From 6cf22781673d75cca459fd668cf291b387d52e0d Mon Sep 17 00:00:00 2001 From: Nicolas Lacasse Date: Tue, 14 Aug 2018 11:49:42 -0700 Subject: Automated rollback of changelist 208284483 PiperOrigin-RevId: 208685417 Change-Id: Ie2849c4811e3a2d14a002f521cef018ded0c6c4a --- pkg/abi/linux/BUILD | 1 - pkg/abi/linux/splice.go | 20 --- pkg/sentry/syscalls/linux/BUILD | 1 - pkg/sentry/syscalls/linux/linux64.go | 2 +- pkg/sentry/syscalls/linux/sys_splice.go | 260 -------------------------------- 5 files changed, 1 insertion(+), 283 deletions(-) delete mode 100644 pkg/abi/linux/splice.go delete mode 100644 pkg/sentry/syscalls/linux/sys_splice.go diff --git a/pkg/abi/linux/BUILD b/pkg/abi/linux/BUILD index 9a44c2042..ac4ceefbc 100644 --- a/pkg/abi/linux/BUILD +++ b/pkg/abi/linux/BUILD @@ -43,7 +43,6 @@ go_library( "shm.go", "signal.go", "socket.go", - "splice.go", "time.go", "tty.go", "uio.go", diff --git a/pkg/abi/linux/splice.go b/pkg/abi/linux/splice.go deleted file mode 100644 index 9331ec84b..000000000 --- a/pkg/abi/linux/splice.go +++ /dev/null @@ -1,20 +0,0 @@ -// Copyright 2018 Google Inc. -// -// 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 - -// Flags for splice(2). -const ( - SPLICE_F_NONBLOCK = 2 -) diff --git a/pkg/sentry/syscalls/linux/BUILD b/pkg/sentry/syscalls/linux/BUILD index 62423c0fa..bbdfad9da 100644 --- a/pkg/sentry/syscalls/linux/BUILD +++ b/pkg/sentry/syscalls/linux/BUILD @@ -34,7 +34,6 @@ go_library( "sys_shm.go", "sys_signal.go", "sys_socket.go", - "sys_splice.go", "sys_stat.go", "sys_sync.go", "sys_sysinfo.go", diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go index 485c96202..c102af101 100644 --- a/pkg/sentry/syscalls/linux/linux64.go +++ b/pkg/sentry/syscalls/linux/linux64.go @@ -319,7 +319,7 @@ var AMD64 = &kernel.SyscallTable{ 272: Unshare, 273: syscalls.Error(syscall.ENOSYS), // SetRobustList, obsolete 274: syscalls.Error(syscall.ENOSYS), // GetRobustList, obsolete - 275: Splice, + // 275: Splice, TODO // 276: Tee, TODO // 277: SyncFileRange, TODO // 278: Vmsplice, TODO diff --git a/pkg/sentry/syscalls/linux/sys_splice.go b/pkg/sentry/syscalls/linux/sys_splice.go deleted file mode 100644 index 8151e3599..000000000 --- a/pkg/sentry/syscalls/linux/sys_splice.go +++ /dev/null @@ -1,260 +0,0 @@ -// Copyright 2018 Google Inc. -// -// 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 - -import ( - "io" - - "gvisor.googlesource.com/gvisor/pkg/abi/linux" - "gvisor.googlesource.com/gvisor/pkg/sentry/arch" - "gvisor.googlesource.com/gvisor/pkg/sentry/fs" - "gvisor.googlesource.com/gvisor/pkg/sentry/kernel" - "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/kdefs" - "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/pipe" - "gvisor.googlesource.com/gvisor/pkg/syserror" -) - -// Splice implements linux syscall splice(2). -func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { - fdIn := kdefs.FD(args[0].Int()) - offIn := args[1].Pointer() - fdOut := kdefs.FD(args[2].Int()) - offOut := args[3].Pointer() - size := int64(args[4].SizeT()) - flags := uint(args[5].Uint()) - - fileIn := t.FDMap().GetFile(fdIn) - if fileIn == nil { - return 0, nil, syserror.EBADF - } - defer fileIn.DecRef() - fileOut := t.FDMap().GetFile(fdOut) - if fileOut == nil { - return 0, nil, syserror.EBADF - } - defer fileOut.DecRef() - - // Check for whether we have pipes. - ipipe := fs.IsPipe(fileIn.Dirent.Inode.StableAttr) - opipe := fs.IsPipe(fileOut.Dirent.Inode.StableAttr) - if (ipipe && offIn != 0) || (opipe && offOut != 0) { - return 0, nil, syserror.ESPIPE - } - - // Check if both file descriptors are pipes. - if ipipe && opipe { - var readPipe *pipe.Pipe - switch p := fileIn.FileOperations.(type) { - case *pipe.Reader: - readPipe = p.ReaderWriter.Pipe - case *pipe.ReaderWriter: - readPipe = p.Pipe - default: - return 0, nil, syserror.EBADF - } - var writePipe *pipe.Pipe - switch p := fileOut.FileOperations.(type) { - case *pipe.Writer: - writePipe = p.ReaderWriter.Pipe - case *pipe.ReaderWriter: - writePipe = p.Pipe - default: - return 0, nil, syserror.EBADF - } - - // Splicing with two ends of the same pipe is not allowed. - if readPipe == writePipe { - return 0, nil, syserror.EINVAL - } - spliced, err := splicePipeToPipe(t, fileIn, fileOut, size, flags) - if err != nil { - return 0, nil, err - } - return uintptr(spliced), nil, nil - } - - // Check if the file descriptor that contains the data to move is a pipe. - if ipipe { - flagsOut := fileOut.Flags() - offset := uint64(fileOut.Offset()) - - // If there is an offset for the file, ensure the file has the Pwrite flag. - if offOut != 0 { - if !flagsOut.Pwrite { - return 0, nil, syserror.EINVAL - } - if _, err := t.CopyIn(offOut, &offset); err != nil { - return 0, nil, err - } - } - - if !flagsOut.Write { - return 0, nil, syserror.EBADF - } - - if flagsOut.Append { - return 0, nil, syserror.EINVAL - } - - switch fileIn.FileOperations.(type) { - case *pipe.Reader, *pipe.ReaderWriter: - // If the pipe in is a Reader or ReaderWriter, we can continue. - default: - return 0, nil, syserror.EBADF - } - spliced, err := spliceWrite(t, fileIn, fileOut, size, offset, flags) - if err != nil { - return 0, nil, err - } - - // Make sure value that offset points to is updated. - if offOut == 0 { - fileOut.Seek(t, fs.SeekSet, spliced+int64(offset)) - } else if _, err := t.CopyOut(offOut, spliced+int64(offset)); err != nil { - return 0, nil, err - } - return uintptr(spliced), nil, nil - } - - // Check if the file descriptor that the data will be moved to is a pipe. - if opipe { - flagsIn := fileIn.Flags() - offset := uint64(fileIn.Offset()) - - // If there is an offset for the file, ensure the file has the Pread flag. - if offIn != 0 { - if !flagsIn.Pread { - return 0, nil, syserror.EINVAL - } - if _, err := t.CopyIn(offIn, &offset); err != nil { - return 0, nil, err - } - } - - if !flagsIn.Read { - return 0, nil, syserror.EBADF - } - - switch fileOut.FileOperations.(type) { - case *pipe.Writer, *pipe.ReaderWriter: - // If the pipe out is a Writer or ReaderWriter, we can continue. - default: - return 0, nil, syserror.EBADF - } - spliced, err := spliceRead(t, fileIn, fileOut, size, offset, flags) - if err != nil { - return 0, nil, err - } - - // Make sure value that offset points to is updated. - if offIn == 0 { - fileOut.Seek(t, fs.SeekSet, spliced+int64(offset)) - } else if _, err := t.CopyOut(offIn, spliced+int64(offset)); err != nil { - return 0, nil, err - } - return uintptr(spliced), nil, nil - } - - // Splice requires one of the file descriptors to be a pipe. - return 0, nil, syserror.EINVAL -} - -// splicePipeToPipe moves data from one pipe to another pipe. -// TODO: Implement with zero copy movement/without copying between -// user and kernel address spaces. -func splicePipeToPipe(t *kernel.Task, inPipe *fs.File, outPipe *fs.File, size int64, flags uint) (int64, error) { - w := &fs.FileWriter{t, outPipe} - if flags == linux.SPLICE_F_NONBLOCK { - r := &io.LimitedReader{R: &fs.FileReader{t, inPipe}, N: size} - return io.Copy(w, r) - } - var n int64 - for read := int64(0); read < size; { - var err error - r := &io.LimitedReader{R: &fs.FileReader{t, inPipe}, N: size} - n, err = io.Copy(w, r) - if err != nil && err != syserror.ErrWouldBlock { - return 0, err - } - read += n - } - return n, nil -} - -// spliceRead moves data from a file to a pipe. -// TODO: Implement with zero copy movement/without copying between -// user and kernel address spaces. -func spliceRead(t *kernel.Task, inFile *fs.File, outPipe *fs.File, size int64, offset uint64, flags uint) (int64, error) { - w := &fs.FileWriter{t, outPipe} - if flags == linux.SPLICE_F_NONBLOCK { - r := io.NewSectionReader(&fs.FileReader{t, inFile}, int64(offset), size) - return io.Copy(w, r) - } - var n int64 - for read := int64(0); read < size; { - r := io.NewSectionReader(&fs.FileReader{t, inFile}, int64(offset), size) - var err error - n, err = io.Copy(w, r) - if err != nil && err != syserror.ErrWouldBlock { - return 0, err - } - read += n - } - return n, nil -} - -// offsetWriter implements io.Writer on a section of an underlying -// WriterAt starting from the offset and ending at the limit. -type offsetWriter struct { - w io.WriterAt - off int64 - limit int64 -} - -// Write implements io.Writer.Write and writes the content of the offsetWriter -// starting at the offset and ending at the limit into the given buffer. -func (o *offsetWriter) Write(p []byte) (n int, err error) { - if o.off >= o.limit { - return 0, io.EOF - } - if max := o.limit - o.off; int64(len(p)) > max { - p = p[0:max] - } - n, err = o.w.WriteAt(p, o.off) - o.off += int64(n) - return n, err -} - -// spliceWrite moves data from a pipe to a file. -// TODO: Implement with zero copy movement/without copying between -// user and kernel address spaces. -func spliceWrite(t *kernel.Task, inPipe *fs.File, outFile *fs.File, size int64, offset uint64, flags uint) (int64, error) { - w := &offsetWriter{&fs.FileWriter{t, outFile}, int64(offset), int64(offset) + size} - if flags == linux.SPLICE_F_NONBLOCK { - r := &io.LimitedReader{R: &fs.FileReader{t, inPipe}, N: size} - return io.Copy(w, r) - } - var n int64 - for read := int64(0); read < size; { - var err error - r := &io.LimitedReader{R: &fs.FileReader{t, inPipe}, N: size} - n, err = io.Copy(w, r) - if err != nil && err != syserror.ErrWouldBlock { - return 0, err - } - read += n - } - return n, nil -} -- cgit v1.2.3