Port timerfd to VFS2.

PiperOrigin-RevId: 305067208

3 files changed, 127 insertions, 3 deletions

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
+}