From 668894d7b584b40ddb46e9e2e2ffa637f4d732e5 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Sat, 24 Oct 2020 14:47:44 -0700 Subject: [PATCH] libgo: update to Go 1.15.3 release Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/265717 --- gcc/go/gofrontend/MERGE | 2 +- libgo/MERGE | 2 +- libgo/VERSION | 2 +- libgo/go/bytes/bytes.go | 50 ++++--- libgo/go/cmd/cgo/gcc.go | 15 ++ libgo/go/cmd/cgo/main.go | 3 +- libgo/go/cmd/cgo/out.go | 3 + libgo/go/cmd/go/internal/base/goflags.go | 17 +++ libgo/go/cmd/go/internal/version/version.go | 9 +- libgo/go/cmd/go/internal/work/init.go | 22 +-- libgo/go/cmd/go/testdata/script/version.txt | 6 + libgo/go/internal/bytealg/index_generic.go | 38 +---- libgo/go/internal/poll/fd_unix.go | 12 +- libgo/go/runtime/chan.go | 22 +++ libgo/go/runtime/chan_test.go | 56 +++++++ libgo/go/runtime/export_test.go | 24 +-- .../go/runtime/internal/atomic/atomic_test.go | 10 ++ libgo/go/runtime/mpagealloc.go | 13 ++ libgo/go/runtime/proc_test.go | 10 +- libgo/go/runtime/runtime2.go | 9 +- libgo/go/runtime/select.go | 19 +++ libgo/go/runtime/trace/trace_stack_test.go | 1 + libgo/go/testing/benchmark.go | 18 ++- libgo/go/testing/sub_test.go | 19 ++- libgo/go/testing/testing.go | 140 ++++++++---------- libgo/misc/cgo/test/testdata/issue41761.go | 20 +++ libgo/misc/cgo/test/testdata/issue41761a/a.go | 14 ++ 27 files changed, 367 insertions(+), 189 deletions(-) create mode 100644 libgo/misc/cgo/test/testdata/issue41761.go create mode 100644 libgo/misc/cgo/test/testdata/issue41761a/a.go diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index 7d065954502..1f65809fc81 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -957591b8a054b692d92203a2420851689875f9c5 +be0d2cc2df9f98d967c242594838f86362dae2e7 The first line of this file holds the git revision number of the last merge done from the gofrontend repository. diff --git a/libgo/MERGE b/libgo/MERGE index cfbf488398e..4b158c05c6e 100644 --- a/libgo/MERGE +++ b/libgo/MERGE @@ -1,4 +1,4 @@ -9706f510a5e2754595d716bd64be8375997311fb +1984ee00048b63eacd2155cd6d74a2d13e998272 The first line of this file holds the git revision number of the last merge done from the master library sources. diff --git a/libgo/VERSION b/libgo/VERSION index c19def3de44..93c7b2d3d78 100644 --- a/libgo/VERSION +++ b/libgo/VERSION @@ -1 +1 @@ -go1.15.2 +go1.15.3 diff --git a/libgo/go/bytes/bytes.go b/libgo/go/bytes/bytes.go index aa07b9fbc16..ce52649f132 100644 --- a/libgo/go/bytes/bytes.go +++ b/libgo/go/bytes/bytes.go @@ -227,19 +227,26 @@ func IndexAny(s []byte, chars string) int { continue } r, width = utf8.DecodeRune(s[i:]) - if r == utf8.RuneError { - for _, r = range chars { - if r == utf8.RuneError { + if r != utf8.RuneError { + // r is 2 to 4 bytes + if len(chars) == width { + if chars == string(r) { return i } + continue + } + // Use bytealg.IndexString for performance if available. + if bytealg.MaxLen >= width { + if bytealg.IndexString(chars, string(r)) >= 0 { + return i + } + continue } - continue } - // r is 2 to 4 bytes. Using strings.Index is more reasonable, but as the bytes - // package should not import the strings package, use bytealg.IndexString - // instead. And this does not seem to lose much performance. - if chars == string(r) || bytealg.IndexString(chars, string(r)) >= 0 { - return i + for _, ch := range chars { + if r == ch { + return i + } } } return -1 @@ -304,19 +311,26 @@ func LastIndexAny(s []byte, chars string) int { } r, size := utf8.DecodeLastRune(s[:i]) i -= size - if r == utf8.RuneError { - for _, r = range chars { - if r == utf8.RuneError { + if r != utf8.RuneError { + // r is 2 to 4 bytes + if len(chars) == size { + if chars == string(r) { return i } + continue + } + // Use bytealg.IndexString for performance if available. + if bytealg.MaxLen >= size { + if bytealg.IndexString(chars, string(r)) >= 0 { + return i + } + continue } - continue } - // r is 2 to 4 bytes. Using strings.Index is more reasonable, but as the bytes - // package should not import the strings package, use bytealg.IndexString - // instead. And this does not seem to lose much performance. - if chars == string(r) || bytealg.IndexString(chars, string(r)) >= 0 { - return i + for _, ch := range chars { + if r == ch { + return i + } } } return -1 diff --git a/libgo/go/cmd/cgo/gcc.go b/libgo/go/cmd/cgo/gcc.go index f774cbb9353..37bafcf189e 100644 --- a/libgo/go/cmd/cgo/gcc.go +++ b/libgo/go/cmd/cgo/gcc.go @@ -2459,6 +2459,18 @@ func (c *typeConv) loadType(dtype dwarf.Type, pos token.Pos, parent string) *Typ tt := *t tt.C = &TypeRepr{"%s %s", []interface{}{dt.Kind, tag}} tt.Go = c.Ident("struct{}") + if dt.Kind == "struct" { + // We don't know what the representation of this struct is, so don't let + // anyone allocate one on the Go side. As a side effect of this annotation, + // pointers to this type will not be considered pointers in Go. They won't + // get writebarrier-ed or adjusted during a stack copy. This should handle + // all the cases badPointerTypedef used to handle, but hopefully will + // continue to work going forward without any more need for cgo changes. + tt.NotInHeap = true + // TODO: we should probably do the same for unions. Unions can't live + // on the Go heap, right? It currently doesn't work for unions because + // they are defined as a type alias for struct{}, not a defined type. + } typedef[name.Name] = &tt break } @@ -2529,6 +2541,7 @@ func (c *typeConv) loadType(dtype dwarf.Type, pos token.Pos, parent string) *Typ } t.Go = name t.BadPointer = sub.BadPointer + t.NotInHeap = sub.NotInHeap if unionWithPointer[sub.Go] { unionWithPointer[t.Go] = true } @@ -2539,6 +2552,7 @@ func (c *typeConv) loadType(dtype dwarf.Type, pos token.Pos, parent string) *Typ tt := *t tt.Go = sub.Go tt.BadPointer = sub.BadPointer + tt.NotInHeap = sub.NotInHeap typedef[name.Name] = &tt } @@ -3047,6 +3061,7 @@ func (c *typeConv) anonymousStructTypedef(dt *dwarf.TypedefType) bool { // non-pointers in this type. // TODO: Currently our best solution is to find these manually and list them as // they come up. A better solution is desired. +// Note: DEPRECATED. There is now a better solution. Search for NotInHeap in this file. func (c *typeConv) badPointerTypedef(dt *dwarf.TypedefType) bool { if c.badCFType(dt) { return true diff --git a/libgo/go/cmd/cgo/main.go b/libgo/go/cmd/cgo/main.go index 6de6d69ce6c..7fc2508021b 100644 --- a/libgo/go/cmd/cgo/main.go +++ b/libgo/go/cmd/cgo/main.go @@ -151,7 +151,8 @@ type Type struct { Go ast.Expr EnumValues map[string]int64 Typedef string - BadPointer bool + BadPointer bool // this pointer type should be represented as a uintptr (deprecated) + NotInHeap bool // this type should have a go:notinheap annotation } // A FuncType collects information about a function type in both the C and Go worlds. diff --git a/libgo/go/cmd/cgo/out.go b/libgo/go/cmd/cgo/out.go index 1d23fc1d255..dd03f7d67a5 100644 --- a/libgo/go/cmd/cgo/out.go +++ b/libgo/go/cmd/cgo/out.go @@ -113,6 +113,9 @@ func (p *Package) writeDefs() { sort.Strings(typedefNames) for _, name := range typedefNames { def := typedef[name] + if def.NotInHeap { + fmt.Fprintf(fgo2, "//go:notinheap\n") + } fmt.Fprintf(fgo2, "type %s ", name) // We don't have source info for these types, so write them out without source info. // Otherwise types would look like: diff --git a/libgo/go/cmd/go/internal/base/goflags.go b/libgo/go/cmd/go/internal/base/goflags.go index 34766134b09..f29cc3cf9a5 100644 --- a/libgo/go/cmd/go/internal/base/goflags.go +++ b/libgo/go/cmd/go/internal/base/goflags.go @@ -153,3 +153,20 @@ func SetFromGOFLAGS(flags *flag.FlagSet) { } } } + +// InGOFLAGS returns whether GOFLAGS contains the given flag, such as "-mod". +func InGOFLAGS(flag string) bool { + for _, goflag := range GOFLAGS() { + name := goflag + if strings.HasPrefix(name, "--") { + name = name[1:] + } + if i := strings.Index(name, "="); i >= 0 { + name = name[:i] + } + if name == flag { + return true + } + } + return false +} diff --git a/libgo/go/cmd/go/internal/version/version.go b/libgo/go/cmd/go/internal/version/version.go index ac2ae501552..a5b13653cd6 100644 --- a/libgo/go/cmd/go/internal/version/version.go +++ b/libgo/go/cmd/go/internal/version/version.go @@ -53,7 +53,14 @@ var ( func runVersion(cmd *base.Command, args []string) { if len(args) == 0 { - if *versionM || *versionV { + // If any of this command's flags were passed explicitly, error + // out, because they only make sense with arguments. + // + // Don't error if the flags came from GOFLAGS, since that can be + // a reasonable use case. For example, imagine GOFLAGS=-v to + // turn "verbose mode" on for all Go commands, which should not + // break "go version". + if (!base.InGOFLAGS("-m") && *versionM) || (!base.InGOFLAGS("-v") && *versionV) { fmt.Fprintf(os.Stderr, "go version: flags can only be used with arguments\n") base.SetExitStatus(2) return diff --git a/libgo/go/cmd/go/internal/work/init.go b/libgo/go/cmd/go/internal/work/init.go index dad3b10111d..c168364cd17 100644 --- a/libgo/go/cmd/go/internal/work/init.go +++ b/libgo/go/cmd/go/internal/work/init.go @@ -254,34 +254,18 @@ func buildModeInit() { case "": // ok case "readonly", "vendor", "mod": - if !cfg.ModulesEnabled && !inGOFLAGS("-mod") { + if !cfg.ModulesEnabled && !base.InGOFLAGS("-mod") { base.Fatalf("build flag -mod=%s only valid when using modules", cfg.BuildMod) } default: base.Fatalf("-mod=%s not supported (can be '', 'mod', 'readonly', or 'vendor')", cfg.BuildMod) } if !cfg.ModulesEnabled { - if cfg.ModCacheRW && !inGOFLAGS("-modcacherw") { + if cfg.ModCacheRW && !base.InGOFLAGS("-modcacherw") { base.Fatalf("build flag -modcacherw only valid when using modules") } - if cfg.ModFile != "" && !inGOFLAGS("-mod") { + if cfg.ModFile != "" && !base.InGOFLAGS("-mod") { base.Fatalf("build flag -modfile only valid when using modules") } } } - -func inGOFLAGS(flag string) bool { - for _, goflag := range base.GOFLAGS() { - name := goflag - if strings.HasPrefix(name, "--") { - name = name[1:] - } - if i := strings.Index(name, "="); i >= 0 { - name = name[:i] - } - if name == flag { - return true - } - } - return false -} diff --git a/libgo/go/cmd/go/testdata/script/version.txt b/libgo/go/cmd/go/testdata/script/version.txt index 0123ac6d53f..87cb6befe93 100644 --- a/libgo/go/cmd/go/testdata/script/version.txt +++ b/libgo/go/cmd/go/testdata/script/version.txt @@ -9,6 +9,12 @@ stderr 'with arguments' ! go version -v stderr 'with arguments' +# Neither of the two flags above should be an issue via GOFLAGS. +env GOFLAGS='-m -v' +go version +stdout '^go version' +env GOFLAGS= + env GO111MODULE=on # Skip the builds below if we are running in short mode. [short] skip diff --git a/libgo/go/internal/bytealg/index_generic.go b/libgo/go/internal/bytealg/index_generic.go index 3dc1c6b2232..c595c231cf0 100644 --- a/libgo/go/internal/bytealg/index_generic.go +++ b/libgo/go/internal/bytealg/index_generic.go @@ -17,42 +17,8 @@ func Index(a, b []byte) int { // IndexString returns the index of the first instance of b in a, or -1 if b is not present in a. // Requires 2 <= len(b) <= MaxLen. -func IndexString(s, substr string) int { - // This is a partial copy of strings.Index, here because bytes.IndexAny and bytes.LastIndexAny - // call bytealg.IndexString. Some platforms have an optimized assembly version of this function. - // This implementation is used for those that do not. Although the pure Go implementation here - // works for the case of len(b) > MaxLen, we do not require that its assembly implementation also - // supports the case of len(b) > MaxLen. And we do not guarantee that this function supports the - // case of len(b) > MaxLen. - n := len(substr) - c0 := substr[0] - c1 := substr[1] - i := 0 - t := len(s) - n + 1 - fails := 0 - for i < t { - if s[i] != c0 { - o := IndexByteString(s[i:t], c0) - if o < 0 { - return -1 - } - i += o - } - if s[i+1] == c1 && s[i:i+n] == substr { - return i - } - i++ - fails++ - if fails >= 4+i>>4 && i < t { - // See comment in src/bytes/bytes.go. - j := IndexRabinKarp(s[i:], substr) - if j < 0 { - return -1 - } - return i + j - } - } - return -1 +func IndexString(a, b string) int { + panic("unimplemented") } // Cutover reports the number of failures of IndexByte we should tolerate diff --git a/libgo/go/internal/poll/fd_unix.go b/libgo/go/internal/poll/fd_unix.go index f177ccf3f6e..10cf1735d6a 100644 --- a/libgo/go/internal/poll/fd_unix.go +++ b/libgo/go/internal/poll/fd_unix.go @@ -152,7 +152,7 @@ func (fd *FD) Read(p []byte) (int, error) { p = p[:maxRW] } for { - n, err := ignoringEINTR(syscall.Read, fd.Sysfd, p) + n, err := ignoringEINTR(func() (int, error) { return syscall.Read(fd.Sysfd, p) }) if err != nil { n = 0 if err == syscall.EAGAIN && fd.pd.pollable() { @@ -264,7 +264,7 @@ func (fd *FD) Write(p []byte) (int, error) { if fd.IsStream && max-nn > maxRW { max = nn + maxRW } - n, err := ignoringEINTR(syscall.Write, fd.Sysfd, p[nn:max]) + n, err := ignoringEINTR(func() (int, error) { return syscall.Write(fd.Sysfd, p[nn:max]) }) if n > 0 { nn += n } @@ -423,7 +423,7 @@ func (fd *FD) ReadDirent(buf []byte) (int, error) { } defer fd.decref() for { - n, err := ignoringEINTR(syscall.ReadDirent, fd.Sysfd, buf) + n, err := ignoringEINTR(func() (int, error) { return syscall.ReadDirent(fd.Sysfd, buf) }) if err != nil { n = 0 if err == syscall.EAGAIN && fd.pd.pollable() { @@ -514,7 +514,7 @@ func (fd *FD) WriteOnce(p []byte) (int, error) { return 0, err } defer fd.writeUnlock() - return ignoringEINTR(syscall.Write, fd.Sysfd, p) + return ignoringEINTR(func() (int, error) { return syscall.Write(fd.Sysfd, p) }) } // RawRead invokes the user-defined function f for a read operation. @@ -562,9 +562,9 @@ func (fd *FD) RawWrite(f func(uintptr) bool) error { // installed without setting SA_RESTART. None of these are the common case, // but there are enough of them that it seems that we can't avoid // an EINTR loop. -func ignoringEINTR(fn func(fd int, p []byte) (int, error), fd int, p []byte) (int, error) { +func ignoringEINTR(fn func() (int, error)) (int, error) { for { - n, err := fn(fd, p) + n, err := fn() if err != syscall.EINTR { return n, err } diff --git a/libgo/go/runtime/chan.go b/libgo/go/runtime/chan.go index de1d80acd30..b909d478d26 100644 --- a/libgo/go/runtime/chan.go +++ b/libgo/go/runtime/chan.go @@ -267,6 +267,11 @@ 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 @@ -586,6 +591,11 @@ 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 @@ -663,7 +673,19 @@ 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 } diff --git a/libgo/go/runtime/chan_test.go b/libgo/go/runtime/chan_test.go index ac81d409bda..85d3e04ffff 100644 --- a/libgo/go/runtime/chan_test.go +++ b/libgo/go/runtime/chan_test.go @@ -628,6 +628,62 @@ 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. diff --git a/libgo/go/runtime/export_test.go b/libgo/go/runtime/export_test.go index 482d014ad58..369230a8b7b 100644 --- a/libgo/go/runtime/export_test.go +++ b/libgo/go/runtime/export_test.go @@ -355,7 +355,11 @@ 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 { @@ -752,11 +756,7 @@ 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. @@ -977,10 +980,9 @@ func MapHashCheck(m interface{}, k interface{}) (uintptr, uintptr) { } func MSpanCountAlloc(bits []byte) int { - s := mspan{ - nelems: uintptr(len(bits) * 8), - gcmarkBits: (*gcBits)(unsafe.Pointer(&bits[0])), - } + s := (*mspan)(mheap_.spanalloc.alloc()) + s.nelems = uintptr(len(bits) * 8) + s.gcmarkBits = (*gcBits)(unsafe.Pointer(&bits[0])) return s.countAlloc() } diff --git a/libgo/go/runtime/internal/atomic/atomic_test.go b/libgo/go/runtime/internal/atomic/atomic_test.go index 0c1125c5583..b0a8fa06103 100644 --- a/libgo/go/runtime/internal/atomic/atomic_test.go +++ b/libgo/go/runtime/internal/atomic/atomic_test.go @@ -220,3 +220,13 @@ func TestBitwiseContended(t *testing.T) { } } } + +func TestStorepNoWB(t *testing.T) { + var p [2]*int + for i := range p { + atomic.StorepNoWB(unsafe.Pointer(&p[i]), unsafe.Pointer(new(int))) + } + if p[0] == p[1] { + t.Error("Bad escape analysis of StorepNoWB") + } +} diff --git a/libgo/go/runtime/mpagealloc.go b/libgo/go/runtime/mpagealloc.go index 8b3c62c375e..c90a6378bda 100644 --- a/libgo/go/runtime/mpagealloc.go +++ b/libgo/go/runtime/mpagealloc.go @@ -326,7 +326,20 @@ func (s *pageAlloc) init(mheapLock *mutex, sysStat *uint64) { s.scav.scavLWM = maxSearchAddr } +// 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()] } diff --git a/libgo/go/runtime/proc_test.go b/libgo/go/runtime/proc_test.go index b9828d98183..a8f0dc39c0c 100644 --- a/libgo/go/runtime/proc_test.go +++ b/libgo/go/runtime/proc_test.go @@ -529,9 +529,17 @@ 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) } } diff --git a/libgo/go/runtime/runtime2.go b/libgo/go/runtime/runtime2.go index 5029dbad027..bf3fbac14c8 100644 --- a/libgo/go/runtime/runtime2.go +++ b/libgo/go/runtime/runtime2.go @@ -450,6 +450,10 @@ 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 @@ -940,11 +944,6 @@ type _defer struct { // panics // This is the gccgo version. -// -// This is marked go:notinheap because _panic values must only ever -// live on the stack. -// -//go:notinheap type _panic struct { // The next entry in the stack. link *_panic diff --git a/libgo/go/runtime/select.go b/libgo/go/runtime/select.go index cf5d0c75a49..c8910b8dc23 100644 --- a/libgo/go/runtime/select.go +++ b/libgo/go/runtime/select.go @@ -7,6 +7,7 @@ package runtime // This file contains the implementation of Go select statements. import ( + "runtime/internal/atomic" "unsafe" ) @@ -72,7 +73,20 @@ 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 diff --git a/libgo/go/runtime/trace/trace_stack_test.go b/libgo/go/runtime/trace/trace_stack_test.go index cfc0419b72c..f856fdcd010 100644 --- a/libgo/go/runtime/trace/trace_stack_test.go +++ b/libgo/go/runtime/trace/trace_stack_test.go @@ -252,6 +252,7 @@ func TestTraceSymbolize(t *testing.T) { {trace.EvGoSysCall, []frame{ {"syscall.read", 0}, {"syscall.Read", 0}, + {"internal/poll.(*FD).Read.func1", 0}, {"internal/poll.ignoringEINTR", 0}, {"internal/poll.(*FD).Read", 0}, {"os.(*File).read", 0}, diff --git a/libgo/go/testing/benchmark.go b/libgo/go/testing/benchmark.go index 52766005bf6..e9687bf26de 100644 --- a/libgo/go/testing/benchmark.go +++ b/libgo/go/testing/benchmark.go @@ -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) diff --git a/libgo/go/testing/sub_test.go b/libgo/go/testing/sub_test.go index 8eb0084b1c8..5ed3fc4afec 100644 --- a/libgo/go/testing/sub_test.go +++ b/libgo/go/testing/sub_test.go @@ -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) diff --git a/libgo/go/testing/testing.go b/libgo/go/testing/testing.go index fe6929d1ba0..80282fca60f 100644 --- a/libgo/go/testing/testing.go +++ b/libgo/go/testing/testing.go @@ -325,7 +325,6 @@ var ( cpuListStr *string parallel *int testlog *string - printer *testPrinter haveExamples bool // are there examples? @@ -335,55 +334,45 @@ 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 @@ -405,12 +394,12 @@ type common struct { cleanupName string // Name of the cleanup function. cleanupPc []uintptr // The stack trace at the point where Cleanup was called. - 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. @@ -572,12 +561,31 @@ 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 { @@ -746,13 +754,13 @@ 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 @@ -1019,34 +1027,22 @@ 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() @@ -1197,14 +1193,8 @@ 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 @@ -1369,8 +1359,6 @@ func (m *M) Run() (code int) { flag.Parse() } - printer = newTestPrinter(Verbose()) - if *parallel < 1 { fmt.Fprintln(os.Stderr, "testing: -parallel can only be given a positive integer") flag.Usage() @@ -1415,7 +1403,7 @@ 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 { @@ -1476,10 +1464,12 @@ 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) diff --git a/libgo/misc/cgo/test/testdata/issue41761.go b/libgo/misc/cgo/test/testdata/issue41761.go new file mode 100644 index 00000000000..919c7492510 --- /dev/null +++ b/libgo/misc/cgo/test/testdata/issue41761.go @@ -0,0 +1,20 @@ +// 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 cgotest + +/* + typedef struct S S; +*/ +import "C" + +import ( + "cgotest/issue41761a" + "testing" +) + +func test41761(t *testing.T) { + var x issue41761a.T + _ = (*C.struct_S)(x.X) +} diff --git a/libgo/misc/cgo/test/testdata/issue41761a/a.go b/libgo/misc/cgo/test/testdata/issue41761a/a.go new file mode 100644 index 00000000000..ca5c18191eb --- /dev/null +++ b/libgo/misc/cgo/test/testdata/issue41761a/a.go @@ -0,0 +1,14 @@ +// 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 issue41761a + +/* + typedef struct S S; +*/ +import "C" + +type T struct { + X *C.S +}