1 /*
2 * Copyright (C) 2020 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <dirent.h>
18 #include <sys/mount.h>
19 #include <sys/stat.h>
20 #include <sys/types.h>
21 #include <sys/utsname.h>
22 #include <sys/wait.h>
23 #include <unistd.h>
24
25 #include <cstdlib>
26 #include <filesystem>
27 #include <fstream>
28 #include <iostream>
29 #include <memory>
30 #include <string>
31 #include <vector>
32
33 #include <modprobe/modprobe.h>
34
35 #include "android-base/logging.h"
36 #include "android-base/strings.h"
37
38 using namespace android::base;
39
40 static constexpr const char MODULE_BASE_DIR[] = "/lib/modules";
41
LoadKernelModules()42 bool LoadKernelModules() {
43 struct utsname uts;
44 if (uname(&uts)) {
45 LOG(ERROR) << "Failed to get kernel version.";
46 return false;
47 }
48 int major, minor;
49 if (sscanf(uts.release, "%d.%d", &major, &minor) != 2) {
50 LOG(ERROR) << "Failed to parse kernel version " << uts.release;
51 return false;
52 }
53
54 std::unique_ptr<DIR, decltype(&closedir)> base_dir(opendir(MODULE_BASE_DIR), closedir);
55 if (!base_dir) {
56 LOG(ERROR) << "Unable to open /lib/modules, skipping module loading.";
57 return false;
58 }
59 dirent* entry;
60 std::vector<std::string> module_dirs;
61 while ((entry = readdir(base_dir.get()))) {
62 if (entry->d_type != DT_DIR) {
63 continue;
64 }
65 int dir_major, dir_minor;
66 if (sscanf(entry->d_name, "%d.%d", &dir_major, &dir_minor) != 2 || dir_major != major ||
67 dir_minor != minor) {
68 continue;
69 }
70 module_dirs.emplace_back(entry->d_name);
71 }
72
73 // Sort the directories so they are iterated over during module loading
74 // in a consistent order. Alphabetical sorting is fine here because the
75 // kernel version at the beginning of the directory name must match the
76 // current kernel version, so the sort only applies to a label that
77 // follows the kernel version, for example /lib/modules/5.4 vs.
78 // /lib/modules/5.4-gki.
79 std::sort(module_dirs.begin(), module_dirs.end());
80
81 for (const auto& module_dir : module_dirs) {
82 std::string dir_path(MODULE_BASE_DIR);
83 dir_path.append("/");
84 dir_path.append(module_dir);
85 Modprobe m({dir_path});
86 bool retval = m.LoadListedModules();
87 int modules_loaded = m.GetModuleCount();
88 if (modules_loaded > 0) {
89 return retval;
90 }
91 }
92
93 Modprobe m({MODULE_BASE_DIR});
94 bool retval = m.LoadListedModules();
95 int modules_loaded = m.GetModuleCount();
96 if (modules_loaded > 0) {
97 return retval;
98 }
99
100 return true;
101 }
102
main(int argc,const char * argv[])103 int main(int argc, const char* argv[]) {
104 SetLogger(StderrLogger);
105
106 LOG(INFO) << "Guest VM init process";
107 LOG(INFO) << "Command line: " << Join(std::vector(argv, argv + argc), " ");
108
109 if (clearenv() != EXIT_SUCCESS) {
110 PLOG(ERROR) << "clearenv";
111 return EXIT_FAILURE;
112 }
113
114 LOG(INFO) << "Loading kernel modules...";
115 if (!LoadKernelModules()) {
116 LOG(ERROR) << "LoadKernelModules failed";
117 return EXIT_FAILURE;
118 }
119
120 LOG(INFO) << "Executing test binary " << argv[1] << "...";
121 execv(argv[1], (char**)(argv + 1));
122
123 PLOG(ERROR) << "execv";
124 return EXIT_FAILURE;
125 }
126