92 lines
2.8 KiB
Go
92 lines
2.8 KiB
Go
// Copyright 2018 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package proc
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import (
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"fmt"
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"io"
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"gvisor.dev/gvisor/pkg/abi/linux"
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"gvisor.dev/gvisor/pkg/context"
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"gvisor.dev/gvisor/pkg/sentry/fs"
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"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
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ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
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"gvisor.dev/gvisor/pkg/syserror"
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"gvisor.dev/gvisor/pkg/usermem"
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"gvisor.dev/gvisor/pkg/waiter"
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)
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// LINT.IfChange
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// uptime is a file containing the system uptime.
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//
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// +stateify savable
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type uptime struct {
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fsutil.SimpleFileInode
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// The "start time" of the sandbox.
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startTime ktime.Time
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}
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// newUptime returns a new uptime file.
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func newUptime(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
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u := &uptime{
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SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC),
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startTime: ktime.NowFromContext(ctx),
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}
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return newProcInode(ctx, u, msrc, fs.SpecialFile, nil)
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}
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// GetFile implements fs.InodeOperations.GetFile.
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func (u *uptime) GetFile(ctx context.Context, dirent *fs.Dirent, flags fs.FileFlags) (*fs.File, error) {
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return fs.NewFile(ctx, dirent, flags, &uptimeFile{startTime: u.startTime}), nil
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}
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// +stateify savable
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type uptimeFile struct {
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fsutil.FileGenericSeek `state:"nosave"`
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fsutil.FileNoIoctl `state:"nosave"`
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fsutil.FileNoMMap `state:"nosave"`
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fsutil.FileNoSplice `state:"nosave"`
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fsutil.FileNoWrite `state:"nosave"`
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fsutil.FileNoopFlush `state:"nosave"`
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fsutil.FileNoopFsync `state:"nosave"`
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fsutil.FileNoopRelease `state:"nosave"`
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fsutil.FileNotDirReaddir `state:"nosave"`
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fsutil.FileUseInodeUnstableAttr `state:"nosave"`
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waiter.AlwaysReady `state:"nosave"`
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startTime ktime.Time
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}
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// Read implements fs.FileOperations.Read.
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func (f *uptimeFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
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if offset < 0 {
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return 0, syserror.EINVAL
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}
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now := ktime.NowFromContext(ctx)
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// Pretend that we've spent zero time sleeping (second number).
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s := []byte(fmt.Sprintf("%.2f 0.00\n", now.Sub(f.startTime).Seconds()))
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if offset >= int64(len(s)) {
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return 0, io.EOF
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}
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n, err := dst.CopyOut(ctx, s[offset:])
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return int64(n), err
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}
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// LINT.ThenChange(../../fsimpl/proc/tasks_files.go)
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