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authornybidari <59618317+nybidari@users.noreply.github.com>2020-02-25 15:33:59 -0800
committerGitHub <noreply@github.com>2020-02-25 15:33:59 -0800
commit818abc2bd5096bf7dc6f621cfd2923bee4e0fc7b (patch)
tree0f7f90cecb6afc332a3229651eba4da391a46b41 /pkg/sentry/syscalls/linux/vfs2
parentacc405ba60834f5dce9ce04cd762d5cda02224cb (diff)
parent72e3f3a3eef3a1dc02db0ff71f98a5d7fe89a6e3 (diff)
Merge branch 'master' into iptables
Diffstat (limited to 'pkg/sentry/syscalls/linux/vfs2')
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/BUILD28
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/epoll.go225
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/epoll_unsafe.go44
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/execve.go137
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/fd.go147
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/filesystem.go326
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/fscontext.go131
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/getdents.go149
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/ioctl.go35
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go216
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/linux64_override_arm64.go2
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/mmap.go92
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/path.go94
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/poll.go584
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/read_write.go511
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/setstat.go380
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/stat.go346
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/sync.go87
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/sys_read.go95
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/xattr.go353
20 files changed, 3795 insertions, 187 deletions
diff --git a/pkg/sentry/syscalls/linux/vfs2/BUILD b/pkg/sentry/syscalls/linux/vfs2/BUILD
index 6b8a00b6e..f51761e81 100644
--- a/pkg/sentry/syscalls/linux/vfs2/BUILD
+++ b/pkg/sentry/syscalls/linux/vfs2/BUILD
@@ -5,18 +5,44 @@ package(licenses = ["notice"])
go_library(
name = "vfs2",
srcs = [
+ "epoll.go",
+ "epoll_unsafe.go",
+ "execve.go",
+ "fd.go",
+ "filesystem.go",
+ "fscontext.go",
+ "getdents.go",
+ "ioctl.go",
"linux64.go",
"linux64_override_amd64.go",
"linux64_override_arm64.go",
- "sys_read.go",
+ "mmap.go",
+ "path.go",
+ "poll.go",
+ "read_write.go",
+ "setstat.go",
+ "stat.go",
+ "sync.go",
+ "xattr.go",
],
+ marshal = True,
visibility = ["//:sandbox"],
deps = [
+ "//pkg/abi/linux",
+ "//pkg/fspath",
+ "//pkg/gohacks",
"//pkg/sentry/arch",
+ "//pkg/sentry/fsbridge",
"//pkg/sentry/kernel",
+ "//pkg/sentry/kernel/auth",
+ "//pkg/sentry/kernel/time",
+ "//pkg/sentry/limits",
+ "//pkg/sentry/loader",
+ "//pkg/sentry/memmap",
"//pkg/sentry/syscalls",
"//pkg/sentry/syscalls/linux",
"//pkg/sentry/vfs",
+ "//pkg/sync",
"//pkg/syserror",
"//pkg/usermem",
"//pkg/waiter",
diff --git a/pkg/sentry/syscalls/linux/vfs2/epoll.go b/pkg/sentry/syscalls/linux/vfs2/epoll.go
new file mode 100644
index 000000000..d6cb0e79a
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/epoll.go
@@ -0,0 +1,225 @@
+// 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 vfs2
+
+import (
+ "math"
+ "time"
+
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+// EpollCreate1 implements Linux syscall epoll_create1(2).
+func EpollCreate1(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ flags := args[0].Int()
+ if flags&^linux.EPOLL_CLOEXEC != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ file, err := t.Kernel().VFS().NewEpollInstanceFD()
+ if err != nil {
+ return 0, nil, err
+ }
+ defer file.DecRef()
+
+ fd, err := t.NewFDFromVFS2(0, file, kernel.FDFlags{
+ CloseOnExec: flags&linux.EPOLL_CLOEXEC != 0,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(fd), nil, nil
+}
+
+// EpollCreate implements Linux syscall epoll_create(2).
+func EpollCreate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ size := args[0].Int()
+
+ // "Since Linux 2.6.8, the size argument is ignored, but must be greater
+ // than zero" - epoll_create(2)
+ if size <= 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ file, err := t.Kernel().VFS().NewEpollInstanceFD()
+ if err != nil {
+ return 0, nil, err
+ }
+ defer file.DecRef()
+
+ fd, err := t.NewFDFromVFS2(0, file, kernel.FDFlags{})
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(fd), nil, nil
+}
+
+// EpollCtl implements Linux syscall epoll_ctl(2).
+func EpollCtl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ epfd := args[0].Int()
+ op := args[1].Int()
+ fd := args[2].Int()
+ eventAddr := args[3].Pointer()
+
+ epfile := t.GetFileVFS2(epfd)
+ if epfile == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer epfile.DecRef()
+ ep, ok := epfile.Impl().(*vfs.EpollInstance)
+ if !ok {
+ return 0, nil, syserror.EINVAL
+ }
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+ if epfile == file {
+ return 0, nil, syserror.EINVAL
+ }
+
+ var event linux.EpollEvent
+ switch op {
+ case linux.EPOLL_CTL_ADD:
+ if err := event.CopyIn(t, eventAddr); err != nil {
+ return 0, nil, err
+ }
+ return 0, nil, ep.AddInterest(file, fd, event)
+ case linux.EPOLL_CTL_DEL:
+ return 0, nil, ep.DeleteInterest(file, fd)
+ case linux.EPOLL_CTL_MOD:
+ if err := event.CopyIn(t, eventAddr); err != nil {
+ return 0, nil, err
+ }
+ return 0, nil, ep.ModifyInterest(file, fd, event)
+ default:
+ return 0, nil, syserror.EINVAL
+ }
+}
+
+// EpollWait implements Linux syscall epoll_wait(2).
+func EpollWait(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ epfd := args[0].Int()
+ eventsAddr := args[1].Pointer()
+ maxEvents := int(args[2].Int())
+ timeout := int(args[3].Int())
+
+ const _EP_MAX_EVENTS = math.MaxInt32 / sizeofEpollEvent // Linux: fs/eventpoll.c:EP_MAX_EVENTS
+ if maxEvents <= 0 || maxEvents > _EP_MAX_EVENTS {
+ return 0, nil, syserror.EINVAL
+ }
+
+ epfile := t.GetFileVFS2(epfd)
+ if epfile == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer epfile.DecRef()
+ ep, ok := epfile.Impl().(*vfs.EpollInstance)
+ if !ok {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Use a fixed-size buffer in a loop, instead of make([]linux.EpollEvent,
+ // maxEvents), so that the buffer can be allocated on the stack.
+ var (
+ events [16]linux.EpollEvent
+ total int
+ ch chan struct{}
+ haveDeadline bool
+ deadline ktime.Time
+ )
+ for {
+ batchEvents := len(events)
+ if batchEvents > maxEvents {
+ batchEvents = maxEvents
+ }
+ n := ep.ReadEvents(events[:batchEvents])
+ maxEvents -= n
+ if n != 0 {
+ // Copy what we read out.
+ copiedEvents, err := copyOutEvents(t, eventsAddr, events[:n])
+ eventsAddr += usermem.Addr(copiedEvents * sizeofEpollEvent)
+ total += copiedEvents
+ if err != nil {
+ if total != 0 {
+ return uintptr(total), nil, nil
+ }
+ return 0, nil, err
+ }
+ // If we've filled the application's event buffer, we're done.
+ if maxEvents == 0 {
+ return uintptr(total), nil, nil
+ }
+ // Loop if we read a full batch, under the expectation that there
+ // may be more events to read.
+ if n == batchEvents {
+ continue
+ }
+ }
+ // We get here if n != batchEvents. If we read any number of events
+ // (just now, or in a previous iteration of this loop), or if timeout
+ // is 0 (such that epoll_wait should be non-blocking), return the
+ // events we've read so far to the application.
+ if total != 0 || timeout == 0 {
+ return uintptr(total), nil, nil
+ }
+ // In the first iteration of this loop, register with the epoll
+ // instance for readability events, but then immediately continue the
+ // loop since we need to retry ReadEvents() before blocking. In all
+ // subsequent iterations, block until events are available, the timeout
+ // expires, or an interrupt arrives.
+ if ch == nil {
+ var w waiter.Entry
+ w, ch = waiter.NewChannelEntry(nil)
+ epfile.EventRegister(&w, waiter.EventIn)
+ defer epfile.EventUnregister(&w)
+ } else {
+ // Set up the timer if a timeout was specified.
+ if timeout > 0 && !haveDeadline {
+ timeoutDur := time.Duration(timeout) * time.Millisecond
+ deadline = t.Kernel().MonotonicClock().Now().Add(timeoutDur)
+ haveDeadline = true
+ }
+ if err := t.BlockWithDeadline(ch, haveDeadline, deadline); err != nil {
+ if err == syserror.ETIMEDOUT {
+ err = nil
+ }
+ // total must be 0 since otherwise we would have returned
+ // above.
+ return 0, nil, err
+ }
+ }
+ }
+}
+
+// EpollPwait implements Linux syscall epoll_pwait(2).
+func EpollPwait(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ maskAddr := args[4].Pointer()
+ maskSize := uint(args[5].Uint())
+
+ if err := setTempSignalSet(t, maskAddr, maskSize); err != nil {
+ return 0, nil, err
+ }
+
+ return EpollWait(t, args)
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/epoll_unsafe.go b/pkg/sentry/syscalls/linux/vfs2/epoll_unsafe.go
new file mode 100644
index 000000000..825f325bf
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/epoll_unsafe.go
@@ -0,0 +1,44 @@
+// 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 vfs2
+
+import (
+ "reflect"
+ "runtime"
+ "unsafe"
+
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/gohacks"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+const sizeofEpollEvent = int(unsafe.Sizeof(linux.EpollEvent{}))
+
+func copyOutEvents(t *kernel.Task, addr usermem.Addr, events []linux.EpollEvent) (int, error) {
+ if len(events) == 0 {
+ return 0, nil
+ }
+ // Cast events to a byte slice for copying.
+ var eventBytes []byte
+ eventBytesHdr := (*reflect.SliceHeader)(unsafe.Pointer(&eventBytes))
+ eventBytesHdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(&events[0])))
+ eventBytesHdr.Len = len(events) * sizeofEpollEvent
+ eventBytesHdr.Cap = len(events) * sizeofEpollEvent
+ copiedBytes, err := t.CopyOutBytes(addr, eventBytes)
+ runtime.KeepAlive(events)
+ copiedEvents := copiedBytes / sizeofEpollEvent // rounded down
+ return copiedEvents, err
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/execve.go b/pkg/sentry/syscalls/linux/vfs2/execve.go
new file mode 100644
index 000000000..aef0078a8
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/execve.go
@@ -0,0 +1,137 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/fsbridge"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/loader"
+ slinux "gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+// Execve implements linux syscall execve(2).
+func Execve(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathnameAddr := args[0].Pointer()
+ argvAddr := args[1].Pointer()
+ envvAddr := args[2].Pointer()
+ return execveat(t, linux.AT_FDCWD, pathnameAddr, argvAddr, envvAddr, 0 /* flags */)
+}
+
+// Execveat implements linux syscall execveat(2).
+func Execveat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ pathnameAddr := args[1].Pointer()
+ argvAddr := args[2].Pointer()
+ envvAddr := args[3].Pointer()
+ flags := args[4].Int()
+ return execveat(t, dirfd, pathnameAddr, argvAddr, envvAddr, flags)
+}
+
+func execveat(t *kernel.Task, dirfd int32, pathnameAddr, argvAddr, envvAddr usermem.Addr, flags int32) (uintptr, *kernel.SyscallControl, error) {
+ if flags&^(linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ pathname, err := t.CopyInString(pathnameAddr, linux.PATH_MAX)
+ if err != nil {
+ return 0, nil, err
+ }
+ var argv, envv []string
+ if argvAddr != 0 {
+ var err error
+ argv, err = t.CopyInVector(argvAddr, slinux.ExecMaxElemSize, slinux.ExecMaxTotalSize)
+ if err != nil {
+ return 0, nil, err
+ }
+ }
+ if envvAddr != 0 {
+ var err error
+ envv, err = t.CopyInVector(envvAddr, slinux.ExecMaxElemSize, slinux.ExecMaxTotalSize)
+ if err != nil {
+ return 0, nil, err
+ }
+ }
+
+ root := t.FSContext().RootDirectoryVFS2()
+ defer root.DecRef()
+ var executable fsbridge.File
+ closeOnExec := false
+ if path := fspath.Parse(pathname); dirfd != linux.AT_FDCWD && !path.Absolute {
+ // We must open the executable ourselves since dirfd is used as the
+ // starting point while resolving path, but the task working directory
+ // is used as the starting point while resolving interpreters (Linux:
+ // fs/binfmt_script.c:load_script() => fs/exec.c:open_exec() =>
+ // do_open_execat(fd=AT_FDCWD)), and the loader package is currently
+ // incapable of handling this correctly.
+ if !path.HasComponents() && flags&linux.AT_EMPTY_PATH == 0 {
+ return 0, nil, syserror.ENOENT
+ }
+ dirfile, dirfileFlags := t.FDTable().GetVFS2(dirfd)
+ if dirfile == nil {
+ return 0, nil, syserror.EBADF
+ }
+ start := dirfile.VirtualDentry()
+ start.IncRef()
+ dirfile.DecRef()
+ closeOnExec = dirfileFlags.CloseOnExec
+ file, err := t.Kernel().VFS().OpenAt(t, t.Credentials(), &vfs.PathOperation{
+ Root: root,
+ Start: start,
+ Path: path,
+ FollowFinalSymlink: flags&linux.AT_SYMLINK_NOFOLLOW == 0,
+ }, &vfs.OpenOptions{
+ Flags: linux.O_RDONLY,
+ FileExec: true,
+ })
+ start.DecRef()
+ if err != nil {
+ return 0, nil, err
+ }
+ defer file.DecRef()
+ executable = fsbridge.NewVFSFile(file)
+ }
+
+ // Load the new TaskContext.
+ mntns := t.MountNamespaceVFS2() // FIXME(jamieliu): useless refcount change
+ defer mntns.DecRef()
+ wd := t.FSContext().WorkingDirectoryVFS2()
+ defer wd.DecRef()
+ remainingTraversals := uint(linux.MaxSymlinkTraversals)
+ loadArgs := loader.LoadArgs{
+ Opener: fsbridge.NewVFSLookup(mntns, root, wd),
+ RemainingTraversals: &remainingTraversals,
+ ResolveFinal: flags&linux.AT_SYMLINK_NOFOLLOW == 0,
+ Filename: pathname,
+ File: executable,
+ CloseOnExec: closeOnExec,
+ Argv: argv,
+ Envv: envv,
+ Features: t.Arch().FeatureSet(),
+ }
+
+ tc, se := t.Kernel().LoadTaskImage(t, loadArgs)
+ if se != nil {
+ return 0, nil, se.ToError()
+ }
+
+ ctrl, err := t.Execve(tc)
+ return 0, ctrl, err
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/fd.go b/pkg/sentry/syscalls/linux/vfs2/fd.go
new file mode 100644
index 000000000..3afcea665
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/fd.go
@@ -0,0 +1,147 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ slinux "gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Close implements Linux syscall close(2).
+func Close(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+
+ // Note that Remove provides a reference on the file that we may use to
+ // flush. It is still active until we drop the final reference below
+ // (and other reference-holding operations complete).
+ _, file := t.FDTable().Remove(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ err := file.OnClose(t)
+ return 0, nil, slinux.HandleIOErrorVFS2(t, false /* partial */, err, syserror.EINTR, "close", file)
+}
+
+// Dup implements Linux syscall dup(2).
+func Dup(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ newFD, err := t.NewFDFromVFS2(0, file, kernel.FDFlags{})
+ if err != nil {
+ return 0, nil, syserror.EMFILE
+ }
+ return uintptr(newFD), nil, nil
+}
+
+// Dup2 implements Linux syscall dup2(2).
+func Dup2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ oldfd := args[0].Int()
+ newfd := args[1].Int()
+
+ if oldfd == newfd {
+ // As long as oldfd is valid, dup2() does nothing and returns newfd.
+ file := t.GetFileVFS2(oldfd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ file.DecRef()
+ return uintptr(newfd), nil, nil
+ }
+
+ return dup3(t, oldfd, newfd, 0)
+}
+
+// Dup3 implements Linux syscall dup3(2).
+func Dup3(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ oldfd := args[0].Int()
+ newfd := args[1].Int()
+ flags := args[2].Uint()
+
+ if oldfd == newfd {
+ return 0, nil, syserror.EINVAL
+ }
+
+ return dup3(t, oldfd, newfd, flags)
+}
+
+func dup3(t *kernel.Task, oldfd, newfd int32, flags uint32) (uintptr, *kernel.SyscallControl, error) {
+ if flags&^linux.O_CLOEXEC != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ file := t.GetFileVFS2(oldfd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ err := t.NewFDAtVFS2(newfd, file, kernel.FDFlags{
+ CloseOnExec: flags&linux.O_CLOEXEC != 0,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(newfd), nil, nil
+}
+
+// Fcntl implements linux syscall fcntl(2).
+func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ cmd := args[1].Int()
+
+ file, flags := t.FDTable().GetVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ switch cmd {
+ case linux.F_DUPFD, linux.F_DUPFD_CLOEXEC:
+ minfd := args[2].Int()
+ fd, err := t.NewFDFromVFS2(minfd, file, kernel.FDFlags{
+ CloseOnExec: cmd == linux.F_DUPFD_CLOEXEC,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(fd), nil, nil
+ case linux.F_GETFD:
+ return uintptr(flags.ToLinuxFDFlags()), nil, nil
+ case linux.F_SETFD:
+ flags := args[2].Uint()
+ t.FDTable().SetFlags(fd, kernel.FDFlags{
+ CloseOnExec: flags&linux.FD_CLOEXEC != 0,
+ })
+ return 0, nil, nil
+ case linux.F_GETFL:
+ return uintptr(file.StatusFlags()), nil, nil
+ case linux.F_SETFL:
+ return 0, nil, file.SetStatusFlags(t, t.Credentials(), args[2].Uint())
+ default:
+ // TODO(gvisor.dev/issue/1623): Everything else is not yet supported.
+ return 0, nil, syserror.EINVAL
+ }
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/filesystem.go b/pkg/sentry/syscalls/linux/vfs2/filesystem.go
new file mode 100644
index 000000000..fc5ceea4c
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/filesystem.go
@@ -0,0 +1,326 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+// Link implements Linux syscall link(2).
+func Link(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ oldpathAddr := args[0].Pointer()
+ newpathAddr := args[1].Pointer()
+ return 0, nil, linkat(t, linux.AT_FDCWD, oldpathAddr, linux.AT_FDCWD, newpathAddr, 0 /* flags */)
+}
+
+// Linkat implements Linux syscall linkat(2).
+func Linkat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ olddirfd := args[0].Int()
+ oldpathAddr := args[1].Pointer()
+ newdirfd := args[2].Int()
+ newpathAddr := args[3].Pointer()
+ flags := args[4].Int()
+ return 0, nil, linkat(t, olddirfd, oldpathAddr, newdirfd, newpathAddr, flags)
+}
+
+func linkat(t *kernel.Task, olddirfd int32, oldpathAddr usermem.Addr, newdirfd int32, newpathAddr usermem.Addr, flags int32) error {
+ if flags&^(linux.AT_EMPTY_PATH|linux.AT_SYMLINK_FOLLOW) != 0 {
+ return syserror.EINVAL
+ }
+ if flags&linux.AT_EMPTY_PATH != 0 && !t.HasCapability(linux.CAP_DAC_READ_SEARCH) {
+ return syserror.ENOENT
+ }
+
+ oldpath, err := copyInPath(t, oldpathAddr)
+ if err != nil {
+ return err
+ }
+ oldtpop, err := getTaskPathOperation(t, olddirfd, oldpath, shouldAllowEmptyPath(flags&linux.AT_EMPTY_PATH != 0), shouldFollowFinalSymlink(flags&linux.AT_SYMLINK_FOLLOW != 0))
+ if err != nil {
+ return err
+ }
+ defer oldtpop.Release()
+
+ newpath, err := copyInPath(t, newpathAddr)
+ if err != nil {
+ return err
+ }
+ newtpop, err := getTaskPathOperation(t, newdirfd, newpath, disallowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer newtpop.Release()
+
+ return t.Kernel().VFS().LinkAt(t, t.Credentials(), &oldtpop.pop, &newtpop.pop)
+}
+
+// Mkdir implements Linux syscall mkdir(2).
+func Mkdir(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+ mode := args[1].ModeT()
+ return 0, nil, mkdirat(t, linux.AT_FDCWD, addr, mode)
+}
+
+// Mkdirat implements Linux syscall mkdirat(2).
+func Mkdirat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ addr := args[1].Pointer()
+ mode := args[2].ModeT()
+ return 0, nil, mkdirat(t, dirfd, addr, mode)
+}
+
+func mkdirat(t *kernel.Task, dirfd int32, addr usermem.Addr, mode uint) error {
+ path, err := copyInPath(t, addr)
+ if err != nil {
+ return err
+ }
+ tpop, err := getTaskPathOperation(t, dirfd, path, disallowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer tpop.Release()
+ return t.Kernel().VFS().MkdirAt(t, t.Credentials(), &tpop.pop, &vfs.MkdirOptions{
+ Mode: linux.FileMode(mode & (0777 | linux.S_ISVTX) &^ t.FSContext().Umask()),
+ })
+}
+
+// Mknod implements Linux syscall mknod(2).
+func Mknod(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+ mode := args[1].ModeT()
+ dev := args[2].Uint()
+ return 0, nil, mknodat(t, linux.AT_FDCWD, addr, mode, dev)
+}
+
+// Mknodat implements Linux syscall mknodat(2).
+func Mknodat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ addr := args[1].Pointer()
+ mode := args[2].ModeT()
+ dev := args[3].Uint()
+ return 0, nil, mknodat(t, dirfd, addr, mode, dev)
+}
+
+func mknodat(t *kernel.Task, dirfd int32, addr usermem.Addr, mode uint, dev uint32) error {
+ path, err := copyInPath(t, addr)
+ if err != nil {
+ return err
+ }
+ tpop, err := getTaskPathOperation(t, dirfd, path, disallowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer tpop.Release()
+ major, minor := linux.DecodeDeviceID(dev)
+ return t.Kernel().VFS().MknodAt(t, t.Credentials(), &tpop.pop, &vfs.MknodOptions{
+ Mode: linux.FileMode(mode &^ t.FSContext().Umask()),
+ DevMajor: uint32(major),
+ DevMinor: minor,
+ })
+}
+
+// Open implements Linux syscall open(2).
+func Open(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+ flags := args[1].Uint()
+ mode := args[2].ModeT()
+ return openat(t, linux.AT_FDCWD, addr, flags, mode)
+}
+
+// Openat implements Linux syscall openat(2).
+func Openat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ addr := args[1].Pointer()
+ flags := args[2].Uint()
+ mode := args[3].ModeT()
+ return openat(t, dirfd, addr, flags, mode)
+}
+
+// Creat implements Linux syscall creat(2).
+func Creat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+ mode := args[1].ModeT()
+ return openat(t, linux.AT_FDCWD, addr, linux.O_WRONLY|linux.O_CREAT|linux.O_TRUNC, mode)
+}
+
+func openat(t *kernel.Task, dirfd int32, pathAddr usermem.Addr, flags uint32, mode uint) (uintptr, *kernel.SyscallControl, error) {
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+ tpop, err := getTaskPathOperation(t, dirfd, path, disallowEmptyPath, shouldFollowFinalSymlink(flags&linux.O_NOFOLLOW == 0))
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ file, err := t.Kernel().VFS().OpenAt(t, t.Credentials(), &tpop.pop, &vfs.OpenOptions{
+ Flags: flags,
+ Mode: linux.FileMode(mode & (0777 | linux.S_ISUID | linux.S_ISGID | linux.S_ISVTX) &^ t.FSContext().Umask()),
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+ defer file.DecRef()
+
+ fd, err := t.NewFDFromVFS2(0, file, kernel.FDFlags{
+ CloseOnExec: flags&linux.O_CLOEXEC != 0,
+ })
+ return uintptr(fd), nil, err
+}
+
+// Rename implements Linux syscall rename(2).
+func Rename(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ oldpathAddr := args[0].Pointer()
+ newpathAddr := args[1].Pointer()
+ return 0, nil, renameat(t, linux.AT_FDCWD, oldpathAddr, linux.AT_FDCWD, newpathAddr, 0 /* flags */)
+}
+
+// Renameat implements Linux syscall renameat(2).
+func Renameat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ olddirfd := args[0].Int()
+ oldpathAddr := args[1].Pointer()
+ newdirfd := args[2].Int()
+ newpathAddr := args[3].Pointer()
+ return 0, nil, renameat(t, olddirfd, oldpathAddr, newdirfd, newpathAddr, 0 /* flags */)
+}
+
+// Renameat2 implements Linux syscall renameat2(2).
+func Renameat2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ olddirfd := args[0].Int()
+ oldpathAddr := args[1].Pointer()
+ newdirfd := args[2].Int()
+ newpathAddr := args[3].Pointer()
+ flags := args[4].Uint()
+ return 0, nil, renameat(t, olddirfd, oldpathAddr, newdirfd, newpathAddr, flags)
+}
+
+func renameat(t *kernel.Task, olddirfd int32, oldpathAddr usermem.Addr, newdirfd int32, newpathAddr usermem.Addr, flags uint32) error {
+ oldpath, err := copyInPath(t, oldpathAddr)
+ if err != nil {
+ return err
+ }
+ // "If oldpath refers to a symbolic link, the link is renamed" - rename(2)
+ oldtpop, err := getTaskPathOperation(t, olddirfd, oldpath, disallowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer oldtpop.Release()
+
+ newpath, err := copyInPath(t, newpathAddr)
+ if err != nil {
+ return err
+ }
+ newtpop, err := getTaskPathOperation(t, newdirfd, newpath, disallowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer newtpop.Release()
+
+ return t.Kernel().VFS().RenameAt(t, t.Credentials(), &oldtpop.pop, &newtpop.pop, &vfs.RenameOptions{
+ Flags: flags,
+ })
+}
+
+// Rmdir implements Linux syscall rmdir(2).
+func Rmdir(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ return 0, nil, rmdirat(t, linux.AT_FDCWD, pathAddr)
+}
+
+func rmdirat(t *kernel.Task, dirfd int32, pathAddr usermem.Addr) error {
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return err
+ }
+ tpop, err := getTaskPathOperation(t, dirfd, path, disallowEmptyPath, followFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer tpop.Release()
+ return t.Kernel().VFS().RmdirAt(t, t.Credentials(), &tpop.pop)
+}
+
+// Unlink implements Linux syscall unlink(2).
+func Unlink(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ return 0, nil, unlinkat(t, linux.AT_FDCWD, pathAddr)
+}
+
+func unlinkat(t *kernel.Task, dirfd int32, pathAddr usermem.Addr) error {
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return err
+ }
+ tpop, err := getTaskPathOperation(t, dirfd, path, disallowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer tpop.Release()
+ return t.Kernel().VFS().UnlinkAt(t, t.Credentials(), &tpop.pop)
+}
+
+// Unlinkat implements Linux syscall unlinkat(2).
+func Unlinkat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ pathAddr := args[1].Pointer()
+ flags := args[2].Int()
+
+ if flags&^linux.AT_REMOVEDIR != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ if flags&linux.AT_REMOVEDIR != 0 {
+ return 0, nil, rmdirat(t, dirfd, pathAddr)
+ }
+ return 0, nil, unlinkat(t, dirfd, pathAddr)
+}
+
+// Symlink implements Linux syscall symlink(2).
+func Symlink(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ targetAddr := args[0].Pointer()
+ linkpathAddr := args[1].Pointer()
+ return 0, nil, symlinkat(t, targetAddr, linux.AT_FDCWD, linkpathAddr)
+}
+
+// Symlinkat implements Linux syscall symlinkat(2).
+func Symlinkat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ targetAddr := args[0].Pointer()
+ newdirfd := args[1].Int()
+ linkpathAddr := args[2].Pointer()
+ return 0, nil, symlinkat(t, targetAddr, newdirfd, linkpathAddr)
+}
+
+func symlinkat(t *kernel.Task, targetAddr usermem.Addr, newdirfd int32, linkpathAddr usermem.Addr) error {
+ target, err := t.CopyInString(targetAddr, linux.PATH_MAX)
+ if err != nil {
+ return err
+ }
+ linkpath, err := copyInPath(t, linkpathAddr)
+ if err != nil {
+ return err
+ }
+ tpop, err := getTaskPathOperation(t, newdirfd, linkpath, disallowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer tpop.Release()
+ return t.Kernel().VFS().SymlinkAt(t, t.Credentials(), &tpop.pop, target)
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/fscontext.go b/pkg/sentry/syscalls/linux/vfs2/fscontext.go
new file mode 100644
index 000000000..317409a18
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/fscontext.go
@@ -0,0 +1,131 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Getcwd implements Linux syscall getcwd(2).
+func Getcwd(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+ size := args[1].SizeT()
+
+ root := t.FSContext().RootDirectoryVFS2()
+ wd := t.FSContext().WorkingDirectoryVFS2()
+ s, err := t.Kernel().VFS().PathnameForGetcwd(t, root, wd)
+ root.DecRef()
+ wd.DecRef()
+ if err != nil {
+ return 0, nil, err
+ }
+
+ // Note this is >= because we need a terminator.
+ if uint(len(s)) >= size {
+ return 0, nil, syserror.ERANGE
+ }
+
+ // Construct a byte slice containing a NUL terminator.
+ buf := t.CopyScratchBuffer(len(s) + 1)
+ copy(buf, s)
+ buf[len(buf)-1] = 0
+
+ // Write the pathname slice.
+ n, err := t.CopyOutBytes(addr, buf)
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(n), nil, nil
+}
+
+// Chdir implements Linux syscall chdir(2).
+func Chdir(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+
+ path, err := copyInPath(t, addr)
+ if err != nil {
+ return 0, nil, err
+ }
+ tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, followFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ vd, err := t.Kernel().VFS().GetDentryAt(t, t.Credentials(), &tpop.pop, &vfs.GetDentryOptions{
+ CheckSearchable: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+ t.FSContext().SetWorkingDirectoryVFS2(vd)
+ vd.DecRef()
+ return 0, nil, nil
+}
+
+// Fchdir implements Linux syscall fchdir(2).
+func Fchdir(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+
+ tpop, err := getTaskPathOperation(t, fd, fspath.Path{}, allowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ vd, err := t.Kernel().VFS().GetDentryAt(t, t.Credentials(), &tpop.pop, &vfs.GetDentryOptions{
+ CheckSearchable: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+ t.FSContext().SetWorkingDirectoryVFS2(vd)
+ vd.DecRef()
+ return 0, nil, nil
+}
+
+// Chroot implements Linux syscall chroot(2).
+func Chroot(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+
+ if !t.HasCapability(linux.CAP_SYS_CHROOT) {
+ return 0, nil, syserror.EPERM
+ }
+
+ path, err := copyInPath(t, addr)
+ if err != nil {
+ return 0, nil, err
+ }
+ tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, followFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ vd, err := t.Kernel().VFS().GetDentryAt(t, t.Credentials(), &tpop.pop, &vfs.GetDentryOptions{
+ CheckSearchable: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+ t.FSContext().SetRootDirectoryVFS2(vd)
+ vd.DecRef()
+ return 0, nil, nil
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/getdents.go b/pkg/sentry/syscalls/linux/vfs2/getdents.go
new file mode 100644
index 000000000..ddc140b65
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/getdents.go
@@ -0,0 +1,149 @@
+// 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 vfs2
+
+import (
+ "fmt"
+
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/sync"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+// Getdents implements Linux syscall getdents(2).
+func Getdents(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return getdents(t, args, false /* isGetdents64 */)
+}
+
+// Getdents64 implements Linux syscall getdents64(2).
+func Getdents64(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return getdents(t, args, true /* isGetdents64 */)
+}
+
+func getdents(t *kernel.Task, args arch.SyscallArguments, isGetdents64 bool) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ size := int(args[2].Uint())
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ cb := getGetdentsCallback(t, addr, size, isGetdents64)
+ err := file.IterDirents(t, cb)
+ n := size - cb.remaining
+ putGetdentsCallback(cb)
+ if n == 0 {
+ return 0, nil, err
+ }
+ return uintptr(n), nil, nil
+}
+
+type getdentsCallback struct {
+ t *kernel.Task
+ addr usermem.Addr
+ remaining int
+ isGetdents64 bool
+}
+
+var getdentsCallbackPool = sync.Pool{
+ New: func() interface{} {
+ return &getdentsCallback{}
+ },
+}
+
+func getGetdentsCallback(t *kernel.Task, addr usermem.Addr, size int, isGetdents64 bool) *getdentsCallback {
+ cb := getdentsCallbackPool.Get().(*getdentsCallback)
+ *cb = getdentsCallback{
+ t: t,
+ addr: addr,
+ remaining: size,
+ isGetdents64: isGetdents64,
+ }
+ return cb
+}
+
+func putGetdentsCallback(cb *getdentsCallback) {
+ cb.t = nil
+ getdentsCallbackPool.Put(cb)
+}
+
+// Handle implements vfs.IterDirentsCallback.Handle.
+func (cb *getdentsCallback) Handle(dirent vfs.Dirent) error {
+ var buf []byte
+ if cb.isGetdents64 {
+ // struct linux_dirent64 {
+ // ino64_t d_ino; /* 64-bit inode number */
+ // off64_t d_off; /* 64-bit offset to next structure */
+ // unsigned short d_reclen; /* Size of this dirent */
+ // unsigned char d_type; /* File type */
+ // char d_name[]; /* Filename (null-terminated) */
+ // };
+ size := 8 + 8 + 2 + 1 + 1 + len(dirent.Name)
+ if size < cb.remaining {
+ return syserror.EINVAL
+ }
+ buf = cb.t.CopyScratchBuffer(size)
+ usermem.ByteOrder.PutUint64(buf[0:8], dirent.Ino)
+ usermem.ByteOrder.PutUint64(buf[8:16], uint64(dirent.NextOff))
+ usermem.ByteOrder.PutUint16(buf[16:18], uint16(size))
+ buf[18] = dirent.Type
+ copy(buf[19:], dirent.Name)
+ buf[size-1] = 0 // NUL terminator
+ } else {
+ // struct linux_dirent {
+ // unsigned long d_ino; /* Inode number */
+ // unsigned long d_off; /* Offset to next linux_dirent */
+ // unsigned short d_reclen; /* Length of this linux_dirent */
+ // char d_name[]; /* Filename (null-terminated) */
+ // /* length is actually (d_reclen - 2 -
+ // offsetof(struct linux_dirent, d_name)) */
+ // /*
+ // char pad; // Zero padding byte
+ // char d_type; // File type (only since Linux
+ // // 2.6.4); offset is (d_reclen - 1)
+ // */
+ // };
+ if cb.t.Arch().Width() != 8 {
+ panic(fmt.Sprintf("unsupported sizeof(unsigned long): %d", cb.t.Arch().Width()))
+ }
+ size := 8 + 8 + 2 + 1 + 1 + 1 + len(dirent.Name)
+ if size < cb.remaining {
+ return syserror.EINVAL
+ }
+ buf = cb.t.CopyScratchBuffer(size)
+ usermem.ByteOrder.PutUint64(buf[0:8], dirent.Ino)
+ usermem.ByteOrder.PutUint64(buf[8:16], uint64(dirent.NextOff))
+ usermem.ByteOrder.PutUint16(buf[16:18], uint16(size))
+ copy(buf[18:], dirent.Name)
+ buf[size-3] = 0 // NUL terminator
+ buf[size-2] = 0 // zero padding byte
+ buf[size-1] = dirent.Type
+ }
+ n, err := cb.t.CopyOutBytes(cb.addr, buf)
+ if err != nil {
+ // Don't report partially-written dirents by advancing cb.addr or
+ // cb.remaining.
+ return err
+ }
+ cb.addr += usermem.Addr(n)
+ cb.remaining -= n
+ return nil
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/ioctl.go b/pkg/sentry/syscalls/linux/vfs2/ioctl.go
new file mode 100644
index 000000000..5a2418da9
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/ioctl.go
@@ -0,0 +1,35 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Ioctl implements Linux syscall ioctl(2).
+func Ioctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ ret, err := file.Ioctl(t, t.MemoryManager(), args)
+ return ret, nil, err
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go b/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go
index e0ac32b33..7d220bc20 100644
--- a/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go
+++ b/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go
@@ -12,6 +12,8 @@
// See the License for the specific language governing permissions and
// limitations under the License.
+// +build amd64
+
package vfs2
import (
@@ -22,110 +24,142 @@ import (
// Override syscall table to add syscalls implementations from this package.
func Override(table map[uintptr]kernel.Syscall) {
table[0] = syscalls.Supported("read", Read)
-
- // Remove syscalls that haven't been converted yet. It's better to get ENOSYS
- // rather than a SIGSEGV deep in the stack.
- delete(table, 1) // write
- delete(table, 2) // open
- delete(table, 3) // close
- delete(table, 4) // stat
- delete(table, 5) // fstat
- delete(table, 6) // lstat
- delete(table, 7) // poll
- delete(table, 8) // lseek
- delete(table, 9) // mmap
- delete(table, 16) // ioctl
- delete(table, 17) // pread64
- delete(table, 18) // pwrite64
- delete(table, 19) // readv
- delete(table, 20) // writev
- delete(table, 21) // access
- delete(table, 22) // pipe
- delete(table, 32) // dup
- delete(table, 33) // dup2
- delete(table, 40) // sendfile
- delete(table, 59) // execve
- delete(table, 72) // fcntl
- delete(table, 73) // flock
- delete(table, 74) // fsync
- delete(table, 75) // fdatasync
- delete(table, 76) // truncate
- delete(table, 77) // ftruncate
- delete(table, 78) // getdents
- delete(table, 79) // getcwd
- delete(table, 80) // chdir
- delete(table, 81) // fchdir
- delete(table, 82) // rename
- delete(table, 83) // mkdir
- delete(table, 84) // rmdir
- delete(table, 85) // creat
- delete(table, 86) // link
- delete(table, 87) // unlink
- delete(table, 88) // symlink
- delete(table, 89) // readlink
- delete(table, 90) // chmod
- delete(table, 91) // fchmod
- delete(table, 92) // chown
- delete(table, 93) // fchown
- delete(table, 94) // lchown
- delete(table, 133) // mknod
- delete(table, 137) // statfs
- delete(table, 138) // fstatfs
- delete(table, 161) // chroot
- delete(table, 162) // sync
+ table[1] = syscalls.Supported("write", Write)
+ table[2] = syscalls.Supported("open", Open)
+ table[3] = syscalls.Supported("close", Close)
+ table[4] = syscalls.Supported("stat", Stat)
+ table[5] = syscalls.Supported("fstat", Fstat)
+ table[6] = syscalls.Supported("lstat", Lstat)
+ table[7] = syscalls.Supported("poll", Poll)
+ table[8] = syscalls.Supported("lseek", Lseek)
+ table[9] = syscalls.Supported("mmap", Mmap)
+ table[16] = syscalls.Supported("ioctl", Ioctl)
+ table[17] = syscalls.Supported("pread64", Pread64)
+ table[18] = syscalls.Supported("pwrite64", Pwrite64)
+ table[19] = syscalls.Supported("readv", Readv)
+ table[20] = syscalls.Supported("writev", Writev)
+ table[21] = syscalls.Supported("access", Access)
+ delete(table, 22) // pipe
+ table[23] = syscalls.Supported("select", Select)
+ table[32] = syscalls.Supported("dup", Dup)
+ table[33] = syscalls.Supported("dup2", Dup2)
+ delete(table, 40) // sendfile
+ delete(table, 41) // socket
+ delete(table, 42) // connect
+ delete(table, 43) // accept
+ delete(table, 44) // sendto
+ delete(table, 45) // recvfrom
+ delete(table, 46) // sendmsg
+ delete(table, 47) // recvmsg
+ delete(table, 48) // shutdown
+ delete(table, 49) // bind
+ delete(table, 50) // listen
+ delete(table, 51) // getsockname
+ delete(table, 52) // getpeername
+ delete(table, 53) // socketpair
+ delete(table, 54) // setsockopt
+ delete(table, 55) // getsockopt
+ table[59] = syscalls.Supported("execve", Execve)
+ table[72] = syscalls.Supported("fcntl", Fcntl)
+ delete(table, 73) // flock
+ table[74] = syscalls.Supported("fsync", Fsync)
+ table[75] = syscalls.Supported("fdatasync", Fdatasync)
+ table[76] = syscalls.Supported("truncate", Truncate)
+ table[77] = syscalls.Supported("ftruncate", Ftruncate)
+ table[78] = syscalls.Supported("getdents", Getdents)
+ table[79] = syscalls.Supported("getcwd", Getcwd)
+ table[80] = syscalls.Supported("chdir", Chdir)
+ table[81] = syscalls.Supported("fchdir", Fchdir)
+ table[82] = syscalls.Supported("rename", Rename)
+ table[83] = syscalls.Supported("mkdir", Mkdir)
+ table[84] = syscalls.Supported("rmdir", Rmdir)
+ table[85] = syscalls.Supported("creat", Creat)
+ table[86] = syscalls.Supported("link", Link)
+ table[87] = syscalls.Supported("unlink", Unlink)
+ table[88] = syscalls.Supported("symlink", Symlink)
+ table[89] = syscalls.Supported("readlink", Readlink)
+ table[90] = syscalls.Supported("chmod", Chmod)
+ table[91] = syscalls.Supported("fchmod", Fchmod)
+ table[92] = syscalls.Supported("chown", Chown)
+ table[93] = syscalls.Supported("fchown", Fchown)
+ table[94] = syscalls.Supported("lchown", Lchown)
+ table[132] = syscalls.Supported("utime", Utime)
+ table[133] = syscalls.Supported("mknod", Mknod)
+ table[137] = syscalls.Supported("statfs", Statfs)
+ table[138] = syscalls.Supported("fstatfs", Fstatfs)
+ table[161] = syscalls.Supported("chroot", Chroot)
+ table[162] = syscalls.Supported("sync", Sync)
delete(table, 165) // mount
delete(table, 166) // umount2
- delete(table, 172) // iopl
- delete(table, 173) // ioperm
delete(table, 187) // readahead
- delete(table, 188) // setxattr
- delete(table, 189) // lsetxattr
- delete(table, 190) // fsetxattr
- delete(table, 191) // getxattr
- delete(table, 192) // lgetxattr
- delete(table, 193) // fgetxattr
+ table[188] = syscalls.Supported("setxattr", Setxattr)
+ table[189] = syscalls.Supported("lsetxattr", Lsetxattr)
+ table[190] = syscalls.Supported("fsetxattr", Fsetxattr)
+ table[191] = syscalls.Supported("getxattr", Getxattr)
+ table[192] = syscalls.Supported("lgetxattr", Lgetxattr)
+ table[193] = syscalls.Supported("fgetxattr", Fgetxattr)
+ table[194] = syscalls.Supported("listxattr", Listxattr)
+ table[195] = syscalls.Supported("llistxattr", Llistxattr)
+ table[196] = syscalls.Supported("flistxattr", Flistxattr)
+ table[197] = syscalls.Supported("removexattr", Removexattr)
+ table[198] = syscalls.Supported("lremovexattr", Lremovexattr)
+ table[199] = syscalls.Supported("fremovexattr", Fremovexattr)
delete(table, 206) // io_setup
delete(table, 207) // io_destroy
delete(table, 208) // io_getevents
delete(table, 209) // io_submit
delete(table, 210) // io_cancel
- delete(table, 213) // epoll_create
- delete(table, 214) // epoll_ctl_old
- delete(table, 215) // epoll_wait_old
- delete(table, 216) // remap_file_pages
- delete(table, 217) // getdents64
- delete(table, 232) // epoll_wait
- delete(table, 233) // epoll_ctl
+ table[213] = syscalls.Supported("epoll_create", EpollCreate)
+ table[217] = syscalls.Supported("getdents64", Getdents64)
+ delete(table, 221) // fdavise64
+ table[232] = syscalls.Supported("epoll_wait", EpollWait)
+ table[233] = syscalls.Supported("epoll_ctl", EpollCtl)
+ table[235] = syscalls.Supported("utimes", Utimes)
delete(table, 253) // inotify_init
delete(table, 254) // inotify_add_watch
delete(table, 255) // inotify_rm_watch
- delete(table, 257) // openat
- delete(table, 258) // mkdirat
- delete(table, 259) // mknodat
- delete(table, 260) // fchownat
- delete(table, 261) // futimesat
- delete(table, 262) // fstatat
- delete(table, 263) // unlinkat
- delete(table, 264) // renameat
- delete(table, 265) // linkat
- delete(table, 266) // symlinkat
- delete(table, 267) // readlinkat
- delete(table, 268) // fchmodat
- delete(table, 269) // faccessat
- delete(table, 270) // pselect
- delete(table, 271) // ppoll
+ table[257] = syscalls.Supported("openat", Openat)
+ table[258] = syscalls.Supported("mkdirat", Mkdirat)
+ table[259] = syscalls.Supported("mknodat", Mknodat)
+ table[260] = syscalls.Supported("fchownat", Fchownat)
+ table[261] = syscalls.Supported("futimens", Futimens)
+ table[262] = syscalls.Supported("newfstatat", Newfstatat)
+ table[263] = syscalls.Supported("unlinkat", Unlinkat)
+ table[264] = syscalls.Supported("renameat", Renameat)
+ table[265] = syscalls.Supported("linkat", Linkat)
+ table[266] = syscalls.Supported("symlinkat", Symlinkat)
+ table[267] = syscalls.Supported("readlinkat", Readlinkat)
+ table[268] = syscalls.Supported("fchmodat", Fchmodat)
+ table[269] = syscalls.Supported("faccessat", Faccessat)
+ table[270] = syscalls.Supported("pselect", Pselect)
+ table[271] = syscalls.Supported("ppoll", Ppoll)
+ delete(table, 275) // splice
+ delete(table, 276) // tee
+ table[277] = syscalls.Supported("sync_file_range", SyncFileRange)
+ table[280] = syscalls.Supported("utimensat", Utimensat)
+ table[281] = syscalls.Supported("epoll_pwait", EpollPwait)
+ delete(table, 282) // signalfd
+ delete(table, 283) // timerfd_create
+ delete(table, 284) // eventfd
delete(table, 285) // fallocate
- delete(table, 291) // epoll_create1
- delete(table, 292) // dup3
+ delete(table, 286) // timerfd_settime
+ delete(table, 287) // timerfd_gettime
+ delete(table, 288) // accept4
+ delete(table, 289) // signalfd4
+ delete(table, 290) // eventfd2
+ table[291] = syscalls.Supported("epoll_create1", EpollCreate1)
+ table[292] = syscalls.Supported("dup3", Dup3)
delete(table, 293) // pipe2
delete(table, 294) // inotify_init1
- delete(table, 295) // preadv
- delete(table, 296) // pwritev
- delete(table, 306) // syncfs
- delete(table, 316) // renameat2
+ table[295] = syscalls.Supported("preadv", Preadv)
+ table[296] = syscalls.Supported("pwritev", Pwritev)
+ delete(table, 299) // recvmmsg
+ table[306] = syscalls.Supported("syncfs", Syncfs)
+ delete(table, 307) // sendmmsg
+ table[316] = syscalls.Supported("renameat2", Renameat2)
delete(table, 319) // memfd_create
- delete(table, 322) // execveat
- delete(table, 327) // preadv2
- delete(table, 328) // pwritev2
- delete(table, 332) // statx
+ table[322] = syscalls.Supported("execveat", Execveat)
+ table[327] = syscalls.Supported("preadv2", Preadv2)
+ table[328] = syscalls.Supported("pwritev2", Pwritev2)
+ table[332] = syscalls.Supported("statx", Statx)
}
diff --git a/pkg/sentry/syscalls/linux/vfs2/linux64_override_arm64.go b/pkg/sentry/syscalls/linux/vfs2/linux64_override_arm64.go
index 6af5c400f..a6b367468 100644
--- a/pkg/sentry/syscalls/linux/vfs2/linux64_override_arm64.go
+++ b/pkg/sentry/syscalls/linux/vfs2/linux64_override_arm64.go
@@ -12,6 +12,8 @@
// See the License for the specific language governing permissions and
// limitations under the License.
+// +build arm64
+
package vfs2
import (
diff --git a/pkg/sentry/syscalls/linux/vfs2/mmap.go b/pkg/sentry/syscalls/linux/vfs2/mmap.go
new file mode 100644
index 000000000..60a43f0a0
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/mmap.go
@@ -0,0 +1,92 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/memmap"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+// Mmap implements Linux syscall mmap(2).
+func Mmap(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ prot := args[2].Int()
+ flags := args[3].Int()
+ fd := args[4].Int()
+ fixed := flags&linux.MAP_FIXED != 0
+ private := flags&linux.MAP_PRIVATE != 0
+ shared := flags&linux.MAP_SHARED != 0
+ anon := flags&linux.MAP_ANONYMOUS != 0
+ map32bit := flags&linux.MAP_32BIT != 0
+
+ // Require exactly one of MAP_PRIVATE and MAP_SHARED.
+ if private == shared {
+ return 0, nil, syserror.EINVAL
+ }
+
+ opts := memmap.MMapOpts{
+ Length: args[1].Uint64(),
+ Offset: args[5].Uint64(),
+ Addr: args[0].Pointer(),
+ Fixed: fixed,
+ Unmap: fixed,
+ Map32Bit: map32bit,
+ Private: private,
+ Perms: usermem.AccessType{
+ Read: linux.PROT_READ&prot != 0,
+ Write: linux.PROT_WRITE&prot != 0,
+ Execute: linux.PROT_EXEC&prot != 0,
+ },
+ MaxPerms: usermem.AnyAccess,
+ GrowsDown: linux.MAP_GROWSDOWN&flags != 0,
+ Precommit: linux.MAP_POPULATE&flags != 0,
+ }
+ if linux.MAP_LOCKED&flags != 0 {
+ opts.MLockMode = memmap.MLockEager
+ }
+ defer func() {
+ if opts.MappingIdentity != nil {
+ opts.MappingIdentity.DecRef()
+ }
+ }()
+
+ if !anon {
+ // Convert the passed FD to a file reference.
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // mmap unconditionally requires that the FD is readable.
+ if !file.IsReadable() {
+ return 0, nil, syserror.EACCES
+ }
+ // MAP_SHARED requires that the FD be writable for PROT_WRITE.
+ if shared && !file.IsWritable() {
+ opts.MaxPerms.Write = false
+ }
+
+ if err := file.ConfigureMMap(t, &opts); err != nil {
+ return 0, nil, err
+ }
+ }
+
+ rv, err := t.MemoryManager().MMap(t, opts)
+ return uintptr(rv), nil, err
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/path.go b/pkg/sentry/syscalls/linux/vfs2/path.go
new file mode 100644
index 000000000..97da6c647
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/path.go
@@ -0,0 +1,94 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+func copyInPath(t *kernel.Task, addr usermem.Addr) (fspath.Path, error) {
+ pathname, err := t.CopyInString(addr, linux.PATH_MAX)
+ if err != nil {
+ return fspath.Path{}, err
+ }
+ return fspath.Parse(pathname), nil
+}
+
+type taskPathOperation struct {
+ pop vfs.PathOperation
+ haveStartRef bool
+}
+
+func getTaskPathOperation(t *kernel.Task, dirfd int32, path fspath.Path, shouldAllowEmptyPath shouldAllowEmptyPath, shouldFollowFinalSymlink shouldFollowFinalSymlink) (taskPathOperation, error) {
+ root := t.FSContext().RootDirectoryVFS2()
+ start := root
+ haveStartRef := false
+ if !path.Absolute {
+ if !path.HasComponents() && !bool(shouldAllowEmptyPath) {
+ root.DecRef()
+ return taskPathOperation{}, syserror.ENOENT
+ }
+ if dirfd == linux.AT_FDCWD {
+ start = t.FSContext().WorkingDirectoryVFS2()
+ haveStartRef = true
+ } else {
+ dirfile := t.GetFileVFS2(dirfd)
+ if dirfile == nil {
+ root.DecRef()
+ return taskPathOperation{}, syserror.EBADF
+ }
+ start = dirfile.VirtualDentry()
+ start.IncRef()
+ haveStartRef = true
+ dirfile.DecRef()
+ }
+ }
+ return taskPathOperation{
+ pop: vfs.PathOperation{
+ Root: root,
+ Start: start,
+ Path: path,
+ FollowFinalSymlink: bool(shouldFollowFinalSymlink),
+ },
+ haveStartRef: haveStartRef,
+ }, nil
+}
+
+func (tpop *taskPathOperation) Release() {
+ tpop.pop.Root.DecRef()
+ if tpop.haveStartRef {
+ tpop.pop.Start.DecRef()
+ tpop.haveStartRef = false
+ }
+}
+
+type shouldAllowEmptyPath bool
+
+const (
+ disallowEmptyPath shouldAllowEmptyPath = false
+ allowEmptyPath shouldAllowEmptyPath = true
+)
+
+type shouldFollowFinalSymlink bool
+
+const (
+ nofollowFinalSymlink shouldFollowFinalSymlink = false
+ followFinalSymlink shouldFollowFinalSymlink = true
+)
diff --git a/pkg/sentry/syscalls/linux/vfs2/poll.go b/pkg/sentry/syscalls/linux/vfs2/poll.go
new file mode 100644
index 000000000..dbf4882da
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/poll.go
@@ -0,0 +1,584 @@
+// 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 vfs2
+
+import (
+ "fmt"
+ "time"
+
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+ "gvisor.dev/gvisor/pkg/sentry/limits"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+// fileCap is the maximum allowable files for poll & select. This has no
+// equivalent in Linux; it exists in gVisor since allocation failure in Go is
+// unrecoverable.
+const fileCap = 1024 * 1024
+
+// Masks for "readable", "writable", and "exceptional" events as defined by
+// select(2).
+const (
+ // selectReadEvents is analogous to the Linux kernel's
+ // fs/select.c:POLLIN_SET.
+ selectReadEvents = linux.POLLIN | linux.POLLHUP | linux.POLLERR
+
+ // selectWriteEvents is analogous to the Linux kernel's
+ // fs/select.c:POLLOUT_SET.
+ selectWriteEvents = linux.POLLOUT | linux.POLLERR
+
+ // selectExceptEvents is analogous to the Linux kernel's
+ // fs/select.c:POLLEX_SET.
+ selectExceptEvents = linux.POLLPRI
+)
+
+// pollState tracks the associated file description and waiter of a PollFD.
+type pollState struct {
+ file *vfs.FileDescription
+ waiter waiter.Entry
+}
+
+// initReadiness gets the current ready mask for the file represented by the FD
+// stored in pfd.FD. If a channel is passed in, the waiter entry in "state" is
+// used to register with the file for event notifications, and a reference to
+// the file is stored in "state".
+func initReadiness(t *kernel.Task, pfd *linux.PollFD, state *pollState, ch chan struct{}) {
+ if pfd.FD < 0 {
+ pfd.REvents = 0
+ return
+ }
+
+ file := t.GetFileVFS2(pfd.FD)
+ if file == nil {
+ pfd.REvents = linux.POLLNVAL
+ return
+ }
+
+ if ch == nil {
+ defer file.DecRef()
+ } else {
+ state.file = file
+ state.waiter, _ = waiter.NewChannelEntry(ch)
+ file.EventRegister(&state.waiter, waiter.EventMaskFromLinux(uint32(pfd.Events)))
+ }
+
+ r := file.Readiness(waiter.EventMaskFromLinux(uint32(pfd.Events)))
+ pfd.REvents = int16(r.ToLinux()) & pfd.Events
+}
+
+// releaseState releases all the pollState in "state".
+func releaseState(state []pollState) {
+ for i := range state {
+ if state[i].file != nil {
+ state[i].file.EventUnregister(&state[i].waiter)
+ state[i].file.DecRef()
+ }
+ }
+}
+
+// pollBlock polls the PollFDs in "pfd" with a bounded time specified in "timeout"
+// when "timeout" is greater than zero.
+//
+// pollBlock returns the remaining timeout, which is always 0 on a timeout; and 0 or
+// positive if interrupted by a signal.
+func pollBlock(t *kernel.Task, pfd []linux.PollFD, timeout time.Duration) (time.Duration, uintptr, error) {
+ var ch chan struct{}
+ if timeout != 0 {
+ ch = make(chan struct{}, 1)
+ }
+
+ // Register for event notification in the files involved if we may
+ // block (timeout not zero). Once we find a file that has a non-zero
+ // result, we stop registering for events but still go through all files
+ // to get their ready masks.
+ state := make([]pollState, len(pfd))
+ defer releaseState(state)
+ n := uintptr(0)
+ for i := range pfd {
+ initReadiness(t, &pfd[i], &state[i], ch)
+ if pfd[i].REvents != 0 {
+ n++
+ ch = nil
+ }
+ }
+
+ if timeout == 0 {
+ return timeout, n, nil
+ }
+
+ haveTimeout := timeout >= 0
+
+ for n == 0 {
+ var err error
+ // Wait for a notification.
+ timeout, err = t.BlockWithTimeout(ch, haveTimeout, timeout)
+ if err != nil {
+ if err == syserror.ETIMEDOUT {
+ err = nil
+ }
+ return timeout, 0, err
+ }
+
+ // We got notified, count how many files are ready. If none,
+ // then this was a spurious notification, and we just go back
+ // to sleep with the remaining timeout.
+ for i := range state {
+ if state[i].file == nil {
+ continue
+ }
+
+ r := state[i].file.Readiness(waiter.EventMaskFromLinux(uint32(pfd[i].Events)))
+ rl := int16(r.ToLinux()) & pfd[i].Events
+ if rl != 0 {
+ pfd[i].REvents = rl
+ n++
+ }
+ }
+ }
+
+ return timeout, n, nil
+}
+
+// copyInPollFDs copies an array of struct pollfd unless nfds exceeds the max.
+func copyInPollFDs(t *kernel.Task, addr usermem.Addr, nfds uint) ([]linux.PollFD, error) {
+ if uint64(nfds) > t.ThreadGroup().Limits().GetCapped(limits.NumberOfFiles, fileCap) {
+ return nil, syserror.EINVAL
+ }
+
+ pfd := make([]linux.PollFD, nfds)
+ if nfds > 0 {
+ if _, err := t.CopyIn(addr, &pfd); err != nil {
+ return nil, err
+ }
+ }
+
+ return pfd, nil
+}
+
+func doPoll(t *kernel.Task, addr usermem.Addr, nfds uint, timeout time.Duration) (time.Duration, uintptr, error) {
+ pfd, err := copyInPollFDs(t, addr, nfds)
+ if err != nil {
+ return timeout, 0, err
+ }
+
+ // Compatibility warning: Linux adds POLLHUP and POLLERR just before
+ // polling, in fs/select.c:do_pollfd(). Since pfd is copied out after
+ // polling, changing event masks here is an application-visible difference.
+ // (Linux also doesn't copy out event masks at all, only revents.)
+ for i := range pfd {
+ pfd[i].Events |= linux.POLLHUP | linux.POLLERR
+ }
+ remainingTimeout, n, err := pollBlock(t, pfd, timeout)
+ err = syserror.ConvertIntr(err, syserror.EINTR)
+
+ // The poll entries are copied out regardless of whether
+ // any are set or not. This aligns with the Linux behavior.
+ if nfds > 0 && err == nil {
+ if _, err := t.CopyOut(addr, pfd); err != nil {
+ return remainingTimeout, 0, err
+ }
+ }
+
+ return remainingTimeout, n, err
+}
+
+// CopyInFDSet copies an fd set from select(2)/pselect(2).
+func CopyInFDSet(t *kernel.Task, addr usermem.Addr, nBytes, nBitsInLastPartialByte int) ([]byte, error) {
+ set := make([]byte, nBytes)
+
+ if addr != 0 {
+ if _, err := t.CopyIn(addr, &set); err != nil {
+ return nil, err
+ }
+ // If we only use part of the last byte, mask out the extraneous bits.
+ //
+ // N.B. This only works on little-endian architectures.
+ if nBitsInLastPartialByte != 0 {
+ set[nBytes-1] &^= byte(0xff) << nBitsInLastPartialByte
+ }
+ }
+ return set, nil
+}
+
+func doSelect(t *kernel.Task, nfds int, readFDs, writeFDs, exceptFDs usermem.Addr, timeout time.Duration) (uintptr, error) {
+ if nfds < 0 || nfds > fileCap {
+ return 0, syserror.EINVAL
+ }
+
+ // Calculate the size of the fd sets (one bit per fd).
+ nBytes := (nfds + 7) / 8
+ nBitsInLastPartialByte := nfds % 8
+
+ // Capture all the provided input vectors.
+ r, err := CopyInFDSet(t, readFDs, nBytes, nBitsInLastPartialByte)
+ if err != nil {
+ return 0, err
+ }
+ w, err := CopyInFDSet(t, writeFDs, nBytes, nBitsInLastPartialByte)
+ if err != nil {
+ return 0, err
+ }
+ e, err := CopyInFDSet(t, exceptFDs, nBytes, nBitsInLastPartialByte)
+ if err != nil {
+ return 0, err
+ }
+
+ // Count how many FDs are actually being requested so that we can build
+ // a PollFD array.
+ fdCount := 0
+ for i := 0; i < nBytes; i++ {
+ v := r[i] | w[i] | e[i]
+ for v != 0 {
+ v &= (v - 1)
+ fdCount++
+ }
+ }
+
+ // Build the PollFD array.
+ pfd := make([]linux.PollFD, 0, fdCount)
+ var fd int32
+ for i := 0; i < nBytes; i++ {
+ rV, wV, eV := r[i], w[i], e[i]
+ v := rV | wV | eV
+ m := byte(1)
+ for j := 0; j < 8; j++ {
+ if (v & m) != 0 {
+ // Make sure the fd is valid and decrement the reference
+ // immediately to ensure we don't leak. Note, another thread
+ // might be about to close fd. This is racy, but that's
+ // OK. Linux is racy in the same way.
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, syserror.EBADF
+ }
+ file.DecRef()
+
+ var mask int16
+ if (rV & m) != 0 {
+ mask |= selectReadEvents
+ }
+
+ if (wV & m) != 0 {
+ mask |= selectWriteEvents
+ }
+
+ if (eV & m) != 0 {
+ mask |= selectExceptEvents
+ }
+
+ pfd = append(pfd, linux.PollFD{
+ FD: fd,
+ Events: mask,
+ })
+ }
+
+ fd++
+ m <<= 1
+ }
+ }
+
+ // Do the syscall, then count the number of bits set.
+ if _, _, err = pollBlock(t, pfd, timeout); err != nil {
+ return 0, syserror.ConvertIntr(err, syserror.EINTR)
+ }
+
+ // r, w, and e are currently event mask bitsets; unset bits corresponding
+ // to events that *didn't* occur.
+ bitSetCount := uintptr(0)
+ for idx := range pfd {
+ events := pfd[idx].REvents
+ i, j := pfd[idx].FD/8, uint(pfd[idx].FD%8)
+ m := byte(1) << j
+ if r[i]&m != 0 {
+ if (events & selectReadEvents) != 0 {
+ bitSetCount++
+ } else {
+ r[i] &^= m
+ }
+ }
+ if w[i]&m != 0 {
+ if (events & selectWriteEvents) != 0 {
+ bitSetCount++
+ } else {
+ w[i] &^= m
+ }
+ }
+ if e[i]&m != 0 {
+ if (events & selectExceptEvents) != 0 {
+ bitSetCount++
+ } else {
+ e[i] &^= m
+ }
+ }
+ }
+
+ // Copy updated vectors back.
+ if readFDs != 0 {
+ if _, err := t.CopyOut(readFDs, r); err != nil {
+ return 0, err
+ }
+ }
+
+ if writeFDs != 0 {
+ if _, err := t.CopyOut(writeFDs, w); err != nil {
+ return 0, err
+ }
+ }
+
+ if exceptFDs != 0 {
+ if _, err := t.CopyOut(exceptFDs, e); err != nil {
+ return 0, err
+ }
+ }
+
+ return bitSetCount, nil
+}
+
+// timeoutRemaining returns the amount of time remaining for the specified
+// timeout or 0 if it has elapsed.
+//
+// startNs must be from CLOCK_MONOTONIC.
+func timeoutRemaining(t *kernel.Task, startNs ktime.Time, timeout time.Duration) time.Duration {
+ now := t.Kernel().MonotonicClock().Now()
+ remaining := timeout - now.Sub(startNs)
+ if remaining < 0 {
+ remaining = 0
+ }
+ return remaining
+}
+
+// copyOutTimespecRemaining copies the time remaining in timeout to timespecAddr.
+//
+// startNs must be from CLOCK_MONOTONIC.
+func copyOutTimespecRemaining(t *kernel.Task, startNs ktime.Time, timeout time.Duration, timespecAddr usermem.Addr) error {
+ if timeout <= 0 {
+ return nil
+ }
+ remaining := timeoutRemaining(t, startNs, timeout)
+ tsRemaining := linux.NsecToTimespec(remaining.Nanoseconds())
+ return tsRemaining.CopyOut(t, timespecAddr)
+}
+
+// copyOutTimevalRemaining copies the time remaining in timeout to timevalAddr.
+//
+// startNs must be from CLOCK_MONOTONIC.
+func copyOutTimevalRemaining(t *kernel.Task, startNs ktime.Time, timeout time.Duration, timevalAddr usermem.Addr) error {
+ if timeout <= 0 {
+ return nil
+ }
+ remaining := timeoutRemaining(t, startNs, timeout)
+ tvRemaining := linux.NsecToTimeval(remaining.Nanoseconds())
+ return tvRemaining.CopyOut(t, timevalAddr)
+}
+
+// pollRestartBlock encapsulates the state required to restart poll(2) via
+// restart_syscall(2).
+//
+// +stateify savable
+type pollRestartBlock struct {
+ pfdAddr usermem.Addr
+ nfds uint
+ timeout time.Duration
+}
+
+// Restart implements kernel.SyscallRestartBlock.Restart.
+func (p *pollRestartBlock) Restart(t *kernel.Task) (uintptr, error) {
+ return poll(t, p.pfdAddr, p.nfds, p.timeout)
+}
+
+func poll(t *kernel.Task, pfdAddr usermem.Addr, nfds uint, timeout time.Duration) (uintptr, error) {
+ remainingTimeout, n, err := doPoll(t, pfdAddr, nfds, timeout)
+ // On an interrupt poll(2) is restarted with the remaining timeout.
+ if err == syserror.EINTR {
+ t.SetSyscallRestartBlock(&pollRestartBlock{
+ pfdAddr: pfdAddr,
+ nfds: nfds,
+ timeout: remainingTimeout,
+ })
+ return 0, kernel.ERESTART_RESTARTBLOCK
+ }
+ return n, err
+}
+
+// Poll implements linux syscall poll(2).
+func Poll(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pfdAddr := args[0].Pointer()
+ nfds := uint(args[1].Uint()) // poll(2) uses unsigned long.
+ timeout := time.Duration(args[2].Int()) * time.Millisecond
+ n, err := poll(t, pfdAddr, nfds, timeout)
+ return n, nil, err
+}
+
+// Ppoll implements linux syscall ppoll(2).
+func Ppoll(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pfdAddr := args[0].Pointer()
+ nfds := uint(args[1].Uint()) // poll(2) uses unsigned long.
+ timespecAddr := args[2].Pointer()
+ maskAddr := args[3].Pointer()
+ maskSize := uint(args[4].Uint())
+
+ timeout, err := copyTimespecInToDuration(t, timespecAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ var startNs ktime.Time
+ if timeout > 0 {
+ startNs = t.Kernel().MonotonicClock().Now()
+ }
+
+ if err := setTempSignalSet(t, maskAddr, maskSize); err != nil {
+ return 0, nil, err
+ }
+
+ _, n, err := doPoll(t, pfdAddr, nfds, timeout)
+ copyErr := copyOutTimespecRemaining(t, startNs, timeout, timespecAddr)
+ // doPoll returns EINTR if interrupted, but ppoll is normally restartable
+ // if interrupted by something other than a signal handled by the
+ // application (i.e. returns ERESTARTNOHAND). However, if
+ // copyOutTimespecRemaining failed, then the restarted ppoll would use the
+ // wrong timeout, so the error should be left as EINTR.
+ //
+ // Note that this means that if err is nil but copyErr is not, copyErr is
+ // ignored. This is consistent with Linux.
+ if err == syserror.EINTR && copyErr == nil {
+ err = kernel.ERESTARTNOHAND
+ }
+ return n, nil, err
+}
+
+// Select implements linux syscall select(2).
+func Select(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ nfds := int(args[0].Int()) // select(2) uses an int.
+ readFDs := args[1].Pointer()
+ writeFDs := args[2].Pointer()
+ exceptFDs := args[3].Pointer()
+ timevalAddr := args[4].Pointer()
+
+ // Use a negative Duration to indicate "no timeout".
+ timeout := time.Duration(-1)
+ if timevalAddr != 0 {
+ var timeval linux.Timeval
+ if err := timeval.CopyIn(t, timevalAddr); err != nil {
+ return 0, nil, err
+ }
+ if timeval.Sec < 0 || timeval.Usec < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+ timeout = time.Duration(timeval.ToNsecCapped())
+ }
+ startNs := t.Kernel().MonotonicClock().Now()
+ n, err := doSelect(t, nfds, readFDs, writeFDs, exceptFDs, timeout)
+ copyErr := copyOutTimevalRemaining(t, startNs, timeout, timevalAddr)
+ // See comment in Ppoll.
+ if err == syserror.EINTR && copyErr == nil {
+ err = kernel.ERESTARTNOHAND
+ }
+ return n, nil, err
+}
+
+// Pselect implements linux syscall pselect(2).
+func Pselect(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ nfds := int(args[0].Int()) // select(2) uses an int.
+ readFDs := args[1].Pointer()
+ writeFDs := args[2].Pointer()
+ exceptFDs := args[3].Pointer()
+ timespecAddr := args[4].Pointer()
+ maskWithSizeAddr := args[5].Pointer()
+
+ timeout, err := copyTimespecInToDuration(t, timespecAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ var startNs ktime.Time
+ if timeout > 0 {
+ startNs = t.Kernel().MonotonicClock().Now()
+ }
+
+ if maskWithSizeAddr != 0 {
+ if t.Arch().Width() != 8 {
+ panic(fmt.Sprintf("unsupported sizeof(void*): %d", t.Arch().Width()))
+ }
+ var maskStruct sigSetWithSize
+ if err := maskStruct.CopyIn(t, maskWithSizeAddr); err != nil {
+ return 0, nil, err
+ }
+ if err := setTempSignalSet(t, usermem.Addr(maskStruct.sigsetAddr), uint(maskStruct.sizeofSigset)); err != nil {
+ return 0, nil, err
+ }
+ }
+
+ n, err := doSelect(t, nfds, readFDs, writeFDs, exceptFDs, timeout)
+ copyErr := copyOutTimespecRemaining(t, startNs, timeout, timespecAddr)
+ // See comment in Ppoll.
+ if err == syserror.EINTR && copyErr == nil {
+ err = kernel.ERESTARTNOHAND
+ }
+ return n, nil, err
+}
+
+// +marshal
+type sigSetWithSize struct {
+ sigsetAddr uint64
+ sizeofSigset uint64
+}
+
+// copyTimespecInToDuration copies a Timespec from the untrusted app range,
+// validates it and converts it to a Duration.
+//
+// If the Timespec is larger than what can be represented in a Duration, the
+// returned value is the maximum that Duration will allow.
+//
+// If timespecAddr is NULL, the returned value is negative.
+func copyTimespecInToDuration(t *kernel.Task, timespecAddr usermem.Addr) (time.Duration, error) {
+ // Use a negative Duration to indicate "no timeout".
+ timeout := time.Duration(-1)
+ if timespecAddr != 0 {
+ var timespec linux.Timespec
+ if err := timespec.CopyIn(t, timespecAddr); err != nil {
+ return 0, err
+ }
+ if !timespec.Valid() {
+ return 0, syserror.EINVAL
+ }
+ timeout = time.Duration(timespec.ToNsecCapped())
+ }
+ return timeout, nil
+}
+
+func setTempSignalSet(t *kernel.Task, maskAddr usermem.Addr, maskSize uint) error {
+ if maskAddr == 0 {
+ return nil
+ }
+ if maskSize != linux.SignalSetSize {
+ return syserror.EINVAL
+ }
+ var mask linux.SignalSet
+ if err := mask.CopyIn(t, maskAddr); err != nil {
+ return err
+ }
+ mask &^= kernel.UnblockableSignals
+ oldmask := t.SignalMask()
+ t.SetSignalMask(mask)
+ t.SetSavedSignalMask(oldmask)
+ return nil
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/read_write.go b/pkg/sentry/syscalls/linux/vfs2/read_write.go
new file mode 100644
index 000000000..35f6308d6
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/read_write.go
@@ -0,0 +1,511 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ slinux "gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+const (
+ eventMaskRead = waiter.EventIn | waiter.EventHUp | waiter.EventErr
+ eventMaskWrite = waiter.EventOut | waiter.EventHUp | waiter.EventErr
+)
+
+// Read implements Linux syscall read(2).
+func Read(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ size := args[2].SizeT()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the size is legitimate.
+ si := int(size)
+ if si < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get the destination of the read.
+ dst, err := t.SingleIOSequence(addr, si, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ n, err := read(t, file, dst, vfs.ReadOptions{})
+ t.IOUsage().AccountReadSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "read", file)
+}
+
+// Readv implements Linux syscall readv(2).
+func Readv(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ iovcnt := int(args[2].Int())
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Get the destination of the read.
+ dst, err := t.IovecsIOSequence(addr, iovcnt, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ n, err := read(t, file, dst, vfs.ReadOptions{})
+ t.IOUsage().AccountReadSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "readv", file)
+}
+
+func read(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
+ n, err := file.Read(t, dst, opts)
+ if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 {
+ return n, err
+ }
+
+ // Register for notifications.
+ w, ch := waiter.NewChannelEntry(nil)
+ file.EventRegister(&w, eventMaskRead)
+
+ total := n
+ for {
+ // Shorten dst to reflect bytes previously read.
+ dst = dst.DropFirst(int(n))
+
+ // Issue the request and break out if it completes with anything other than
+ // "would block".
+ n, err := file.Read(t, dst, opts)
+ total += n
+ if err != syserror.ErrWouldBlock {
+ break
+ }
+ if err := t.Block(ch); err != nil {
+ break
+ }
+ }
+ file.EventUnregister(&w)
+
+ return total, err
+}
+
+// Pread64 implements Linux syscall pread64(2).
+func Pread64(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ size := args[2].SizeT()
+ offset := args[3].Int64()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the offset is legitimate.
+ if offset < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Check that the size is legitimate.
+ si := int(size)
+ if si < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get the destination of the read.
+ dst, err := t.SingleIOSequence(addr, si, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ n, err := pread(t, file, dst, offset, vfs.ReadOptions{})
+ t.IOUsage().AccountReadSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "pread64", file)
+}
+
+// Preadv implements Linux syscall preadv(2).
+func Preadv(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ iovcnt := int(args[2].Int())
+ offset := args[3].Int64()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the offset is legitimate.
+ if offset < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get the destination of the read.
+ dst, err := t.IovecsIOSequence(addr, iovcnt, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ n, err := pread(t, file, dst, offset, vfs.ReadOptions{})
+ t.IOUsage().AccountReadSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "preadv", file)
+}
+
+// Preadv2 implements Linux syscall preadv2(2).
+func Preadv2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ // While the glibc signature is
+ // preadv2(int fd, struct iovec* iov, int iov_cnt, off_t offset, int flags)
+ // the actual syscall
+ // (https://elixir.bootlin.com/linux/v5.5/source/fs/read_write.c#L1142)
+ // splits the offset argument into a high/low value for compatibility with
+ // 32-bit architectures. The flags argument is the 6th argument (index 5).
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ iovcnt := int(args[2].Int())
+ offset := args[3].Int64()
+ flags := args[5].Int()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the offset is legitimate.
+ if offset < -1 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get the destination of the read.
+ dst, err := t.IovecsIOSequence(addr, iovcnt, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ opts := vfs.ReadOptions{
+ Flags: uint32(flags),
+ }
+ var n int64
+ if offset == -1 {
+ n, err = read(t, file, dst, opts)
+ } else {
+ n, err = pread(t, file, dst, offset, opts)
+ }
+ t.IOUsage().AccountReadSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "preadv2", file)
+}
+
+func pread(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
+ n, err := file.PRead(t, dst, offset, opts)
+ if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 {
+ return n, err
+ }
+
+ // Register for notifications.
+ w, ch := waiter.NewChannelEntry(nil)
+ file.EventRegister(&w, eventMaskRead)
+
+ total := n
+ for {
+ // Shorten dst to reflect bytes previously read.
+ dst = dst.DropFirst(int(n))
+
+ // Issue the request and break out if it completes with anything other than
+ // "would block".
+ n, err := file.PRead(t, dst, offset+total, opts)
+ total += n
+ if err != syserror.ErrWouldBlock {
+ break
+ }
+ if err := t.Block(ch); err != nil {
+ break
+ }
+ }
+ file.EventUnregister(&w)
+
+ return total, err
+}
+
+// Write implements Linux syscall write(2).
+func Write(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ size := args[2].SizeT()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the size is legitimate.
+ si := int(size)
+ if si < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get the source of the write.
+ src, err := t.SingleIOSequence(addr, si, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ n, err := write(t, file, src, vfs.WriteOptions{})
+ t.IOUsage().AccountWriteSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "write", file)
+}
+
+// Writev implements Linux syscall writev(2).
+func Writev(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ iovcnt := int(args[2].Int())
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Get the source of the write.
+ src, err := t.IovecsIOSequence(addr, iovcnt, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ n, err := write(t, file, src, vfs.WriteOptions{})
+ t.IOUsage().AccountWriteSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "writev", file)
+}
+
+func write(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
+ n, err := file.Write(t, src, opts)
+ if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 {
+ return n, err
+ }
+
+ // Register for notifications.
+ w, ch := waiter.NewChannelEntry(nil)
+ file.EventRegister(&w, eventMaskWrite)
+
+ total := n
+ for {
+ // Shorten src to reflect bytes previously written.
+ src = src.DropFirst(int(n))
+
+ // Issue the request and break out if it completes with anything other than
+ // "would block".
+ n, err := file.Write(t, src, opts)
+ total += n
+ if err != syserror.ErrWouldBlock {
+ break
+ }
+ if err := t.Block(ch); err != nil {
+ break
+ }
+ }
+ file.EventUnregister(&w)
+
+ return total, err
+}
+
+// Pwrite64 implements Linux syscall pwrite64(2).
+func Pwrite64(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ size := args[2].SizeT()
+ offset := args[3].Int64()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the offset is legitimate.
+ if offset < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Check that the size is legitimate.
+ si := int(size)
+ if si < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get the source of the write.
+ src, err := t.SingleIOSequence(addr, si, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ n, err := pwrite(t, file, src, offset, vfs.WriteOptions{})
+ t.IOUsage().AccountWriteSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "pwrite64", file)
+}
+
+// Pwritev implements Linux syscall pwritev(2).
+func Pwritev(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ iovcnt := int(args[2].Int())
+ offset := args[3].Int64()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the offset is legitimate.
+ if offset < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get the source of the write.
+ src, err := t.IovecsIOSequence(addr, iovcnt, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ n, err := pwrite(t, file, src, offset, vfs.WriteOptions{})
+ t.IOUsage().AccountReadSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "pwritev", file)
+}
+
+// Pwritev2 implements Linux syscall pwritev2(2).
+func Pwritev2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ // While the glibc signature is
+ // pwritev2(int fd, struct iovec* iov, int iov_cnt, off_t offset, int flags)
+ // the actual syscall
+ // (https://elixir.bootlin.com/linux/v5.5/source/fs/read_write.c#L1162)
+ // splits the offset argument into a high/low value for compatibility with
+ // 32-bit architectures. The flags argument is the 6th argument (index 5).
+ fd := args[0].Int()
+ addr := args[1].Pointer()
+ iovcnt := int(args[2].Int())
+ offset := args[3].Int64()
+ flags := args[5].Int()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the offset is legitimate.
+ if offset < -1 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Get the source of the write.
+ src, err := t.IovecsIOSequence(addr, iovcnt, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ opts := vfs.WriteOptions{
+ Flags: uint32(flags),
+ }
+ var n int64
+ if offset == -1 {
+ n, err = write(t, file, src, opts)
+ } else {
+ n, err = pwrite(t, file, src, offset, opts)
+ }
+ t.IOUsage().AccountWriteSyscall(n)
+ return uintptr(n), nil, slinux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "pwritev2", file)
+}
+
+func pwrite(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
+ n, err := file.PWrite(t, src, offset, opts)
+ if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 {
+ return n, err
+ }
+
+ // Register for notifications.
+ w, ch := waiter.NewChannelEntry(nil)
+ file.EventRegister(&w, eventMaskWrite)
+
+ total := n
+ for {
+ // Shorten src to reflect bytes previously written.
+ src = src.DropFirst(int(n))
+
+ // Issue the request and break out if it completes with anything other than
+ // "would block".
+ n, err := file.PWrite(t, src, offset+total, opts)
+ total += n
+ if err != syserror.ErrWouldBlock {
+ break
+ }
+ if err := t.Block(ch); err != nil {
+ break
+ }
+ }
+ file.EventUnregister(&w)
+
+ return total, err
+}
+
+// Lseek implements Linux syscall lseek(2).
+func Lseek(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ offset := args[1].Int64()
+ whence := args[2].Int()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ newoff, err := file.Seek(t, offset, whence)
+ return uintptr(newoff), nil, err
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/setstat.go b/pkg/sentry/syscalls/linux/vfs2/setstat.go
new file mode 100644
index 000000000..9250659ff
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/setstat.go
@@ -0,0 +1,380 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+const chmodMask = 0777 | linux.S_ISUID | linux.S_ISGID | linux.S_ISVTX
+
+// Chmod implements Linux syscall chmod(2).
+func Chmod(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ mode := args[1].ModeT()
+ return 0, nil, fchmodat(t, linux.AT_FDCWD, pathAddr, mode)
+}
+
+// Fchmodat implements Linux syscall fchmodat(2).
+func Fchmodat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ pathAddr := args[1].Pointer()
+ mode := args[2].ModeT()
+ return 0, nil, fchmodat(t, dirfd, pathAddr, mode)
+}
+
+func fchmodat(t *kernel.Task, dirfd int32, pathAddr usermem.Addr, mode uint) error {
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return err
+ }
+
+ return setstatat(t, dirfd, path, disallowEmptyPath, followFinalSymlink, &vfs.SetStatOptions{
+ Stat: linux.Statx{
+ Mask: linux.STATX_MODE,
+ Mode: uint16(mode & chmodMask),
+ },
+ })
+}
+
+// Fchmod implements Linux syscall fchmod(2).
+func Fchmod(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ mode := args[1].ModeT()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ return 0, nil, file.SetStat(t, vfs.SetStatOptions{
+ Stat: linux.Statx{
+ Mask: linux.STATX_MODE,
+ Mode: uint16(mode & chmodMask),
+ },
+ })
+}
+
+// Chown implements Linux syscall chown(2).
+func Chown(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ owner := args[1].Int()
+ group := args[2].Int()
+ return 0, nil, fchownat(t, linux.AT_FDCWD, pathAddr, owner, group, 0 /* flags */)
+}
+
+// Lchown implements Linux syscall lchown(2).
+func Lchown(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ owner := args[1].Int()
+ group := args[2].Int()
+ return 0, nil, fchownat(t, linux.AT_FDCWD, pathAddr, owner, group, linux.AT_SYMLINK_NOFOLLOW)
+}
+
+// Fchownat implements Linux syscall fchownat(2).
+func Fchownat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ pathAddr := args[1].Pointer()
+ owner := args[2].Int()
+ group := args[3].Int()
+ flags := args[4].Int()
+ return 0, nil, fchownat(t, dirfd, pathAddr, owner, group, flags)
+}
+
+func fchownat(t *kernel.Task, dirfd int32, pathAddr usermem.Addr, owner, group, flags int32) error {
+ if flags&^(linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW) != 0 {
+ return syserror.EINVAL
+ }
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return err
+ }
+
+ var opts vfs.SetStatOptions
+ if err := populateSetStatOptionsForChown(t, owner, group, &opts); err != nil {
+ return err
+ }
+
+ return setstatat(t, dirfd, path, shouldAllowEmptyPath(flags&linux.AT_EMPTY_PATH != 0), shouldFollowFinalSymlink(flags&linux.AT_SYMLINK_NOFOLLOW == 0), &opts)
+}
+
+func populateSetStatOptionsForChown(t *kernel.Task, owner, group int32, opts *vfs.SetStatOptions) error {
+ userns := t.UserNamespace()
+ if owner != -1 {
+ kuid := userns.MapToKUID(auth.UID(owner))
+ if !kuid.Ok() {
+ return syserror.EINVAL
+ }
+ opts.Stat.Mask |= linux.STATX_UID
+ opts.Stat.UID = uint32(kuid)
+ }
+ if group != -1 {
+ kgid := userns.MapToKGID(auth.GID(group))
+ if !kgid.Ok() {
+ return syserror.EINVAL
+ }
+ opts.Stat.Mask |= linux.STATX_GID
+ opts.Stat.GID = uint32(kgid)
+ }
+ return nil
+}
+
+// Fchown implements Linux syscall fchown(2).
+func Fchown(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ owner := args[1].Int()
+ group := args[2].Int()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ var opts vfs.SetStatOptions
+ if err := populateSetStatOptionsForChown(t, owner, group, &opts); err != nil {
+ return 0, nil, err
+ }
+ return 0, nil, file.SetStat(t, opts)
+}
+
+// Truncate implements Linux syscall truncate(2).
+func Truncate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ addr := args[0].Pointer()
+ length := args[1].Int64()
+
+ if length < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ path, err := copyInPath(t, addr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ return 0, nil, setstatat(t, linux.AT_FDCWD, path, disallowEmptyPath, followFinalSymlink, &vfs.SetStatOptions{
+ Stat: linux.Statx{
+ Mask: linux.STATX_SIZE,
+ Size: uint64(length),
+ },
+ })
+}
+
+// Ftruncate implements Linux syscall ftruncate(2).
+func Ftruncate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ length := args[1].Int64()
+
+ if length < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ return 0, nil, file.SetStat(t, vfs.SetStatOptions{
+ Stat: linux.Statx{
+ Mask: linux.STATX_SIZE,
+ Size: uint64(length),
+ },
+ })
+}
+
+// Utime implements Linux syscall utime(2).
+func Utime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ timesAddr := args[1].Pointer()
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ opts := vfs.SetStatOptions{
+ Stat: linux.Statx{
+ Mask: linux.STATX_ATIME | linux.STATX_MTIME,
+ },
+ }
+ if timesAddr == 0 {
+ opts.Stat.Atime.Nsec = linux.UTIME_NOW
+ opts.Stat.Mtime.Nsec = linux.UTIME_NOW
+ } else {
+ var times linux.Utime
+ if err := times.CopyIn(t, timesAddr); err != nil {
+ return 0, nil, err
+ }
+ opts.Stat.Atime.Sec = times.Actime
+ opts.Stat.Mtime.Sec = times.Modtime
+ }
+
+ return 0, nil, setstatat(t, linux.AT_FDCWD, path, disallowEmptyPath, followFinalSymlink, &opts)
+}
+
+// Utimes implements Linux syscall utimes(2).
+func Utimes(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ timesAddr := args[1].Pointer()
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ opts := vfs.SetStatOptions{
+ Stat: linux.Statx{
+ Mask: linux.STATX_ATIME | linux.STATX_MTIME,
+ },
+ }
+ if timesAddr == 0 {
+ opts.Stat.Atime.Nsec = linux.UTIME_NOW
+ opts.Stat.Mtime.Nsec = linux.UTIME_NOW
+ } else {
+ var times [2]linux.Timeval
+ if _, err := t.CopyIn(timesAddr, &times); err != nil {
+ return 0, nil, err
+ }
+ opts.Stat.Atime = linux.StatxTimestamp{
+ Sec: times[0].Sec,
+ Nsec: uint32(times[0].Usec * 1000),
+ }
+ opts.Stat.Mtime = linux.StatxTimestamp{
+ Sec: times[1].Sec,
+ Nsec: uint32(times[1].Usec * 1000),
+ }
+ }
+
+ return 0, nil, setstatat(t, linux.AT_FDCWD, path, disallowEmptyPath, followFinalSymlink, &opts)
+}
+
+// Utimensat implements Linux syscall utimensat(2).
+func Utimensat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ pathAddr := args[1].Pointer()
+ timesAddr := args[2].Pointer()
+ flags := args[3].Int()
+
+ if flags&^linux.AT_SYMLINK_NOFOLLOW != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ var opts vfs.SetStatOptions
+ if err := populateSetStatOptionsForUtimens(t, timesAddr, &opts); err != nil {
+ return 0, nil, err
+ }
+
+ return 0, nil, setstatat(t, dirfd, path, disallowEmptyPath, followFinalSymlink, &opts)
+}
+
+// Futimens implements Linux syscall futimens(2).
+func Futimens(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ timesAddr := args[1].Pointer()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ var opts vfs.SetStatOptions
+ if err := populateSetStatOptionsForUtimens(t, timesAddr, &opts); err != nil {
+ return 0, nil, err
+ }
+
+ return 0, nil, file.SetStat(t, opts)
+}
+
+func populateSetStatOptionsForUtimens(t *kernel.Task, timesAddr usermem.Addr, opts *vfs.SetStatOptions) error {
+ if timesAddr == 0 {
+ opts.Stat.Mask = linux.STATX_ATIME | linux.STATX_MTIME
+ opts.Stat.Atime.Nsec = linux.UTIME_NOW
+ opts.Stat.Mtime.Nsec = linux.UTIME_NOW
+ return nil
+ }
+ var times [2]linux.Timespec
+ if _, err := t.CopyIn(timesAddr, &times); err != nil {
+ return err
+ }
+ if times[0].Nsec != linux.UTIME_OMIT {
+ opts.Stat.Mask |= linux.STATX_ATIME
+ opts.Stat.Atime = linux.StatxTimestamp{
+ Sec: times[0].Sec,
+ Nsec: uint32(times[0].Nsec),
+ }
+ }
+ if times[1].Nsec != linux.UTIME_OMIT {
+ opts.Stat.Mask |= linux.STATX_MTIME
+ opts.Stat.Mtime = linux.StatxTimestamp{
+ Sec: times[1].Sec,
+ Nsec: uint32(times[1].Nsec),
+ }
+ }
+ return nil
+}
+
+func setstatat(t *kernel.Task, dirfd int32, path fspath.Path, shouldAllowEmptyPath shouldAllowEmptyPath, shouldFollowFinalSymlink shouldFollowFinalSymlink, opts *vfs.SetStatOptions) error {
+ root := t.FSContext().RootDirectoryVFS2()
+ defer root.DecRef()
+ start := root
+ if !path.Absolute {
+ if !path.HasComponents() && !bool(shouldAllowEmptyPath) {
+ return syserror.ENOENT
+ }
+ if dirfd == linux.AT_FDCWD {
+ start = t.FSContext().WorkingDirectoryVFS2()
+ defer start.DecRef()
+ } else {
+ dirfile := t.GetFileVFS2(dirfd)
+ if dirfile == nil {
+ return syserror.EBADF
+ }
+ if !path.HasComponents() {
+ // Use FileDescription.SetStat() instead of
+ // VirtualFilesystem.SetStatAt(), since the former may be able
+ // to use opened file state to expedite the SetStat.
+ err := dirfile.SetStat(t, *opts)
+ dirfile.DecRef()
+ return err
+ }
+ start = dirfile.VirtualDentry()
+ start.IncRef()
+ defer start.DecRef()
+ dirfile.DecRef()
+ }
+ }
+ return t.Kernel().VFS().SetStatAt(t, t.Credentials(), &vfs.PathOperation{
+ Root: root,
+ Start: start,
+ Path: path,
+ FollowFinalSymlink: bool(shouldFollowFinalSymlink),
+ }, opts)
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/stat.go b/pkg/sentry/syscalls/linux/vfs2/stat.go
new file mode 100644
index 000000000..dca8d7011
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/stat.go
@@ -0,0 +1,346 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/fspath"
+ "gvisor.dev/gvisor/pkg/gohacks"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+// Stat implements Linux syscall stat(2).
+func Stat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ statAddr := args[1].Pointer()
+ return 0, nil, fstatat(t, linux.AT_FDCWD, pathAddr, statAddr, 0 /* flags */)
+}
+
+// Lstat implements Linux syscall lstat(2).
+func Lstat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ statAddr := args[1].Pointer()
+ return 0, nil, fstatat(t, linux.AT_FDCWD, pathAddr, statAddr, linux.AT_SYMLINK_NOFOLLOW)
+}
+
+// Newfstatat implements Linux syscall newfstatat, which backs fstatat(2).
+func Newfstatat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ pathAddr := args[1].Pointer()
+ statAddr := args[2].Pointer()
+ flags := args[3].Int()
+ return 0, nil, fstatat(t, dirfd, pathAddr, statAddr, flags)
+}
+
+func fstatat(t *kernel.Task, dirfd int32, pathAddr, statAddr usermem.Addr, flags int32) error {
+ if flags&^(linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW) != 0 {
+ return syserror.EINVAL
+ }
+
+ opts := vfs.StatOptions{
+ Mask: linux.STATX_BASIC_STATS,
+ }
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return err
+ }
+
+ root := t.FSContext().RootDirectoryVFS2()
+ defer root.DecRef()
+ start := root
+ if !path.Absolute {
+ if !path.HasComponents() && flags&linux.AT_EMPTY_PATH == 0 {
+ return syserror.ENOENT
+ }
+ if dirfd == linux.AT_FDCWD {
+ start = t.FSContext().WorkingDirectoryVFS2()
+ defer start.DecRef()
+ } else {
+ dirfile := t.GetFileVFS2(dirfd)
+ if dirfile == nil {
+ return syserror.EBADF
+ }
+ if !path.HasComponents() {
+ // Use FileDescription.Stat() instead of
+ // VirtualFilesystem.StatAt() for fstatat(fd, ""), since the
+ // former may be able to use opened file state to expedite the
+ // Stat.
+ statx, err := dirfile.Stat(t, opts)
+ dirfile.DecRef()
+ if err != nil {
+ return err
+ }
+ var stat linux.Stat
+ convertStatxToUserStat(t, &statx, &stat)
+ return stat.CopyOut(t, statAddr)
+ }
+ start = dirfile.VirtualDentry()
+ start.IncRef()
+ defer start.DecRef()
+ dirfile.DecRef()
+ }
+ }
+
+ statx, err := t.Kernel().VFS().StatAt(t, t.Credentials(), &vfs.PathOperation{
+ Root: root,
+ Start: start,
+ Path: path,
+ FollowFinalSymlink: flags&linux.AT_SYMLINK_NOFOLLOW == 0,
+ }, &opts)
+ if err != nil {
+ return err
+ }
+ var stat linux.Stat
+ convertStatxToUserStat(t, &statx, &stat)
+ return stat.CopyOut(t, statAddr)
+}
+
+// This takes both input and output as pointer arguments to avoid copying large
+// structs.
+func convertStatxToUserStat(t *kernel.Task, statx *linux.Statx, stat *linux.Stat) {
+ // Linux just copies fields from struct kstat without regard to struct
+ // kstat::result_mask (fs/stat.c:cp_new_stat()), so we do too.
+ userns := t.UserNamespace()
+ *stat = linux.Stat{
+ Dev: uint64(linux.MakeDeviceID(uint16(statx.DevMajor), statx.DevMinor)),
+ Ino: statx.Ino,
+ Nlink: uint64(statx.Nlink),
+ Mode: uint32(statx.Mode),
+ UID: uint32(auth.KUID(statx.UID).In(userns).OrOverflow()),
+ GID: uint32(auth.KGID(statx.GID).In(userns).OrOverflow()),
+ Rdev: uint64(linux.MakeDeviceID(uint16(statx.RdevMajor), statx.RdevMinor)),
+ Size: int64(statx.Size),
+ Blksize: int64(statx.Blksize),
+ Blocks: int64(statx.Blocks),
+ ATime: timespecFromStatxTimestamp(statx.Atime),
+ MTime: timespecFromStatxTimestamp(statx.Mtime),
+ CTime: timespecFromStatxTimestamp(statx.Ctime),
+ }
+}
+
+func timespecFromStatxTimestamp(sxts linux.StatxTimestamp) linux.Timespec {
+ return linux.Timespec{
+ Sec: sxts.Sec,
+ Nsec: int64(sxts.Nsec),
+ }
+}
+
+// Fstat implements Linux syscall fstat(2).
+func Fstat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ statAddr := args[1].Pointer()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ statx, err := file.Stat(t, vfs.StatOptions{
+ Mask: linux.STATX_BASIC_STATS,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+ var stat linux.Stat
+ convertStatxToUserStat(t, &statx, &stat)
+ return 0, nil, stat.CopyOut(t, statAddr)
+}
+
+// Statx implements Linux syscall statx(2).
+func Statx(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ pathAddr := args[1].Pointer()
+ flags := args[2].Int()
+ mask := args[3].Uint()
+ statxAddr := args[4].Pointer()
+
+ if flags&^(linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ opts := vfs.StatOptions{
+ Mask: mask,
+ Sync: uint32(flags & linux.AT_STATX_SYNC_TYPE),
+ }
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ root := t.FSContext().RootDirectoryVFS2()
+ defer root.DecRef()
+ start := root
+ if !path.Absolute {
+ if !path.HasComponents() && flags&linux.AT_EMPTY_PATH == 0 {
+ return 0, nil, syserror.ENOENT
+ }
+ if dirfd == linux.AT_FDCWD {
+ start = t.FSContext().WorkingDirectoryVFS2()
+ defer start.DecRef()
+ } else {
+ dirfile := t.GetFileVFS2(dirfd)
+ if dirfile == nil {
+ return 0, nil, syserror.EBADF
+ }
+ if !path.HasComponents() {
+ // Use FileDescription.Stat() instead of
+ // VirtualFilesystem.StatAt() for statx(fd, ""), since the
+ // former may be able to use opened file state to expedite the
+ // Stat.
+ statx, err := dirfile.Stat(t, opts)
+ dirfile.DecRef()
+ if err != nil {
+ return 0, nil, err
+ }
+ userifyStatx(t, &statx)
+ return 0, nil, statx.CopyOut(t, statxAddr)
+ }
+ start = dirfile.VirtualDentry()
+ start.IncRef()
+ defer start.DecRef()
+ dirfile.DecRef()
+ }
+ }
+
+ statx, err := t.Kernel().VFS().StatAt(t, t.Credentials(), &vfs.PathOperation{
+ Root: root,
+ Start: start,
+ Path: path,
+ FollowFinalSymlink: flags&linux.AT_SYMLINK_NOFOLLOW == 0,
+ }, &opts)
+ if err != nil {
+ return 0, nil, err
+ }
+ userifyStatx(t, &statx)
+ return 0, nil, statx.CopyOut(t, statxAddr)
+}
+
+func userifyStatx(t *kernel.Task, statx *linux.Statx) {
+ userns := t.UserNamespace()
+ statx.UID = uint32(auth.KUID(statx.UID).In(userns).OrOverflow())
+ statx.GID = uint32(auth.KGID(statx.GID).In(userns).OrOverflow())
+}
+
+// Readlink implements Linux syscall readlink(2).
+func Readlink(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ bufAddr := args[1].Pointer()
+ size := args[2].SizeT()
+ return readlinkat(t, linux.AT_FDCWD, pathAddr, bufAddr, size)
+}
+
+// Access implements Linux syscall access(2).
+func Access(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ // FIXME(jamieliu): actually implement
+ return 0, nil, nil
+}
+
+// Faccessat implements Linux syscall access(2).
+func Faccessat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ // FIXME(jamieliu): actually implement
+ return 0, nil, nil
+}
+
+// Readlinkat implements Linux syscall mknodat(2).
+func Readlinkat(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ dirfd := args[0].Int()
+ pathAddr := args[1].Pointer()
+ bufAddr := args[2].Pointer()
+ size := args[3].SizeT()
+ return readlinkat(t, dirfd, pathAddr, bufAddr, size)
+}
+
+func readlinkat(t *kernel.Task, dirfd int32, pathAddr, bufAddr usermem.Addr, size uint) (uintptr, *kernel.SyscallControl, error) {
+ if int(size) <= 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+ // "Since Linux 2.6.39, pathname can be an empty string, in which case the
+ // call operates on the symbolic link referred to by dirfd ..." -
+ // readlinkat(2)
+ tpop, err := getTaskPathOperation(t, dirfd, path, allowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ target, err := t.Kernel().VFS().ReadlinkAt(t, t.Credentials(), &tpop.pop)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ if len(target) > int(size) {
+ target = target[:size]
+ }
+ n, err := t.CopyOutBytes(bufAddr, gohacks.ImmutableBytesFromString(target))
+ if n == 0 {
+ return 0, nil, err
+ }
+ return uintptr(n), nil, nil
+}
+
+// Statfs implements Linux syscall statfs(2).
+func Statfs(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ bufAddr := args[1].Pointer()
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+ tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, followFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ statfs, err := t.Kernel().VFS().StatFSAt(t, t.Credentials(), &tpop.pop)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ return 0, nil, statfs.CopyOut(t, bufAddr)
+}
+
+// Fstatfs implements Linux syscall fstatfs(2).
+func Fstatfs(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ bufAddr := args[1].Pointer()
+
+ tpop, err := getTaskPathOperation(t, fd, fspath.Path{}, allowEmptyPath, nofollowFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ statfs, err := t.Kernel().VFS().StatFSAt(t, t.Credentials(), &tpop.pop)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ return 0, nil, statfs.CopyOut(t, bufAddr)
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/sync.go b/pkg/sentry/syscalls/linux/vfs2/sync.go
new file mode 100644
index 000000000..365250b0b
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/sync.go
@@ -0,0 +1,87 @@
+// 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 vfs2
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Sync implements Linux syscall sync(2).
+func Sync(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return 0, nil, t.Kernel().VFS().SyncAllFilesystems(t)
+}
+
+// Syncfs implements Linux syscall syncfs(2).
+func Syncfs(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ return 0, nil, file.SyncFS(t)
+}
+
+// Fsync implements Linux syscall fsync(2).
+func Fsync(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ return 0, nil, file.Sync(t)
+}
+
+// Fdatasync implements Linux syscall fdatasync(2).
+func Fdatasync(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ // TODO(gvisor.dev/issue/1897): Avoid writeback of unnecessary metadata.
+ return Fsync(t, args)
+}
+
+// SyncFileRange implements Linux syscall sync_file_range(2).
+func SyncFileRange(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ offset := args[1].Int64()
+ nbytes := args[2].Int64()
+ flags := args[3].Uint()
+
+ if offset < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+ if nbytes < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+ if flags&^(linux.SYNC_FILE_RANGE_WAIT_BEFORE|linux.SYNC_FILE_RANGE_WRITE|linux.SYNC_FILE_RANGE_WAIT_AFTER) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // TODO(gvisor.dev/issue/1897): Avoid writeback of data ranges outside of
+ // [offset, offset+nbytes).
+ return 0, nil, file.Sync(t)
+}
diff --git a/pkg/sentry/syscalls/linux/vfs2/sys_read.go b/pkg/sentry/syscalls/linux/vfs2/sys_read.go
deleted file mode 100644
index 7667524c7..000000000
--- a/pkg/sentry/syscalls/linux/vfs2/sys_read.go
+++ /dev/null
@@ -1,95 +0,0 @@
-// 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 vfs2
-
-import (
- "gvisor.dev/gvisor/pkg/sentry/arch"
- "gvisor.dev/gvisor/pkg/sentry/kernel"
- "gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
- "gvisor.dev/gvisor/pkg/sentry/vfs"
- "gvisor.dev/gvisor/pkg/syserror"
- "gvisor.dev/gvisor/pkg/usermem"
- "gvisor.dev/gvisor/pkg/waiter"
-)
-
-const (
- // EventMaskRead contains events that can be triggered on reads.
- EventMaskRead = waiter.EventIn | waiter.EventHUp | waiter.EventErr
-)
-
-// Read implements linux syscall read(2). Note that we try to get a buffer that
-// is exactly the size requested because some applications like qemu expect
-// they can do large reads all at once. Bug for bug. Same for other read
-// calls below.
-func Read(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
- fd := args[0].Int()
- addr := args[1].Pointer()
- size := args[2].SizeT()
-
- file := t.GetFileVFS2(fd)
- if file == nil {
- return 0, nil, syserror.EBADF
- }
- defer file.DecRef()
-
- // Check that the size is legitimate.
- si := int(size)
- if si < 0 {
- return 0, nil, syserror.EINVAL
- }
-
- // Get the destination of the read.
- dst, err := t.SingleIOSequence(addr, si, usermem.IOOpts{
- AddressSpaceActive: true,
- })
- if err != nil {
- return 0, nil, err
- }
-
- n, err := read(t, file, dst, vfs.ReadOptions{})
- t.IOUsage().AccountReadSyscall(n)
- return uintptr(n), nil, linux.HandleIOErrorVFS2(t, n != 0, err, kernel.ERESTARTSYS, "read", file)
-}
-
-func read(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
- n, err := file.Read(t, dst, opts)
- if err != syserror.ErrWouldBlock {
- return n, err
- }
-
- // Register for notifications.
- w, ch := waiter.NewChannelEntry(nil)
- file.EventRegister(&w, EventMaskRead)
-
- total := n
- for {
- // Shorten dst to reflect bytes previously read.
- dst = dst.DropFirst(int(n))
-
- // Issue the request and break out if it completes with anything other than
- // "would block".
- n, err := file.Read(t, dst, opts)
- total += n
- if err != syserror.ErrWouldBlock {
- break
- }
- if err := t.Block(ch); err != nil {
- break
- }
- }
- file.EventUnregister(&w)
-
- return total, err
-}
diff --git a/pkg/sentry/syscalls/linux/vfs2/xattr.go b/pkg/sentry/syscalls/linux/vfs2/xattr.go
new file mode 100644
index 000000000..89e9ff4d7
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/xattr.go
@@ -0,0 +1,353 @@
+// 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 vfs2
+
+import (
+ "bytes"
+
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/gohacks"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+)
+
+// Listxattr implements Linux syscall listxattr(2).
+func Listxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return listxattr(t, args, followFinalSymlink)
+}
+
+// Llistxattr implements Linux syscall llistxattr(2).
+func Llistxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return listxattr(t, args, nofollowFinalSymlink)
+}
+
+func listxattr(t *kernel.Task, args arch.SyscallArguments, shouldFollowFinalSymlink shouldFollowFinalSymlink) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ listAddr := args[1].Pointer()
+ size := args[2].SizeT()
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+ tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, shouldFollowFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ names, err := t.Kernel().VFS().ListxattrAt(t, t.Credentials(), &tpop.pop)
+ if err != nil {
+ return 0, nil, err
+ }
+ n, err := copyOutXattrNameList(t, listAddr, size, names)
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(n), nil, nil
+}
+
+// Flistxattr implements Linux syscall flistxattr(2).
+func Flistxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ listAddr := args[1].Pointer()
+ size := args[2].SizeT()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ names, err := file.Listxattr(t)
+ if err != nil {
+ return 0, nil, err
+ }
+ n, err := copyOutXattrNameList(t, listAddr, size, names)
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(n), nil, nil
+}
+
+// Getxattr implements Linux syscall getxattr(2).
+func Getxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return getxattr(t, args, followFinalSymlink)
+}
+
+// Lgetxattr implements Linux syscall lgetxattr(2).
+func Lgetxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return getxattr(t, args, nofollowFinalSymlink)
+}
+
+func getxattr(t *kernel.Task, args arch.SyscallArguments, shouldFollowFinalSymlink shouldFollowFinalSymlink) (uintptr, *kernel.SyscallControl, error) {
+ pathAddr := args[0].Pointer()
+ nameAddr := args[1].Pointer()
+ valueAddr := args[2].Pointer()
+ size := args[3].SizeT()
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+ tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, shouldFollowFinalSymlink)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer tpop.Release()
+
+ name, err := copyInXattrName(t, nameAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ value, err := t.Kernel().VFS().GetxattrAt(t, t.Credentials(), &tpop.pop, name)
+ if err != nil {
+ return 0, nil, err
+ }
+ n, err := copyOutXattrValue(t, valueAddr, size, value)
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(n), nil, nil
+}
+
+// Fgetxattr implements Linux syscall fgetxattr(2).
+func Fgetxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ nameAddr := args[1].Pointer()
+ valueAddr := args[2].Pointer()
+ size := args[3].SizeT()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ name, err := copyInXattrName(t, nameAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ value, err := file.Getxattr(t, name)
+ if err != nil {
+ return 0, nil, err
+ }
+ n, err := copyOutXattrValue(t, valueAddr, size, value)
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(n), nil, nil
+}
+
+// Setxattr implements Linux syscall setxattr(2).
+func Setxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return 0, nil, setxattr(t, args, followFinalSymlink)
+}
+
+// Lsetxattr implements Linux syscall lsetxattr(2).
+func Lsetxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return 0, nil, setxattr(t, args, nofollowFinalSymlink)
+}
+
+func setxattr(t *kernel.Task, args arch.SyscallArguments, shouldFollowFinalSymlink shouldFollowFinalSymlink) error {
+ pathAddr := args[0].Pointer()
+ nameAddr := args[1].Pointer()
+ valueAddr := args[2].Pointer()
+ size := args[3].SizeT()
+ flags := args[4].Int()
+
+ if flags&^(linux.XATTR_CREATE|linux.XATTR_REPLACE) != 0 {
+ return syserror.EINVAL
+ }
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return err
+ }
+ tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, shouldFollowFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer tpop.Release()
+
+ name, err := copyInXattrName(t, nameAddr)
+ if err != nil {
+ return err
+ }
+ value, err := copyInXattrValue(t, valueAddr, size)
+ if err != nil {
+ return err
+ }
+
+ return t.Kernel().VFS().SetxattrAt(t, t.Credentials(), &tpop.pop, &vfs.SetxattrOptions{
+ Name: name,
+ Value: value,
+ Flags: uint32(flags),
+ })
+}
+
+// Fsetxattr implements Linux syscall fsetxattr(2).
+func Fsetxattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ nameAddr := args[1].Pointer()
+ valueAddr := args[2].Pointer()
+ size := args[3].SizeT()
+ flags := args[4].Int()
+
+ if flags&^(linux.XATTR_CREATE|linux.XATTR_REPLACE) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ name, err := copyInXattrName(t, nameAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+ value, err := copyInXattrValue(t, valueAddr, size)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ return 0, nil, file.Setxattr(t, vfs.SetxattrOptions{
+ Name: name,
+ Value: value,
+ Flags: uint32(flags),
+ })
+}
+
+// Removexattr implements Linux syscall removexattr(2).
+func Removexattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return 0, nil, removexattr(t, args, followFinalSymlink)
+}
+
+// Lremovexattr implements Linux syscall lremovexattr(2).
+func Lremovexattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ return 0, nil, removexattr(t, args, nofollowFinalSymlink)
+}
+
+func removexattr(t *kernel.Task, args arch.SyscallArguments, shouldFollowFinalSymlink shouldFollowFinalSymlink) error {
+ pathAddr := args[0].Pointer()
+ nameAddr := args[1].Pointer()
+
+ path, err := copyInPath(t, pathAddr)
+ if err != nil {
+ return err
+ }
+ tpop, err := getTaskPathOperation(t, linux.AT_FDCWD, path, disallowEmptyPath, shouldFollowFinalSymlink)
+ if err != nil {
+ return err
+ }
+ defer tpop.Release()
+
+ name, err := copyInXattrName(t, nameAddr)
+ if err != nil {
+ return err
+ }
+
+ return t.Kernel().VFS().RemovexattrAt(t, t.Credentials(), &tpop.pop, name)
+}
+
+// Fremovexattr implements Linux syscall fremovexattr(2).
+func Fremovexattr(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ nameAddr := args[1].Pointer()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ name, err := copyInXattrName(t, nameAddr)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ return 0, nil, file.Removexattr(t, name)
+}
+
+func copyInXattrName(t *kernel.Task, nameAddr usermem.Addr) (string, error) {
+ name, err := t.CopyInString(nameAddr, linux.XATTR_NAME_MAX+1)
+ if err != nil {
+ if err == syserror.ENAMETOOLONG {
+ return "", syserror.ERANGE
+ }
+ return "", err
+ }
+ if len(name) == 0 {
+ return "", syserror.ERANGE
+ }
+ return name, nil
+}
+
+func copyOutXattrNameList(t *kernel.Task, listAddr usermem.Addr, size uint, names []string) (int, error) {
+ if size > linux.XATTR_LIST_MAX {
+ size = linux.XATTR_LIST_MAX
+ }
+ var buf bytes.Buffer
+ for _, name := range names {
+ buf.WriteString(name)
+ buf.WriteByte(0)
+ }
+ if size == 0 {
+ // Return the size that would be required to accomodate the list.
+ return buf.Len(), nil
+ }
+ if buf.Len() > int(size) {
+ if size >= linux.XATTR_LIST_MAX {
+ return 0, syserror.E2BIG
+ }
+ return 0, syserror.ERANGE
+ }
+ return t.CopyOutBytes(listAddr, buf.Bytes())
+}
+
+func copyInXattrValue(t *kernel.Task, valueAddr usermem.Addr, size uint) (string, error) {
+ if size > linux.XATTR_SIZE_MAX {
+ return "", syserror.E2BIG
+ }
+ buf := make([]byte, size)
+ if _, err := t.CopyInBytes(valueAddr, buf); err != nil {
+ return "", err
+ }
+ return gohacks.StringFromImmutableBytes(buf), nil
+}
+
+func copyOutXattrValue(t *kernel.Task, valueAddr usermem.Addr, size uint, value string) (int, error) {
+ if size > linux.XATTR_SIZE_MAX {
+ size = linux.XATTR_SIZE_MAX
+ }
+ if size == 0 {
+ // Return the size that would be required to accomodate the value.
+ return len(value), nil
+ }
+ if len(value) > int(size) {
+ if size >= linux.XATTR_SIZE_MAX {
+ return 0, syserror.E2BIG
+ }
+ return 0, syserror.ERANGE
+ }
+ return t.CopyOutBytes(valueAddr, gohacks.ImmutableBytesFromString(value))
+}