cmd/compile: add edge from lock rank edge from forceGC to traceStackTab

This edge can happen when forcegchelper() calls
goparkunlock(&forcegc.lock, ...) while holding the forcegc lock.
goparkunlock() eventually calls park_m(). In park_m(), traceGoPark()
(which leads to (*traceStackTable).put() and acquires the traceStackTab
lock) can be called before the forcegc lock is released.

Fixes #45774

Change-Id: If0fceab596712eb9ec0b9b47326778bc0ff80913
Reviewed-on: https://go-review.googlesource.com/c/go/+/316029
Run-TryBot: Dan Scales <danscales@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Trust: Carlos Amedee <carlos@golang.org>

diff --git a/src/runtime/lockrank.go b/src/runtime/lockrank.go
index b600c2132b6f6f557f228bda9a591308328e7e24..dde9f7c21a7f3aa0f6d1ab5a61128e890e56238e 100644 (file)
--- a/src/runtime/lockrank.go
+++ b/src/runtime/lockrank.go
@@ -217,7 +217,7 @@ var lockPartialOrder [][]lockRank = [][]lockRank{
        lockRankGcBitsArenas:  {lockRankSysmon, lockRankScavenge, lockRankAssistQueue, lockRankCpuprof, lockRankSched, lockRankAllg, lockRankTimers, lockRankItab, lockRankReflectOffs, lockRankHchan, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings},
        lockRankRoot:          {},
        lockRankTrace:         {lockRankSysmon, lockRankScavenge, lockRankForcegc, lockRankAssistQueue, lockRankSweep, lockRankSched, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankRoot},
-       lockRankTraceStackTab: {lockRankScavenge, lockRankSweepWaiters, lockRankAssistQueue, lockRankSweep, lockRankSched, lockRankAllg, lockRankTimers, lockRankHchan, lockRankFin, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankRoot, lockRankTrace},
+       lockRankTraceStackTab: {lockRankScavenge, lockRankForcegc, lockRankSweepWaiters, lockRankAssistQueue, lockRankSweep, lockRankSched, lockRankAllg, lockRankTimers, lockRankHchan, lockRankFin, lockRankNotifyList, lockRankTraceBuf, lockRankTraceStrings, lockRankRoot, lockRankTrace},
        lockRankNetpollInit:   {lockRankTimers},
 
        lockRankRwmutexW: {},