Revert "su: allocate new pty (#1693)"

This reverts commit 935dc18.

Author: tiann

userspace/ksud/src/cli.rs

@@ -1,6 +1,6 @@
 use anyhow::{Ok, Result};
 use clap::Parser;
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 
 #[cfg(target_os = "android")]
 use android_logger::Config;
@@ -283,7 +283,7 @@ pub fn run() -> Result<()> {
 
     // the kernel executes su with argv[0] = "su" and replace it with us
     let arg0 = std::env::args().next().unwrap_or_default();
-    if Path::new(&arg0).file_name().and_then(|f| f.to_str()) == Some("su") {
+    if arg0 == "su" || arg0 == "/system/bin/su" {
         return crate::su::root_shell();
     }
 

userspace/ksud/src/defs.rs

@@ -43,5 +43,3 @@ pub const VERSION_NAME: &str = include_str!(concat!(env!("OUT_DIR"), "/VERSION_N
 pub const KSU_BACKUP_DIR: &str = WORKING_DIR;
 pub const KSU_BACKUP_FILE_PREFIX: &str = "ksu_backup_";
 pub const BACKUP_FILENAME: &str = "stock_image.sha1";
-
-pub const PTS_NAME: &str = "pts";

userspace/ksud/src/init_event.rs

@@ -2,7 +2,6 @@ use anyhow::{bail, Context, Result};
 use log::{info, warn};
 use std::{collections::HashMap, path::Path};
 
-use crate::defs::PTS_NAME;
 use crate::module::prune_modules;
 use crate::{
     assets, defs, ksucalls, mount, restorecon,
@@ -194,11 +193,6 @@ pub fn on_post_data_fs() -> Result<()> {
     // mount temp dir
     if let Err(e) = mount::mount_tmpfs(utils::get_tmp_path()) {
         warn!("do temp dir mount failed: {}", e);
-    } else {
-        let pts_dir = format!("{}/{PTS_NAME}", utils::get_tmp_path());
-        if let Err(e) = mount::mount_devpts(pts_dir) {
-            warn!("do devpts mount failed: {}", e);
-        }
     }
 
     // exec modules post-fs-data scripts

userspace/ksud/src/main.rs

@@ -9,8 +9,6 @@ mod ksucalls;
 mod module;
 mod mount;
 mod profile;
-#[cfg(any(target_os = "linux", target_os = "android"))]
-mod pty;
 mod restorecon;
 mod sepolicy;
 mod su;

userspace/ksud/src/mount.rs

@@ -1,5 +1,4 @@
 use anyhow::{anyhow, bail, Ok, Result};
-use std::fs::create_dir;
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
 use anyhow::Context;
@@ -182,19 +181,6 @@ pub fn mount_tmpfs(dest: impl AsRef<Path>) -> Result<()> {
     Ok(())
 }
 
-#[cfg(any(target_os = "linux", target_os = "android"))]
-pub fn mount_devpts(dest: impl AsRef<Path>) -> Result<()> {
-    create_dir(dest.as_ref())?;
-    mount(
-        KSU_OVERLAY_SOURCE,
-        dest.as_ref(),
-        "devpts",
-        MountFlags::empty(),
-        "newinstance",
-    )?;
-    Ok(())
-}
-
 #[cfg(any(target_os = "linux", target_os = "android"))]
 pub fn bind_mount(from: impl AsRef<Path>, to: impl AsRef<Path>) -> Result<()> {
     info!(
@@ -339,8 +325,3 @@ pub fn mount_overlay(
 pub fn mount_tmpfs(_dest: impl AsRef<Path>) -> Result<()> {
     unimplemented!()
 }
-
-#[cfg(not(any(target_os = "linux", target_os = "android")))]
-pub fn mount_devpts(_dest: impl AsRef<Path>) -> Result<()> {
-    unimplemented!()
-}

userspace/ksud/src/pty.rs

@@ -11,8 +11,6 @@ use crate::{
     utils::{self, umask},
 };
 
-#[cfg(any(target_os = "linux", target_os = "android"))]
-use crate::pty::prepare_pty;
 #[cfg(any(target_os = "linux", target_os = "android"))]
 use rustix::{
     process::getuid,
@@ -140,7 +138,6 @@ pub fn root_shell() -> Result<()> {
         "Specify a supplementary group. The first specified supplementary group is also used as a primary group if the option -g is not specified.",
         "GROUP",
     );
-    opts.optflag("", "no-pty", "Do not allocate a new pseudo terminal.");
 
     // Replace -cn with -z, -mm with -M for supporting getopt_long
     let args = args
@@ -268,13 +265,6 @@ pub fn root_shell() -> Result<()> {
         command = command.env("ENV", defs::KSURC_PATH);
     }
 
-    #[cfg(target_os = "android")]
-    if !matches.opt_present("no-pty") {
-        if let Err(e) = prepare_pty() {
-            log::error!("failed to prepare pty: {:?}", e);
-        }
-    }
-
     // escape from the current cgroup and become session leader
     // WARNING!!! This cause some root shell hang forever!
     // command = command.process_group(0);