init: Support reboot reason with thermal warmreset

Thermal shutdown could be due to tskin temperature or
battery temperature. Pass reason while rebooting the
system to reflect properly in boot.reason

Bug: 238464124
Test: Build and boot on device. Check reboot reason
for thermal shutdown and battery thermal shutdown with
thermal warmreset enabled.

Ignore-AOSP-First: AOSP already contains the change
Change-Id: I192562fed48ae7da7843e383362cd22a76ce479f
Merged-In: I192562fed48ae7da7843e383362cd22a76ce479f

init/reboot.cpp

@@ -608,7 +608,7 @@ static void DoReboot(unsigned int cmd, const std::string& reason, const std::str
     if (sem_init(&reboot_semaphore, false, 0) == -1) {
         // These should never fail, but if they do, skip the graceful reboot and reboot immediately.
         LOG(ERROR) << "sem_init() fail and RebootSystem() return!";
-        RebootSystem(cmd, reboot_target);
+        RebootSystem(cmd, reboot_target, reason);
     }
 
     // Start a thread to monitor init shutdown process
@@ -636,7 +636,7 @@ static void DoReboot(unsigned int cmd, const std::string& reason, const std::str
     // worry about unmounting it.
     if (!IsDataMounted("*")) {
         sync();
-        RebootSystem(cmd, reboot_target);
+        RebootSystem(cmd, reboot_target, reason);
         abort();
     }
 
@@ -769,7 +769,7 @@ static void DoReboot(unsigned int cmd, const std::string& reason, const std::str
             LOG(INFO) << "Shutdown /data";
         }
     }
-    RebootSystem(cmd, reboot_target);
+    RebootSystem(cmd, reboot_target, reason);
     abort();
 }
 

init/reboot_utils.cpp

@@ -106,7 +106,8 @@ bool IsRebootCapable() {
     return value == CAP_SET;
 }
 
-void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& rebootTarget) {
+void __attribute__((noreturn))
+RebootSystem(unsigned int cmd, const std::string& rebootTarget, const std::string& reboot_reason) {
     LOG(INFO) << "Reboot ending, jumping to kernel";
 
     if (!IsRebootCapable()) {
@@ -127,10 +128,12 @@ void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string&
 
         case ANDROID_RB_THERMOFF:
             if (android::base::GetBoolProperty("ro.thermal_warmreset", false)) {
+                std::string reason = "shutdown,thermal";
+                if (!reboot_reason.empty()) reason = reboot_reason;
+
                 LOG(INFO) << "Try to trigger a warm reset for thermal shutdown";
-                static constexpr const char kThermalShutdownTarget[] = "shutdown,thermal";
                 syscall(__NR_reboot, LINUX_REBOOT_MAGIC1, LINUX_REBOOT_MAGIC2,
-                        LINUX_REBOOT_CMD_RESTART2, kThermalShutdownTarget);
+                        LINUX_REBOOT_CMD_RESTART2, reason.c_str());
             } else {
                 reboot(RB_POWER_OFF);
             }

init/reboot_utils.h

@@ -29,7 +29,8 @@ void SetFatalRebootTarget(const std::optional<std::string>& reboot_target = std:
 // so if any of the attempts to determine this fail, it will still return true.
 bool IsRebootCapable();
 // This is a wrapper around the actual reboot calls.
-void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& reboot_target);
+void __attribute__((noreturn)) RebootSystem(unsigned int cmd, const std::string& reboot_target,
+                                            const std::string& reboot_reason = "");
 void __attribute__((noreturn)) InitFatalReboot(int signal_number);
 void InstallRebootSignalHandlers();