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[dev.boringcrypto.go1.14] all: merge go1.14.10 into dev.boringcrypto.go1.14

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Change-Id: I1a32a12c342fca3b4d6bbf446e297c1adf6ce99b
This commit is contained in:
Filippo Valsorda 2020-10-16 22:30:37 +02:00
commit b5fc12785b
20 changed files with 393 additions and 248 deletions
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117
src/cmd/compile/internal/gc/plive.go
View File

@ -126,24 +126,14 @@ type Liveness struct {
regMaps []liveRegMask
cache progeffectscache
// These are only populated if open-coded defers are being used.
// List of vars/stack slots storing defer args
openDeferVars []openDeferVarInfo
// Map from defer arg OpVarDef to the block where the OpVarDef occurs.
openDeferVardefToBlockMap map[*Node]*ssa.Block
// Map of blocks that cannot reach a return or exit (panic)
nonReturnBlocks map[*ssa.Block]bool
}
type openDeferVarInfo struct {
n *Node // Var/stack slot storing a defer arg
varsIndex int // Index of variable in lv.vars
}
// LivenessMap maps from *ssa.Value to LivenessIndex.
type LivenessMap struct {
m []LivenessIndex
// The set of live, pointer-containing variables at the deferreturn
// call (only set when open-coded defers are used).
deferreturn LivenessIndex
}
func (m *LivenessMap) reset(ids int) {
@ -158,6 +148,7 @@ func (m *LivenessMap) reset(ids int) {
m2[i] = none
}
m.m = m2
m.deferreturn = LivenessInvalid
}
func (m *LivenessMap) set(v *ssa.Value, i LivenessIndex) {
@ -505,7 +496,7 @@ func newliveness(fn *Node, f *ssa.Func, vars []*Node, idx map[*Node]int32, stkpt
if cap(lc.be) >= f.NumBlocks() {
lv.be = lc.be[:f.NumBlocks()]
}
lv.livenessMap = LivenessMap{lc.livenessMap.m[:0]}
lv.livenessMap = LivenessMap{m: lc.livenessMap.m[:0], deferreturn: LivenessInvalid}
}
if lv.be == nil {
lv.be = make([]BlockEffects, f.NumBlocks())
@ -838,58 +829,12 @@ func (lv *Liveness) issafepoint(v *ssa.Value) bool {
func (lv *Liveness) prologue() {
lv.initcache()
if lv.fn.Func.HasDefer() && !lv.fn.Func.OpenCodedDeferDisallowed() {
lv.openDeferVardefToBlockMap = make(map[*Node]*ssa.Block)
for i, n := range lv.vars {
if n.Name.OpenDeferSlot() {
lv.openDeferVars = append(lv.openDeferVars, openDeferVarInfo{n: n, varsIndex: i})
}
}
// Find any blocks that cannot reach a return or a BlockExit
// (panic) -- these must be because of an infinite loop.
reachesRet := make(map[ssa.ID]bool)
blockList := make([]*ssa.Block, 0, 256)
for _, b := range lv.f.Blocks {
if b.Kind == ssa.BlockRet || b.Kind == ssa.BlockRetJmp || b.Kind == ssa.BlockExit {
blockList = append(blockList, b)
}
}
for len(blockList) > 0 {
b := blockList[0]
blockList = blockList[1:]
if reachesRet[b.ID] {
continue
}
reachesRet[b.ID] = true
for _, e := range b.Preds {
blockList = append(blockList, e.Block())
}
}
lv.nonReturnBlocks = make(map[*ssa.Block]bool)
for _, b := range lv.f.Blocks {
if !reachesRet[b.ID] {
lv.nonReturnBlocks[b] = true
//fmt.Println("No reach ret", lv.f.Name, b.ID, b.Kind)
}
}
}
for _, b := range lv.f.Blocks {
be := lv.blockEffects(b)
// Walk the block instructions backward and update the block
// effects with the each prog effects.
for j := len(b.Values) - 1; j >= 0; j-- {
if b.Values[j].Op == ssa.OpVarDef {
n := b.Values[j].Aux.(*Node)
if n.Name.OpenDeferSlot() {
lv.openDeferVardefToBlockMap[n] = b
}
}
pos, e := lv.valueEffects(b.Values[j])
regUevar, regKill := lv.regEffects(b.Values[j])
if e&varkill != 0 {
@ -906,20 +851,6 @@ func (lv *Liveness) prologue() {
}
}
// markDeferVarsLive marks each variable storing an open-coded defer arg as
// specially live in block b if the variable definition dominates block b.
func (lv *Liveness) markDeferVarsLive(b *ssa.Block, newliveout *varRegVec) {
// Only force computation of dominators if we have a block where we need
// to specially mark defer args live.
sdom := lv.f.Sdom()
for _, info := range lv.openDeferVars {
defB := lv.openDeferVardefToBlockMap[info.n]
if sdom.IsAncestorEq(defB, b) {
newliveout.vars.Set(int32(info.varsIndex))
}
}
}
// Solve the liveness dataflow equations.
func (lv *Liveness) solve() {
// These temporary bitvectors exist to avoid successive allocations and
@ -963,23 +894,6 @@ func (lv *Liveness) solve() {
}
}
if lv.fn.Func.HasDefer() && !lv.fn.Func.OpenCodedDeferDisallowed() &&
(b.Kind == ssa.BlockExit || lv.nonReturnBlocks[b]) {
// Open-coded defer args slots must be live
// everywhere in a function, since a panic can
// occur (almost) anywhere. Force all appropriate
// defer arg slots to be live in BlockExit (panic)
// blocks and in blocks that do not reach a return
// (because of infinite loop).
//
// We are assuming that the defer exit code at
// BlockReturn/BlockReturnJmp accesses all of the
// defer args (with pointers), and so keeps them
// live. This analysis may have to be adjusted if
// that changes (because of optimizations).
lv.markDeferVarsLive(b, &newliveout)
}
if !be.liveout.Eq(newliveout) {
change = true
be.liveout.Copy(newliveout)
@ -1032,6 +946,17 @@ func (lv *Liveness) epilogue() {
n.Name.SetNeedzero(true)
livedefer.Set(int32(i))
}
if n.Name.OpenDeferSlot() {
// Open-coded defer args slots must be live
// everywhere in a function, since a panic can
// occur (almost) anywhere. Because it is live
// everywhere, it must be zeroed on entry.
livedefer.Set(int32(i))
// It was already marked as Needzero when created.
if !n.Name.Needzero() {
Fatalf("all pointer-containing defer arg slots should have Needzero set")
}
}
}
}
@ -1133,6 +1058,16 @@ func (lv *Liveness) epilogue() {
lv.compact(b)
}
// If we have an open-coded deferreturn call, make a liveness map for it.
if lv.fn.Func.OpenCodedDeferDisallowed() {
lv.livenessMap.deferreturn = LivenessInvalid
} else {
lv.livenessMap.deferreturn = LivenessIndex{
stackMapIndex: lv.stackMapSet.add(livedefer),
regMapIndex: 0, // entry regMap, containing no live registers
}
}
// Done compacting. Throw out the stack map set.
lv.stackMaps = lv.stackMapSet.extractUniqe()
lv.stackMapSet = bvecSet{}

19
src/cmd/compile/internal/gc/ssa.go
View File

@ -4309,12 +4309,6 @@ func (s *state) openDeferExit() {
}
}
if i == len(s.openDefers)-1 {
// Record the call of the first defer. This will be used
// to set liveness info for the deferreturn (which is also
// used for any location that causes a runtime panic)
s.f.LastDeferExit = call
}
s.endBlock()
s.startBlock(bEnd)
}
@ -5773,11 +5767,6 @@ type SSAGenState struct {
// wasm: The number of values on the WebAssembly stack. This is only used as a safeguard.
OnWasmStackSkipped int
// Liveness index for the first function call in the final defer exit code
// path that we generated. All defer functions and args should be live at
// this point. This will be used to set the liveness for the deferreturn.
lastDeferLiveness LivenessIndex
}
// Prog appends a new Prog.
@ -6022,12 +6011,6 @@ func genssa(f *ssa.Func, pp *Progs) {
// instruction.
s.pp.nextLive = s.livenessMap.Get(v)
// Remember the liveness index of the first defer call of
// the last defer exit
if v.Block.Func.LastDeferExit != nil && v == v.Block.Func.LastDeferExit {
s.lastDeferLiveness = s.pp.nextLive
}
// Special case for first line in function; move it to the start.
if firstPos != src.NoXPos {
s.SetPos(firstPos)
@ -6088,7 +6071,7 @@ func genssa(f *ssa.Func, pp *Progs) {
// When doing open-coded defers, generate a disconnected call to
// deferreturn and a return. This will be used to during panic
// recovery to unwind the stack and return back to the runtime.
s.pp.nextLive = s.lastDeferLiveness
s.pp.nextLive = s.livenessMap.deferreturn
gencallret(pp, Deferreturn)
}

11
src/cmd/compile/internal/ssa/func.go
View File

@ -33,15 +33,8 @@ type Func struct {
Blocks []*Block // unordered set of all basic blocks (note: not indexable by ID)
Entry *Block // the entry basic block
// If we are using open-coded defers, this is the first call to a deferred
// function in the final defer exit sequence that we generated. This call
// should be after all defer statements, and will have all args, etc. of
// all defer calls as live. The liveness info of this call will be used
// for the deferreturn/ret segment generated for functions with open-coded
// defers.
LastDeferExit *Value
bid idAlloc // block ID allocator
vid idAlloc // value ID allocator
bid idAlloc // block ID allocator
vid idAlloc // value ID allocator
// Given an environment variable used for debug hash match,
// what file (if any) receives the yes/no logging?

68
src/cmd/compile/internal/x86/387.go
View File

@ -139,12 +139,18 @@ func ssaGenValue387(s *gc.SSAGenState, v *ssa.Value) {
// Set precision if needed. 64 bits is the default.
switch v.Op {
case ssa.Op386ADDSS, ssa.Op386SUBSS, ssa.Op386MULSS, ssa.Op386DIVSS:
p := s.Prog(x86.AFSTCW)
// Save AX so we can use it as scratch space.
p := s.Prog(x86.AMOVL)
p.From.Type = obj.TYPE_REG
p.From.Reg = x86.REG_AX
s.AddrScratch(&p.To)
p = s.Prog(x86.AFLDCW)
p.From.Type = obj.TYPE_MEM
p.From.Name = obj.NAME_EXTERN
p.From.Sym = gc.ControlWord32
// Install a 32-bit version of the control word.
installControlWord(s, gc.ControlWord32, x86.REG_AX)
// Restore AX.
p = s.Prog(x86.AMOVL)
s.AddrScratch(&p.From)
p.To.Type = obj.TYPE_REG
p.To.Reg = x86.REG_AX
}
var op obj.As
@ -167,8 +173,7 @@ func ssaGenValue387(s *gc.SSAGenState, v *ssa.Value) {
// Restore precision if needed.
switch v.Op {
case ssa.Op386ADDSS, ssa.Op386SUBSS, ssa.Op386MULSS, ssa.Op386DIVSS:
p := s.Prog(x86.AFLDCW)
s.AddrScratch(&p.From)
restoreControlWord(s)
}
case ssa.Op386UCOMISS, ssa.Op386UCOMISD:
@ -225,19 +230,11 @@ func ssaGenValue387(s *gc.SSAGenState, v *ssa.Value) {
case ssa.Op386CVTTSD2SL, ssa.Op386CVTTSS2SL:
push(s, v.Args[0])
// Save control word.
p := s.Prog(x86.AFSTCW)
s.AddrScratch(&p.To)
p.To.Offset += 4
// Load control word which truncates (rounds towards zero).
p = s.Prog(x86.AFLDCW)
p.From.Type = obj.TYPE_MEM
p.From.Name = obj.NAME_EXTERN
p.From.Sym = gc.ControlWord64trunc
installControlWord(s, gc.ControlWord64trunc, v.Reg())
// Now do the conversion.
p = s.Prog(x86.AFMOVLP)
p := s.Prog(x86.AFMOVLP)
p.From.Type = obj.TYPE_REG
p.From.Reg = x86.REG_F0
s.AddrScratch(&p.To)
@ -247,9 +244,7 @@ func ssaGenValue387(s *gc.SSAGenState, v *ssa.Value) {
p.To.Reg = v.Reg()
// Restore control word.
p = s.Prog(x86.AFLDCW)
s.AddrScratch(&p.From)
p.From.Offset += 4
restoreControlWord(s)
case ssa.Op386CVTSS2SD:
// float32 -> float64 is a nop
@ -373,3 +368,36 @@ func ssaGenBlock387(s *gc.SSAGenState, b, next *ssa.Block) {
ssaGenBlock(s, b, next)
}
// installControlWord saves the current floating-point control
// word and installs a new one loaded from cw.
// scratchReg must be an unused register.
// This call must be paired with restoreControlWord.
// Bytes 4-5 of the scratch space (s.AddrScratch) are used between
// this call and restoreControlWord.
func installControlWord(s *gc.SSAGenState, cw *obj.LSym, scratchReg int16) {
// Save current control word.
p := s.Prog(x86.AFSTCW)
s.AddrScratch(&p.To)
p.To.Offset += 4
// Materialize address of new control word.
// Note: this must be a seperate instruction to handle PIE correctly.
// See issue 41503.
p = s.Prog(x86.ALEAL)
p.From.Type = obj.TYPE_MEM
p.From.Name = obj.NAME_EXTERN
p.From.Sym = cw
p.To.Type = obj.TYPE_REG
p.To.Reg = scratchReg
// Load replacement control word.
p = s.Prog(x86.AFLDCW)
p.From.Type = obj.TYPE_MEM
p.From.Reg = scratchReg
}
func restoreControlWord(s *gc.SSAGenState) {
p := s.Prog(x86.AFLDCW)
s.AddrScratch(&p.From)
p.From.Offset += 4
}

11
src/cmd/internal/obj/s390x/objz.go
View File

@ -283,17 +283,6 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) {
ACMPUBNE:
q = p
p.Mark |= BRANCH
if p.Pcond != nil {
q := p.Pcond
for q.As == obj.ANOP {
q = q.Link
p.Pcond = q
}
}
case obj.ANOP:
q.Link = p.Link /* q is non-nop */
p.Link.Mark |= p.Mark
default:
q = p

7
src/database/sql/sql.go
View File

@ -2729,10 +2729,17 @@ func (rs *Rows) lasterrOrErrLocked(err error) error {
return err
}
// bypassRowsAwaitDone is only used for testing.
// If true, it will not close the Rows automatically from the context.
var bypassRowsAwaitDone = false
func (rs *Rows) initContextClose(ctx, txctx context.Context) {
if ctx.Done() == nil && (txctx == nil || txctx.Done() == nil) {
return
}
if bypassRowsAwaitDone {
return
}
ctx, rs.cancel = context.WithCancel(ctx)
go rs.awaitDone(ctx, txctx)
}

6
src/database/sql/sql_test.go
View File

@ -2724,7 +2724,7 @@ func TestManyErrBadConn(t *testing.T) {
}
}
// Issue 34755: Ensure that a Tx cannot commit after a rollback.
// Issue 34775: Ensure that a Tx cannot commit after a rollback.
func TestTxCannotCommitAfterRollback(t *testing.T) {
db := newTestDB(t, "tx_status")
defer closeDB(t, db)
@ -2766,6 +2766,9 @@ func TestTxCannotCommitAfterRollback(t *testing.T) {
// 2. (A) Start a query, (B) begin Tx rollback through a ctx cancel.
// 3. Check if 2.A has committed in Tx (pass) or outside of Tx (fail).
sendQuery := make(chan struct{})
// The Tx status is returned through the row results, ensure
// that the rows results are not cancelled.
bypassRowsAwaitDone = true
hookTxGrabConn = func() {
cancel()
<-sendQuery
@ -2776,6 +2779,7 @@ func TestTxCannotCommitAfterRollback(t *testing.T) {
defer func() {
hookTxGrabConn = nil
rollbackHook = nil
bypassRowsAwaitDone = false
}()
err = tx.QueryRow("SELECT|tx_status|tx_status|").Scan(&txStatus)

22
src/runtime/chan.go
View File

@ -233,6 +233,11 @@ func chansend(c *hchan, ep unsafe.Pointer, block bool, callerpc uintptr) bool {
gp.waiting = mysg
gp.param = nil
c.sendq.enqueue(mysg)
// Signal to anyone trying to shrink our stack that we're about
// to park on a channel. The window between when this G's status
// changes and when we set gp.activeStackChans is not safe for
// stack shrinking.
atomic.Store8(&gp.parkingOnChan, 1)
gopark(chanparkcommit, unsafe.Pointer(&c.lock), waitReasonChanSend, traceEvGoBlockSend, 2)
// Ensure the value being sent is kept alive until the
// receiver copies it out. The sudog has a pointer to the
@ -522,6 +527,11 @@ func chanrecv(c *hchan, ep unsafe.Pointer, block bool) (selected, received bool)
mysg.c = c
gp.param = nil
c.recvq.enqueue(mysg)
// Signal to anyone trying to shrink our stack that we're about
// to park on a channel. The window between when this G's status
// changes and when we set gp.activeStackChans is not safe for
// stack shrinking.
atomic.Store8(&gp.parkingOnChan, 1)
gopark(chanparkcommit, unsafe.Pointer(&c.lock), waitReasonChanReceive, traceEvGoBlockRecv, 2)
// someone woke us up
@ -599,7 +609,19 @@ func recv(c *hchan, sg *sudog, ep unsafe.Pointer, unlockf func(), skip int) {
func chanparkcommit(gp *g, chanLock unsafe.Pointer) bool {
// There are unlocked sudogs that point into gp's stack. Stack
// copying must lock the channels of those sudogs.
// Set activeStackChans here instead of before we try parking
// because we could self-deadlock in stack growth on the
// channel lock.
gp.activeStackChans = true
// Mark that it's safe for stack shrinking to occur now,
// because any thread acquiring this G's stack for shrinking
// is guaranteed to observe activeStackChans after this store.
atomic.Store8(&gp.parkingOnChan, 0)
// Make sure we unlock after setting activeStackChans and
// unsetting parkingOnChan. The moment we unlock chanLock
// we risk gp getting readied by a channel operation and
// so gp could continue running before everything before
// the unlock is visible (even to gp itself).
unlock((*mutex)(chanLock))
return true
}

56
src/runtime/chan_test.go
View File

@ -623,6 +623,62 @@ func TestShrinkStackDuringBlockedSend(t *testing.T) {
<-done
}
func TestNoShrinkStackWhileParking(t *testing.T) {
// The goal of this test is to trigger a "racy sudog adjustment"
// throw. Basically, there's a window between when a goroutine
// becomes available for preemption for stack scanning (and thus,
// stack shrinking) but before the goroutine has fully parked on a
// channel. See issue 40641 for more details on the problem.
//
// The way we try to induce this failure is to set up two
// goroutines: a sender and a reciever that communicate across
// a channel. We try to set up a situation where the sender
// grows its stack temporarily then *fully* blocks on a channel
// often. Meanwhile a GC is triggered so that we try to get a
// mark worker to shrink the sender's stack and race with the
// sender parking.
//
// Unfortunately the race window here is so small that we
// either need a ridiculous number of iterations, or we add
// "usleep(1000)" to park_m, just before the unlockf call.
const n = 10
send := func(c chan<- int, done chan struct{}) {
for i := 0; i < n; i++ {
c <- i
// Use lots of stack briefly so that
// the GC is going to want to shrink us
// when it scans us. Make sure not to
// do any function calls otherwise
// in order to avoid us shrinking ourselves
// when we're preempted.
stackGrowthRecursive(20)
}
done <- struct{}{}
}
recv := func(c <-chan int, done chan struct{}) {
for i := 0; i < n; i++ {
// Sleep here so that the sender always
// fully blocks.
time.Sleep(10 * time.Microsecond)
<-c
}
done <- struct{}{}
}
for i := 0; i < n*20; i++ {
c := make(chan int)
done := make(chan struct{})
go recv(c, done)
go send(c, done)
// Wait a little bit before triggering
// the GC to make sure the sender and
// reciever have gotten into their groove.
time.Sleep(50 * time.Microsecond)
runtime.GC()
<-done
<-done
}
}
func TestSelectDuplicateChannel(t *testing.T) {
// This test makes sure we can queue a G on
// the same channel multiple times.

17
src/runtime/export_test.go
View File

@ -360,7 +360,11 @@ func ReadMemStatsSlow() (base, slow MemStats) {
}
for i := mheap_.pages.start; i < mheap_.pages.end; i++ {
pg := mheap_.pages.chunkOf(i).scavenged.popcntRange(0, pallocChunkPages)
chunk := mheap_.pages.tryChunkOf(i)
if chunk == nil {
continue
}
pg := chunk.scavenged.popcntRange(0, pallocChunkPages)
slow.HeapReleased += uint64(pg) * pageSize
}
for _, p := range allp {
@ -753,11 +757,7 @@ func (p *PageAlloc) InUse() []AddrRange {
// Returns nil if the PallocData's L2 is missing.
func (p *PageAlloc) PallocData(i ChunkIdx) *PallocData {
ci := chunkIdx(i)
l2 := (*pageAlloc)(p).chunks[ci.l1()]
if l2 == nil {
return nil
}
return (*PallocData)(&l2[ci.l2()])
return (*PallocData)((*pageAlloc)(p).tryChunkOf(ci))
}
// AddrRange represents a range over addresses.
@ -896,7 +896,10 @@ func CheckScavengedBitsCleared(mismatches []BitsMismatch) (n int, ok bool) {
lock(&mheap_.lock)
chunkLoop:
for i := mheap_.pages.start; i < mheap_.pages.end; i++ {
chunk := mheap_.pages.chunkOf(i)
chunk := mheap_.pages.tryChunkOf(i)
if chunk == nil {
continue
}
for j := 0; j < pallocChunkPages/64; j++ {
// Run over each 64-bit bitmap section and ensure
// scavenged is being cleared properly on allocation.

13
src/runtime/mpagealloc.go
View File

@ -331,7 +331,20 @@ func (s *pageAlloc) compareSearchAddrTo(addr uintptr) int {
return 0
}
// tryChunkOf returns the bitmap data for the given chunk.
//
// Returns nil if the chunk data has not been mapped.
func (s *pageAlloc) tryChunkOf(ci chunkIdx) *pallocData {
l2 := s.chunks[ci.l1()]
if l2 == nil {
return nil
}
return &l2[ci.l2()]
}
// chunkOf returns the chunk at the given chunk index.
//
// The chunk index must be valid or this method may throw.
func (s *pageAlloc) chunkOf(ci chunkIdx) *pallocData {
return &s.chunks[ci.l1()][ci.l2()]
}

10
src/runtime/proc_test.go
View File

@ -517,9 +517,17 @@ func BenchmarkPingPongHog(b *testing.B) {
<-done
}
var padData [128]uint64
func stackGrowthRecursive(i int) {
var pad [128]uint64
if i != 0 && pad[0] == 0 {
pad = padData
for j := range pad {
if pad[j] != 0 {
return
}
}
if i != 0 {
stackGrowthRecursive(i - 1)
}
}

4
src/runtime/runtime2.go
View File

@ -436,6 +436,10 @@ type g struct {
// copying needs to acquire channel locks to protect these
// areas of the stack.
activeStackChans bool
// parkingOnChan indicates that the goroutine is about to
// park on a chansend or chanrecv. Used to signal an unsafe point
// for stack shrinking. It's a boolean value, but is updated atomically.
parkingOnChan uint8
raceignore int8 // ignore race detection events
sysblocktraced bool // StartTrace has emitted EvGoInSyscall about this goroutine

19
src/runtime/select.go
View File

@ -7,6 +7,7 @@ package runtime
// This file contains the implementation of Go select statements.
import (
"runtime/internal/atomic"
"unsafe"
)
@ -77,7 +78,20 @@ func selunlock(scases []scase, lockorder []uint16) {
func selparkcommit(gp *g, _ unsafe.Pointer) bool {
// There are unlocked sudogs that point into gp's stack. Stack
// copying must lock the channels of those sudogs.
// Set activeStackChans here instead of before we try parking
// because we could self-deadlock in stack growth on a
// channel lock.
gp.activeStackChans = true
// Mark that it's safe for stack shrinking to occur now,
// because any thread acquiring this G's stack for shrinking
// is guaranteed to observe activeStackChans after this store.
atomic.Store8(&gp.parkingOnChan, 0)
// Make sure we unlock after setting activeStackChans and
// unsetting parkingOnChan. The moment we unlock any of the
// channel locks we risk gp getting readied by a channel operation
// and so gp could continue running before everything before the
// unlock is visible (even to gp itself).
// This must not access gp's stack (see gopark). In
// particular, it must not access the *hselect. That's okay,
// because by the time this is called, gp.waiting has all
@ -313,6 +327,11 @@ loop:
// wait for someone to wake us up
gp.param = nil
// Signal to anyone trying to shrink our stack that we're about
// to park on a channel. The window between when this G's status
// changes and when we set gp.activeStackChans is not safe for
// stack shrinking.
atomic.Store8(&gp.parkingOnChan, 1)
gopark(selparkcommit, nil, waitReasonSelect, traceEvGoBlockSelect, 1)
gp.activeStackChans = false

13
src/runtime/stack.go
View File

@ -850,6 +850,13 @@ func copystack(gp *g, newsize uintptr) {
// Adjust sudogs, synchronizing with channel ops if necessary.
ncopy := used
if !gp.activeStackChans {
if newsize < old.hi-old.lo && atomic.Load8(&gp.parkingOnChan) != 0 {
// It's not safe for someone to shrink this stack while we're actively
// parking on a channel, but it is safe to grow since we do that
// ourselves and explicitly don't want to synchronize with channels
// since we could self-deadlock.
throw("racy sudog adjustment due to parking on channel")
}
adjustsudogs(gp, &adjinfo)
} else {
// sudogs may be pointing in to the stack and gp has
@ -1078,7 +1085,11 @@ func isShrinkStackSafe(gp *g) bool {
// We also can't copy the stack if we're at an asynchronous
// safe-point because we don't have precise pointer maps for
// all frames.
return gp.syscallsp == 0 && !gp.asyncSafePoint
//
// We also can't *shrink* the stack in the window between the
// goroutine calling gopark to park on a channel and
// gp.activeStackChans being set.
return gp.syscallsp == 0 && !gp.asyncSafePoint && atomic.Load8(&gp.parkingOnChan) == 0
}
// Maybe shrink the stack being used by gp.

2
src/runtime/stubs32.go
View File

@ -11,4 +11,4 @@ import "unsafe"
// Declarations for runtime services implemented in C or assembly that
// are only present on 32 bit systems.
func call16(fn, arg unsafe.Pointer, n, retoffset uint32)
func call16(typ, fn, arg unsafe.Pointer, n, retoffset uint32)

18
src/testing/benchmark.go
View File

@ -242,7 +242,7 @@ func (b *B) run1() bool {
if b.skipped {
tag = "SKIP"
}
if b.chatty && (len(b.output) > 0 || b.finished) {
if b.chatty != nil && (len(b.output) > 0 || b.finished) {
b.trimOutput()
fmt.Fprintf(b.w, "--- %s: %s\n%s", tag, b.name, b.output)
}
@ -523,10 +523,9 @@ func runBenchmarks(importPath string, matchString func(pat, str string) (bool, e
}
main := &B{
common: common{
name: "Main",
w: os.Stdout,
chatty: *chatty,
bench: true,
name: "Main",
w: os.Stdout,
bench: true,
},
importPath: importPath,
benchFunc: func(b *B) {
@ -537,6 +536,9 @@ func runBenchmarks(importPath string, matchString func(pat, str string) (bool, e
benchTime: benchTime,
context: ctx,
}
if Verbose() {
main.chatty = newChattyPrinter(main.w)
}
main.runN(1)
return !main.failed
}
@ -549,7 +551,7 @@ func (ctx *benchContext) processBench(b *B) {
benchName := benchmarkName(b.name, procs)
// If it's chatty, we've already printed this information.
if !b.chatty {
if b.chatty == nil {
fmt.Fprintf(b.w, "%-*s\t", ctx.maxLen, benchName)
}
// Recompute the running time for all but the first iteration.
@ -576,7 +578,7 @@ func (ctx *benchContext) processBench(b *B) {
continue
}
results := r.String()
if b.chatty {
if b.chatty != nil {
fmt.Fprintf(b.w, "%-*s\t", ctx.maxLen, benchName)
}
if *benchmarkMemory || b.showAllocResult {
@ -639,7 +641,7 @@ func (b *B) Run(name string, f func(b *B)) bool {
atomic.StoreInt32(&sub.hasSub, 1)
}
if b.chatty {
if b.chatty != nil {
labelsOnce.Do(func() {
fmt.Printf("goos: %s\n", runtime.GOOS)
fmt.Printf("goarch: %s\n", runtime.GOARCH)

19
src/testing/sub_test.go
View File

@ -483,10 +483,12 @@ func TestTRun(t *T) {
signal: make(chan bool),
name: "Test",
w: buf,
chatty: tc.chatty,
},
context: ctx,
}
if tc.chatty {
root.chatty = newChattyPrinter(root.w)
}
ok := root.Run(tc.desc, tc.f)
ctx.release()
@ -665,11 +667,13 @@ func TestBRun(t *T) {
signal: make(chan bool),
name: "root",
w: buf,
chatty: tc.chatty,
},
benchFunc: func(b *B) { ok = b.Run("test", tc.f) }, // Use Run to catch failure.
benchTime: benchTimeFlag{d: 1 * time.Microsecond},
}
if tc.chatty {
root.chatty = newChattyPrinter(root.w)
}
root.runN(1)
if ok != !tc.failed {
t.Errorf("%s:ok: got %v; want %v", tc.desc, ok, !tc.failed)
@ -741,9 +745,13 @@ func TestParallelSub(t *T) {
}
}
type funcWriter func([]byte) (int, error)
type funcWriter struct {
write func([]byte) (int, error)
}
func (fw funcWriter) Write(b []byte) (int, error) { return fw(b) }
func (fw *funcWriter) Write(b []byte) (int, error) {
return fw.write(b)
}
func TestRacyOutput(t *T) {
var runs int32 // The number of running Writes
@ -761,9 +769,10 @@ func TestRacyOutput(t *T) {
var wg sync.WaitGroup
root := &T{
common: common{w: funcWriter(raceDetector), chatty: true},
common: common{w: &funcWriter{raceDetector}},
context: newTestContext(1, newMatcher(regexp.MatchString, "", "")),
}
root.chatty = newChattyPrinter(root.w)
root.Run("", func(t *T) {
for i := 0; i < 100; i++ {
wg.Add(1)

140
src/testing/testing.go
View File

@ -320,7 +320,6 @@ var (
cpuListStr *string
parallel *int
testlog *string
printer *testPrinter
haveExamples bool // are there examples?
@ -330,55 +329,45 @@ var (
numFailed uint32 // number of test failures
)
type testPrinter struct {
chatty bool
type chattyPrinter struct {
w io.Writer
lastNameMu sync.Mutex // guards lastName
lastName string // last printed test name in chatty mode
}
func newTestPrinter(chatty bool) *testPrinter {
return &testPrinter{
chatty: chatty,
}
func newChattyPrinter(w io.Writer) *chattyPrinter {
return &chattyPrinter{w: w}
}
func (p *testPrinter) Print(testName, out string) {
p.Fprint(os.Stdout, testName, out)
}
func (p *testPrinter) Fprint(w io.Writer, testName, out string) {
// Updatef prints a message about the status of the named test to w.
//
// The formatted message must include the test name itself.
func (p *chattyPrinter) Updatef(testName, format string, args ...interface{}) {
p.lastNameMu.Lock()
defer p.lastNameMu.Unlock()
if !p.chatty ||
strings.HasPrefix(out, "--- PASS: ") ||
strings.HasPrefix(out, "--- FAIL: ") ||
strings.HasPrefix(out, "--- SKIP: ") ||
strings.HasPrefix(out, "=== RUN ") ||
strings.HasPrefix(out, "=== CONT ") ||
strings.HasPrefix(out, "=== PAUSE ") {
// If we're buffering test output (!p.chatty), we don't really care which
// test is emitting which line so long as they are serialized.
//
// If the message already implies an association with a specific new test,
// we don't need to check what the old test name was or log an extra CONT
// line for it. (We're updating it anyway, and the current message already
// includes the test name.)
p.lastName = testName
fmt.Fprint(w, out)
return
}
// Since the message already implies an association with a specific new test,
// we don't need to check what the old test name was or log an extra CONT line
// for it. (We're updating it anyway, and the current message already includes
// the test name.)
p.lastName = testName
fmt.Fprintf(p.w, format, args...)
}
// Printf prints a message, generated by the named test, that does not
// necessarily mention that tests's name itself.
func (p *chattyPrinter) Printf(testName, format string, args ...interface{}) {
p.lastNameMu.Lock()
defer p.lastNameMu.Unlock()
if p.lastName == "" {
p.lastName = testName
} else if p.lastName != testName {
// Always printed as-is, with 0 decoration or indentation. So, we skip
// printing to w.
fmt.Printf("=== CONT %s\n", testName)
fmt.Fprintf(p.w, "=== CONT %s\n", testName)
p.lastName = testName
}
fmt.Fprint(w, out)
fmt.Fprintf(p.w, format, args...)
}
// The maximum number of stack frames to go through when skipping helper functions for
@ -398,12 +387,12 @@ type common struct {
helpers map[string]struct{} // functions to be skipped when writing file/line info
cleanup func() // optional function to be called at the end of the test
chatty bool // A copy of the chatty flag.
bench bool // Whether the current test is a benchmark.
finished bool // Test function has completed.
hasSub int32 // Written atomically.
raceErrors int // Number of races detected during test.
runner string // Function name of tRunner running the test.
chatty *chattyPrinter // A copy of chattyPrinter, if the chatty flag is set.
bench bool // Whether the current test is a benchmark.
finished bool // Test function has completed.
hasSub int32 // Written atomically.
raceErrors int // Number of races detected during test.
runner string // Function name of tRunner running the test.
parent *common
level int // Nesting depth of test or benchmark.
@ -556,12 +545,31 @@ func (c *common) flushToParent(testName, format string, args ...interface{}) {
p.mu.Lock()
defer p.mu.Unlock()
printer.Fprint(p.w, testName, fmt.Sprintf(format, args...))
c.mu.Lock()
defer c.mu.Unlock()
io.Copy(p.w, bytes.NewReader(c.output))
c.output = c.output[:0]
if len(c.output) > 0 {
format += "%s"
args = append(args[:len(args):len(args)], c.output)
c.output = c.output[:0] // but why?
}
if c.chatty != nil && p.w == c.chatty.w {
// We're flushing to the actual output, so track that this output is
// associated with a specific test (and, specifically, that the next output
// is *not* associated with that test).
//
// Moreover, if c.output is non-empty it is important that this write be
// atomic with respect to the output of other tests, so that we don't end up
// with confusing '=== CONT' lines in the middle of our '--- PASS' block.
// Neither humans nor cmd/test2json can parse those easily.
// (See https://golang.org/issue/40771.)
c.chatty.Updatef(testName, format, args...)
} else {
// We're flushing to the output buffer of the parent test, which will
// itself follow a test-name header when it is finally flushed to stdout.
fmt.Fprintf(p.w, format, args...)
}
}
type indenter struct {
@ -729,13 +737,13 @@ func (c *common) logDepth(s string, depth int) {
}
panic("Log in goroutine after " + c.name + " has completed")
} else {
if c.chatty {
if c.chatty != nil {
if c.bench {
// Benchmarks don't print === CONT, so we should skip the test
// printer and just print straight to stdout.
fmt.Print(c.decorate(s, depth+1))
} else {
printer.Print(c.name, c.decorate(s, depth+1))
c.chatty.Printf(c.name, "%s", c.decorate(s, depth+1))
}
return
@ -910,34 +918,22 @@ func (t *T) Parallel() {
t.parent.sub = append(t.parent.sub, t)
t.raceErrors += race.Errors()
if t.chatty {
// Print directly to root's io.Writer so there is no delay.
root := t.parent
for ; root.parent != nil; root = root.parent {
}
root.mu.Lock()
if t.chatty != nil {
// Unfortunately, even though PAUSE indicates that the named test is *no
// longer* running, cmd/test2json interprets it as changing the active test
// for the purpose of log parsing. We could fix cmd/test2json, but that
// won't fix existing deployments of third-party tools that already shell
// out to older builds of cmd/test2json — so merely fixing cmd/test2json
// isn't enough for now.
printer.Fprint(root.w, t.name, fmt.Sprintf("=== PAUSE %s\n", t.name))
root.mu.Unlock()
t.chatty.Updatef(t.name, "=== PAUSE %s\n", t.name)
}
t.signal <- true // Release calling test.
<-t.parent.barrier // Wait for the parent test to complete.
t.context.waitParallel()
if t.chatty {
// Print directly to root's io.Writer so there is no delay.
root := t.parent
for ; root.parent != nil; root = root.parent {
}
root.mu.Lock()
printer.Fprint(root.w, t.name, fmt.Sprintf("=== CONT %s\n", t.name))
root.mu.Unlock()
if t.chatty != nil {
t.chatty.Updatef(t.name, "=== CONT %s\n", t.name)
}
t.start = time.Now()
@ -1088,14 +1084,8 @@ func (t *T) Run(name string, f func(t *T)) bool {
}
t.w = indenter{&t.common}
if t.chatty {
// Print directly to root's io.Writer so there is no delay.
root := t.parent
for ; root.parent != nil; root = root.parent {
}
root.mu.Lock()
printer.Fprint(root.w, t.name, fmt.Sprintf("=== RUN %s\n", t.name))
root.mu.Unlock()
if t.chatty != nil {
t.chatty.Updatef(t.name, "=== RUN %s\n", t.name)
}
// Instead of reducing the running count of this test before calling the
// tRunner and increasing it afterwards, we rely on tRunner keeping the
@ -1242,8 +1232,6 @@ func (m *M) Run() int {
flag.Parse()
}
printer = newTestPrinter(Verbose())
if *parallel < 1 {
fmt.Fprintln(os.Stderr, "testing: -parallel can only be given a positive integer")
flag.Usage()
@ -1284,7 +1272,7 @@ func (t *T) report() {
format := "--- %s: %s (%s)\n"
if t.Failed() {
t.flushToParent(t.name, format, "FAIL", t.name, dstr)
} else if t.chatty {
} else if t.chatty != nil {
if t.Skipped() {
t.flushToParent(t.name, format, "SKIP", t.name, dstr)
} else {
@ -1340,10 +1328,12 @@ func runTests(matchString func(pat, str string) (bool, error), tests []InternalT
signal: make(chan bool),
barrier: make(chan bool),
w: os.Stdout,
chatty: *chatty,
},
context: ctx,
}
if Verbose() {
t.chatty = newChattyPrinter(t.w)
}
tRunner(t, func(t *T) {
for _, test := range tests {
t.Run(test.Name, test.F)

69
test/fixedbugs/issue40629.go Normal file
View File

@ -0,0 +1,69 @@
// run
// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import "fmt"
const N = 40
func main() {
var x [N]int // stack-allocated memory
for i := range x {
x[i] = 0x999
}
// This defer checks to see if x is uncorrupted.
defer func(p *[N]int) {
recover()
for i := range p {
if p[i] != 0x999 {
for j := range p {
fmt.Printf("p[%d]=0x%x\n", j, p[j])
}
panic("corrupted stack variable")
}
}
}(&x)
// This defer starts a new goroutine, which will (hopefully)
// overwrite x on the garbage stack.
defer func() {
c := make(chan bool)
go func() {
useStack(1000)
c <- true
}()
<-c
}()
// This defer causes a stack copy.
// The old stack is now garbage.
defer func() {
useStack(1000)
}()
// Trigger a segfault.
*g = 0
// Make the return statement unreachable.
// That makes the stack map at the deferreturn call empty.
// In particular, the argument to the first defer is not
// marked as a pointer, so it doesn't get adjusted
// during the stack copy.
for {
}
}
var g *int64
func useStack(n int) {
if n == 0 {
return
}
useStack(n - 1)
}