Revert "kernel: remove unused CONFIG guard becuase GKI kernel enable kprobe by default" (#2495)

follow up to
https://github.com/tiann/KernelSU/pull/2475#issuecomment-2680947145

kernel/core_hook.c

@@ -886,7 +886,9 @@ void __init ksu_core_init(void)
 
 void ksu_core_exit(void)
 {
+#ifdef CONFIG_KPROBES
 	pr_info("ksu_core_kprobe_exit\n");
 	// we dont use this now
 	// ksu_kprobe_exit();
+#endif
 }

kernel/ksu.c

@@ -57,8 +57,12 @@ int __init kernelsu_init(void)
 
 	ksu_throne_tracker_init();
 
+#ifdef CONFIG_KPROBES
 	ksu_sucompat_init();
 	ksu_ksud_init();
+#else
+	pr_alert("KPROBES is disabled, KernelSU may not work, please check https://kernelsu.org/guide/how-to-integrate-for-non-gki.html");
+#endif
 
 #ifdef MODULE
 #ifndef CONFIG_KSU_DEBUG
@@ -76,8 +80,10 @@ void kernelsu_exit(void)
 
 	destroy_workqueue(ksu_workqueue);
 
+#ifdef CONFIG_KPROBES
 	ksu_ksud_exit();
 	ksu_sucompat_exit();
+#endif
 
 	ksu_core_exit();
 }

kernel/ksud.c

@@ -47,9 +47,15 @@ static void stop_vfs_read_hook();
 static void stop_execve_hook();
 static void stop_input_hook();
 
+#ifdef CONFIG_KPROBES
 static struct work_struct stop_vfs_read_work;
 static struct work_struct stop_execve_hook_work;
 static struct work_struct stop_input_hook_work;
+#else
+bool ksu_vfs_read_hook __read_mostly = true;
+bool ksu_execveat_hook __read_mostly = true;
+bool ksu_input_hook __read_mostly = true;
+#endif
 
 u32 ksu_devpts_sid;
 
@@ -144,6 +150,11 @@ int ksu_handle_execveat_ksud(int *fd, struct filename **filename_ptr,
 			     struct user_arg_ptr *argv,
 			     struct user_arg_ptr *envp, int *flags)
 {
+#ifndef CONFIG_KPROBES
+	if (!ksu_execveat_hook) {
+		return 0;
+	}
+#endif
 	struct filename *filename;
 
 	static const char app_process[] = "/system/bin/app_process";
@@ -295,6 +306,11 @@ static ssize_t read_iter_proxy(struct kiocb *iocb, struct iov_iter *to)
 int ksu_handle_vfs_read(struct file **file_ptr, char __user **buf_ptr,
 			size_t *count_ptr, loff_t **pos)
 {
+#ifndef CONFIG_KPROBES
+	if (!ksu_vfs_read_hook) {
+		return 0;
+	}
+#endif
 	struct file *file;
 	char __user *buf;
 	size_t count;
@@ -403,6 +419,11 @@ static bool is_volumedown_enough(unsigned int count)
 int ksu_handle_input_handle_event(unsigned int *type, unsigned int *code,
 				  int *value)
 {
+#ifndef CONFIG_KPROBES
+	if (!ksu_input_hook) {
+		return 0;
+	}
+#endif
 	if (*type == EV_KEY && *code == KEY_VOLUMEDOWN) {
 		int val = *value;
 		pr_info("KEY_VOLUMEDOWN val: %d\n", val);
@@ -440,6 +461,8 @@ bool ksu_is_safe_mode()
 	return false;
 }
 
+#ifdef CONFIG_KPROBES
+
 static int sys_execve_handler_pre(struct kprobe *p, struct pt_regs *regs)
 {
 	struct pt_regs *real_regs = PT_REAL_REGS(regs);
@@ -492,6 +515,7 @@ static struct kprobe vfs_read_kp = {
 	.pre_handler = sys_read_handler_pre,
 };
 
+
 static struct kprobe input_event_kp = {
 	.symbol_name = "input_event",
 	.pre_handler = input_handle_event_handler_pre,
@@ -511,17 +535,28 @@ static void do_stop_input_hook(struct work_struct *work)
 {
 	unregister_kprobe(&input_event_kp);
 }
+#endif
 
 static void stop_vfs_read_hook()
 {
+#ifdef CONFIG_KPROBES
 	bool ret = schedule_work(&stop_vfs_read_work);
 	pr_info("unregister vfs_read kprobe: %d!\n", ret);
+#else
+	ksu_vfs_read_hook = false;
+	pr_info("stop vfs_read_hook\n");
+#endif
 }
 
 static void stop_execve_hook()
 {
+#ifdef CONFIG_KPROBES
 	bool ret = schedule_work(&stop_execve_hook_work);
 	pr_info("unregister execve kprobe: %d!\n", ret);
+#else
+	ksu_execveat_hook = false;
+	pr_info("stop execve_hook\n");
+#endif
 }
 
 static void stop_input_hook()
@@ -531,13 +566,19 @@ static void stop_input_hook()
 		return;
 	}
 	input_hook_stopped = true;
+#ifdef CONFIG_KPROBES
 	bool ret = schedule_work(&stop_input_hook_work);
 	pr_info("unregister input kprobe: %d!\n", ret);
+#else
+	ksu_input_hook = false;
+	pr_info("stop input_hook\n");
+#endif
 }
 
 // ksud: module support
 void ksu_ksud_init()
 {
+#ifdef CONFIG_KPROBES
 	int ret;
 
 	ret = register_kprobe(&execve_kp);
@@ -552,12 +593,15 @@ void ksu_ksud_init()
 	INIT_WORK(&stop_vfs_read_work, do_stop_vfs_read_hook);
 	INIT_WORK(&stop_execve_hook_work, do_stop_execve_hook);
 	INIT_WORK(&stop_input_hook_work, do_stop_input_hook);
+#endif
 }
 
 void ksu_ksud_exit()
 {
+#ifdef CONFIG_KPROBES
 	unregister_kprobe(&execve_kp);
 	// this should be done before unregister vfs_read_kp
 	// unregister_kprobe(&vfs_read_kp);
 	unregister_kprobe(&input_event_kp);
+#endif
 }

kernel/sucompat.c

@@ -189,6 +189,8 @@ int ksu_handle_devpts(struct inode *inode)
 	return 0;
 }
 
+#ifdef CONFIG_KPROBES
+
 static int faccessat_handler_pre(struct kprobe *p, struct pt_regs *regs)
 {
 	struct pt_regs *real_regs = PT_REAL_REGS(regs);
@@ -261,19 +263,24 @@ static void destroy_kprobe(struct kprobe **kp_ptr)
 }
 
 static struct kprobe *su_kps[4];
+#endif
 
 // sucompat: permited process can execute 'su' to gain root access.
 void ksu_sucompat_init()
 {
+#ifdef CONFIG_KPROBES
 	su_kps[0] = init_kprobe(SYS_EXECVE_SYMBOL, execve_handler_pre);
 	su_kps[1] = init_kprobe(SYS_FACCESSAT_SYMBOL, faccessat_handler_pre);
 	su_kps[2] = init_kprobe(SYS_NEWFSTATAT_SYMBOL, newfstatat_handler_pre);
 	su_kps[3] = init_kprobe("pts_unix98_lookup", pts_unix98_lookup_pre);
+#endif
 }
 
 void ksu_sucompat_exit()
 {
+#ifdef CONFIG_KPROBES
 	for (int i = 0; i < ARRAY_SIZE(su_kps); i++) {
 		destroy_kprobe(&su_kps[i]);
 	}
+#endif
 }