snapshot: sagernet/gvisor v0.0.0-20250811.0-sing-box-mod.1

Содержимое пина, зафиксированного в go.mod sing-box-lx, одним коммитом
без истории. Полная история SagerNet/gvisor — 1.45 ГБ и клонируется в
каждой CI-джобе; наша дельта — одна вставка в одну функцию, история для
неё не нужна.

Module path github.com/sagernet/gvisor сохранён намеренно: на него
опирается replace-директива суперпроекта.

Патч поверх — отдельным коммитом, чтобы дельта читалась одним git show
и переносилась на новый пин копированием.

SPECS/TASKS/048-GVISOR_HANDSHAKE_NIL_CRASH

pkg/refs/refs_map.go

@@ -0,0 +1,179 @@
+// 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 refs
+
+import (
+	"fmt"
+
+	"github.com/sagernet/gvisor/pkg/log"
+	"github.com/sagernet/gvisor/pkg/sync"
+)
+
+var (
+	// liveObjects is a global map of reference-counted objects. Objects are
+	// inserted when leak check is enabled, and they are removed when they are
+	// destroyed. It is protected by liveObjectsMu.
+	liveObjects   map[CheckedObject]struct{}
+	liveObjectsMu sync.Mutex
+)
+
+// CheckedObject represents a reference-counted object with an informative
+// leak detection message.
+type CheckedObject interface {
+	// RefType is the type of the reference-counted object.
+	RefType() string
+
+	// LeakMessage supplies a warning to be printed upon leak detection.
+	LeakMessage() string
+
+	// LogRefs indicates whether reference-related events should be logged.
+	LogRefs() bool
+}
+
+func init() {
+	liveObjects = make(map[CheckedObject]struct{})
+}
+
+// LeakCheckEnabled returns whether leak checking is enabled. The following
+// functions should only be called if it returns true.
+func LeakCheckEnabled() bool {
+	mode := GetLeakMode()
+	return mode != NoLeakChecking
+}
+
+// leakCheckPanicEnabled returns whether DoLeakCheck() should panic when leaks
+// are detected.
+func leakCheckPanicEnabled() bool {
+	return GetLeakMode() == LeaksPanic
+}
+
+// Register adds obj to the live object map.
+func Register(obj CheckedObject) {
+	if LeakCheckEnabled() {
+		liveObjectsMu.Lock()
+		if _, ok := liveObjects[obj]; ok {
+			panic(fmt.Sprintf("Unexpected entry in leak checking map: reference %p already added", obj))
+		}
+		liveObjects[obj] = struct{}{}
+		liveObjectsMu.Unlock()
+		if LeakCheckEnabled() && obj.LogRefs() {
+			logEvent(obj, "registered")
+		}
+	}
+}
+
+// Unregister removes obj from the live object map.
+func Unregister(obj CheckedObject) {
+	if LeakCheckEnabled() {
+		liveObjectsMu.Lock()
+		defer liveObjectsMu.Unlock()
+		if _, ok := liveObjects[obj]; !ok {
+			panic(fmt.Sprintf("Expected to find entry in leak checking map for reference %p", obj))
+		}
+		delete(liveObjects, obj)
+		if LeakCheckEnabled() && obj.LogRefs() {
+			logEvent(obj, "unregistered")
+		}
+	}
+}
+
+// LogIncRef logs a reference increment.
+func LogIncRef(obj CheckedObject, refs int64) {
+	if LeakCheckEnabled() && obj.LogRefs() {
+		logEvent(obj, fmt.Sprintf("IncRef to %d", refs))
+	}
+}
+
+// LogTryIncRef logs a successful TryIncRef call.
+func LogTryIncRef(obj CheckedObject, refs int64) {
+	if LeakCheckEnabled() && obj.LogRefs() {
+		logEvent(obj, fmt.Sprintf("TryIncRef to %d", refs))
+	}
+}
+
+// LogDecRef logs a reference decrement.
+func LogDecRef(obj CheckedObject, refs int64) {
+	if LeakCheckEnabled() && obj.LogRefs() {
+		logEvent(obj, fmt.Sprintf("DecRef to %d", refs))
+	}
+}
+
+// logEvent logs a message for the given reference-counted object.
+//
+// obj.LogRefs() should be checked before calling logEvent, in order to avoid
+// calling any text processing needed to evaluate msg.
+func logEvent(obj CheckedObject, msg string) {
+	log.Infof("[%s %p] %s:\n%s", obj.RefType(), obj, msg, FormatStack(RecordStack()))
+}
+
+// checkOnce makes sure that leak checking is only done once. DoLeakCheck is
+// called from multiple places (which may overlap) to cover different sandbox
+// exit scenarios.
+var checkOnce sync.Once
+
+// DoLeakCheck iterates through the live object map and logs a message for each
+// object. It should be called when no reference-counted objects are reachable
+// anymore, at which point anything left in the map is considered a leak. On
+// multiple calls, only the first call will perform the leak check.
+func DoLeakCheck() {
+	if LeakCheckEnabled() {
+		checkOnce.Do(doLeakCheck)
+	}
+}
+
+// DoRepeatedLeakCheck is the same as DoLeakCheck except that it can be called
+// multiple times by the caller to incrementally perform leak checking.
+func DoRepeatedLeakCheck() {
+	if LeakCheckEnabled() {
+		doLeakCheck()
+	}
+}
+
+type leakCheckDisabled interface {
+	LeakCheckDisabled() bool
+}
+
+// CleanupSync is used to wait for async cleanup actions.
+var CleanupSync sync.WaitGroup
+
+func doLeakCheck() {
+	CleanupSync.Wait()
+	liveObjectsMu.Lock()
+	defer liveObjectsMu.Unlock()
+	leaked := len(liveObjects)
+	if leaked > 0 {
+		n := 0
+		msg := fmt.Sprintf("Leak checking detected %d leaked objects:\n", leaked)
+		for obj := range liveObjects {
+			skip := false
+			if o, ok := obj.(leakCheckDisabled); ok {
+				skip = o.LeakCheckDisabled()
+			}
+			if skip {
+				log.Debugf(obj.LeakMessage())
+				continue
+			}
+			msg += obj.LeakMessage() + "\n"
+			n++
+		}
+		if n == 0 {
+			return
+		}
+		if leakCheckPanicEnabled() {
+			panic(msg)
+		}
+		log.Warningf(msg)
+	}
+}