Fix magiskhide daemon enable/disable

jni/daemon/log_monitor.c

@@ -20,8 +20,10 @@ static void *logger_thread(void *args) {
 	// Disable buffering
 	setbuf(logfile, NULL);
 	// Start logcat
-	FILE *log_monitor = popen("logcat -s Magisk -v time", "r");
-	while (fgets(buffer, sizeof(buffer), log_monitor)) {
+	char *const command[] = { "logcat", "-s", "Magisk", "-v", "time", NULL };
+	int fd;
+	run_command(&fd, "/system/bin/logcat", command);
+	while (fdgets(buffer, sizeof(buffer), fd)) {
 		fprintf(logfile, "%s", buffer);
 	}
 	return NULL;

jni/daemon/post_fs_data.c

@@ -37,7 +37,7 @@ static char *loopsetup(const char *img) {
 char *mount_image(const char *img, const char *target) {
 	char *device = loopsetup(img);
 	if (device)
-		mount(device, target, "ext4", 0, NULL);
+		xmount(device, target, "ext4", 0, NULL);
 	return device;
 }
 

jni/magiskhide/magiskhide.c

@@ -41,10 +41,8 @@ static void usage(char *arg0) {
 }
 
 void launch_magiskhide(int client) {
-	if (isEnabled) {
-		write_int(client, 0);
-		return;
-	}
+	if (isEnabled)
+		goto success;
 	/*
 	 * The setns system call do not support multithread processes
 	 * We have to fork a new process, and communicate with pipe
@@ -84,6 +82,7 @@ void launch_magiskhide(int client) {
 		goto error;
 
 	isEnabled = 1;
+success:
 	write_int(client, 0);
 	close(client);
 	return;
@@ -107,12 +106,6 @@ void stop_magiskhide(int client) {
 
 	LOGI("* Stopping MagiskHide\n");
 
-	int kill = -1;
-	// Terminate hide daemon
-	write(sv[0], &kill, sizeof(kill));
-	close(sv[0]);
-	waitpid(hide_pid, NULL, 0);
-	// Stop process monitor
 	pthread_kill(proc_monitor_thread, SIGUSR1);
 	pthread_join(proc_monitor_thread, NULL);
 

jni/magiskhide/proc_monitor.c

@@ -19,6 +19,7 @@
 
 static int zygote_num = 0;
 static char init_ns[32], zygote_ns[2][32];
+static int log_pid = 0, log_fd;
 
 static void read_namespace(const int pid, char* target, const size_t size) {
 	char path[32];
@@ -41,11 +42,24 @@ static void quit_pthread(int sig) {
 	}
 	hide_list = new_list = NULL;
 	isEnabled = 0;
+	// Kill the logging if possible
+	if (log_pid) {
+		kill(log_pid, SIGTERM);
+		waitpid(log_pid, NULL, 0);
+		close(log_fd);
+		log_pid = 0;
+	}
+	int kill = -1;
+	// If process monitor dies, kill hide daemon too
+	write(sv[0], &kill, sizeof(kill));
+	close(sv[0]);
+	waitpid(hide_pid, NULL, 0);
 	LOGD("proc_monitor: terminating...\n");
 	pthread_exit(NULL);
 }
 
 static void store_zygote_ns(int pid) {
+	if (zygote_num == 2) return;
 	do {
 		usleep(500);
 		read_namespace(pid, zygote_ns[zygote_num], 32);
@@ -55,11 +69,6 @@ static void store_zygote_ns(int pid) {
 
 static void proc_monitor_err() {
 	LOGD("proc_monitor: error occured, stopping magiskhide services\n");
-	int kill = -1;
-	// If process monitor dies, kill hide daemon too
-	write(sv[0], &kill, sizeof(kill));
-	close(sv[0]);
-	waitpid(hide_pid, NULL, 0);
 	quit_pthread(SIGUSR1);
 }
 
@@ -92,10 +101,12 @@ void *proc_monitor(void *args) {
 		break;
 	}
 
-	// Monitor am_proc_start (the command shall never end)
-	FILE *p = popen("while true; do logcat -b events -c; logcat -b events -v raw -s am_proc_start; sleep 1; done", "r");
+	// Monitor am_proc_start
+	system("logcat -b events -c");
+	char *const command[] = { "logcat", "-b", "events", "-v", "raw", "-s", "am_proc_start", NULL };
+	log_pid = run_command(&log_fd, "/system/bin/logcat", command);
 
-	while(fgets(buffer, sizeof(buffer), p)) {
+	while(fdgets(buffer, sizeof(buffer), log_fd)) {
 		int ret, comma = 0;
 		char *pos = buffer, *line, processName[256];
 		struct vector *temp = NULL;
@@ -167,7 +178,6 @@ void *proc_monitor(void *args) {
 	}
 
 	// Should never be here
-	pclose(p);
-	pthread_exit(NULL);
+	quit_pthread(SIGUSR1);
 	return NULL;
 }

jni/utils/misc.c

@@ -81,19 +81,16 @@ int isNum(const char *s) {
 }
 
 /* Read a whole line from file descriptor */
-ssize_t fdreadline(int fd, char *buf, size_t size) {
+ssize_t fdgets(char *buf, const size_t size, int fd) {
 	ssize_t read = 0;
 	buf[0] = '\0';
-	while (xread(fd, buf + read, 1)) {
-		if (buf[read] == '\n')
+	while (xread(fd, buf + read, 1) && read < size - 1) {
+		if (buf[read] == '\0' || buf[read++] == '\n') {
 			buf[read] = '\0';
-		if (buf[read++] == '\0')
-			break;
-		if (read == size) {
-			buf[read - 1] = '\0';
 			break;
 		}
 	}
+	buf[size - 1] = '\0';
 	return read;
 }
 
@@ -121,11 +118,11 @@ static void proc_name_filter(int pid) {
 	char buf[64];
 	snprintf(buf, sizeof(buf), "/proc/%d/cmdline", pid);
 	int fd = xopen(buf, O_RDONLY);
-	if (fdreadline(fd, buf, sizeof(buf)) == 0) {
+	if (fdgets(buf, sizeof(buf), fd) == 0) {
 		snprintf(buf, sizeof(buf), "/proc/%d/comm", pid);
 		close(fd);
 		fd = xopen(buf, O_RDONLY);
-		fdreadline(fd, buf, sizeof(buf));
+		fdgets(buf, sizeof(buf), fd);
 	}
 	if (strstr(buf, ps_filter_pattern)) {
 		// printf("%d: %s\n", pid, buf);
@@ -189,14 +186,31 @@ void unblock_boot_process() {
 
 void setup_sighandlers(void (*handler)(int)) {
 	struct sigaction act;
-
-	// Install the termination handlers
-	// Note: we're assuming that none of these signal handlers are already trapped.
-	// If they are, we'll need to modify this code to save the previous handler and
-	// call it after we restore stdin to its previous state.
 	memset(&act, 0, sizeof(act));
 	act.sa_handler = handler;
 	for (int i = 0; quit_signals[i]; ++i) {
 		sigaction(quit_signals[i], &act, NULL);
 	}
 }
+
+int run_command(int *fd, const char *path, char *const argv[]) {
+	int sv[2];
+	if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sv) == -1)
+		return -1;
+	// We use sv[0], give them sv[1] for communication
+	*fd = sv[1];
+
+	int pid = fork();
+	if (pid != 0) {
+		close(sv[0]);
+		return pid;
+	}
+
+	close(sv[1]);
+	dup2(sv[0], STDIN_FILENO);
+	dup2(sv[0], STDOUT_FILENO);
+	dup2(sv[0], STDERR_FILENO);
+	execv(path, argv);
+	PLOGE("execv");
+	return -1;
+}

jni/utils/utils.h

@@ -65,12 +65,13 @@ unsigned get_radio_uid();
 int check_data();
 void file_to_vector(struct vector *v, FILE *fp);
 int isNum(const char *s);
-ssize_t fdreadline(int fd, char *buf, size_t size);
+ssize_t fdgets(char *buf, size_t size, int fd);
 void ps(void (*func)(int));
 void ps_filter_proc_name(const char *filter, void (*func)(int));
 int create_links(const char *bin, const char *path);
 void unlock_blocks();
 void unblock_boot_process();
 void setup_sighandlers(void (*handler)(int));
+int run_command(int *fd, const char *path, char *const argv[]);
 
 #endif