err := parseStackPCs(crash)
	if err != nil {
		t.Fatal(err)
	}

	// Unwind the stack using this executable's symbol table.
	got := formatStack(pcs)
	want := `redacted.go:0: runtime.gopanic
traceback_system_test.go:85: runtime_test.child7: 	panic("oops")

	g0 := getg()
	if g0 == nil || g0.m.curg == nil {
		// No g available, nothing to do here.
		return _EXCEPTION_CONTINUE_SEARCH_SEH
	}
	// The Windows SEH machinery will unwind the stack until it finds
	// a frame with a handler for the exception or until the frame is
	// outside the stack boundaries, in which case it will call the
	// UnhandledExceptionFilter. Unfortunately, it doesn't know about

//go:noinline
func ddd() bool { return f() }

//go:noinline
func eee() bool { return true }

var f = eee

func main() {
	_ = aaa()
}
`

// TestGdbBacktrace tests that gdb can unwind the stack correctly
// using only the DWARF debug info.
func TestGdbBacktrace(t *testing.T) {
	if runtime.GOOS == "netbsd" {
		testenv.SkipFlaky(t, 15603)
	}

	if err := syscall.Close(*pipeFD); err != nil {
		panic(fmt.Sprintf("error closing control pipe fd %d: %v", *pipeFD, err))
	}

	for {}
}
`

// TestGdbCoreSignalBacktrace tests that gdb can unwind the stack correctly
// through a signal handler in a core file
func TestGdbCoreSignalBacktrace(t *testing.T) {
	if runtime.GOOS != "linux" {
		// N.B. This test isn't fundamentally Linux-only, but it needs

	s := spanOfUnchecked(uintptr(src))
	if s.state.get() == mSpanManual {
		// There are no heap bits for value stored on the stack.
		// For a channel receive src might be on the stack of some
		// other goroutine, so we can't unwind the stack even if
		// we wanted to.
		// We can't expand the GC program without extra storage
		// space we can't easily get.
		// Fortunately we have the type information.
		systemstack(func() {

	MOVL	m_cgoCallersUse(AX), CX
	TESTL	CX, CX
	JNZ	sigtramp	// g.m.cgoCallersUse != 0

	// Jump to a function in runtime/cgo.
	// That function, written in C, will call the user's traceback
	// function with proper unwind info, and will then call back here.
	// The first three arguments, and the fifth, are already in registers.
	// Set the two remaining arguments now.
	MOVQ	runtime·cgoTraceback(SB), CX
	MOVQ	$runtime·sigtramp(SB), R9

				os.Exit(2)
			}
			if !filepath.IsAbs(p) {
				if cfg.Getenv("GOPATH") == "" {
					// We inferred $GOPATH from $HOME and did a bad job at it.
					// Instead of dying, uninfer it.
					cfg.BuildContext.GOPATH = ""
				} else {
					counterErrorsGOPATHEntryRelative.Inc()