diff --git a/src/runtime/traceback.go b/src/runtime/traceback.go index 229e3a9105..56128dc882 100644 --- a/src/runtime/traceback.go +++ b/src/runtime/traceback.go @@ -82,6 +82,7 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in } waspanic := false cgoCtxt := gp.cgoCtxt + stack := gp.stack printing := pcbuf == nil && callback == nil // If the PC is zero, it's likely a nil function call. @@ -114,7 +115,7 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in if !f.valid() { if callback != nil || printing { print("runtime: unknown pc ", hex(frame.pc), "\n") - tracebackHexdump(gp.stack, &frame, 0) + tracebackHexdump(stack, &frame, 0) } if callback != nil { throw("unknown pc") @@ -174,12 +175,15 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in frame.fn = findfunc(frame.pc) f = frame.fn flag = f.flag + frame.lr = gp.m.curg.sched.lr frame.sp = gp.m.curg.sched.sp + stack = gp.m.curg.stack cgoCtxt = gp.m.curg.cgoCtxt case funcID_systemstack: // systemstack returns normally, so just follow the // stack transition. frame.sp = gp.m.curg.sched.sp + stack = gp.m.curg.stack cgoCtxt = gp.m.curg.cgoCtxt flag &^= funcFlag_SPWRITE } @@ -248,7 +252,7 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in } if callback != nil || doPrint { print("runtime: unexpected return pc for ", funcname(f), " called from ", hex(frame.lr), "\n") - tracebackHexdump(gp.stack, &frame, lrPtr) + tracebackHexdump(stack, &frame, lrPtr) } if callback != nil { throw("unknown caller pc") @@ -477,6 +481,13 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in break } + if frame.pc == frame.lr && frame.sp == frame.fp { + // If the next frame is identical to the current frame, we cannot make progress. + print("runtime: traceback stuck. pc=", hex(frame.pc), " sp=", hex(frame.sp), "\n") + tracebackHexdump(stack, &frame, frame.sp) + throw("traceback stuck") + } + // Unwind to next frame. frame.fn = flr frame.pc = frame.lr