diff options
| author | gVisor bot <gvisor-bot@google.com> | 2019-06-02 06:44:55 +0000 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2019-06-02 06:44:55 +0000 |
| commit | ceb0d792f328d1fc0692197d8856a43c3936a571 (patch) | |
| tree | 83155f302eff44a78bcc30a3a08f4efe59a79379 /pkg/sentry/syscalls/linux/sys_eventfd.go | |
| parent | deb7ecf1e46862d54f4b102f2d163cfbcfc37f3b (diff) | |
| parent | 216da0b733dbed9aad9b2ab92ac75bcb906fd7ee (diff) | |
Merge 216da0b7 (automated)
Diffstat (limited to 'pkg/sentry/syscalls/linux/sys_eventfd.go')
| -rw-r--r-- | pkg/sentry/syscalls/linux/sys_eventfd.go | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/pkg/sentry/syscalls/linux/sys_eventfd.go b/pkg/sentry/syscalls/linux/sys_eventfd.go new file mode 100644 index 000000000..ca4ead488 --- /dev/null +++ b/pkg/sentry/syscalls/linux/sys_eventfd.go @@ -0,0 +1,65 @@ +// 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 linux + +import ( + "syscall" + + "gvisor.googlesource.com/gvisor/pkg/sentry/arch" + "gvisor.googlesource.com/gvisor/pkg/sentry/fs" + "gvisor.googlesource.com/gvisor/pkg/sentry/kernel" + "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/eventfd" +) + +const ( + // EFD_SEMAPHORE is a flag used in syscall eventfd(2) and eventfd2(2). Please + // see its man page for more information. + EFD_SEMAPHORE = 1 + EFD_NONBLOCK = 0x800 + EFD_CLOEXEC = 0x80000 +) + +// Eventfd2 implements linux syscall eventfd2(2). +func Eventfd2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + initVal := args[0].Int() + flags := uint(args[1].Uint()) + allOps := uint(EFD_SEMAPHORE | EFD_NONBLOCK | EFD_CLOEXEC) + + if flags & ^allOps != 0 { + return 0, nil, syscall.EINVAL + } + + event := eventfd.New(t, uint64(initVal), flags&EFD_SEMAPHORE != 0) + event.SetFlags(fs.SettableFileFlags{ + NonBlocking: flags&EFD_NONBLOCK != 0, + }) + defer event.DecRef() + + fd, err := t.FDMap().NewFDFrom(0, event, kernel.FDFlags{ + CloseOnExec: flags&EFD_CLOEXEC != 0, + }, + t.ThreadGroup().Limits()) + if err != nil { + return 0, nil, err + } + + return uintptr(fd), nil, nil +} + +// Eventfd implements linux syscall eventfd(2). +func Eventfd(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) { + args[1].Value = 0 + return Eventfd2(t, args) +} |