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/abi/linux/futex.go

@@ -0,0 +1,80 @@
+// 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 linux
+
+// From <linux/futex.h> and <sys/time.h>.
+// Flags are used in syscall futex(2).
+const (
+	FUTEX_WAIT            = 0
+	FUTEX_WAKE            = 1
+	FUTEX_FD              = 2
+	FUTEX_REQUEUE         = 3
+	FUTEX_CMP_REQUEUE     = 4
+	FUTEX_WAKE_OP         = 5
+	FUTEX_LOCK_PI         = 6
+	FUTEX_UNLOCK_PI       = 7
+	FUTEX_TRYLOCK_PI      = 8
+	FUTEX_WAIT_BITSET     = 9
+	FUTEX_WAKE_BITSET     = 10
+	FUTEX_WAIT_REQUEUE_PI = 11
+	FUTEX_CMP_REQUEUE_PI  = 12
+
+	FUTEX_PRIVATE_FLAG   = 128
+	FUTEX_CLOCK_REALTIME = 256
+)
+
+// These are flags are from <linux/futex.h> and are used in FUTEX_WAKE_OP
+// to define the operations.
+const (
+	FUTEX_OP_SET         = 0
+	FUTEX_OP_ADD         = 1
+	FUTEX_OP_OR          = 2
+	FUTEX_OP_ANDN        = 3
+	FUTEX_OP_XOR         = 4
+	FUTEX_OP_OPARG_SHIFT = 8
+	FUTEX_OP_CMP_EQ      = 0
+	FUTEX_OP_CMP_NE      = 1
+	FUTEX_OP_CMP_LT      = 2
+	FUTEX_OP_CMP_LE      = 3
+	FUTEX_OP_CMP_GT      = 4
+	FUTEX_OP_CMP_GE      = 5
+)
+
+// FUTEX_TID_MASK is the TID portion of a PI futex word.
+const FUTEX_TID_MASK = 0x3fffffff
+
+// Constants used for priority-inheritance futexes.
+const (
+	FUTEX_WAITERS    = 0x80000000
+	FUTEX_OWNER_DIED = 0x40000000
+)
+
+// FUTEX_BITSET_MATCH_ANY has all bits set.
+const FUTEX_BITSET_MATCH_ANY = 0xffffffff
+
+// ROBUST_LIST_LIMIT protects against a deliberately circular list.
+const ROBUST_LIST_LIMIT = 2048
+
+// RobustListHead corresponds to Linux's struct robust_list_head.
+//
+// +marshal
+type RobustListHead struct {
+	List          uint64
+	FutexOffset   uint64
+	ListOpPending uint64
+}
+
+// SizeOfRobustListHead is the size of a RobustListHead struct.
+var SizeOfRobustListHead = (*RobustListHead)(nil).SizeBytes()