refine mount prop

loader/src/common/daemon.cpp

@@ -125,4 +125,15 @@ namespace zygiskd {
             PLOGE("Failed to request ZygoteRestart");
         }
     }
+
+    void SystemServerStarted() {
+        UniqueFd fd = Connect(1);
+        if (fd == -1) {
+            PLOGE("Failed to report system server started");
+        } else {
+            if (!socket_utils::write_u8(fd, (uint8_t) SocketAction::SystemServerStarted)) {
+                PLOGE("Failed to report system server started");
+            }
+        }
+    }
 }

loader/src/include/daemon.h

@@ -60,6 +60,7 @@ namespace zygiskd {
         RequestCompanionSocket,
         GetModuleDir,
         ZygoteRestart,
+        SystemServerStarted,
     };
 
     void Init(const char *path = TMP_PATH);
@@ -77,4 +78,6 @@ namespace zygiskd {
     int GetModuleDir(size_t index);
 
     void ZygoteRestart();
+
+    void SystemServerStarted();
 }

loader/src/injector/hook.cpp

@@ -634,6 +634,7 @@ void ZygiskContext::nativeForkSystemServer_pre() {
         return;
 
     run_modules_pre();
+    zygiskd::SystemServerStarted();
 
     sanitize_fds();
 }

loader/src/ptracer/main.hpp

@@ -15,6 +15,7 @@ enum Command {
     DAEMON32_SET_INFO = 7,
     DAEMON64_SET_ERROR_INFO = 8,
     DAEMON32_SET_ERROR_INFO = 9,
+    SYSTEM_SERVER_STARTED = 10
 };
 
 void send_control_command(Command cmd);

loader/src/ptracer/monitor.cpp

@@ -108,6 +108,7 @@ public:
 };
 
 static TracingState tracing_state = TRACING;
+static std::string prop_path;
 
 
 struct Status {
@@ -170,7 +171,7 @@ struct SocketHandler : public EventHandler {
                 LOGE("read %zu < %zu", nread, sizeof(Command));
                 continue;
             }
-            if (msg.cmd >= Command::DAEMON64_SET_INFO) {
+            if (msg.cmd >= Command::DAEMON64_SET_INFO && msg.cmd != Command::SYSTEM_SERVER_STARTED) {
                 if (nread != sizeof(msg)) {
                     LOGE("cmd %d size %zu != %zu", msg.cmd, nread, sizeof(MsgHead));
                     continue;
@@ -253,6 +254,12 @@ struct SocketHandler : public EventHandler {
                     status32.daemon_error_info = std::string(msg.data);
                     updateStatus();
                     break;
+                case SYSTEM_SERVER_STARTED:
+                    LOGD("system server started, mounting prop");
+                    if (mount(prop_path.c_str(), "/data/adb/modules/zygisksu/module.prop", nullptr, MS_BIND, nullptr) == -1) {
+                        PLOGE("failed to mount prop");
+                    }
+                    break;
             }
         }
     }
@@ -282,9 +289,12 @@ bool should_stop_inject##abi() { \
 CREATE_ZYGOTE_START_COUNTER(64)
 CREATE_ZYGOTE_START_COUNTER(32)
 
-
 static bool ensure_daemon_created(bool is_64bit) {
     auto &status = is_64bit ? status64 : status32;
+    if (is_64bit) {
+        LOGD("new zygote started, unmounting prop ...");
+        umount2(prop_path.c_str(), MNT_DETACH);
+    }
     status.zygote_injected = false;
     if (status.daemon_pid == -1) {
         auto pid = fork();
@@ -480,7 +490,6 @@ public:
     }
 };
 
-static std::string prop_path;
 static std::string pre_section;
 static std::string post_section;
 
@@ -568,10 +577,6 @@ static bool prepare_environment() {
         PLOGE("chdir %s", wd);
         return false;
     }
-    if (mount(prop_path.c_str(), "/data/adb/modules/zygisksu/module.prop", nullptr, MS_BIND, nullptr) == -1) {
-        PLOGE("failed to mount prop");
-        return false;
-    }
     if (!switch_mnt_ns(0, &old_ns)) return false;
     if (chdir(wd) == -1) {
         PLOGE("chdir %s", wd);

zygiskd/src/constants.rs

@@ -23,6 +23,7 @@ pub const PATH_MODULE_PROP: &str = "module.prop";
 pub const ZYGOTE_INJECTED: i32 = lp_select!(5, 4);
 pub const DAEMON_SET_INFO: i32 = lp_select!(7, 6);
 pub const DAEMON_SET_ERROR_INFO: i32 = lp_select!(9, 8);
+pub const SYSTEM_SERVER_STARTED: i32 = 10;
 pub const TMP_DIR: &str = "/debug_ramdisk/zygisksu";
 pub const CONTROLLER_SOCKET: &str = concatcp!(TMP_DIR, "/init_monitor");
 pub const PATH_CP_NAME: &str = concatcp!(TMP_DIR, lp_select!("/cp32.sock", "/cp64.sock"));
@@ -39,6 +40,7 @@ pub enum DaemonSocketAction {
     RequestCompanionSocket,
     GetModuleDir,
     ZygoteRestart,
+    SystemServerStarted,
 }
 
 // Zygisk process flags

zygiskd/src/zygiskd.rs

@@ -80,6 +80,10 @@ pub fn main() -> Result<()> {
                     companion.take();
                 }
             }
+            DaemonSocketAction::SystemServerStarted => {
+                let value = constants::SYSTEM_SERVER_STARTED;
+                utils::unix_datagram_sendto(constants::CONTROLLER_SOCKET, &value.to_le_bytes())?;
+            }
             _ => {
                 thread::spawn(move || {
                     if let Err(e) = handle_daemon_action(action, stream, &context) {