Attempt to rescan zygote multiple times

Close #1654

native/jni/core/bootstages.cpp

@@ -757,6 +757,8 @@ void boot_complete(int client) {
 	if (!pfs_done)
 		return;
 
+	auto_start_magiskhide();
+
 	if (access(MANAGERAPK, F_OK) == 0) {
 		// Install Magisk Manager if exists
 		rename(MANAGERAPK, "/data/magisk.apk");

native/jni/magiskhide/hide_utils.cpp

@@ -217,7 +217,7 @@ static void set_hide_config() {
 	db_err(err);
 }
 
-static inline void launch_err(int client, int code = DAEMON_ERROR) {
+[[noreturn]] static void launch_err(int client, int code = DAEMON_ERROR) {
 	if (code != HIDE_IS_ENABLED)
 		hide_enabled = false;
 	if (client >= 0) {
@@ -280,10 +280,14 @@ int stop_magiskhide() {
 }
 
 void auto_start_magiskhide() {
-	db_settings dbs;
-	get_db_settings(dbs, HIDE_CONFIG);
-	if (dbs[HIDE_CONFIG]) {
-		new_daemon_thread([]{ launch_magiskhide(-1); });
+	if (hide_enabled) {
+		pthread_kill(proc_monitor_thread, SIGZYGOTE);
+	} else if (SDK_INT >= 19) {
+		db_settings dbs;
+		get_db_settings(dbs, HIDE_CONFIG);
+		if (dbs[HIDE_CONFIG]) {
+			new_daemon_thread([]{ launch_magiskhide(-1); });
+		}
 	}
 }
 

native/jni/magiskhide/magiskhide.h

@@ -13,6 +13,7 @@
 #include <daemon.h>
 
 #define SIGTERMTHRD SIGUSR1
+#define SIGZYGOTE   SIGUSR2
 
 #define SAFETYNET_COMPONENT  "com.google.android.gms/.droidguard.DroidGuardService"
 #define SAFETYNET_PROCESS    "com.google.android.gms.unstable"

native/jni/magiskhide/proc_monitor.cpp

@@ -155,6 +155,10 @@ static void inotify_event(int) {
 	check_zygote();
 }
 
+static void check_zygote(int) {
+	check_zygote();
+}
+
 // Workaround for the lack of pthread_cancel
 static void term_thread(int) {
 	LOGD("proc_monitor: cleaning up\n");
@@ -312,6 +316,8 @@ void proc_monitor() {
 	sigaction(SIGTERMTHRD, &act, nullptr);
 	act.sa_handler = inotify_event;
 	sigaction(SIGIO, &act, nullptr);
+	act.sa_handler = check_zygote;
+	sigaction(SIGZYGOTE, &act, nullptr);
 
 	setup_inotify();