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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
// 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 (
"time"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/errors/linuxerr"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/kernel"
)
const nsecPerSec = int64(time.Second)
// Getitimer implements linux syscall getitimer(2).
func Getitimer(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
if t.Arch().Width() != 8 {
// Definition of linux.ItimerVal assumes 64-bit architecture.
return 0, nil, linuxerr.ENOSYS
}
timerID := args[0].Int()
addr := args[1].Pointer()
olditv, err := t.Getitimer(timerID)
if err != nil {
return 0, nil, err
}
// A NULL address is allowed, in which case no copy out takes place.
if addr == 0 {
return 0, nil, nil
}
_, err = olditv.CopyOut(t, addr)
return 0, nil, err
}
// Setitimer implements linux syscall setitimer(2).
func Setitimer(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
if t.Arch().Width() != 8 {
// Definition of linux.ItimerVal assumes 64-bit architecture.
return 0, nil, linuxerr.ENOSYS
}
timerID := args[0].Int()
newAddr := args[1].Pointer()
oldAddr := args[2].Pointer()
var newitv linux.ItimerVal
// A NULL address is allowed because because Linux allows
// setitimer(which, NULL, &old_value) which disables the timer. There is a
// KERN_WARN message saying this misfeature will be removed. However, that
// hasn't happened as of 3.19, so we continue to support it.
if newAddr != 0 {
if _, err := newitv.CopyIn(t, newAddr); err != nil {
return 0, nil, err
}
}
olditv, err := t.Setitimer(timerID, newitv)
if err != nil {
return 0, nil, err
}
// A NULL address is allowed, in which case no copy out takes place.
if oldAddr == 0 {
return 0, nil, nil
}
_, err = olditv.CopyOut(t, oldAddr)
return 0, nil, err
}
// Alarm implements linux syscall alarm(2).
func Alarm(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
duration := time.Duration(args[0].Uint()) * time.Second
olditv, err := t.Setitimer(linux.ITIMER_REAL, linux.ItimerVal{
Value: linux.DurationToTimeval(duration),
})
if err != nil {
return 0, nil, err
}
olddur := olditv.Value.ToDuration()
secs := olddur.Round(time.Second).Nanoseconds() / nsecPerSec
if secs == 0 && olddur != 0 {
// We can't return 0 if an alarm was previously scheduled.
secs = 1
}
return uintptr(secs), nil, nil
}
// TimerCreate implements linux syscall timer_create(2).
func TimerCreate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
clockID := args[0].Int()
sevp := args[1].Pointer()
timerIDp := args[2].Pointer()
c, err := getClock(t, clockID)
if err != nil {
return 0, nil, err
}
var sev *linux.Sigevent
if sevp != 0 {
sev = &linux.Sigevent{}
if _, err = sev.CopyIn(t, sevp); err != nil {
return 0, nil, err
}
}
id, err := t.IntervalTimerCreate(c, sev)
if err != nil {
return 0, nil, err
}
if _, err := id.CopyOut(t, timerIDp); err != nil {
t.IntervalTimerDelete(id)
return 0, nil, err
}
return 0, nil, nil
}
// TimerSettime implements linux syscall timer_settime(2).
func TimerSettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
timerID := linux.TimerID(args[0].Value)
flags := args[1].Int()
newValAddr := args[2].Pointer()
oldValAddr := args[3].Pointer()
var newVal linux.Itimerspec
if _, err := newVal.CopyIn(t, newValAddr); err != nil {
return 0, nil, err
}
oldVal, err := t.IntervalTimerSettime(timerID, newVal, flags&linux.TIMER_ABSTIME != 0)
if err != nil {
return 0, nil, err
}
if oldValAddr != 0 {
_, err = oldVal.CopyOut(t, oldValAddr)
return 0, nil, err
}
return 0, nil, nil
}
// TimerGettime implements linux syscall timer_gettime(2).
func TimerGettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
timerID := linux.TimerID(args[0].Value)
curValAddr := args[1].Pointer()
curVal, err := t.IntervalTimerGettime(timerID)
if err != nil {
return 0, nil, err
}
_, err = curVal.CopyOut(t, curValAddr)
return 0, nil, err
}
// TimerGetoverrun implements linux syscall timer_getoverrun(2).
func TimerGetoverrun(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
timerID := linux.TimerID(args[0].Value)
o, err := t.IntervalTimerGetoverrun(timerID)
if err != nil {
return 0, nil, err
}
return uintptr(o), nil, nil
}
// TimerDelete implements linux syscall timer_delete(2).
func TimerDelete(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
timerID := linux.TimerID(args[0].Value)
return 0, nil, t.IntervalTimerDelete(timerID)
}
|
