Tom Cherry | 44aceed | 2018-08-03 13:36:18 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2018 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 <sys/capability.h> |
| 18 | #include <sys/reboot.h> |
| 19 | #include <sys/syscall.h> |
| 20 | #include <unistd.h> |
| 21 | |
Woody Lin | 45215ae | 2019-12-26 22:22:28 +0800 | [diff] [blame] | 22 | #include <optional> |
Tom Cherry | 59656fb | 2019-05-28 10:19:44 -0700 | [diff] [blame] | 23 | #include <string> |
| 24 | |
Wei Wang | 5f181bc | 2019-08-27 16:35:35 -0700 | [diff] [blame] | 25 | #include <android-base/file.h> |
| 26 | #include <android-base/logging.h> |
| 27 | #include <android-base/properties.h> |
| 28 | #include <android-base/strings.h> |
| 29 | #include <backtrace/Backtrace.h> |
| 30 | #include <cutils/android_reboot.h> |
Tom Cherry | 44aceed | 2018-08-03 13:36:18 -0700 | [diff] [blame] | 31 | |
| 32 | #include "capabilities.h" |
Woody Lin | be1cf90 | 2020-05-08 16:26:56 +0800 | [diff] [blame] | 33 | #include "reboot_utils.h" |
Devin Moore | 2652fdb | 2021-06-18 14:47:25 -0700 | [diff] [blame] | 34 | #include "util.h" |
Tom Cherry | 44aceed | 2018-08-03 13:36:18 -0700 | [diff] [blame] | 35 | |
| 36 | namespace android { |
| 37 | namespace init { |
| 38 | |
Tom Cherry | 75e13ba | 2019-05-21 13:53:05 -0700 | [diff] [blame] | 39 | static std::string init_fatal_reboot_target = "bootloader"; |
Woody Lin | 6bbfa26 | 2019-12-27 18:14:13 +0800 | [diff] [blame] | 40 | static bool init_fatal_panic = false; |
Tom Cherry | 75e13ba | 2019-05-21 13:53:05 -0700 | [diff] [blame] | 41 | |
Devin Moore | 2652fdb | 2021-06-18 14:47:25 -0700 | [diff] [blame] | 42 | // this needs to read the /proc/* files directly because it is called before |
| 43 | // ro.boot.* properties are initialized |
Woody Lin | 45215ae | 2019-12-26 22:22:28 +0800 | [diff] [blame] | 44 | void SetFatalRebootTarget(const std::optional<std::string>& reboot_target) { |
Tom Cherry | 75e13ba | 2019-05-21 13:53:05 -0700 | [diff] [blame] | 45 | std::string cmdline; |
| 46 | android::base::ReadFileToString("/proc/cmdline", &cmdline); |
| 47 | cmdline = android::base::Trim(cmdline); |
| 48 | |
Devin Moore | 2652fdb | 2021-06-18 14:47:25 -0700 | [diff] [blame] | 49 | const std::string kInitFatalPanicParamString = "androidboot.init_fatal_panic"; |
| 50 | if (cmdline.find(kInitFatalPanicParamString) == std::string::npos) { |
| 51 | init_fatal_panic = false; |
| 52 | ImportBootconfig( |
| 53 | [kInitFatalPanicParamString](const std::string& key, const std::string& value) { |
| 54 | if (key == kInitFatalPanicParamString && value == "true") { |
| 55 | init_fatal_panic = true; |
| 56 | } |
| 57 | }); |
| 58 | } else { |
| 59 | const std::string kInitFatalPanicString = kInitFatalPanicParamString + "=true"; |
| 60 | init_fatal_panic = cmdline.find(kInitFatalPanicString) != std::string::npos; |
| 61 | } |
Woody Lin | 6bbfa26 | 2019-12-27 18:14:13 +0800 | [diff] [blame] | 62 | |
Woody Lin | 45215ae | 2019-12-26 22:22:28 +0800 | [diff] [blame] | 63 | if (reboot_target) { |
| 64 | init_fatal_reboot_target = *reboot_target; |
| 65 | return; |
| 66 | } |
| 67 | |
Devin Moore | 2652fdb | 2021-06-18 14:47:25 -0700 | [diff] [blame] | 68 | const std::string kRebootTargetString = "androidboot.init_fatal_reboot_target"; |
Tom Cherry | 75e13ba | 2019-05-21 13:53:05 -0700 | [diff] [blame] | 69 | auto start_pos = cmdline.find(kRebootTargetString); |
| 70 | if (start_pos == std::string::npos) { |
Devin Moore | 2652fdb | 2021-06-18 14:47:25 -0700 | [diff] [blame] | 71 | ImportBootconfig([kRebootTargetString](const std::string& key, const std::string& value) { |
| 72 | if (key == kRebootTargetString) { |
| 73 | init_fatal_reboot_target = value; |
| 74 | } |
| 75 | }); |
| 76 | // We already default to bootloader if no setting is provided. |
| 77 | } else { |
| 78 | const std::string kRebootTargetStringPattern = kRebootTargetString + "="; |
| 79 | start_pos += sizeof(kRebootTargetStringPattern) - 1; |
Tom Cherry | 75e13ba | 2019-05-21 13:53:05 -0700 | [diff] [blame] | 80 | |
Devin Moore | 2652fdb | 2021-06-18 14:47:25 -0700 | [diff] [blame] | 81 | auto end_pos = cmdline.find(' ', start_pos); |
| 82 | // if end_pos isn't found, then we've run off the end, but this is okay as this is the last |
| 83 | // entry, and -1 is a valid size for string::substr(); |
| 84 | auto size = end_pos == std::string::npos ? -1 : end_pos - start_pos; |
| 85 | init_fatal_reboot_target = cmdline.substr(start_pos, size); |
| 86 | } |
Tom Cherry | 75e13ba | 2019-05-21 13:53:05 -0700 | [diff] [blame] | 87 | } |
| 88 | |
Tom Cherry | 44aceed | 2018-08-03 13:36:18 -0700 | [diff] [blame] | 89 | bool IsRebootCapable() { |
| 90 | if (!CAP_IS_SUPPORTED(CAP_SYS_BOOT)) { |
| 91 | PLOG(WARNING) << "CAP_SYS_BOOT is not supported"; |
| 92 | return true; |
| 93 | } |
| 94 | |
| 95 | ScopedCaps caps(cap_get_proc()); |
| 96 | if (!caps) { |
| 97 | PLOG(WARNING) << "cap_get_proc() failed"; |
| 98 | return true; |
| 99 | } |
| 100 | |
| 101 | cap_flag_value_t value = CAP_SET; |
| 102 | if (cap_get_flag(caps.get(), CAP_SYS_BOOT, CAP_EFFECTIVE, &value) != 0) { |
| 103 | PLOG(WARNING) << "cap_get_flag(CAP_SYS_BOOT, EFFECTIVE) failed"; |
| 104 | return true; |
| 105 | } |
| 106 | return value == CAP_SET; |
| 107 | } |
| 108 | |
| 109 | void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& rebootTarget) { |
| 110 | LOG(INFO) << "Reboot ending, jumping to kernel"; |
| 111 | |
| 112 | if (!IsRebootCapable()) { |
| 113 | // On systems where init does not have the capability of rebooting the |
| 114 | // device, just exit cleanly. |
| 115 | exit(0); |
| 116 | } |
| 117 | |
| 118 | switch (cmd) { |
| 119 | case ANDROID_RB_POWEROFF: |
| 120 | reboot(RB_POWER_OFF); |
| 121 | break; |
| 122 | |
| 123 | case ANDROID_RB_RESTART2: |
| 124 | syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, |
| 125 | LINUX_REBOOT_CMD_RESTART2, rebootTarget.c_str()); |
| 126 | break; |
| 127 | |
| 128 | case ANDROID_RB_THERMOFF: |
Wei Wang | 5f181bc | 2019-08-27 16:35:35 -0700 | [diff] [blame] | 129 | if (android::base::GetBoolProperty("ro.thermal_warmreset", false)) { |
| 130 | LOG(INFO) << "Try to trigger a warm reset for thermal shutdown"; |
| 131 | static constexpr const char kThermalShutdownTarget[] = "shutdown,thermal"; |
| 132 | syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2, |
| 133 | LINUX_REBOOT_CMD_RESTART2, kThermalShutdownTarget); |
| 134 | } else { |
| 135 | reboot(RB_POWER_OFF); |
| 136 | } |
Tom Cherry | 44aceed | 2018-08-03 13:36:18 -0700 | [diff] [blame] | 137 | break; |
| 138 | } |
| 139 | // In normal case, reboot should not return. |
| 140 | PLOG(ERROR) << "reboot call returned"; |
| 141 | abort(); |
| 142 | } |
| 143 | |
Elliott Hughes | 636ebc9 | 2019-10-07 18:16:23 -0700 | [diff] [blame] | 144 | void __attribute__((noreturn)) InitFatalReboot(int signal_number) { |
Tom Cherry | 59656fb | 2019-05-28 10:19:44 -0700 | [diff] [blame] | 145 | auto pid = fork(); |
| 146 | |
| 147 | if (pid == -1) { |
| 148 | // Couldn't fork, don't even try to backtrace, just reboot. |
Tom Cherry | 75e13ba | 2019-05-21 13:53:05 -0700 | [diff] [blame] | 149 | RebootSystem(ANDROID_RB_RESTART2, init_fatal_reboot_target); |
Tom Cherry | 59656fb | 2019-05-28 10:19:44 -0700 | [diff] [blame] | 150 | } else if (pid == 0) { |
| 151 | // Fork a child for safety, since we always want to shut down if something goes wrong, but |
| 152 | // its worth trying to get the backtrace, even in the signal handler, since typically it |
| 153 | // does work despite not being async-signal-safe. |
| 154 | sleep(5); |
Tom Cherry | 75e13ba | 2019-05-21 13:53:05 -0700 | [diff] [blame] | 155 | RebootSystem(ANDROID_RB_RESTART2, init_fatal_reboot_target); |
Tom Cherry | 59656fb | 2019-05-28 10:19:44 -0700 | [diff] [blame] | 156 | } |
| 157 | |
| 158 | // In the parent, let's try to get a backtrace then shutdown. |
Elliott Hughes | 636ebc9 | 2019-10-07 18:16:23 -0700 | [diff] [blame] | 159 | LOG(ERROR) << __FUNCTION__ << ": signal " << signal_number; |
Tom Cherry | 59656fb | 2019-05-28 10:19:44 -0700 | [diff] [blame] | 160 | std::unique_ptr<Backtrace> backtrace( |
| 161 | Backtrace::Create(BACKTRACE_CURRENT_PROCESS, BACKTRACE_CURRENT_THREAD)); |
| 162 | if (!backtrace->Unwind(0)) { |
| 163 | LOG(ERROR) << __FUNCTION__ << ": Failed to unwind callstack."; |
| 164 | } |
| 165 | for (size_t i = 0; i < backtrace->NumFrames(); i++) { |
| 166 | LOG(ERROR) << backtrace->FormatFrameData(i); |
| 167 | } |
Woody Lin | 6bbfa26 | 2019-12-27 18:14:13 +0800 | [diff] [blame] | 168 | if (init_fatal_panic) { |
Woody Lin | be1cf90 | 2020-05-08 16:26:56 +0800 | [diff] [blame] | 169 | LOG(ERROR) << __FUNCTION__ << ": Trigger crash"; |
| 170 | android::base::WriteStringToFile("c", PROC_SYSRQ); |
| 171 | LOG(ERROR) << __FUNCTION__ << ": Sys-Rq failed to crash the system; fallback to exit()."; |
Woody Lin | 6bbfa26 | 2019-12-27 18:14:13 +0800 | [diff] [blame] | 172 | _exit(signal_number); |
| 173 | } |
Tom Cherry | 75e13ba | 2019-05-21 13:53:05 -0700 | [diff] [blame] | 174 | RebootSystem(ANDROID_RB_RESTART2, init_fatal_reboot_target); |
Tom Cherry | 59656fb | 2019-05-28 10:19:44 -0700 | [diff] [blame] | 175 | } |
| 176 | |
Tom Cherry | 44aceed | 2018-08-03 13:36:18 -0700 | [diff] [blame] | 177 | void InstallRebootSignalHandlers() { |
| 178 | // Instead of panic'ing the kernel as is the default behavior when init crashes, |
| 179 | // we prefer to reboot to bootloader on development builds, as this will prevent |
| 180 | // boot looping bad configurations and allow both developers and test farms to easily |
| 181 | // recover. |
| 182 | struct sigaction action; |
| 183 | memset(&action, 0, sizeof(action)); |
| 184 | sigfillset(&action.sa_mask); |
| 185 | action.sa_handler = [](int signal) { |
| 186 | // These signal handlers are also caught for processes forked from init, however we do not |
| 187 | // want them to trigger reboot, so we directly call _exit() for children processes here. |
| 188 | if (getpid() != 1) { |
| 189 | _exit(signal); |
| 190 | } |
| 191 | |
| 192 | // Calling DoReboot() or LOG(FATAL) is not a good option as this is a signal handler. |
| 193 | // RebootSystem uses syscall() which isn't actually async-signal-safe, but our only option |
| 194 | // and probably good enough given this is already an error case and only enabled for |
| 195 | // development builds. |
Elliott Hughes | 636ebc9 | 2019-10-07 18:16:23 -0700 | [diff] [blame] | 196 | InitFatalReboot(signal); |
Tom Cherry | 44aceed | 2018-08-03 13:36:18 -0700 | [diff] [blame] | 197 | }; |
| 198 | action.sa_flags = SA_RESTART; |
| 199 | sigaction(SIGABRT, &action, nullptr); |
| 200 | sigaction(SIGBUS, &action, nullptr); |
| 201 | sigaction(SIGFPE, &action, nullptr); |
| 202 | sigaction(SIGILL, &action, nullptr); |
| 203 | sigaction(SIGSEGV, &action, nullptr); |
| 204 | #if defined(SIGSTKFLT) |
| 205 | sigaction(SIGSTKFLT, &action, nullptr); |
| 206 | #endif |
| 207 | sigaction(SIGSYS, &action, nullptr); |
| 208 | sigaction(SIGTRAP, &action, nullptr); |
| 209 | } |
| 210 | |
| 211 | } // namespace init |
| 212 | } // namespace android |