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-rw-r--r--pkg/sentry/kernel/kernel.go28
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/BUILD1
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go6
-rw-r--r--pkg/sentry/syscalls/linux/vfs2/sys_timerfd.go123
-rw-r--r--pkg/sentry/vfs/BUILD2
-rw-r--r--pkg/sentry/vfs/file_description.go7
-rw-r--r--pkg/sentry/vfs/timerfd.go142
7 files changed, 295 insertions, 14 deletions
diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go
index ba8935a82..de8a95854 100644
--- a/pkg/sentry/kernel/kernel.go
+++ b/pkg/sentry/kernel/kernel.go
@@ -1044,14 +1044,17 @@ func (k *Kernel) pauseTimeLocked() {
// This means we'll iterate FDTables shared by multiple tasks repeatedly,
// but ktime.Timer.Pause is idempotent so this is harmless.
if t.fdTable != nil {
- // TODO(gvisor.dev/issue/1663): Add save support for VFS2.
- if !VFS2Enabled {
- t.fdTable.forEach(func(_ int32, file *fs.File, _ *vfs.FileDescription, _ FDFlags) {
+ t.fdTable.forEach(func(_ int32, file *fs.File, fd *vfs.FileDescription, _ FDFlags) {
+ if VFS2Enabled {
+ if tfd, ok := fd.Impl().(*vfs.TimerFileDescription); ok {
+ tfd.PauseTimer()
+ }
+ } else {
if tfd, ok := file.FileOperations.(*timerfd.TimerOperations); ok {
tfd.PauseTimer()
}
- })
- }
+ }
+ })
}
}
k.timekeeper.PauseUpdates()
@@ -1076,15 +1079,18 @@ func (k *Kernel) resumeTimeLocked() {
it.ResumeTimer()
}
}
- // TODO(gvisor.dev/issue/1663): Add save support for VFS2.
- if !VFS2Enabled {
- if t.fdTable != nil {
- t.fdTable.forEach(func(_ int32, file *fs.File, _ *vfs.FileDescription, _ FDFlags) {
+ if t.fdTable != nil {
+ t.fdTable.forEach(func(_ int32, file *fs.File, fd *vfs.FileDescription, _ FDFlags) {
+ if VFS2Enabled {
+ if tfd, ok := fd.Impl().(*vfs.TimerFileDescription); ok {
+ tfd.ResumeTimer()
+ }
+ } else {
if tfd, ok := file.FileOperations.(*timerfd.TimerOperations); ok {
tfd.ResumeTimer()
}
- })
- }
+ }
+ })
}
}
}
diff --git a/pkg/sentry/syscalls/linux/vfs2/BUILD b/pkg/sentry/syscalls/linux/vfs2/BUILD
index 2eb210014..0004e60d9 100644
--- a/pkg/sentry/syscalls/linux/vfs2/BUILD
+++ b/pkg/sentry/syscalls/linux/vfs2/BUILD
@@ -25,6 +25,7 @@ go_library(
"stat_amd64.go",
"stat_arm64.go",
"sync.go",
+ "sys_timerfd.go",
"xattr.go",
],
marshal = True,
diff --git a/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go b/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go
index 7d220bc20..63febc2f7 100644
--- a/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go
+++ b/pkg/sentry/syscalls/linux/vfs2/linux64_override_amd64.go
@@ -139,11 +139,11 @@ func Override(table map[uintptr]kernel.Syscall) {
table[280] = syscalls.Supported("utimensat", Utimensat)
table[281] = syscalls.Supported("epoll_pwait", EpollPwait)
delete(table, 282) // signalfd
- delete(table, 283) // timerfd_create
+ table[283] = syscalls.Supported("timerfd_create", TimerfdCreate)
delete(table, 284) // eventfd
delete(table, 285) // fallocate
- delete(table, 286) // timerfd_settime
- delete(table, 287) // timerfd_gettime
+ table[286] = syscalls.Supported("timerfd_settime", TimerfdSettime)
+ table[287] = syscalls.Supported("timerfd_gettime", TimerfdGettime)
delete(table, 288) // accept4
delete(table, 289) // signalfd4
delete(table, 290) // eventfd2
diff --git a/pkg/sentry/syscalls/linux/vfs2/sys_timerfd.go b/pkg/sentry/syscalls/linux/vfs2/sys_timerfd.go
new file mode 100644
index 000000000..7938a5249
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/sys_timerfd.go
@@ -0,0 +1,123 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package vfs2
+
+import (
+ "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"
+)
+
+// TimerfdCreate implements Linux syscall timerfd_create(2).
+func TimerfdCreate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ clockID := args[0].Int()
+ flags := args[1].Int()
+
+ if flags&^(linux.TFD_CLOEXEC|linux.TFD_NONBLOCK) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ var fileFlags uint32
+ if flags&linux.TFD_NONBLOCK != 0 {
+ fileFlags = linux.O_NONBLOCK
+ }
+
+ var clock ktime.Clock
+ switch clockID {
+ case linux.CLOCK_REALTIME:
+ clock = t.Kernel().RealtimeClock()
+ case linux.CLOCK_MONOTONIC, linux.CLOCK_BOOTTIME:
+ clock = t.Kernel().MonotonicClock()
+ default:
+ return 0, nil, syserror.EINVAL
+ }
+ file, err := t.Kernel().VFS().NewTimerFD(clock, fileFlags)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer file.DecRef()
+ fd, err := t.NewFDFromVFS2(0, file, kernel.FDFlags{
+ CloseOnExec: flags&linux.TFD_CLOEXEC != 0,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+ return uintptr(fd), nil, nil
+}
+
+// TimerfdSettime implements Linux syscall timerfd_settime(2).
+func TimerfdSettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ flags := args[1].Int()
+ newValAddr := args[2].Pointer()
+ oldValAddr := args[3].Pointer()
+
+ if flags&^(linux.TFD_TIMER_ABSTIME) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ tfd, ok := file.Impl().(*vfs.TimerFileDescription)
+ if !ok {
+ return 0, nil, syserror.EINVAL
+ }
+
+ var newVal linux.Itimerspec
+ if _, err := t.CopyIn(newValAddr, &newVal); err != nil {
+ return 0, nil, err
+ }
+ newS, err := ktime.SettingFromItimerspec(newVal, flags&linux.TFD_TIMER_ABSTIME != 0, tfd.Clock())
+ if err != nil {
+ return 0, nil, err
+ }
+ tm, oldS := tfd.SetTime(newS)
+ if oldValAddr != 0 {
+ oldVal := ktime.ItimerspecFromSetting(tm, oldS)
+ if _, err := t.CopyOut(oldValAddr, &oldVal); err != nil {
+ return 0, nil, err
+ }
+ }
+ return 0, nil, nil
+}
+
+// TimerfdGettime implements Linux syscall timerfd_gettime(2).
+func TimerfdGettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ curValAddr := args[1].Pointer()
+
+ file := t.GetFileVFS2(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ tfd, ok := file.Impl().(*vfs.TimerFileDescription)
+ if !ok {
+ return 0, nil, syserror.EINVAL
+ }
+
+ tm, s := tfd.GetTime()
+ curVal := ktime.ItimerspecFromSetting(tm, s)
+ _, err := t.CopyOut(curValAddr, &curVal)
+ return 0, nil, err
+}
diff --git a/pkg/sentry/vfs/BUILD b/pkg/sentry/vfs/BUILD
index bf4d27c7d..9aeb83fb0 100644
--- a/pkg/sentry/vfs/BUILD
+++ b/pkg/sentry/vfs/BUILD
@@ -36,6 +36,7 @@ go_library(
"pathname.go",
"permissions.go",
"resolving_path.go",
+ "timerfd.go",
"vfs.go",
],
visibility = ["//pkg/sentry:internal"],
@@ -51,6 +52,7 @@ go_library(
"//pkg/sentry/fs",
"//pkg/sentry/fs/lock",
"//pkg/sentry/kernel/auth",
+ "//pkg/sentry/kernel/time",
"//pkg/sentry/limits",
"//pkg/sentry/memmap",
"//pkg/sentry/socket/unix/transport",
diff --git a/pkg/sentry/vfs/file_description.go b/pkg/sentry/vfs/file_description.go
index 28e93a441..20c545fca 100644
--- a/pkg/sentry/vfs/file_description.go
+++ b/pkg/sentry/vfs/file_description.go
@@ -91,6 +91,10 @@ type FileDescriptionOptions struct {
// ESPIPE.
DenyPWrite bool
+ // if InvalidWrite is true, calls to FileDescription.Write() return
+ // EINVAL.
+ InvalidWrite bool
+
// If UseDentryMetadata is true, calls to FileDescription methods that
// interact with file and filesystem metadata (Stat, SetStat, StatFS,
// Listxattr, Getxattr, Setxattr, Removexattr) are implemented by calling
@@ -562,6 +566,9 @@ func (fd *FileDescription) PWrite(ctx context.Context, src usermem.IOSequence, o
// Write is similar to PWrite, but does not specify an offset.
func (fd *FileDescription) Write(ctx context.Context, src usermem.IOSequence, opts WriteOptions) (int64, error) {
+ if fd.opts.InvalidWrite {
+ return 0, syserror.EINVAL
+ }
if !fd.writable {
return 0, syserror.EBADF
}
diff --git a/pkg/sentry/vfs/timerfd.go b/pkg/sentry/vfs/timerfd.go
new file mode 100644
index 000000000..42b880656
--- /dev/null
+++ b/pkg/sentry/vfs/timerfd.go
@@ -0,0 +1,142 @@
+// 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 vfs
+
+import (
+ "sync/atomic"
+
+ "gvisor.dev/gvisor/pkg/context"
+ ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/usermem"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+// TimerFileDescription implements FileDescriptionImpl for timer fds. It also
+// implements ktime.TimerListener.
+type TimerFileDescription struct {
+ vfsfd FileDescription
+ FileDescriptionDefaultImpl
+ DentryMetadataFileDescriptionImpl
+
+ events waiter.Queue
+ timer *ktime.Timer
+
+ // val is the number of timer expirations since the last successful
+ // call to PRead, or SetTime. val must be accessed using atomic memory
+ // operations.
+ val uint64
+}
+
+var _ FileDescriptionImpl = (*TimerFileDescription)(nil)
+var _ ktime.TimerListener = (*TimerFileDescription)(nil)
+
+// NewTimerFD returns a new timer fd.
+func (vfs *VirtualFilesystem) NewTimerFD(clock ktime.Clock, flags uint32) (*FileDescription, error) {
+ vd := vfs.NewAnonVirtualDentry("[timerfd]")
+ defer vd.DecRef()
+ tfd := &TimerFileDescription{}
+ tfd.timer = ktime.NewTimer(clock, tfd)
+ if err := tfd.vfsfd.Init(tfd, flags, vd.Mount(), vd.Dentry(), &FileDescriptionOptions{
+ UseDentryMetadata: true,
+ DenyPRead: true,
+ DenyPWrite: true,
+ InvalidWrite: true,
+ }); err != nil {
+ return nil, err
+ }
+ return &tfd.vfsfd, nil
+}
+
+// Read implements FileDescriptionImpl.Read.
+func (tfd *TimerFileDescription) Read(ctx context.Context, dst usermem.IOSequence, opts ReadOptions) (int64, error) {
+ const sizeofUint64 = 8
+ if dst.NumBytes() < sizeofUint64 {
+ return 0, syserror.EINVAL
+ }
+ if val := atomic.SwapUint64(&tfd.val, 0); val != 0 {
+ var buf [sizeofUint64]byte
+ usermem.ByteOrder.PutUint64(buf[:], val)
+ if _, err := dst.CopyOut(ctx, buf[:]); err != nil {
+ // Linux does not undo consuming the number of
+ // expirations even if writing to userspace fails.
+ return 0, err
+ }
+ return sizeofUint64, nil
+ }
+ return 0, syserror.ErrWouldBlock
+}
+
+// Clock returns the timer fd's Clock.
+func (tfd *TimerFileDescription) Clock() ktime.Clock {
+ return tfd.timer.Clock()
+}
+
+// GetTime returns the associated Timer's setting and the time at which it was
+// observed.
+func (tfd *TimerFileDescription) GetTime() (ktime.Time, ktime.Setting) {
+ return tfd.timer.Get()
+}
+
+// SetTime atomically changes the associated Timer's setting, resets the number
+// of expirations to 0, and returns the previous setting and the time at which
+// it was observed.
+func (tfd *TimerFileDescription) SetTime(s ktime.Setting) (ktime.Time, ktime.Setting) {
+ return tfd.timer.SwapAnd(s, func() { atomic.StoreUint64(&tfd.val, 0) })
+}
+
+// Readiness implements waiter.Waitable.Readiness.
+func (tfd *TimerFileDescription) Readiness(mask waiter.EventMask) waiter.EventMask {
+ var ready waiter.EventMask
+ if atomic.LoadUint64(&tfd.val) != 0 {
+ ready |= waiter.EventIn
+ }
+ return ready
+}
+
+// EventRegister implements waiter.Waitable.EventRegister.
+func (tfd *TimerFileDescription) EventRegister(e *waiter.Entry, mask waiter.EventMask) {
+ tfd.events.EventRegister(e, mask)
+}
+
+// EventUnregister implements waiter.Waitable.EventUnregister.
+func (tfd *TimerFileDescription) EventUnregister(e *waiter.Entry) {
+ tfd.events.EventUnregister(e)
+}
+
+// PauseTimer pauses the associated Timer.
+func (tfd *TimerFileDescription) PauseTimer() {
+ tfd.timer.Pause()
+}
+
+// ResumeTimer resumes the associated Timer.
+func (tfd *TimerFileDescription) ResumeTimer() {
+ tfd.timer.Resume()
+}
+
+// Release implements FileDescriptionImpl.Release()
+func (tfd *TimerFileDescription) Release() {
+ tfd.timer.Destroy()
+}
+
+// Notify implements ktime.TimerListener.Notify.
+func (tfd *TimerFileDescription) Notify(exp uint64, setting ktime.Setting) (ktime.Setting, bool) {
+ atomic.AddUint64(&tfd.val, exp)
+ tfd.events.Notify(waiter.EventIn)
+ return ktime.Setting{}, false
+}
+
+// Destroy implements ktime.TimerListener.Destroy.
+func (tfd *TimerFileDescription) Destroy() {}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 07:56:46 +0000