diff options
Diffstat (limited to 'src/runtime/stack.go')
| -rw-r--r-- | src/runtime/stack.go | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/src/runtime/stack.go b/src/runtime/stack.go index 90db4204a9..49499d4433 100644 --- a/src/runtime/stack.go +++ b/src/runtime/stack.go @@ -925,7 +925,10 @@ func round2(x int32) int32 { // // g->atomicstatus will be Grunning or Gscanrunning upon entry. // If the GC is trying to stop this g then it will set preemptscan to true. -func newstack() { +// +// ctxt is the value of the context register on morestack. newstack +// will write it to g.sched.ctxt. +func newstack(ctxt unsafe.Pointer) { thisg := getg() // TODO: double check all gp. shouldn't be getg(). if thisg.m.morebuf.g.ptr().stackguard0 == stackFork { @@ -937,8 +940,13 @@ func newstack() { traceback(morebuf.pc, morebuf.sp, morebuf.lr, morebuf.g.ptr()) throw("runtime: wrong goroutine in newstack") } + + gp := thisg.m.curg + // Write ctxt to gp.sched. We do this here instead of in + // morestack so it has the necessary write barrier. + gp.sched.ctxt = ctxt + if thisg.m.curg.throwsplit { - gp := thisg.m.curg // Update syscallsp, syscallpc in case traceback uses them. morebuf := thisg.m.morebuf gp.syscallsp = morebuf.sp @@ -951,7 +959,6 @@ func newstack() { throw("runtime: stack split at bad time") } - gp := thisg.m.curg morebuf := thisg.m.morebuf thisg.m.morebuf.pc = 0 thisg.m.morebuf.lr = 0 @@ -1003,14 +1010,6 @@ func newstack() { throw("runtime: split stack overflow") } - if gp.sched.ctxt != nil { - // morestack wrote sched.ctxt on its way in here, - // without a write barrier. Run the write barrier now. - // It is not possible to be preempted between then - // and now, so it's okay. - writebarrierptr_nostore((*uintptr)(unsafe.Pointer(&gp.sched.ctxt)), uintptr(gp.sched.ctxt)) - } - if preempt { if gp == thisg.m.g0 { throw("runtime: preempt g0") |