1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
// Copyright 2019 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 proc
import (
"sort"
"strconv"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
"gvisor.dev/gvisor/pkg/sentry/kernel"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
)
// subtasksInode represents the inode for /proc/[pid]/task/ directory.
//
// +stateify savable
type subtasksInode struct {
kernfs.InodeNotSymlink
kernfs.InodeDirectoryNoNewChildren
kernfs.InodeAttrs
kernfs.OrderedChildren
kernfs.AlwaysValid
task *kernel.Task
pidns *kernel.PIDNamespace
inoGen InoGenerator
cgroupControllers map[string]string
}
var _ kernfs.Inode = (*subtasksInode)(nil)
func newSubtasks(task *kernel.Task, pidns *kernel.PIDNamespace, inoGen InoGenerator, cgroupControllers map[string]string) *kernfs.Dentry {
subInode := &subtasksInode{
task: task,
pidns: pidns,
inoGen: inoGen,
cgroupControllers: cgroupControllers,
}
// Note: credentials are overridden by taskOwnedInode.
subInode.InodeAttrs.Init(task.Credentials(), inoGen.NextIno(), linux.ModeDirectory|0555)
subInode.OrderedChildren.Init(kernfs.OrderedChildrenOptions{})
inode := &taskOwnedInode{Inode: subInode, owner: task}
dentry := &kernfs.Dentry{}
dentry.Init(inode)
return dentry
}
// Lookup implements kernfs.inodeDynamicLookup.
func (i *subtasksInode) Lookup(ctx context.Context, name string) (*vfs.Dentry, error) {
tid, err := strconv.ParseUint(name, 10, 32)
if err != nil {
return nil, syserror.ENOENT
}
subTask := i.pidns.TaskWithID(kernel.ThreadID(tid))
if subTask == nil {
return nil, syserror.ENOENT
}
if subTask.ThreadGroup() != i.task.ThreadGroup() {
return nil, syserror.ENOENT
}
subTaskDentry := newTaskInode(i.inoGen, subTask, i.pidns, false, i.cgroupControllers)
return subTaskDentry.VFSDentry(), nil
}
// IterDirents implements kernfs.inodeDynamicLookup.
func (i *subtasksInode) IterDirents(ctx context.Context, cb vfs.IterDirentsCallback, offset, relOffset int64) (int64, error) {
tasks := i.task.ThreadGroup().MemberIDs(i.pidns)
if len(tasks) == 0 {
return offset, syserror.ENOENT
}
tids := make([]int, 0, len(tasks))
for _, tid := range tasks {
tids = append(tids, int(tid))
}
sort.Ints(tids)
for _, tid := range tids[relOffset:] {
dirent := vfs.Dirent{
Name: strconv.FormatUint(uint64(tid), 10),
Type: linux.DT_DIR,
Ino: i.inoGen.NextIno(),
NextOff: offset + 1,
}
if err := cb.Handle(dirent); err != nil {
return offset, err
}
offset++
}
return offset, nil
}
// Open implements kernfs.Inode.
func (i *subtasksInode) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
fd := &kernfs.GenericDirectoryFD{}
fd.Init(rp.Mount(), vfsd, &i.OrderedChildren, &opts)
return fd.VFSFileDescription(), nil
}
// Stat implements kernfs.Inode.
func (i *subtasksInode) Stat(vsfs *vfs.Filesystem, opts vfs.StatOptions) (linux.Statx, error) {
stat, err := i.InodeAttrs.Stat(vsfs, opts)
if err != nil {
return linux.Statx{}, err
}
if opts.Mask&linux.STATX_NLINK != 0 {
stat.Nlink += uint32(i.task.ThreadGroup().Count())
}
return stat, nil
}
// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
func (*subtasksInode) SetStat(*vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error {
return syserror.EPERM
}
|
