// We're probably in the trailing function padding, where findfunc
			// still returns f but there's no symbolic information. Just keep
			// going until we definitely hit the end. If we see a "?" in the
			// middle of unwinding, that's a real problem.
			//
			// TODO: If we ever have function end information, use that to make
			// this robust.
			continue
		}
		for ; uf.valid(); uf = u.next(uf) {
			file, line := u.fileLine(uf)

ongothread:
	// Trigger a SIGSEGV panic.
	//
	// The goal is to arrange the stack so it looks like the runtime
	// function sigpanic was called from the PC that faulted. It has
	// to be sigpanic, as the stack unwinding code in traceback.go
	// looks explicitly for it.
	//
	// To do this we call into runtime·setsigsegv, which sets the
	// appropriate state inside the g object. We give it the faulting

	// 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.
	FuncFlagSPWrite

	// FuncFlagAsm indicates that a function was implemented in assembly.
	FuncFlagAsm
)

		pc := c.pc()
		sp := c.sp()

		// If we don't recognize the PC as code
		// but we do recognize the top pointer on the stack as code,
		// then assume this was a call to non-code and treat like
		// pc == 0, to make unwinding show the context.
		if pc != 0 && !findfunc(pc).valid() && findfunc(*(*uintptr)(unsafe.Pointer(sp))).valid() {
			pc = 0
		}

		// IF LR exists, sigpanictramp must save it to the stack

}

func TestFPUnwindAfterRecovery(t *testing.T) {
	if !runtime.FramePointerEnabled {
		t.Skip("frame pointers not supported for this architecture")
	}
	// Make sure that frame pointer unwinding succeeds from a deferred
	// function run after recovering from a panic. It can fail if the
	// recovery does not properly restore the caller's frame pointer before
	// running the remaining deferred functions.
	//

	// a call to runtime.read_tls_fallback which jumps to __kuser_get_tls.
	// The replacement function saves LR in R11 over the call to read_tls_fallback.
	// To make stack unwinding work, this function should NOT be marked as NOFRAME,
	// as it may contain a call, which clobbers LR even just temporarily.
	MRC	15, 0, R0, C13, C0, 3 // fetch TLS base pointer

// is a problem because sometimes functions exit via panic instead
// of an ordinary return, so panic would have to know to do the
// same math when unwinding the stack. It gets complicated fast.
// This particular test never worked with the old scheme, because
// panic never did the right unwinding math.
//
// The new scheme adjusts Panic.argp on entry to a wrapper.
// It has no exit work, so if a wrapper is interrupted by a panic,

	}

	// After this point, it is safe to grow the stack.

	// Make it look like a call to the signal func.
	// Have to pass arguments out of band since
	// augmenting the stack frame would break
	// the unwinding code.
	gp.sig = info.exceptioncode
	gp.sigcode0 = info.exceptioninformation[0]
	gp.sigcode1 = info.exceptioninformation[1]
	gp.sigpc = r.ip()

	// Only push runtime·sigpanic if r.ip() != 0.

		// here we'll see a seemingly self-recursive call, which is in
		// fact not.
		// This is normally ok, as we use the return address saved on
		// stack for unwinding, not the LR value. But if this is a
		// call to morestack, we haven't created the frame, and we'll
		// use the LR for unwinding, which will be bad.
		return false, 0
	}
	up, startpc := pcdatavalue2(f, abi.PCDATA_UnsafePoint, pc)
	if up == abi.UnsafePointUnsafe {

	// and String methods to prepare the panic strings before startpanic.
	preprintpanics(&p)

	fatalpanic(&p)   // should not return
	*(*int)(nil) = 0 // not reached
}

// start initializes a panic to start unwinding the stack.
//
// If p.goexit is true, then start may return multiple times.
func (p *_panic) start(pc uintptr, sp unsafe.Pointer) {
	gp := getg()

	// Record the caller's PC and SP, so recovery can identify panics