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/fcntl.go

@@ -0,0 +1,79 @@
+// 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
+
+// Commands from linux/fcntl.h.
+const (
+	F_DUPFD         = 0
+	F_GETFD         = 1
+	F_SETFD         = 2
+	F_GETFL         = 3
+	F_SETFL         = 4
+	F_GETLK         = 5
+	F_SETLK         = 6
+	F_SETLKW        = 7
+	F_SETOWN        = 8
+	F_GETOWN        = 9
+	F_SETSIG        = 10
+	F_GETSIG        = 11
+	F_SETOWN_EX     = 15
+	F_GETOWN_EX     = 16
+	F_OFD_GETLK     = 36
+	F_OFD_SETLK     = 37
+	F_OFD_SETLKW    = 38
+	F_DUPFD_CLOEXEC = 1024 + 6
+	F_SETPIPE_SZ    = 1024 + 7
+	F_GETPIPE_SZ    = 1024 + 8
+)
+
+// Commands for F_SETLK.
+const (
+	F_RDLCK = 0
+	F_WRLCK = 1
+	F_UNLCK = 2
+)
+
+// Flags for fcntl.
+const (
+	FD_CLOEXEC = 0o0000001
+)
+
+// Flock is the lock structure for F_SETLK.
+//
+// +marshal
+type Flock struct {
+	Type   int16
+	Whence int16
+	_      [4]byte
+	Start  int64
+	Len    int64
+	PID    int32
+	_      [4]byte
+}
+
+// Owner types for F_SETOWN_EX and F_GETOWN_EX.
+const (
+	F_OWNER_TID  = 0
+	F_OWNER_PID  = 1
+	F_OWNER_PGRP = 2
+)
+
+// FOwnerEx is the owner structure for F_SETOWN_EX and F_GETOWN_EX.
+//
+// +marshal
+type FOwnerEx struct {
+	Type int32
+	PID  int32
+}