unwind_for_each_frame
unwind_for_each_frame(&state, task, NULL, (unsigned long) stack)
unwind_for_each_frame(&state, current, regs, 0) {
unwind_for_each_frame(&state, p, NULL, 0) {
unwind_for_each_frame(&state, task, regs, 0) {
unwind_for_each_frame(&state, task, NULL, 0) {
unwind_for_each_frame(&state, task, regs, sp) {
unwind_for_each_frame(&state, NULL, NULL, 0) {