Check logd before logging

native/jni/core/daemon.c

@@ -265,6 +265,9 @@ void start_daemon() {
 		exit(1);
 	xlisten(fd, 10);
 
+	// Start the log monitor
+	monitor_logs();
+
 	if ((is_daemon_init = (access(MAGISKTMP, F_OK) == 0))) {
 		// Restart stuffs if the daemon is restarted
 		exec_command_sync("logcat", "-b", "all", "-c", NULL);
@@ -274,9 +277,6 @@ void start_daemon() {
 		daemon_init();
 	}
 
-	// Start the log monitor
-	monitor_logs();
-
 	LOGI("Magisk v" xstr(MAGISK_VERSION) "(" xstr(MAGISK_VER_CODE) ") daemon started\n");
 
 	// Change process name

native/jni/core/log_monitor.c

@@ -12,8 +12,10 @@
 
 #include "magisk.h"
 #include "utils.h"
+#include "resetprop.h"
 
 extern int is_daemon_init;
+int logd = 0;
 
 static int am_proc_start_filter(const char *log) {
 	return strstr(log, "am_proc_start") != NULL;
@@ -44,9 +46,20 @@ struct log_listener log_events[] = {
 };
 
 #ifdef MAGISK_DEBUG
-static int debug_log_pid, debug_log_fd;
+static int debug_log_pid = -1, debug_log_fd = -1;
 #endif
 
+static void check_logd() {
+	char *prop = getprop("init.svc.logd");
+	if (prop != NULL) {
+		free(prop);
+		logd = 1;
+	} else {
+		LOGD("log_monitor: logd not started, disable logging");
+		logd = 0;
+	}
+}
+
 static void *logger_thread(void *args) {
 	int log_fd = -1, log_pid;
 	char line[4096];
@@ -54,6 +67,15 @@ static void *logger_thread(void *args) {
 	LOGD("log_monitor: logger start");
 
 	while (1) {
+		if (!logd) {
+			// Disable all services
+			for (int i = 0; i < (sizeof(log_events) / sizeof(struct log_listener)); ++i) {
+				close(log_events[i].fd);
+				log_events[i].fd = -1;
+			}
+			return NULL;
+		}
+
 		// Start logcat
 		log_pid = exec_command(0, &log_fd, NULL, "logcat", "-b", "events", "-b", "main", "-v", "threadtime", "-s", "am_proc_start", "-s", "Magisk", NULL);
 		while (fdgets(line, sizeof(line), log_fd)) {
@@ -75,6 +97,8 @@ static void *logger_thread(void *args) {
 
 		// Clear buffer before restart
 		exec_command_sync("logcat", "-b", "events", "-b", "main", "-c", NULL);
+
+		check_logd();
 	}
 
 	// Should never be here, but well...
@@ -139,6 +163,9 @@ static void *debug_magisk_log_thread(void *args) {
 void monitor_logs() {
 	pthread_t thread;
 
+	check_logd();
+
+	if (logd) {
 		// Start log file dumper before monitor
 		xpthread_create(&thread, NULL, magisk_log_thread, NULL);
 		pthread_detach(thread);
@@ -146,33 +173,39 @@ void monitor_logs() {
 		// Start logcat monitor
 		xpthread_create(&thread, NULL, logger_thread, NULL);
 		pthread_detach(thread);
-
+	}
 }
 
 void start_debug_full_log() {
 #ifdef MAGISK_DEBUG
+	if (logd) {
 		// Log everything initially
 		debug_log_fd = xopen(DEBUG_LOG, O_WRONLY | O_CREAT | O_CLOEXEC | O_TRUNC, 0644);
 		debug_log_pid = exec_command(0, &debug_log_fd, NULL, "logcat", "-v", "threadtime", NULL);
 		close(debug_log_fd);
+	}
 #endif
 }
 
 void stop_debug_full_log() {
 #ifdef MAGISK_DEBUG
 	// Stop recording the boot logcat after every boot task is done
+	if (debug_log_pid > 0) {
 		kill(debug_log_pid, SIGTERM);
 		waitpid(debug_log_pid, NULL, 0);
 		// Start debug thread
 		start_debug_log();
+	}
 #endif
 }
 
 void start_debug_log() {
 #ifdef MAGISK_DEBUG
+	if (logd) {
 		pthread_t thread;
 		// Start debug thread
 		xpthread_create(&thread, NULL, debug_magisk_log_thread, NULL);
 		pthread_detach(thread);
+	}
 #endif
 }

native/jni/include/daemon.h

@@ -13,18 +13,17 @@ extern int is_daemon_init, seperate_vendor;
 // Commands require connecting to daemon
 enum {
 	DO_NOTHING = 0,
-	LAUNCH_MAGISKHIDE,
-	STOP_MAGISKHIDE,
-	ADD_HIDELIST,
-	RM_HIDELIST,
-	LS_HIDELIST,
 	SUPERUSER,
 	CHECK_VERSION,
 	CHECK_VERSION_CODE,
 	POST_FS,
 	POST_FS_DATA,
 	LATE_START,
-	TEST
+	LAUNCH_MAGISKHIDE,
+	STOP_MAGISKHIDE,
+	ADD_HIDELIST,
+	RM_HIDELIST,
+	LS_HIDELIST
 };
 
 // Return codes for daemon
@@ -32,6 +31,7 @@ enum {
 	DAEMON_ERROR = -1,
 	DAEMON_SUCCESS = 0,
 	ROOT_REQUIRED,
+	LOGD_DISABLED,
 	HIDE_IS_ENABLED,
 	HIDE_NOT_ENABLED,
 	HIDE_ITEM_EXIST,

native/jni/include/logging.h

@@ -58,6 +58,7 @@ struct log_listener {
 };
 
 extern struct log_listener log_events[];
+extern int logd;
 
 void monitor_logs();
 void start_debug_full_log();

native/jni/magiskhide/magiskhide.c

@@ -49,6 +49,14 @@ void launch_magiskhide(int client) {
 		return;
 	}
 
+	if (!logd) {
+		if (client > 0) {
+			write_int(client, LOGD_DISABLED);
+			close(client);
+		}
+		return;
+	}
+
 	hideEnabled = 1;
 	LOGI("* Starting MagiskHide\n");
 
@@ -136,6 +144,9 @@ int magiskhide_main(int argc, char *argv[]) {
 	case ROOT_REQUIRED:
 		fprintf(stderr, "Root is required for this operation\n");
 		return code;
+	case LOGD_DISABLED:
+		fprintf(stderr, "Logd is not running, cannot run logcat\n");
+		return (code);
 	case HIDE_NOT_ENABLED:
 		fprintf(stderr, "Magisk hide is not enabled yet\n");
 		return code;