diff options
Diffstat (limited to 'pkg/sentry/fsimpl/devpts')
-rw-r--r-- | pkg/sentry/fsimpl/devpts/BUILD | 59 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/devpts/devpts_state_autogen.go | 185 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/devpts/devpts_test.go | 56 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/devpts/root_inode_refs.go | 118 |
4 files changed, 303 insertions, 115 deletions
diff --git a/pkg/sentry/fsimpl/devpts/BUILD b/pkg/sentry/fsimpl/devpts/BUILD deleted file mode 100644 index 3f64fab3a..000000000 --- a/pkg/sentry/fsimpl/devpts/BUILD +++ /dev/null @@ -1,59 +0,0 @@ -load("//tools:defs.bzl", "go_library", "go_test") -load("//tools/go_generics:defs.bzl", "go_template_instance") - -licenses(["notice"]) - -go_template_instance( - name = "root_inode_refs", - out = "root_inode_refs.go", - package = "devpts", - prefix = "rootInode", - template = "//pkg/refs_vfs2:refs_template", - types = { - "T": "rootInode", - }, -) - -go_library( - name = "devpts", - srcs = [ - "devpts.go", - "line_discipline.go", - "master.go", - "queue.go", - "root_inode_refs.go", - "slave.go", - "terminal.go", - ], - visibility = ["//pkg/sentry:internal"], - deps = [ - "//pkg/abi/linux", - "//pkg/context", - "//pkg/log", - "//pkg/refs", - "//pkg/safemem", - "//pkg/sentry/arch", - "//pkg/sentry/fs/lock", - "//pkg/sentry/fsimpl/kernfs", - "//pkg/sentry/kernel", - "//pkg/sentry/kernel/auth", - "//pkg/sentry/unimpl", - "//pkg/sentry/vfs", - "//pkg/sync", - "//pkg/syserror", - "//pkg/usermem", - "//pkg/waiter", - ], -) - -go_test( - name = "devpts_test", - size = "small", - srcs = ["devpts_test.go"], - library = ":devpts", - deps = [ - "//pkg/abi/linux", - "//pkg/sentry/contexttest", - "//pkg/usermem", - ], -) diff --git a/pkg/sentry/fsimpl/devpts/devpts_state_autogen.go b/pkg/sentry/fsimpl/devpts/devpts_state_autogen.go new file mode 100644 index 000000000..adc184d1b --- /dev/null +++ b/pkg/sentry/fsimpl/devpts/devpts_state_autogen.go @@ -0,0 +1,185 @@ +// automatically generated by stateify. + +package devpts + +import ( + "gvisor.dev/gvisor/pkg/state" +) + +func (x *lineDiscipline) StateTypeName() string { + return "pkg/sentry/fsimpl/devpts.lineDiscipline" +} + +func (x *lineDiscipline) StateFields() []string { + return []string{ + "size", + "inQueue", + "outQueue", + "termios", + "column", + } +} + +func (x *lineDiscipline) beforeSave() {} + +func (x *lineDiscipline) StateSave(m state.Sink) { + x.beforeSave() + if !state.IsZeroValue(&x.masterWaiter) { + state.Failf("masterWaiter is %#v, expected zero", &x.masterWaiter) + } + if !state.IsZeroValue(&x.slaveWaiter) { + state.Failf("slaveWaiter is %#v, expected zero", &x.slaveWaiter) + } + m.Save(0, &x.size) + m.Save(1, &x.inQueue) + m.Save(2, &x.outQueue) + m.Save(3, &x.termios) + m.Save(4, &x.column) +} + +func (x *lineDiscipline) afterLoad() {} + +func (x *lineDiscipline) StateLoad(m state.Source) { + m.Load(0, &x.size) + m.Load(1, &x.inQueue) + m.Load(2, &x.outQueue) + m.Load(3, &x.termios) + m.Load(4, &x.column) +} + +func (x *outputQueueTransformer) StateTypeName() string { + return "pkg/sentry/fsimpl/devpts.outputQueueTransformer" +} + +func (x *outputQueueTransformer) StateFields() []string { + return []string{} +} + +func (x *outputQueueTransformer) beforeSave() {} + +func (x *outputQueueTransformer) StateSave(m state.Sink) { + x.beforeSave() +} + +func (x *outputQueueTransformer) afterLoad() {} + +func (x *outputQueueTransformer) StateLoad(m state.Source) { +} + +func (x *inputQueueTransformer) StateTypeName() string { + return "pkg/sentry/fsimpl/devpts.inputQueueTransformer" +} + +func (x *inputQueueTransformer) StateFields() []string { + return []string{} +} + +func (x *inputQueueTransformer) beforeSave() {} + +func (x *inputQueueTransformer) StateSave(m state.Sink) { + x.beforeSave() +} + +func (x *inputQueueTransformer) afterLoad() {} + +func (x *inputQueueTransformer) StateLoad(m state.Source) { +} + +func (x *queue) StateTypeName() string { + return "pkg/sentry/fsimpl/devpts.queue" +} + +func (x *queue) StateFields() []string { + return []string{ + "readBuf", + "waitBuf", + "waitBufLen", + "readable", + "transformer", + } +} + +func (x *queue) beforeSave() {} + +func (x *queue) StateSave(m state.Sink) { + x.beforeSave() + m.Save(0, &x.readBuf) + m.Save(1, &x.waitBuf) + m.Save(2, &x.waitBufLen) + m.Save(3, &x.readable) + m.Save(4, &x.transformer) +} + +func (x *queue) afterLoad() {} + +func (x *queue) StateLoad(m state.Source) { + m.Load(0, &x.readBuf) + m.Load(1, &x.waitBuf) + m.Load(2, &x.waitBufLen) + m.Load(3, &x.readable) + m.Load(4, &x.transformer) +} + +func (x *rootInodeRefs) StateTypeName() string { + return "pkg/sentry/fsimpl/devpts.rootInodeRefs" +} + +func (x *rootInodeRefs) StateFields() []string { + return []string{ + "refCount", + } +} + +func (x *rootInodeRefs) beforeSave() {} + +func (x *rootInodeRefs) StateSave(m state.Sink) { + x.beforeSave() + m.Save(0, &x.refCount) +} + +func (x *rootInodeRefs) afterLoad() {} + +func (x *rootInodeRefs) StateLoad(m state.Source) { + m.Load(0, &x.refCount) +} + +func (x *Terminal) StateTypeName() string { + return "pkg/sentry/fsimpl/devpts.Terminal" +} + +func (x *Terminal) StateFields() []string { + return []string{ + "n", + "ld", + "masterKTTY", + "slaveKTTY", + } +} + +func (x *Terminal) beforeSave() {} + +func (x *Terminal) StateSave(m state.Sink) { + x.beforeSave() + m.Save(0, &x.n) + m.Save(1, &x.ld) + m.Save(2, &x.masterKTTY) + m.Save(3, &x.slaveKTTY) +} + +func (x *Terminal) afterLoad() {} + +func (x *Terminal) StateLoad(m state.Source) { + m.Load(0, &x.n) + m.Load(1, &x.ld) + m.Load(2, &x.masterKTTY) + m.Load(3, &x.slaveKTTY) +} + +func init() { + state.Register((*lineDiscipline)(nil)) + state.Register((*outputQueueTransformer)(nil)) + state.Register((*inputQueueTransformer)(nil)) + state.Register((*queue)(nil)) + state.Register((*rootInodeRefs)(nil)) + state.Register((*Terminal)(nil)) +} diff --git a/pkg/sentry/fsimpl/devpts/devpts_test.go b/pkg/sentry/fsimpl/devpts/devpts_test.go deleted file mode 100644 index b7c149047..000000000 --- a/pkg/sentry/fsimpl/devpts/devpts_test.go +++ /dev/null @@ -1,56 +0,0 @@ -// Copyright 2018 The gVisor Authors. -// -// Licensed under the Apache License, Version 2.0 (the "License"); -// you may not use this file except in compliance with the License. -// You may obtain a copy of the License at -// -// http://www.apache.org/licenses/LICENSE-2.0 -// -// Unless required by applicable law or agreed to in writing, software -// distributed under the License is distributed on an "AS IS" BASIS, -// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -// See the License for the specific language governing permissions and -// limitations under the License. - -package devpts - -import ( - "testing" - - "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/sentry/contexttest" - "gvisor.dev/gvisor/pkg/usermem" -) - -func TestSimpleMasterToSlave(t *testing.T) { - ld := newLineDiscipline(linux.DefaultSlaveTermios) - ctx := contexttest.Context(t) - inBytes := []byte("hello, tty\n") - src := usermem.BytesIOSequence(inBytes) - outBytes := make([]byte, 32) - dst := usermem.BytesIOSequence(outBytes) - - // Write to the input queue. - nw, err := ld.inputQueueWrite(ctx, src) - if err != nil { - t.Fatalf("error writing to input queue: %v", err) - } - if nw != int64(len(inBytes)) { - t.Fatalf("wrote wrong length: got %d, want %d", nw, len(inBytes)) - } - - // Read from the input queue. - nr, err := ld.inputQueueRead(ctx, dst) - if err != nil { - t.Fatalf("error reading from input queue: %v", err) - } - if nr != int64(len(inBytes)) { - t.Fatalf("read wrong length: got %d, want %d", nr, len(inBytes)) - } - - outStr := string(outBytes[:nr]) - inStr := string(inBytes) - if outStr != inStr { - t.Fatalf("written and read strings do not match: got %q, want %q", outStr, inStr) - } -} diff --git a/pkg/sentry/fsimpl/devpts/root_inode_refs.go b/pkg/sentry/fsimpl/devpts/root_inode_refs.go new file mode 100644 index 000000000..051801202 --- /dev/null +++ b/pkg/sentry/fsimpl/devpts/root_inode_refs.go @@ -0,0 +1,118 @@ +package devpts + +import ( + "fmt" + "runtime" + "sync/atomic" + + "gvisor.dev/gvisor/pkg/log" + refs_vfs1 "gvisor.dev/gvisor/pkg/refs" +) + +// ownerType is used to customize logging. Note that we use a pointer to T so +// that we do not copy the entire object when passed as a format parameter. +var rootInodeownerType *rootInode + +// Refs implements refs.RefCounter. It keeps a reference count using atomic +// operations and calls the destructor when the count reaches zero. +// +// Note that the number of references is actually refCount + 1 so that a default +// zero-value Refs object contains one reference. +// +// TODO(gvisor.dev/issue/1486): Store stack traces when leak check is enabled in +// a map with 16-bit hashes, and store the hash in the top 16 bits of refCount. +// This will allow us to add stack trace information to the leak messages +// without growing the size of Refs. +// +// +stateify savable +type rootInodeRefs struct { + // refCount is composed of two fields: + // + // [32-bit speculative references]:[32-bit real references] + // + // Speculative references are used for TryIncRef, to avoid a CompareAndSwap + // loop. See IncRef, DecRef and TryIncRef for details of how these fields are + // used. + refCount int64 +} + +func (r *rootInodeRefs) finalize() { + var note string + switch refs_vfs1.GetLeakMode() { + case refs_vfs1.NoLeakChecking: + return + case refs_vfs1.UninitializedLeakChecking: + note = "(Leak checker uninitialized): " + } + if n := r.ReadRefs(); n != 0 { + log.Warningf("%sRefs %p owned by %T garbage collected with ref count of %d (want 0)", note, r, rootInodeownerType, n) + } +} + +// EnableLeakCheck checks for reference leaks when Refs gets garbage collected. +func (r *rootInodeRefs) EnableLeakCheck() { + if refs_vfs1.GetLeakMode() != refs_vfs1.NoLeakChecking { + runtime.SetFinalizer(r, (*rootInodeRefs).finalize) + } +} + +// ReadRefs returns the current number of references. The returned count is +// inherently racy and is unsafe to use without external synchronization. +func (r *rootInodeRefs) ReadRefs() int64 { + + return atomic.LoadInt64(&r.refCount) + 1 +} + +// IncRef implements refs.RefCounter.IncRef. +// +//go:nosplit +func (r *rootInodeRefs) IncRef() { + if v := atomic.AddInt64(&r.refCount, 1); v <= 0 { + panic(fmt.Sprintf("Incrementing non-positive ref count %p owned by %T", r, rootInodeownerType)) + } +} + +// TryIncRef implements refs.RefCounter.TryIncRef. +// +// To do this safely without a loop, a speculative reference is first acquired +// on the object. This allows multiple concurrent TryIncRef calls to distinguish +// other TryIncRef calls from genuine references held. +// +//go:nosplit +func (r *rootInodeRefs) TryIncRef() bool { + const speculativeRef = 1 << 32 + v := atomic.AddInt64(&r.refCount, speculativeRef) + if int32(v) < 0 { + + atomic.AddInt64(&r.refCount, -speculativeRef) + return false + } + + atomic.AddInt64(&r.refCount, -speculativeRef+1) + return true +} + +// DecRef implements refs.RefCounter.DecRef. +// +// Note that speculative references are counted here. Since they were added +// prior to real references reaching zero, they will successfully convert to +// real references. In other words, we see speculative references only in the +// following case: +// +// A: TryIncRef [speculative increase => sees non-negative references] +// B: DecRef [real decrease] +// A: TryIncRef [transform speculative to real] +// +//go:nosplit +func (r *rootInodeRefs) DecRef(destroy func()) { + switch v := atomic.AddInt64(&r.refCount, -1); { + case v < -1: + panic(fmt.Sprintf("Decrementing non-positive ref count %p, owned by %T", r, rootInodeownerType)) + + case v == -1: + + if destroy != nil { + destroy() + } + } +} |