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-rw-r--r--pkg/goid/goid.go72
-rw-r--r--pkg/goid/goid_amd64.s21
-rw-r--r--pkg/goid/goid_arm64.s21
-rw-r--r--pkg/goid/goid_state_autogen.go6
-rw-r--r--pkg/sentry/kernel/aio.go50
-rw-r--r--pkg/sentry/kernel/context.go17
-rw-r--r--pkg/sentry/kernel/task.go69
-rw-r--r--pkg/sentry/kernel/task_block.go16
-rw-r--r--pkg/sentry/kernel/task_context.go189
-rw-r--r--pkg/sentry/kernel/task_run.go15
10 files changed, 345 insertions, 131 deletions
diff --git a/pkg/goid/goid.go b/pkg/goid/goid.go
new file mode 100644
index 000000000..17c384cb0
--- /dev/null
+++ b/pkg/goid/goid.go
@@ -0,0 +1,72 @@
+// Copyright 2020 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.
+
+// +build go1.12
+// +build !go1.17
+
+// Check type signatures when updating Go version.
+
+// Package goid provides the Get function.
+package goid
+
+// Get returns the ID of the current goroutine.
+func Get() int64 {
+ return getg().goid
+}
+
+// Structs from Go runtime. These may change in the future and require
+// updating. These structs are currently the same on both AMD64 and ARM64,
+// but may diverge in the future.
+
+type stack struct {
+ lo uintptr
+ hi uintptr
+}
+
+type gobuf struct {
+ sp uintptr
+ pc uintptr
+ g uintptr
+ ctxt uintptr
+ ret uint64
+ lr uintptr
+ bp uintptr
+}
+
+type g struct {
+ stack stack
+ stackguard0 uintptr
+ stackguard1 uintptr
+
+ _panic uintptr
+ _defer uintptr
+ m uintptr
+ sched gobuf
+ syscallsp uintptr
+ syscallpc uintptr
+ stktopsp uintptr
+ param uintptr
+ atomicstatus uint32
+ stackLock uint32
+ goid int64
+
+ // More fields...
+ //
+ // We only use goid and the fields before it are only listed to
+ // calculate the correct offset.
+}
+
+// Defined in assembly. This can't use go:linkname since runtime.getg() isn't a
+// real function, it's a compiler intrinsic.
+func getg() *g
diff --git a/pkg/goid/goid_amd64.s b/pkg/goid/goid_amd64.s
new file mode 100644
index 000000000..d9f5cd2a3
--- /dev/null
+++ b/pkg/goid/goid_amd64.s
@@ -0,0 +1,21 @@
+// Copyright 2020 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.
+
+#include "textflag.h"
+
+// func getg() *g
+TEXT ·getg(SB),NOSPLIT,$0-8
+ MOVQ (TLS), R14
+ MOVQ R14, ret+0(FP)
+ RET
diff --git a/pkg/goid/goid_arm64.s b/pkg/goid/goid_arm64.s
new file mode 100644
index 000000000..a7465b75d
--- /dev/null
+++ b/pkg/goid/goid_arm64.s
@@ -0,0 +1,21 @@
+// Copyright 2020 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.
+
+#include "textflag.h"
+
+// func getg() *g
+TEXT ·getg(SB),NOSPLIT,$0-8
+ MOVD g, R0 // g
+ MOVD R0, ret+0(FP)
+ RET
diff --git a/pkg/goid/goid_state_autogen.go b/pkg/goid/goid_state_autogen.go
new file mode 100644
index 000000000..a461704fc
--- /dev/null
+++ b/pkg/goid/goid_state_autogen.go
@@ -0,0 +1,6 @@
+// automatically generated by stateify.
+
+// +build go1.12
+// +build !go1.17
+
+package goid
diff --git a/pkg/sentry/kernel/aio.go b/pkg/sentry/kernel/aio.go
index 0ac78c0b8..ec36d1a49 100644
--- a/pkg/sentry/kernel/aio.go
+++ b/pkg/sentry/kernel/aio.go
@@ -15,10 +15,7 @@
package kernel
import (
- "time"
-
"gvisor.dev/gvisor/pkg/context"
- "gvisor.dev/gvisor/pkg/log"
)
// AIOCallback is an function that does asynchronous I/O on behalf of a task.
@@ -26,7 +23,7 @@ type AIOCallback func(context.Context)
// QueueAIO queues an AIOCallback which will be run asynchronously.
func (t *Task) QueueAIO(cb AIOCallback) {
- ctx := taskAsyncContext{t: t}
+ ctx := t.AsyncContext()
wg := &t.TaskSet().aioGoroutines
wg.Add(1)
go func() {
@@ -34,48 +31,3 @@ func (t *Task) QueueAIO(cb AIOCallback) {
wg.Done()
}()
}
-
-type taskAsyncContext struct {
- context.NoopSleeper
- t *Task
-}
-
-// Debugf implements log.Logger.Debugf.
-func (ctx taskAsyncContext) Debugf(format string, v ...interface{}) {
- ctx.t.Debugf(format, v...)
-}
-
-// Infof implements log.Logger.Infof.
-func (ctx taskAsyncContext) Infof(format string, v ...interface{}) {
- ctx.t.Infof(format, v...)
-}
-
-// Warningf implements log.Logger.Warningf.
-func (ctx taskAsyncContext) Warningf(format string, v ...interface{}) {
- ctx.t.Warningf(format, v...)
-}
-
-// IsLogging implements log.Logger.IsLogging.
-func (ctx taskAsyncContext) IsLogging(level log.Level) bool {
- return ctx.t.IsLogging(level)
-}
-
-// Deadline implements context.Context.Deadline.
-func (ctx taskAsyncContext) Deadline() (time.Time, bool) {
- return ctx.t.Deadline()
-}
-
-// Done implements context.Context.Done.
-func (ctx taskAsyncContext) Done() <-chan struct{} {
- return ctx.t.Done()
-}
-
-// Err implements context.Context.Err.
-func (ctx taskAsyncContext) Err() error {
- return ctx.t.Err()
-}
-
-// Value implements context.Context.Value.
-func (ctx taskAsyncContext) Value(key interface{}) interface{} {
- return ctx.t.Value(key)
-}
diff --git a/pkg/sentry/kernel/context.go b/pkg/sentry/kernel/context.go
index bb94769c4..a8596410f 100644
--- a/pkg/sentry/kernel/context.go
+++ b/pkg/sentry/kernel/context.go
@@ -15,8 +15,6 @@
package kernel
import (
- "time"
-
"gvisor.dev/gvisor/pkg/context"
)
@@ -98,18 +96,3 @@ func TaskFromContext(ctx context.Context) *Task {
}
return nil
}
-
-// Deadline implements context.Context.Deadline.
-func (*Task) Deadline() (time.Time, bool) {
- return time.Time{}, false
-}
-
-// Done implements context.Context.Done.
-func (*Task) Done() <-chan struct{} {
- return nil
-}
-
-// Err implements context.Context.Err.
-func (*Task) Err() error {
- return nil
-}
diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go
index e830cf948..c0ab53c94 100644
--- a/pkg/sentry/kernel/task.go
+++ b/pkg/sentry/kernel/task.go
@@ -21,7 +21,6 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/bpf"
- "gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/inet"
@@ -29,11 +28,7 @@ import (
"gvisor.dev/gvisor/pkg/sentry/kernel/futex"
"gvisor.dev/gvisor/pkg/sentry/kernel/sched"
ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
- "gvisor.dev/gvisor/pkg/sentry/limits"
- "gvisor.dev/gvisor/pkg/sentry/pgalloc"
"gvisor.dev/gvisor/pkg/sentry/platform"
- "gvisor.dev/gvisor/pkg/sentry/unimpl"
- "gvisor.dev/gvisor/pkg/sentry/uniqueid"
"gvisor.dev/gvisor/pkg/sentry/usage"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/sync"
@@ -63,6 +58,12 @@ import (
type Task struct {
taskNode
+ // goid is the task goroutine's ID. goid is owned by the task goroutine,
+ // but since it's used to detect cases where non-task goroutines
+ // incorrectly access state owned by, or exclusive to, the task goroutine,
+ // goid is always accessed using atomic memory operations.
+ goid int64 `state:"nosave"`
+
// runState is what the task goroutine is executing if it is not stopped.
// If runState is nil, the task goroutine should exit or has exited.
// runState is exclusive to the task goroutine.
@@ -641,64 +642,6 @@ func (t *Task) Kernel() *Kernel {
return t.k
}
-// Value implements context.Context.Value.
-//
-// Preconditions: The caller must be running on the task goroutine (as implied
-// by the requirements of context.Context).
-func (t *Task) Value(key interface{}) interface{} {
- switch key {
- case CtxCanTrace:
- return t.CanTrace
- case CtxKernel:
- return t.k
- case CtxPIDNamespace:
- return t.tg.pidns
- case CtxUTSNamespace:
- return t.utsns
- case CtxIPCNamespace:
- ipcns := t.IPCNamespace()
- ipcns.IncRef()
- return ipcns
- case CtxTask:
- return t
- case auth.CtxCredentials:
- return t.Credentials()
- case context.CtxThreadGroupID:
- return int32(t.ThreadGroup().ID())
- case fs.CtxRoot:
- return t.fsContext.RootDirectory()
- case vfs.CtxRoot:
- return t.fsContext.RootDirectoryVFS2()
- case vfs.CtxMountNamespace:
- t.mountNamespaceVFS2.IncRef()
- return t.mountNamespaceVFS2
- case fs.CtxDirentCacheLimiter:
- return t.k.DirentCacheLimiter
- case inet.CtxStack:
- return t.NetworkContext()
- case ktime.CtxRealtimeClock:
- return t.k.RealtimeClock()
- case limits.CtxLimits:
- return t.tg.limits
- case pgalloc.CtxMemoryFile:
- return t.k.mf
- case pgalloc.CtxMemoryFileProvider:
- return t.k
- case platform.CtxPlatform:
- return t.k
- case uniqueid.CtxGlobalUniqueID:
- return t.k.UniqueID()
- case uniqueid.CtxGlobalUniqueIDProvider:
- return t.k
- case uniqueid.CtxInotifyCookie:
- return t.k.GenerateInotifyCookie()
- case unimpl.CtxEvents:
- return t.k
- default:
- return nil
- }
-}
-
// SetClearTID sets t's cleartid.
//
// Preconditions: The caller must be running on the task goroutine.
diff --git a/pkg/sentry/kernel/task_block.go b/pkg/sentry/kernel/task_block.go
index 4a4a69ee2..147a3d286 100644
--- a/pkg/sentry/kernel/task_block.go
+++ b/pkg/sentry/kernel/task_block.go
@@ -20,6 +20,7 @@ import (
"time"
ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+ "gvisor.dev/gvisor/pkg/sync"
"gvisor.dev/gvisor/pkg/syserror"
)
@@ -32,6 +33,8 @@ import (
//
// - An error which is nil if an event is received from C, ETIMEDOUT if the timeout
// expired, and syserror.ErrInterrupted if t is interrupted.
+//
+// Preconditions: The caller must be running on the task goroutine.
func (t *Task) BlockWithTimeout(C chan struct{}, haveTimeout bool, timeout time.Duration) (time.Duration, error) {
if !haveTimeout {
return timeout, t.block(C, nil)
@@ -112,7 +115,14 @@ func (t *Task) Block(C <-chan struct{}) error {
// block blocks a task on one of many events.
// N.B. defer is too expensive to be used here.
+//
+// Preconditions: The caller must be running on the task goroutine.
func (t *Task) block(C <-chan struct{}, timerChan <-chan struct{}) error {
+ // This function is very hot; skip this check outside of +race builds.
+ if sync.RaceEnabled {
+ t.assertTaskGoroutine()
+ }
+
// Fast path if the request is already done.
select {
case <-C:
@@ -156,14 +166,15 @@ func (t *Task) block(C <-chan struct{}, timerChan <-chan struct{}) error {
}
}
-// SleepStart implements amutex.Sleeper.SleepStart.
+// SleepStart implements context.ChannelSleeper.SleepStart.
func (t *Task) SleepStart() <-chan struct{} {
+ t.assertTaskGoroutine()
t.Deactivate()
t.accountTaskGoroutineEnter(TaskGoroutineBlockedInterruptible)
return t.interruptChan
}
-// SleepFinish implements amutex.Sleeper.SleepFinish.
+// SleepFinish implements context.ChannelSleeper.SleepFinish.
func (t *Task) SleepFinish(success bool) {
if !success {
// The interrupted notification is consumed only at the top-level
@@ -183,6 +194,7 @@ func (t *Task) Interrupted() bool {
// UninterruptibleSleepStart implements context.Context.UninterruptibleSleepStart.
func (t *Task) UninterruptibleSleepStart(deactivate bool) {
+ t.assertTaskGoroutine()
if deactivate {
t.Deactivate()
}
diff --git a/pkg/sentry/kernel/task_context.go b/pkg/sentry/kernel/task_context.go
new file mode 100644
index 000000000..70b0699dc
--- /dev/null
+++ b/pkg/sentry/kernel/task_context.go
@@ -0,0 +1,189 @@
+// Copyright 2020 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 kernel
+
+import (
+ "time"
+
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/log"
+ "gvisor.dev/gvisor/pkg/sentry/fs"
+ "gvisor.dev/gvisor/pkg/sentry/inet"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+ "gvisor.dev/gvisor/pkg/sentry/limits"
+ "gvisor.dev/gvisor/pkg/sentry/pgalloc"
+ "gvisor.dev/gvisor/pkg/sentry/platform"
+ "gvisor.dev/gvisor/pkg/sentry/unimpl"
+ "gvisor.dev/gvisor/pkg/sentry/uniqueid"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/sync"
+)
+
+// Deadline implements context.Context.Deadline.
+func (t *Task) Deadline() (time.Time, bool) {
+ return time.Time{}, false
+}
+
+// Done implements context.Context.Done.
+func (t *Task) Done() <-chan struct{} {
+ return nil
+}
+
+// Err implements context.Context.Err.
+func (t *Task) Err() error {
+ return nil
+}
+
+// Value implements context.Context.Value.
+//
+// Preconditions: The caller must be running on the task goroutine.
+func (t *Task) Value(key interface{}) interface{} {
+ // This function is very hot; skip this check outside of +race builds.
+ if sync.RaceEnabled {
+ t.assertTaskGoroutine()
+ }
+ return t.contextValue(key, true /* isTaskGoroutine */)
+}
+
+func (t *Task) contextValue(key interface{}, isTaskGoroutine bool) interface{} {
+ switch key {
+ case CtxCanTrace:
+ return t.CanTrace
+ case CtxKernel:
+ return t.k
+ case CtxPIDNamespace:
+ return t.tg.pidns
+ case CtxUTSNamespace:
+ if !isTaskGoroutine {
+ t.mu.Lock()
+ defer t.mu.Unlock()
+ }
+ return t.utsns
+ case CtxIPCNamespace:
+ if !isTaskGoroutine {
+ t.mu.Lock()
+ defer t.mu.Unlock()
+ }
+ ipcns := t.ipcns
+ ipcns.IncRef()
+ return ipcns
+ case CtxTask:
+ return t
+ case auth.CtxCredentials:
+ return t.creds.Load()
+ case context.CtxThreadGroupID:
+ return int32(t.tg.ID())
+ case fs.CtxRoot:
+ if !isTaskGoroutine {
+ t.mu.Lock()
+ defer t.mu.Unlock()
+ }
+ return t.fsContext.RootDirectory()
+ case vfs.CtxRoot:
+ if !isTaskGoroutine {
+ t.mu.Lock()
+ defer t.mu.Unlock()
+ }
+ return t.fsContext.RootDirectoryVFS2()
+ case vfs.CtxMountNamespace:
+ if !isTaskGoroutine {
+ t.mu.Lock()
+ defer t.mu.Unlock()
+ }
+ t.mountNamespaceVFS2.IncRef()
+ return t.mountNamespaceVFS2
+ case fs.CtxDirentCacheLimiter:
+ return t.k.DirentCacheLimiter
+ case inet.CtxStack:
+ return t.NetworkContext()
+ case ktime.CtxRealtimeClock:
+ return t.k.RealtimeClock()
+ case limits.CtxLimits:
+ return t.tg.limits
+ case pgalloc.CtxMemoryFile:
+ return t.k.mf
+ case pgalloc.CtxMemoryFileProvider:
+ return t.k
+ case platform.CtxPlatform:
+ return t.k
+ case uniqueid.CtxGlobalUniqueID:
+ return t.k.UniqueID()
+ case uniqueid.CtxGlobalUniqueIDProvider:
+ return t.k
+ case uniqueid.CtxInotifyCookie:
+ return t.k.GenerateInotifyCookie()
+ case unimpl.CtxEvents:
+ return t.k
+ default:
+ return nil
+ }
+}
+
+// taskAsyncContext implements context.Context for a goroutine that performs
+// work on behalf of a Task, but is not the task goroutine.
+type taskAsyncContext struct {
+ context.NoopSleeper
+
+ t *Task
+}
+
+// AsyncContext returns a context.Context representing t. The returned
+// context.Context is intended for use by goroutines other than t's task
+// goroutine; for example, signal delivery to t will not interrupt goroutines
+// that are blocking using the returned context.Context.
+func (t *Task) AsyncContext() context.Context {
+ return taskAsyncContext{t: t}
+}
+
+// Debugf implements log.Logger.Debugf.
+func (ctx taskAsyncContext) Debugf(format string, v ...interface{}) {
+ ctx.t.Debugf(format, v...)
+}
+
+// Infof implements log.Logger.Infof.
+func (ctx taskAsyncContext) Infof(format string, v ...interface{}) {
+ ctx.t.Infof(format, v...)
+}
+
+// Warningf implements log.Logger.Warningf.
+func (ctx taskAsyncContext) Warningf(format string, v ...interface{}) {
+ ctx.t.Warningf(format, v...)
+}
+
+// IsLogging implements log.Logger.IsLogging.
+func (ctx taskAsyncContext) IsLogging(level log.Level) bool {
+ return ctx.t.IsLogging(level)
+}
+
+// Deadline implements context.Context.Deadline.
+func (ctx taskAsyncContext) Deadline() (time.Time, bool) {
+ return time.Time{}, false
+}
+
+// Done implements context.Context.Done.
+func (ctx taskAsyncContext) Done() <-chan struct{} {
+ return nil
+}
+
+// Err implements context.Context.Err.
+func (ctx taskAsyncContext) Err() error {
+ return nil
+}
+
+// Value implements context.Context.Value.
+func (ctx taskAsyncContext) Value(key interface{}) interface{} {
+ return ctx.t.contextValue(key, false /* isTaskGoroutine */)
+}
diff --git a/pkg/sentry/kernel/task_run.go b/pkg/sentry/kernel/task_run.go
index 0f8294dcd..c5858da30 100644
--- a/pkg/sentry/kernel/task_run.go
+++ b/pkg/sentry/kernel/task_run.go
@@ -16,11 +16,13 @@ package kernel
import (
"bytes"
+ "fmt"
"runtime"
"runtime/trace"
"sync/atomic"
"gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/goid"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/hostcpu"
ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
@@ -57,6 +59,8 @@ type taskRunState interface {
// make it visible in stack dumps. A goroutine for a given task can be identified
// searching for Task.run()'s argument value.
func (t *Task) run(threadID uintptr) {
+ atomic.StoreInt64(&t.goid, goid.Get())
+
// Construct t.blockingTimer here. We do this here because we can't
// reconstruct t.blockingTimer during restore in Task.afterLoad(), because
// kernel.timekeeper.SetClocks() hasn't been called yet.
@@ -99,6 +103,9 @@ func (t *Task) run(threadID uintptr) {
t.tg.pidns.owner.runningGoroutines.Done()
t.p.Release()
+ // Deferring this store triggers a false positive in the race
+ // detector (https://github.com/golang/go/issues/42599).
+ atomic.StoreInt64(&t.goid, 0)
// Keep argument alive because stack trace for dead variables may not be correct.
runtime.KeepAlive(threadID)
return
@@ -375,6 +382,14 @@ func (app *runApp) execute(t *Task) taskRunState {
}
}
+// assertTaskGoroutine panics if the caller is not running on t's task
+// goroutine.
+func (t *Task) assertTaskGoroutine() {
+ if got, want := goid.Get(), atomic.LoadInt64(&t.goid); got != want {
+ panic(fmt.Sprintf("running on goroutine %d (task goroutine for kernel.Task %p is %d)", got, t, want))
+ }
+}
+
// waitGoroutineStoppedOrExited blocks until t's task goroutine stops or exits.
func (t *Task) waitGoroutineStoppedOrExited() {
t.goroutineStopped.Wait()