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
|
// Copyright 2022 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.
package build
import (
"archive/tar"
"compress/gzip"
"fmt"
"io"
"os"
"path/filepath"
"strings"
"time"
"github.com/google/syzkaller/pkg/osutil"
)
const (
kernelConfig = "common/build.config.gki_kasan.x86_64"
moduleConfig = "common-modules/virtual-device/build.config.virtual_device_kasan.x86_64"
bazelTarget = "//common-modules/virtual-device:virtual_device_x86_64_dist"
)
type cuttlefish struct{}
func (c cuttlefish) runBuild(kernelDir, buildConfig string) error {
cmd := osutil.Command("build/build.sh")
cmd.Dir = kernelDir
cmd.Env = append(cmd.Env, "OUT_DIR=out", "DIST_DIR=dist", fmt.Sprintf("BUILD_CONFIG=%s", buildConfig))
_, err := osutil.Run(time.Hour, cmd)
return err
}
func (c cuttlefish) runBazel(kernelDir string) error {
cmd := osutil.Command("tools/bazel", "run", "--kasan", bazelTarget, "--", "--dist_dir=dist")
if err := osutil.Sandbox(cmd, true, false); err != nil {
return fmt.Errorf("failed to sandbox build command: %w", err)
}
cmd.Dir = kernelDir
_, err := osutil.Run(time.Hour, cmd)
return err
}
func (c cuttlefish) readCompiler(archivePath string) (string, error) {
f, err := os.Open(archivePath)
if err != nil {
return "", err
}
defer f.Close()
gr, err := gzip.NewReader(f)
if err != nil {
return "", err
}
defer gr.Close()
tr := tar.NewReader(gr)
h, err := tr.Next()
for ; err == nil; h, err = tr.Next() {
if filepath.Base(h.Name) == "compile.h" {
bytes, err := io.ReadAll(tr)
if err != nil {
return "", err
}
result := linuxCompilerRegexp.FindSubmatch(bytes)
if result == nil {
return "", fmt.Errorf("include/generated/compile.h does not contain build information")
}
return string(result[1]), nil
}
}
return "", fmt.Errorf("archive %s doesn't contain include/generated/compile.h", archivePath)
}
func (c cuttlefish) build(params Params) (ImageDetails, error) {
var details ImageDetails
if params.CmdlineFile != "" {
return details, fmt.Errorf("cmdline file is not supported for android cuttlefish images")
}
if params.SysctlFile != "" {
return details, fmt.Errorf("sysctl file is not supported for android cuttlefish images")
}
var config string
var err error
// Clean output directory if it exists.
if err := osutil.RemoveAll(filepath.Join(params.KernelDir, "out")); err != nil {
return details, fmt.Errorf("failed to clean before kernel build: %w", err)
}
// Default to build.sh if compiler is not specified.
if params.Compiler == "bazel" {
if err := c.runBazel(params.KernelDir); err != nil {
return details, fmt.Errorf("failed to build kernel: %w", err)
}
// Find the .config file; it is placed in a temporary output directory during the build.
cmd := osutil.Command("find", ".", "-regex", ".*virtual_device_x86_64_config.*/\\.config")
cmd.Dir = params.KernelDir
configBytes, err := osutil.Run(time.Minute, cmd)
if err != nil {
return details, fmt.Errorf("failed to find build config: %w", err)
}
config = filepath.Join(params.KernelDir, strings.TrimSpace(string(configBytes)))
} else {
if err := c.runBuild(params.KernelDir, kernelConfig); err != nil {
return details, fmt.Errorf("failed to build kernel: %w", err)
}
if err := c.runBuild(params.KernelDir, moduleConfig); err != nil {
return details, fmt.Errorf("failed to build modules: %w", err)
}
config = filepath.Join(params.KernelDir, "out", "common", ".config")
}
buildDistDir := filepath.Join(params.KernelDir, "dist")
bzImage := filepath.Join(buildDistDir, "bzImage")
vmlinux := filepath.Join(buildDistDir, "vmlinux")
initramfs := filepath.Join(buildDistDir, "initramfs.img")
details.CompilerID, err = c.readCompiler(filepath.Join(buildDistDir, "kernel-headers.tar.gz"))
if err != nil {
return details, err
}
if err := embedFiles(params, func(mountDir string) error {
homeDir := filepath.Join(mountDir, "root")
if err := osutil.CopyFile(bzImage, filepath.Join(homeDir, "bzImage")); err != nil {
return err
}
if err := osutil.CopyFile(vmlinux, filepath.Join(homeDir, "vmlinux")); err != nil {
return err
}
if err := osutil.CopyFile(initramfs, filepath.Join(homeDir, "initramfs.img")); err != nil {
return err
}
return nil
}); err != nil {
return details, err
}
if err := osutil.CopyFile(vmlinux, filepath.Join(params.OutputDir, "obj", "vmlinux")); err != nil {
return details, err
}
if err := osutil.CopyFile(initramfs, filepath.Join(params.OutputDir, "obj", "initrd")); err != nil {
return details, err
}
if err := osutil.CopyFile(config, filepath.Join(params.OutputDir, "kernel.config")); err != nil {
return details, err
}
if err := copyModuleFiles(filepath.Join(params.KernelDir, "out"), params.OutputDir); err != nil {
return details, err
}
details.Signature, err = elfBinarySignature(vmlinux, params.Tracer)
if err != nil {
return details, fmt.Errorf("failed to generate signature: %w", err)
}
return details, nil
}
func (c cuttlefish) clean(params Params) error {
if err := osutil.RemoveAll(filepath.Join(params.KernelDir, "out")); err != nil {
return err
}
return osutil.RemoveAll(filepath.Join(params.KernelDir, "dist"))
}
|
