kernel: added CMD_HOOK_MODE prctl to get the enabled su hook mode value

kernel/core_hook.c

@@ -339,6 +339,18 @@ int ksu_handle_prctl(int option, unsigned long arg2, unsigned long arg3,
 		return 0;
 	}
 
+	if (arg2 == CMD_HOOK_MODE) {
+#ifdef CONFIG_KSU_KPROBES_HOOK
+		const char *mode = "Kprobes";
+#else
+		const char *mode = "Manual";
+#endif
+		if (copy_to_user((void __user *)arg3, mode, strlen(mode) + 1)) {
+			pr_info("hook: copy_to_user() failed\n");
+		}
+		return 0;
+	}
+
 	if (arg2 == CMD_REPORT_EVENT) {
 		if (!from_root) {
 			return 0;

kernel/ksu.h

@@ -23,6 +23,7 @@
 #define CMD_UID_SHOULD_UMOUNT 13
 #define CMD_IS_SU_ENABLED 14
 #define CMD_ENABLE_SU 15
+#define CMD_HOOK_MODE 16
 
 #define EVENT_POST_FS_DATA 1
 #define EVENT_BOOT_COMPLETED 2

manager/app/src/main/cpp/jni.cc

@@ -25,6 +25,16 @@ Java_com_rifsxd_ksunext_Natives_getVersion(JNIEnv *env, jobject) {
     return get_version();
 }
 
+extern "C"
+JNIEXPORT jstring JNICALL
+Java_com_rifsxd_ksunext_Natives_getHookMode(JNIEnv *env, jobject) {
+    char mode[16] = {0};
+    if (get_hook_mode(mode, sizeof(mode))) {
+        return env->NewStringUTF(mode);
+    }
+    return nullptr;
+}
+
 extern "C"
 JNIEXPORT jintArray JNICALL
 Java_com_rifsxd_ksunext_Natives_getAllowList(JNIEnv *env, jobject) {

manager/app/src/main/cpp/ksu.cc

@@ -29,6 +29,7 @@
 #define CMD_IS_UID_SHOULD_UMOUNT 13
 #define CMD_IS_SU_ENABLED 14
 #define CMD_ENABLE_SU 15
+#define CMD_HOOK_MODE 16
 
 static bool ksuctl(int cmd, void* arg1, void* arg2) {
     int32_t result = 0;
@@ -61,6 +62,12 @@ int get_version() {
     return version;
 }
 
+bool get_hook_mode(char *mode, int mode_len) {
+    if (!mode || mode_len == 0) return false;
+    memset(mode, 0, mode_len);
+    return ksuctl(CMD_HOOK_MODE, mode, nullptr);
+}
+
 bool get_allow_list(int *uids, int *size) {
     return ksuctl(CMD_GET_SU_LIST, uids, size);
 }

manager/app/src/main/cpp/ksu.h

@@ -11,6 +11,8 @@ bool become_manager(const char *);
 
 int get_version();
 
+bool get_hook_mode(char *mode, int mode_len);
+
 bool get_allow_list(int *uids, int *size);
 
 bool uid_should_umount(int uid);

manager/app/src/main/java/com/rifsxd/ksunext/Natives.kt

@@ -50,6 +50,16 @@ object Natives {
 
     external fun uidShouldUmount(uid: Int): Boolean
 
+    /**
+     * Get a string indicating the SU hook mode enabled in kernel.
+     * The return values are:
+     * - "Manual": Manual hooks was enabled.
+     * - "Kprobes": Kprobes hooks was enabled (CONFIG_KSU_KPROBES_HOOK).
+     *
+     * @return return hook mode, or null if unavailable.
+     */
+    external fun getHookMode(): String?
+
     /**
      * Get the profile of the given package.
      * @param key usually the package name