diff options
| -rw-r--r-- | src/runtime/traceback.go | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/runtime/traceback.go b/src/runtime/traceback.go index 2def3592d6..aed6cbd694 100644 --- a/src/runtime/traceback.go +++ b/src/runtime/traceback.go @@ -188,6 +188,34 @@ func gentraceback(pc0, sp0, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max in } f := findfunc(frame.pc) + if f.entry == stackBarrierPC { + // We got caught in the middle of a stack barrier + // (presumably by a signal), so stkbar may be + // inconsistent with the barriers on the stack. + // Simulate the completion of the barrier. + // + // On x86, SP will be exactly one word above + // savedLRPtr. On LR machines, SP will be above + // savedLRPtr by some frame size. + var stkbarPos uintptr + if len(stkbar) > 0 && stkbar[0].savedLRPtr < sp0 { + // stackBarrier has not incremented stkbarPos. + stkbarPos = gp.stkbarPos + } else if gp.stkbarPos > 0 && gp.stkbar[gp.stkbarPos-1].savedLRPtr < sp0 { + // stackBarrier has incremented stkbarPos. + stkbarPos = gp.stkbarPos - 1 + } else { + printlock() + print("runtime: failed to unwind through stackBarrier at SP ", hex(sp0), " index ", gp.stkbarPos, "; ") + gcPrintStkbars(gp.stkbar) + print("\n") + throw("inconsistent state in stackBarrier") + } + + frame.pc = gp.stkbar[stkbarPos].savedLRVal + stkbar = gp.stkbar[stkbarPos+1:] + f = findfunc(frame.pc) + } if f == nil { if callback != nil { print("runtime: unknown pc ", hex(frame.pc), "\n") |