1 files changed, 29 insertions, 32 deletions

diff --git a/src/runtime/stack.go b/src/runtime/stack.go
index 525d0b14c1..eb0716c18d 100644
--- a/src/runtime/stack.go
+++ b/src/runtime/stack.go
@@ -578,29 +578,30 @@ func adjustpointers(scanp unsafe.Pointer, cbv *bitvector, adjinfo *adjustinfo, f
 		if stackDebug >= 4 {
 			print("        ", add(scanp, i*sys.PtrSize), ":", ptrnames[ptrbit(&bv, i)], ":", hex(*(*uintptr)(add(scanp, i*sys.PtrSize))), " # ", i, " ", bv.bytedata[i/8], "\n")
 		}
-		if ptrbit(&bv, i) == 1 {
-			pp := (*uintptr)(add(scanp, i*sys.PtrSize))
-		retry:
-			p := *pp
-			if f.valid() && 0 < p && p < minLegalPointer && debug.invalidptr != 0 {
-				// Looks like a junk value in a pointer slot.
-				// Live analysis wrong?
-				getg().m.traceback = 2
-				print("runtime: bad pointer in frame ", funcname(f), " at ", pp, ": ", hex(p), "\n")
-				throw("invalid pointer found on stack")
+		if ptrbit(&bv, i) != 1 {
+			continue
+		}
+		pp := (*uintptr)(add(scanp, i*sys.PtrSize))
+	retry:
+		p := *pp
+		if f.valid() && 0 < p && p < minLegalPointer && debug.invalidptr != 0 {
+			// Looks like a junk value in a pointer slot.
+			// Live analysis wrong?
+			getg().m.traceback = 2
+			print("runtime: bad pointer in frame ", funcname(f), " at ", pp, ": ", hex(p), "\n")
+			throw("invalid pointer found on stack")
+		}
+		if minp <= p && p < maxp {
+			if stackDebug >= 3 {
+				print("adjust ptr ", hex(p), " ", funcname(f), "\n")
 			}
-			if minp <= p && p < maxp {
-				if stackDebug >= 3 {
-					print("adjust ptr ", hex(p), " ", funcname(f), "\n")
-				}
-				if useCAS {
-					ppu := (*unsafe.Pointer)(unsafe.Pointer(pp))
-					if !atomic.Casp1(ppu, unsafe.Pointer(p), unsafe.Pointer(p+delta)) {
-						goto retry
-					}
-				} else {
-					*pp = p + delta
+			if useCAS {
+				ppu := (*unsafe.Pointer)(unsafe.Pointer(pp))
+				if !atomic.Casp1(ppu, unsafe.Pointer(p), unsafe.Pointer(p+delta)) {
+					goto retry
 				}
+			} else {
+				*pp = p + delta
 			}
 		}
 	}
@@ -751,7 +752,6 @@ func adjustsudogs(gp *g, adjinfo *adjustinfo) {
 	// might be in the stack.
 	for s := gp.waiting; s != nil; s = s.waitlink {
 		adjustpointer(adjinfo, unsafe.Pointer(&s.elem))
-		adjustpointer(adjinfo, unsafe.Pointer(&s.selectdone))
 	}
 }
 
@@ -768,10 +768,6 @@ func findsghi(gp *g, stk stack) uintptr {
 		if stk.lo <= p && p < stk.hi && p > sghi {
 			sghi = p
 		}
-		p = uintptr(unsafe.Pointer(sg.selectdone)) + unsafe.Sizeof(sg.selectdone)
-		if stk.lo <= p && p < stk.hi && p > sghi {
-			sghi = p
-		}
 	}
 	return sghi
 }
@@ -917,9 +913,12 @@ 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.
 //
-// ctxt is the value of the context register on morestack. newstack
-// will write it to g.sched.ctxt.
-func newstack(ctxt unsafe.Pointer) {
+// This must be nowritebarrierrec because it can be called as part of
+// stack growth from other nowritebarrierrec functions, but the
+// compiler doesn't check this.
+//
+//go:nowritebarrierrec
+func newstack() {
 	thisg := getg()
 	// TODO: double check all gp. shouldn't be getg().
 	if thisg.m.morebuf.g.ptr().stackguard0 == stackFork {
@@ -933,9 +932,6 @@ func newstack(ctxt unsafe.Pointer) {
 	}
 
 	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 {
 		// Update syscallsp, syscallpc in case traceback uses them.
@@ -946,6 +942,7 @@ func newstack(ctxt unsafe.Pointer) {
 			"\tmorebuf={pc:", hex(morebuf.pc), " sp:", hex(morebuf.sp), " lr:", hex(morebuf.lr), "}\n",
 			"\tsched={pc:", hex(gp.sched.pc), " sp:", hex(gp.sched.sp), " lr:", hex(gp.sched.lr), " ctxt:", gp.sched.ctxt, "}\n")
 
+		thisg.m.traceback = 2 // Include runtime frames
 		traceback(morebuf.pc, morebuf.sp, morebuf.lr, gp)
 		throw("runtime: stack split at bad time")
 	}