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 2017 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.
//go:build freebsd || netbsd || openbsd || linux || darwin
package osutil
import (
"fmt"
"io"
"os"
"os/signal"
"path/filepath"
"strconv"
"syscall"
)
// ProcessTempDir creates a new temp dir in where and returns its path and an unique index.
// It also cleans up old, unused temp dirs after dead processes.
func ProcessTempDir(where string) (string, error) {
lk := filepath.Join(where, "instance-lock")
lkf, err := syscall.Open(lk, syscall.O_RDWR|syscall.O_CREAT, DefaultFilePerm)
if err != nil {
return "", err
}
defer syscall.Close(lkf)
if err := syscall.Flock(lkf, syscall.LOCK_EX); err != nil {
return "", err
}
defer syscall.Flock(lkf, syscall.LOCK_UN)
for i := 0; i < 1e3; i++ {
path := filepath.Join(where, fmt.Sprintf("instance-%v", i))
pidfile := filepath.Join(path, ".pid")
err := os.Mkdir(path, DefaultDirPerm)
if os.IsExist(err) {
// Try to clean up.
if cleanupTempDir(path, pidfile) {
i--
}
continue
}
if err != nil {
return "", err
}
if err := WriteFile(pidfile, []byte(strconv.Itoa(syscall.Getpid()))); err != nil {
return "", err
}
return path, nil
}
return "", fmt.Errorf("too many live instances")
}
func cleanupTempDir(path, pidfile string) bool {
data, err := os.ReadFile(pidfile)
if err == nil && len(data) > 0 {
pid, err := strconv.Atoi(string(data))
if err == nil && pid > 1 {
if err := syscall.Kill(pid, 0); err == syscall.ESRCH {
if os.Remove(pidfile) == nil {
return os.RemoveAll(path) == nil
}
}
}
}
// If err != nil, assume that the pid file is not created yet.
return false
}
// HandleInterrupts closes shutdown chan on first SIGINT
// (expecting that the program will gracefully shutdown and exit)
// and terminates the process on third SIGINT.
func HandleInterrupts(shutdown chan struct{}) {
go func() {
c := make(chan os.Signal, 3)
signal.Notify(c, syscall.SIGINT, syscall.SIGTERM)
<-c
close(shutdown)
fmt.Fprint(os.Stderr, "SIGINT: shutting down...\n")
<-c
fmt.Fprint(os.Stderr, "SIGINT: shutting down harder...\n")
<-c
fmt.Fprint(os.Stderr, "SIGINT: terminating\n")
os.Exit(int(syscall.SIGINT))
}()
}
func LongPipe() (io.ReadCloser, io.WriteCloser, error) {
r, w, err := os.Pipe()
if err != nil {
return nil, nil, fmt.Errorf("failed to create pipe: %w", err)
}
prolongPipe(r, w)
return r, w, err
}
// ProcessExitStatus returns process exit status.
// This is here only because of fuchsia that does not implement WaitStatus.
func ProcessExitStatus(ps *os.ProcessState) int {
return ps.Sys().(syscall.WaitStatus).ExitStatus()
}
// CreateMemMappedFile creates a temp file with the requested size and maps it into memory.
func CreateMemMappedFile(size int) (f *os.File, mem []byte, err error) {
f, err = CreateSharedMemFile(size)
if err != nil {
return
}
if err = f.Truncate(int64(size)); err != nil {
err = fmt.Errorf("failed to truncate shared mem file: %w", err)
CloseSharedMemFile(f)
return
}
mem, err = syscall.Mmap(int(f.Fd()), 0, size, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED)
if err != nil {
err = fmt.Errorf("failed to mmap shm file: %w", err)
CloseSharedMemFile(f)
}
return
}
// CloseMemMappedFile destroys memory mapping created by CreateMemMappedFile.
func CloseMemMappedFile(f *os.File, mem []byte) error {
err1 := syscall.Munmap(mem)
err2 := CloseSharedMemFile(f)
switch {
case err1 != nil:
return err1
case err2 != nil:
return err2
default:
return nil
}
}
|
