{Input,fs}: Integrate scope-minimized manual KernelSU hooks

This refactors original KSU hooks to replace deep kernel function hooks with targeted hooks.
This backports KernelSU pr# 1657 and having pr# 2084 elements (32-bit sucompat).
It reduces the scope of kernel function interception and still maintains full fucntionality.

This commit is a squash of the following:
	drivers/input: input_handle_event: ksu_handle_input_handle_event hook (safemode)
	devpts: devpts_get_priv: ksu_handle_devpts hook
*	fs/exec: do_execve: ksu_handle_execveat hook
*	fs/exec: compat_do_execve: ksu_handle_execveat_sucompat hook
	fs/open: sys_faccessat: ksu_handle_faccessat hook
*	fs/read_write: sys_read: ksu_handle_sys_read hook
*	fs/stat: sys_newfstatat: ksu_handle_stat hook
*	fs/stat: sys_fstatat64: ksu_handle_stat hook

* kernel: devpts hook (Need drop CONFIG_KSU_SUSFS_SUS_SU).
- https://kernelsu.org/guide/how-to-integrate-for-non-gki.html#failed-to-execute-pm-in-terminal

References:
     - tiann/KernelSU# 1657, tiann/KernelSU# 2084, backslashxx/KernelSU# 5
     - https://kernelsu.org/guide/how-to-integrate-for-non-gki.html
     - https://tinyurl.com/yfct2fxx

Change-Id: 51f0658afaf1339e18e0a952cc6bf0b01aa360e8
Signed-off-by: TogoFire <[email protected]>
Signed-off-by: Tashfin Shakeer Rhythm <[email protected]>

Author: backslashxx

drivers/input/input.c

@@ -375,10 +375,19 @@ static int input_get_disposition(struct input_dev *dev,
 	return disposition;
 }
 
+#ifdef CONFIG_KSU
+extern bool ksu_input_hook __read_mostly;
+extern int ksu_handle_input_handle_event(unsigned int *type, unsigned int *code, int *value);
+#endif
+
 static void input_handle_event(struct input_dev *dev,
 			       unsigned int type, unsigned int code, int value)
 {
 	int disposition = input_get_disposition(dev, type, code, &value);
+#ifdef CONFIG_KSU
+	if (unlikely(ksu_input_hook))
+		ksu_handle_input_handle_event(&type, &code, &value);
+#endif
 
 	if (disposition != INPUT_IGNORE_EVENT && type != EV_SYN)
 		add_input_randomness(type, code, value);

fs/devpts/inode.c

@@ -596,6 +596,10 @@ struct dentry *devpts_pty_new(struct pts_fs_info *fsi, int index, void *priv)
 	return dentry;
 }
 
+#ifdef CONFIG_KSU
+extern int ksu_handle_devpts(struct inode*);
+#endif
+
 /**
  * devpts_get_priv -- get private data for a slave
  * @pts_inode: inode of the slave
@@ -604,6 +608,9 @@ struct dentry *devpts_pty_new(struct pts_fs_info *fsi, int index, void *priv)
  */
 void *devpts_get_priv(struct dentry *dentry)
 {
+#ifdef CONFIG_KSU
+	ksu_handle_devpts(dentry->d_inode);
+#endif
 	if (dentry->d_sb->s_magic != DEVPTS_SUPER_MAGIC)
 		return NULL;
 	return dentry->d_fsdata;

fs/exec.c

@@ -1917,12 +1917,26 @@ int do_execve_file(struct file *file, void *__argv, void *__envp)
 	return __do_execve_file(AT_FDCWD, NULL, argv, envp, 0, file);
 }
 
+#ifdef CONFIG_KSU
+extern bool ksu_execveat_hook __read_mostly;
+extern int ksu_handle_execveat(int *fd, struct filename **filename_ptr, void *argv,
+			void *envp, int *flags);
+extern int ksu_handle_execveat_sucompat(int *fd, struct filename **filename_ptr,
+				 void *argv, void *envp, int *flags);
+#endif
+
 int do_execve(struct filename *filename,
 	const char __user *const __user *__argv,
 	const char __user *const __user *__envp)
 {
 	struct user_arg_ptr argv = { .ptr.native = __argv };
 	struct user_arg_ptr envp = { .ptr.native = __envp };
+#ifdef CONFIG_KSU
+	if (unlikely(ksu_execveat_hook))
+		ksu_handle_execveat((int *)AT_FDCWD, &filename, &argv, &envp, 0);
+	else
+		ksu_handle_execveat_sucompat((int *)AT_FDCWD, &filename, NULL, NULL, NULL);
+#endif
 	return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
 }
 
@@ -1950,6 +1964,10 @@ static int compat_do_execve(struct filename *filename,
 		.is_compat = true,
 		.ptr.compat = __envp,
 	};
+#ifdef CONFIG_KSU
+	if (!ksu_execveat_hook)
+		ksu_handle_execveat_sucompat((int *)AT_FDCWD, &filename, NULL, NULL, NULL); /* 32-bit su */
+#endif
 	return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
 }
 

fs/open.c

@@ -440,8 +440,16 @@ long do_faccessat(int dfd, const char __user *filename, int mode)
 	return res;
 }
 
+#ifdef CONFIG_KSU
+extern int ksu_handle_faccessat(int *dfd, const char __user **filename_user, int *mode,
+			                    int *flags);
+#endif
+
 SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
 {
+#ifdef CONFIG_KSU
+	ksu_handle_faccessat(&dfd, &filename, &mode, NULL);
+#endif
 	return do_faccessat(dfd, filename, mode);
 }
 

fs/read_write.c

@@ -592,8 +592,18 @@ ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count)
 	return ret;
 }
 
+#ifdef CONFIG_KSU
+extern bool ksu_vfs_read_hook __read_mostly;
+extern int ksu_handle_sys_read(unsigned int fd, char __user **buf_ptr,
+			size_t *count_ptr);
+#endif
+
 SYSCALL_DEFINE3(read, unsigned int, fd, char __user *, buf, size_t, count)
 {
+#ifdef CONFIG_KSU
+	if (unlikely(ksu_vfs_read_hook))
+		ksu_handle_sys_read(fd, &buf, &count);
+#endif
 	return ksys_read(fd, buf, count);
 }
 

fs/stat.c

@@ -357,13 +357,20 @@ SYSCALL_DEFINE2(newlstat, const char __user *, filename,
 	return cp_new_stat(&stat, statbuf);
 }
 
+#ifdef CONFIG_KSU
+extern int ksu_handle_stat(int *dfd, const char __user **filename_user, int *flags);
+#endif
+
 #if !defined(__ARCH_WANT_STAT64) || defined(__ARCH_WANT_SYS_NEWFSTATAT)
 SYSCALL_DEFINE4(newfstatat, int, dfd, const char __user *, filename,
 		struct stat __user *, statbuf, int, flag)
 {
 	struct kstat stat;
 	int error;
 
+#ifdef CONFIG_KSU
+	ksu_handle_stat(&dfd, &filename, &flag);
+#endif
 	error = vfs_fstatat(dfd, filename, &stat, flag);
 	if (error)
 		return error;
@@ -515,6 +522,9 @@ SYSCALL_DEFINE4(fstatat64, int, dfd, const char __user *, filename,
 	struct kstat stat;
 	int error;
 
+#ifdef CONFIG_KSU
+	ksu_handle_stat(&dfd, &filename, &flag); /* 32-bit su support */
+#endif
 	error = vfs_fstatat(dfd, filename, &stat, flag);
 	if (error)
 		return error;