Allow ADB shell to remove modules and reboot

native/jni/core/bootstages.cpp

@@ -1,10 +1,3 @@
-/* bootstages.c - Core bootstage operations
- *
- * All bootstage operations, including simple mount in post-fs,
- * magisk mount in post-fs-data, various image handling, script
- * execution, load modules, install Magisk Manager etc.
- */
-
 #include <sys/mount.h>
 #include <sys/wait.h>
 #include <stdlib.h>
@@ -718,10 +711,7 @@ void late_start(int client) {
 		if (access(SECURE_DIR, F_OK) != 0)
 			xmkdir(SECURE_DIR, 0700);
 		// And reboot to make proper setup possible
-		if (RECOVERY_MODE)
-			exec_command_sync("/system/bin/reboot", "recovery");
-		else
-			exec_command_sync("/system/bin/reboot");
+		reboot();
 	}
 
 	if (access(BBPATH, F_OK) != 0){

native/jni/core/daemon.cpp

@@ -1,9 +1,3 @@
-/* daemon.c - Magisk Daemon
- *
- * Start the daemon and wait for requests
- * Connect the daemon and send requests through sockets
- */
-
 #include <stdlib.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -30,14 +24,20 @@ static void verify_client(int client, pid_t pid) {
 	// Verify caller is the same as server
 	char path[32];
 	sprintf(path, "/proc/%d/exe", pid);
-	struct stat st{};
-	stat(path, &st);
-	if (st.st_dev != SERVER_STAT.st_dev || st.st_ino != SERVER_STAT.st_ino) {
+	struct stat st;
+	if (stat(path, &st) || st.st_dev != SERVER_STAT.st_dev || st.st_ino != SERVER_STAT.st_ino) {
 		close(client);
 		pthread_exit(nullptr);
 	}
 }
 
+static void remove_modules() {
+	LOGI("* Remove all modules and reboot");
+	rm_rf(MODULEROOT);
+	rm_rf(MODULEUPGRADE);
+	reboot();
+}
+
 static void *request_handler(void *args) {
 	int client = *((int *) args);
 	delete (int *) args;
@@ -95,6 +95,16 @@ static void *request_handler(void *args) {
 		LOGD("* Use broadcasts for su logging and notify\n");
 		CONNECT_BROADCAST = true;
 		close(client);
+		break;
+	case REMOVE_MODULES:
+		if (credential.uid == UID_SHELL || credential.uid == UID_ROOT) {
+			remove_modules();
+			write_int(client, 0);
+		} else {
+			write_int(client, 1);
+		}
+		close(client);
+		break;
 	default:
 		close(client);
 		break;
@@ -169,6 +179,13 @@ static void main_daemon() {
 	}
 }
 
+void reboot() {
+	if (RECOVERY_MODE)
+		exec_command_sync("/system/bin/reboot", "recovery");
+	else
+		exec_command_sync("/system/bin/reboot");
+}
+
 int switch_mnt_ns(int pid) {
 	char mnt[32];
 	snprintf(mnt, sizeof(mnt), "/proc/%d/ns/mnt", pid);

native/jni/core/magisk.cpp

@@ -16,31 +16,33 @@ using namespace std::literals;
 
 [[noreturn]] static void usage() {
 	fprintf(stderr,
-		FULL_VER(Magisk) " multi-call binary\n"
-		"\n"
-		"Usage: magisk [applet [arguments]...]\n"
-		"   or: magisk [options]...\n"
-		"\n"
-		"Options:\n"
-		"   -c                        print current binary version\n"
-		"   -v                        print running daemon version\n"
-		"   -V                        print running daemon version code\n"
-		"   --list                    list all available applets\n"
-		"   --daemon                  manually start magisk daemon\n"
-		"   --[init trigger]          start service for init trigger\n"
-		"\n"
-		"Advanced Options (Internal APIs):\n"
-		"   --unlock-blocks           set BLKROSET flag to OFF for all block devices\n"
-		"   --restorecon              restore selinux context on Magisk files\n"
-		"   --clone-attr SRC DEST     clone permission, owner, and selinux context\n"
-		"   --clone SRC DEST          clone SRC to DEST\n"
-  		"   --sqlite SQL              exec SQL to Magisk database\n"
-		"   --use-broadcast           use broadcast for su logging and notify\n"
-		"\n"
-		"Supported init triggers:\n"
-		"   post-fs-data, service, boot-complete\n"
-		"\n"
-		"Supported applets:\n");
+FULL_VER(Magisk) R"EOF( multi-call binary
+
+Usage: magisk [applet [arguments]...]
+   or: magisk [options]...
+
+Options:
+   -c                        print current binary version
+   -v                        print running daemon version
+   -V                        print running daemon version code
+   --list                    list all available applets
+   --daemon                  manually start magisk daemon
+   --remove-modules          remove all modules and reboot
+   --[init trigger]          start service for init trigger
+
+Advanced Options (Internal APIs):
+   --unlock-blocks           set BLKROSET flag to OFF for all block devices
+   --restorecon              restore selinux context on Magisk files
+   --clone-attr SRC DEST     clone permission, owner, and selinux context
+   --clone SRC DEST          clone SRC to DEST
+   --sqlite SQL              exec SQL commands to Magisk database
+   --use-broadcast           use broadcast for su logging and notify
+
+Supported init triggers:
+   post-fs-data, service, boot-complete
+
+Supported applets:
+)EOF");
 
 	for (int i = 0; applet_names[i]; ++i)
 		fprintf(stderr, i ? ", %s" : "    %s", applet_names[i]);
@@ -117,6 +119,10 @@ int magisk_main(int argc, char *argv[]) {
 		int fd = connect_daemon();
 		write_int(fd, BROADCAST_ACK);
 		return 0;
+	} else if (argv[1] == "--remove-modules"sv) {
+		int fd = connect_daemon();
+		write_int(fd, REMOVE_MODULES);
+		return read_int(fd);
 	}
 #if 0
 	/* Entry point for testing stuffs */

native/jni/include/daemon.h

@@ -18,6 +18,7 @@ enum {
 	MAGISKHIDE,
 	SQLITE_CMD,
 	BROADCAST_ACK,
+	REMOVE_MODULES,
 };
 
 // Return codes for daemon
@@ -32,6 +33,7 @@ enum {
 
 int connect_daemon(bool create = false);
 int switch_mnt_ns(int pid);
+void reboot();
 
 // socket.c