From dfa4b3b90861a61653d0bef8f144bb4e82d21d78 Mon Sep 17 00:00:00 2001 From: Jamie Liu Date: Wed, 23 Jun 2021 13:15:44 -0700 Subject: Move flipcall.packetWindowMmap to memutil. PiperOrigin-RevId: 381100861 --- pkg/memutil/BUILD | 6 +++++- pkg/memutil/memfd_linux_unsafe.go | 40 ++++++++++++++++++++++++++++++++++++++ pkg/memutil/memutil.go | 16 +++++++++++++++ pkg/memutil/memutil_unsafe.go | 41 --------------------------------------- pkg/memutil/mmap.go | 29 +++++++++++++++++++++++++++ 5 files changed, 90 insertions(+), 42 deletions(-) create mode 100644 pkg/memutil/memfd_linux_unsafe.go create mode 100644 pkg/memutil/memutil.go delete mode 100644 pkg/memutil/memutil_unsafe.go create mode 100644 pkg/memutil/mmap.go (limited to 'pkg/memutil') diff --git a/pkg/memutil/BUILD b/pkg/memutil/BUILD index 9d07d98b4..bea595286 100644 --- a/pkg/memutil/BUILD +++ b/pkg/memutil/BUILD @@ -4,7 +4,11 @@ package(licenses = ["notice"]) go_library( name = "memutil", - srcs = ["memutil_unsafe.go"], + srcs = [ + "memfd_linux_unsafe.go", + "memutil.go", + "mmap.go", + ], visibility = ["//visibility:public"], deps = ["@org_golang_x_sys//unix:go_default_library"], ) diff --git a/pkg/memutil/memfd_linux_unsafe.go b/pkg/memutil/memfd_linux_unsafe.go new file mode 100644 index 000000000..504382213 --- /dev/null +++ b/pkg/memutil/memfd_linux_unsafe.go @@ -0,0 +1,40 @@ +// 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. + +// +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 +} diff --git a/pkg/memutil/memutil.go b/pkg/memutil/memutil.go new file mode 100644 index 000000000..3185882fd --- /dev/null +++ b/pkg/memutil/memutil.go @@ -0,0 +1,16 @@ +// 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 diff --git a/pkg/memutil/memutil_unsafe.go b/pkg/memutil/memutil_unsafe.go deleted file mode 100644 index 6676d1ce3..000000000 --- a/pkg/memutil/memutil_unsafe.go +++ /dev/null @@ -1,41 +0,0 @@ -// 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. - -// +build linux - -// Package memutil provides a wrapper for the memfd_create() system call. -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 -} diff --git a/pkg/memutil/mmap.go b/pkg/memutil/mmap.go new file mode 100644 index 000000000..7c939293f --- /dev/null +++ b/pkg/memutil/mmap.go @@ -0,0 +1,29 @@ +// 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 memutil + +import ( + "golang.org/x/sys/unix" +) + +// MapFile returns a memory mapping configured by the given options as per +// mmap(2). +func MapFile(addr, len, prot, flags, fd, offset uintptr) (uintptr, error) { + m, _, e := unix.RawSyscall6(unix.SYS_MMAP, addr, len, prot, flags, fd, offset) + if e != 0 { + return 0, e + } + return m, nil +} -- cgit v1.2.3