Split init's source files init first stage and second stage
This is a baseline for splitting init first and second stage into
their own executables.
Bug: 79758715
Test: sailfish boots
Change-Id: I549ad4502893b3a5e4c2a9886f66850f6d31b619
diff --git a/init/reboot_utils.cpp b/init/reboot_utils.cpp
new file mode 100644
index 0000000..9610304
--- /dev/null
+++ b/init/reboot_utils.cpp
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include <sys/capability.h>
+#include <sys/reboot.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+#include <android-base/logging.h>
+#include <cutils/android_reboot.h>
+
+#include "capabilities.h"
+
+namespace android {
+namespace init {
+
+bool IsRebootCapable() {
+ if (!CAP_IS_SUPPORTED(CAP_SYS_BOOT)) {
+ PLOG(WARNING) << "CAP_SYS_BOOT is not supported";
+ return true;
+ }
+
+ ScopedCaps caps(cap_get_proc());
+ if (!caps) {
+ PLOG(WARNING) << "cap_get_proc() failed";
+ return true;
+ }
+
+ cap_flag_value_t value = CAP_SET;
+ if (cap_get_flag(caps.get(), CAP_SYS_BOOT, CAP_EFFECTIVE, &value) != 0) {
+ PLOG(WARNING) << "cap_get_flag(CAP_SYS_BOOT, EFFECTIVE) failed";
+ return true;
+ }
+ return value == CAP_SET;
+}
+
+void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& rebootTarget) {
+ LOG(INFO) << "Reboot ending, jumping to kernel";
+
+ if (!IsRebootCapable()) {
+ // On systems where init does not have the capability of rebooting the
+ // device, just exit cleanly.
+ exit(0);
+ }
+
+ switch (cmd) {
+ case ANDROID_RB_POWEROFF:
+ reboot(RB_POWER_OFF);
+ break;
+
+ case ANDROID_RB_RESTART2:
+ syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
+ LINUX_REBOOT_CMD_RESTART2, rebootTarget.c_str());
+ break;
+
+ case ANDROID_RB_THERMOFF:
+ reboot(RB_POWER_OFF);
+ break;
+ }
+ // In normal case, reboot should not return.
+ PLOG(ERROR) << "reboot call returned";
+ abort();
+}
+
+void InstallRebootSignalHandlers() {
+ // Instead of panic'ing the kernel as is the default behavior when init crashes,
+ // we prefer to reboot to bootloader on development builds, as this will prevent
+ // boot looping bad configurations and allow both developers and test farms to easily
+ // recover.
+ struct sigaction action;
+ memset(&action, 0, sizeof(action));
+ sigfillset(&action.sa_mask);
+ action.sa_handler = [](int signal) {
+ // These signal handlers are also caught for processes forked from init, however we do not
+ // want them to trigger reboot, so we directly call _exit() for children processes here.
+ if (getpid() != 1) {
+ _exit(signal);
+ }
+
+ // Calling DoReboot() or LOG(FATAL) is not a good option as this is a signal handler.
+ // RebootSystem uses syscall() which isn't actually async-signal-safe, but our only option
+ // and probably good enough given this is already an error case and only enabled for
+ // development builds.
+ RebootSystem(ANDROID_RB_RESTART2, "bootloader");
+ };
+ action.sa_flags = SA_RESTART;
+ sigaction(SIGABRT, &action, nullptr);
+ sigaction(SIGBUS, &action, nullptr);
+ sigaction(SIGFPE, &action, nullptr);
+ sigaction(SIGILL, &action, nullptr);
+ sigaction(SIGSEGV, &action, nullptr);
+#if defined(SIGSTKFLT)
+ sigaction(SIGSTKFLT, &action, nullptr);
+#endif
+ sigaction(SIGSYS, &action, nullptr);
+ sigaction(SIGTRAP, &action, nullptr);
+}
+
+} // namespace init
+} // namespace android