runtime: add mayAcquire annotation for finlock

We're missing lock edges to finlock that happen only rarely. Anything
that calls mallocgc can potentially trigger sweeping, which can
potentially queue a finalizer, which acquires finlock. While this can
happen on any malloc, it happens relatively rarely, so we simply
haven't seen some of the lock edges that could happen.

Add a mayAcquire annotation to mallocgc to capture the possibility of
acquiring finlock.

With this change, we add "fin" to the set of "malloc" locks. Several
of these edges were already there, but not quite all of them.

This was found by inspecting the rank graph for things that didn't
make sense.

For #53789.

Change-Id: Idc10ce6f250596b0c07ba07ac93f2198fb38c22b
Reviewed-on: https://go-review.googlesource.com/c/go/+/418717
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/runtime/lockrank.go b/src/runtime/lockrank.go
index c817de1aa4687644eb1d43c2a3de1a8ac9aacb28..21c65233e3afbffc2f4455e4cfdb3e0f8aba4b25 100644 (file)
--- a/src/runtime/lockrank.go
+++ b/src/runtime/lockrank.go
@@ -32,7 +32,6 @@ const (
        lockRankReflectOffs
        lockRankHchan
        lockRankTraceBuf
-       lockRankFin
        lockRankTraceStrings
        lockRankMspanSpecial
        lockRankProfInsert
@@ -41,6 +40,7 @@ const (
        lockRankGcBitsArenas
        lockRankSpanSetSpine
        lockRankMheapSpecial
+       lockRankFin
        lockRankProfMemFuture
        lockRankTrace
        lockRankTraceStackTab
@@ -84,7 +84,6 @@ var lockNames = []string{
        lockRankReflectOffs:   "reflectOffs",
        lockRankHchan:         "hchan",
        lockRankTraceBuf:      "traceBuf",
-       lockRankFin:           "fin",
        lockRankTraceStrings:  "traceStrings",
        lockRankMspanSpecial:  "mspanSpecial",
        lockRankProfInsert:    "profInsert",
@@ -93,6 +92,7 @@ var lockNames = []string{
        lockRankGcBitsArenas:  "gcBitsArenas",
        lockRankSpanSetSpine:  "spanSetSpine",
        lockRankMheapSpecial:  "mheapSpecial",
+       lockRankFin:           "fin",
        lockRankProfMemFuture: "profMemFuture",
        lockRankTrace:         "trace",
        lockRankTraceStackTab: "traceStackTab",
@@ -149,7 +149,6 @@ var lockPartialOrder [][]lockRank = [][]lockRank{
        lockRankReflectOffs:   {lockRankItab},
        lockRankHchan:         {lockRankSysmon, lockRankSweep, lockRankScavenge, lockRankHchan},
        lockRankTraceBuf:      {lockRankSysmon, lockRankScavenge},
-       lockRankFin:           {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf},
        lockRankTraceStrings:  {lockRankSysmon, lockRankScavenge, lockRankTraceBuf},
        lockRankMspanSpecial:  {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings},
        lockRankProfInsert:    {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings},
@@ -158,18 +157,19 @@ var lockPartialOrder [][]lockRank = [][]lockRank{
        lockRankGcBitsArenas:  {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings},
        lockRankSpanSetSpine:  {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings},
        lockRankMheapSpecial:  {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings},
+       lockRankFin:           {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings},
        lockRankProfMemFuture: {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankProfMemActive},
-       lockRankTrace:         {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankFin, lockRankTraceStrings},
-       lockRankTraceStackTab: {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankFin, lockRankTraceStrings, lockRankTrace},
+       lockRankTrace:         {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankFin},
+       lockRankTraceStackTab: {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankFin, lockRankTrace},
        lockRankNetpollInit:   {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllp, lockRankTimers},
        lockRankRwmutexR:      {lockRankSysmon, lockRankRwmutexW},
-       lockRankGscan:         {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankFin, lockRankTraceStrings, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit},
-       lockRankStackpool:     {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankRwmutexW, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankFin, lockRankTraceStrings, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankRwmutexR, lockRankGscan},
-       lockRankStackLarge:    {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankFin, lockRankTraceStrings, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankGscan},
-       lockRankHchanLeaf:     {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankFin, lockRankTraceStrings, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankGscan, lockRankHchanLeaf},
+       lockRankGscan:         {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankFin, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit},
+       lockRankStackpool:     {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankRwmutexW, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankFin, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankRwmutexR, lockRankGscan},
+       lockRankStackLarge:    {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankFin, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankGscan},
+       lockRankHchanLeaf:     {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankFin, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankGscan, lockRankHchanLeaf},
        lockRankSudog:         {lockRankSysmon, lockRankSweep, lockRankNotifyList, lockRankScavenge, lockRankHchan},
-       lockRankWbufSpans:     {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankDefer, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankFin, lockRankTraceStrings, lockRankMspanSpecial, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankGscan, lockRankSudog},
-       lockRankMheap:         {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankRwmutexW, lockRankDefer, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankFin, lockRankTraceStrings, lockRankMspanSpecial, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankRwmutexR, lockRankGscan, lockRankStackpool, lockRankStackLarge, lockRankSudog, lockRankWbufSpans},
-       lockRankGlobalAlloc:   {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankRwmutexW, lockRankDefer, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankFin, lockRankTraceStrings, lockRankMspanSpecial, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankMheapSpecial, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankRwmutexR, lockRankGscan, lockRankStackpool, lockRankStackLarge, lockRankSudog, lockRankWbufSpans, lockRankMheap},
+       lockRankWbufSpans:     {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankDefer, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankMspanSpecial, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankFin, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankGscan, lockRankSudog},
+       lockRankMheap:         {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankRwmutexW, lockRankDefer, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankMspanSpecial, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankFin, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankRwmutexR, lockRankGscan, lockRankStackpool, lockRankStackLarge, lockRankSudog, lockRankWbufSpans},
+       lockRankGlobalAlloc:   {lockRankSysmon, lockRankSweepWaiters, lockRankAssistQueue, lockRankCpuprof, lockRankSweep, lockRankPollDesc, lockRankItab, lockRankNotifyList, lockRankRoot, lockRankRwmutexW, lockRankDefer, lockRankScavenge, lockRankForcegc, lockRankSched, lockRankAllg, lockRankAllp, lockRankTimers, lockRankReflectOffs, lockRankHchan, lockRankTraceBuf, lockRankTraceStrings, lockRankMspanSpecial, lockRankProfInsert, lockRankProfBlock, lockRankProfMemActive, lockRankGcBitsArenas, lockRankSpanSetSpine, lockRankMheapSpecial, lockRankFin, lockRankProfMemFuture, lockRankTrace, lockRankTraceStackTab, lockRankNetpollInit, lockRankRwmutexR, lockRankGscan, lockRankStackpool, lockRankStackLarge, lockRankSudog, lockRankWbufSpans, lockRankMheap},
        lockRankPanic:         {lockRankDeadlock},
 }

diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index 5866a4597b1c1f78b7a0a69bc713a909686ddd63..b044e29d9581a414e00aa07a891d2277456b62dc 100644 (file)
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -847,6 +847,11 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer {
        if size == 0 {
                return unsafe.Pointer(&zerobase)
        }
+
+       // It's possible for any malloc to trigger sweeping, which may in
+       // turn queue finalizers. Record this dynamic lock edge.
+       lockRankMayQueueFinalizer()
+
        userSize := size
        if asanenabled {
                // Refer to ASAN runtime library, the malloc() function allocates extra memory,

diff --git a/src/runtime/mfinal.go b/src/runtime/mfinal.go
index f3f3a79fa58c76305f53340f8ad7cace1ba5fda8..a379cce8a3f839ad65d2028b5d9ce3b169bf772d 100644 (file)
--- a/src/runtime/mfinal.go
+++ b/src/runtime/mfinal.go
@@ -75,6 +75,12 @@ var finalizer1 = [...]byte{
        0<<0 | 1<<1 | 1<<2 | 1<<3 | 1<<4 | 0<<5 | 1<<6 | 1<<7,
 }
 
+// lockRankMayQueueFinalizer records the lock ranking effects of a
+// function that may call queuefinalizer.
+func lockRankMayQueueFinalizer() {
+       lockWithRankMayAcquire(&finlock, getLockRank(&finlock))
+}
+
 func queuefinalizer(p unsafe.Pointer, fn *funcval, nret uintptr, fint *_type, ot *ptrtype) {
        if gcphase != _GCoff {
                // Currently we assume that the finalizer queue won't

diff --git a/src/runtime/mklockrank.go b/src/runtime/mklockrank.go
index 110d57faf07c69a842e620916edfd6c591c104af..d0b882415c11d742c19328a1e3677efbfa2ed455 100644 (file)
--- a/src/runtime/mklockrank.go
+++ b/src/runtime/mklockrank.go
@@ -43,9 +43,8 @@ allp < timers;
 itab < reflectOffs;
 scavenge, sweep < hchan;
 scavenge < traceBuf;
-allg, hchan, reflectOffs, timers, traceBuf < fin;
 traceBuf < traceStrings;
-allg, hchan, notifyList, reflectOffs, timers, traceStrings < mspanSpecial, profInsert, profBlock, profMemActive, gcBitsArenas, spanSetSpine, mheapSpecial;
+allg, hchan, notifyList, reflectOffs, timers, traceStrings < mspanSpecial, profInsert, profBlock, profMemActive, gcBitsArenas, spanSetSpine, mheapSpecial, fin;
 profMemActive < profMemFuture;
 hchan, root, sched, traceStrings, notifyList, fin < trace;
 trace < traceStackTab;