Remove Zygote notifier

Temporary trigger process scan on packages.xml updates, will find better methods

native/jni/core/applets.cpp

@@ -18,8 +18,6 @@ static int (*applet_main[]) (int, char *[]) =
 			exit((*applet_main[i])(argc, argv));
 		}
 	}
-	if (strncmp(basename(argv[0]), "app_process", 11) == 0)
-		exit(app_process_main(argc, argv));
 	fprintf(stderr, "%s: applet not found\n", argv[0]);
 	exit(1);
 }

native/jni/core/bootstages.cpp

@@ -577,15 +577,6 @@ static void dump_logs() {
 
 [[noreturn]] static void core_only() {
 	auto_start_magiskhide();
-	cp_afc("/sbin/magisk", MAGISKTMP "/app_process");
-	struct stat st;
-	for (const char *app : { "app_process", "app_process32", "app_process64" }) {
-		sprintf(buf, "/system/bin/%s", app);
-		if (lstat(buf, &st) == 0 && S_ISREG(st.st_mode)) {
-			clone_attr(buf, MAGISKTMP "/app_process");
-			bind_mount(MAGISKTMP "/app_process", buf, false);
-		}
-	}
 	unblock_boot_process();
 }
 

native/jni/core/daemon.cpp

@@ -89,9 +89,6 @@ static void *request_handler(void *args) {
 	case SQLITE_CMD:
 		exec_sql(client);
 		break;
-	case ZYGOTE_NOTIFY:
-		zygote_notify(client, &credential);
-		break;
 	default:
 		close(client);
 		break;

native/jni/core/magisk.cpp

@@ -112,30 +112,3 @@ int magisk_main(int argc, char *argv[]) {
 #endif
 	usage();
 }
-
-int app_process_main(int argc, char *argv[]) {
-	char path[512];
-	bool zygote = false;
-	for (int i = 0; i < argc; ++i) {
-		if (strcmp(argv[i], "--zygote") == 0) {
-			zygote = true;
-			break;
-		}
-	}
-	if (zygote) {
-		// Notify main daemon
-		sprintf(path, "/system/bin/%s", basename(argv[0]));
-		umount2(path, MNT_DETACH);
-		int fd = connect_daemon();
-		write_int(fd, ZYGOTE_NOTIFY);
-		write_string(fd, path);
-		read_int(fd);
-		close(fd);
-	} else {
-		// Redirect to system mirror
-		sprintf(path, MIRRDIR "/system/bin/%s", basename(argv[0]));
-	}
-	argv[0] = path;
-	execve(path, argv, environ);
-	return -1;
-}

native/jni/include/magisk.h

@@ -50,6 +50,5 @@ int magiskhide_main(int argc, char *argv[]);
 int magiskpolicy_main(int argc, char *argv[]);
 int su_client_main(int argc, char *argv[]);
 int resetprop_main(int argc, char *argv[]);
-int app_process_main(int argc, char *argv[]);
 
 #endif

native/jni/magiskhide/magiskhide.h

@@ -12,7 +12,6 @@
 #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"
@@ -42,7 +41,6 @@ extern pthread_t proc_monitor_thread;
 extern bool hide_enabled;
 extern pthread_mutex_t monitor_lock;
 extern std::set<std::pair<std::string, std::string>> hide_set;
-extern int next_zygote;
 
 enum {
 	LAUNCH_MAGISKHIDE,

native/jni/magiskhide/proc_monitor.cpp

@@ -114,8 +114,22 @@ static bool parse_packages_xml(string_view s) {
 	return true;
 }
 
+static void check_zygote() {
+	crawl_procfs([](int pid) -> bool {
+		char buf[512];
+		snprintf(buf, sizeof(buf), "/proc/%d/cmdline", pid);
+		FILE *f = fopen(buf, "re");
+		if (f) {
+			fgets(buf, sizeof(buf), f);
+			if (strncmp(buf, "zygote", 6) == 0)
+				new_zygote(pid);
+			fclose(f);
+		}
+		return true;
+	});
+}
+
 void *update_uid_map(void*) {
-	LOGD("proc_monitor: Updating uid maps\n");
 	MutexGuard lock(monitor_lock);
 	uid_proc_map.clear();
 	file_readline("/data/system/packages.xml", parse_packages_xml, true);
@@ -194,22 +208,11 @@ static void inotify_event(int) {
 	read(inotify_fd, buf, sizeof(buf));
 	if ((event->mask & IN_CLOSE_WRITE) && strcmp(event->name, "packages.xml") == 0) {
 		LOGD("proc_monitor: /data/system/packages.xml updated\n");
-		// Use new thread to parse xml, don't block zygote tracing
-		new_daemon_thread(update_uid_map);
+		check_zygote();
+		update_uid_map();
 	}
 }
 
-static void zygote_sig(int) {
-	int pid;
-	{
-		MutexGuard lock(monitor_lock);
-		pid = next_zygote;
-		next_zygote = -1;
-	}
-	if (pid > 0)
-		new_zygote(pid);
-}
-
 // Workaround for the lack of pthread_cancel
 static void term_thread(int) {
 	LOGD("proc_monitor: cleaning up\n");
@@ -241,32 +244,6 @@ static void term_thread(int) {
 //#define PTRACE_LOG(fmt, args...) LOGD("PID=[%d] " fmt, pid, ##args)
 #define PTRACE_LOG(...)
 
-int next_zygote = -1;
-
-void zygote_notify(int client, struct ucred *cred) {
-	char *path = read_string(client);
-
-	xptrace(PTRACE_ATTACH, cred->pid);
-	// Wait for attach
-	waitpid(cred->pid, nullptr, __WALL | __WNOTHREAD);
-	xptrace(PTRACE_CONT, cred->pid);
-	write_int(client, 0);
-	close(client);
-	// Wait for exec
-	waitpid(cred->pid, nullptr, __WALL | __WNOTHREAD);
-	xptrace(PTRACE_DETACH, cred->pid);
-
-	if (hide_enabled) {
-		MutexGuard lock(monitor_lock);
-		next_zygote = cred->pid;
-		pthread_kill(proc_monitor_thread, SIGZYGOTE);
-	}
-
-	// Remount zygote notifier ASAP
-	xmount(MAGISKTMP "/app_process", path, nullptr, MS_BIND, nullptr);
-	free(path);
-}
-
 static bool check_pid(int pid) {
 	char path[128];
 	char cmdline[1024];
@@ -357,15 +334,12 @@ void proc_monitor() {
 	sigset_t block_set;
 	sigemptyset(&block_set);
 	sigaddset(&block_set, SIGTERMTHRD);
-	sigaddset(&block_set, SIGZYGOTE);
 	sigaddset(&block_set, SIGIO);
 	pthread_sigmask(SIG_UNBLOCK, &block_set, nullptr);
 
 	struct sigaction act{};
 	act.sa_handler = term_thread;
 	sigaction(SIGTERMTHRD, &act, nullptr);
-	act.sa_handler = zygote_sig;
-	sigaction(SIGZYGOTE, &act, nullptr);
 	act.sa_handler = inotify_event;
 	sigaction(SIGIO, &act, nullptr);
 
@@ -381,18 +355,7 @@ void proc_monitor() {
 	inotify_add_watch(inotify_fd, "/data/system", IN_CLOSE_WRITE);
 
 	// First find existing zygotes
-	crawl_procfs([](int pid) -> bool {
-		char buf[512];
-		snprintf(buf, sizeof(buf), "/proc/%d/cmdline", pid);
-		FILE *f = fopen(buf, "re");
-		if (f) {
-			fgets(buf, sizeof(buf), f);
-			if (strncmp(buf, "zygote", 6) == 0)
-				new_zygote(pid);
-			fclose(f);
-		}
-		return true;
-	});
+	check_zygote();
 
 	int status;