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/memutil/memfd_linux_unsafe.go

@@ -0,0 +1,41 @@
+// 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.
+
+//go:build linux
+// +build linux
+
+package memutil
+
+import (
+	"fmt"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// CreateMemFD creates a memfd file and returns the fd.
+func CreateMemFD(name string, flags int) (int, error) {
+	p, err := unix.BytePtrFromString(name)
+	if err != nil {
+		return -1, err
+	}
+	fd, _, e := unix.Syscall(unix.SYS_MEMFD_CREATE, uintptr(unsafe.Pointer(p)), uintptr(flags), 0)
+	if e != 0 {
+		if e == unix.ENOSYS {
+			return -1, fmt.Errorf("memfd_create(2) is not implemented. Check that you have Linux 3.17 or higher")
+		}
+		return -1, e
+	}
+	return int(fd), nil
+}

pkg/memutil/memutil_linux_unsafe_state_autogen.go

@@ -0,0 +1,6 @@
+// automatically generated by stateify.
+
+//go:build linux
+// +build linux
+
+package memutil

pkg/memutil/memutil_state_autogen.go

@@ -0,0 +1,6 @@
+// automatically generated by stateify.
+
+//go:build !false
+// +build !false
+
+package memutil

pkg/memutil/memutil_unsafe.go

@@ -0,0 +1,44 @@
+// 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 memutil provides utilities for working with shared memory files.
+package memutil
+
+import (
+	"reflect"
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+// MapSlice is like MapFile, but returns a slice instead of a uintptr.
+func MapSlice(addr, size, prot, flags, fd, offset uintptr) ([]byte, error) {
+	addr, err := MapFile(addr, size, prot, flags, fd, offset)
+	if err != nil {
+		return nil, err
+	}
+	var slice []byte
+	hdr := (*reflect.SliceHeader)(unsafe.Pointer(&slice))
+	hdr.Data = addr
+	hdr.Len = int(size)
+	hdr.Cap = int(size)
+	return slice, nil
+}
+
+// UnmapSlice unmaps a mapping returned by MapSlice.
+func UnmapSlice(slice []byte) error {
+	hdr := (*reflect.SliceHeader)(unsafe.Pointer(&slice))
+	_, _, err := unix.RawSyscall6(unix.SYS_MUNMAP, uintptr(unsafe.Pointer(hdr.Data)), uintptr(hdr.Cap), 0, 0, 0, 0)
+	return err
+}

pkg/memutil/memutil_unsafe_state_autogen.go

@@ -0,0 +1,3 @@
+// automatically generated by stateify.
+
+package memutil

pkg/memutil/mmap.go

@@ -0,0 +1,32 @@
+// 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.
+
+//go:build !false
+// +build !false
+
+package memutil
+
+import (
+	"golang.org/x/sys/unix"
+)
+
+// MapFile returns a memory mapping configured by the given options as per
+// mmap(2).
+func MapFile(addr, size, prot, flags, fd, offset uintptr) (uintptr, error) {
+	m, _, e := unix.RawSyscall6(unix.SYS_MMAP, addr, size, prot, flags, fd, offset)
+	if e != 0 {
+		return 0, e
+	}
+	return m, nil
+}