runtime: zero a few more dead pointers.

In channels, zeroing of gp.waiting is missed on a closed channel panic.
m.morebuf.g is not zeroed.

I don't expect the latter causes any problems, but just in case.

LGTM=iant
R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/151610043

diff --git a/src/runtime/chan.go b/src/runtime/chan.go
index 10503f4e105de2aaca84aeafe8686322f35901ba..004970182686da6f5a214abd0909a9a6fe6b8d5a 100644 (file)
--- a/src/runtime/chan.go
+++ b/src/runtime/chan.go
@@ -174,6 +174,10 @@ func chansend(t *chantype, c *hchan, ep unsafe.Pointer, block bool, callerpc uin
                goparkunlock(&c.lock, "chan send")
 
                // someone woke us up.
+               if mysg != gp.waiting {
+                       gothrow("G waiting list is corrupted!")
+               }
+               gp.waiting = nil
                if gp.param == nil {
                        if c.closed == 0 {
                                gothrow("chansend: spurious wakeup")
@@ -184,10 +188,6 @@ func chansend(t *chantype, c *hchan, ep unsafe.Pointer, block bool, callerpc uin
                if mysg.releasetime > 0 {
                        blockevent(int64(mysg.releasetime)-t0, 2)
                }
-               if mysg != gp.waiting {
-                       gothrow("G waiting list is corrupted!")
-               }
-               gp.waiting = nil
                releaseSudog(mysg)
                return true
        }
@@ -410,6 +410,9 @@ func chanrecv(t *chantype, c *hchan, ep unsafe.Pointer, block bool) (selected, r
                goparkunlock(&c.lock, "chan receive")
 
                // someone woke us up
+               if mysg != gp.waiting {
+                       gothrow("G waiting list is corrupted!")
+               }
                gp.waiting = nil
                if mysg.releasetime > 0 {
                        blockevent(mysg.releasetime-t0, 2)

diff --git a/src/runtime/stack.c b/src/runtime/stack.c
index d1ea3ff73bf3fbe649013419c6dea02d4ae21187..e402691f450d1c338b79e720ba0edc914e447fdd 100644 (file)
--- a/src/runtime/stack.c
+++ b/src/runtime/stack.c
@@ -725,6 +725,7 @@ runtime·newstack(void)
        g->m->morebuf.pc = (uintptr)nil;
        g->m->morebuf.lr = (uintptr)nil;
        g->m->morebuf.sp = (uintptr)nil;
+       g->m->morebuf.g = (G*)nil;
 
        runtime·casgstatus(gp, Grunning, Gwaiting);
        gp->waitreason = runtime·gostringnocopy((byte*)"stack growth");