su: allocate new pty (#1693)

userspace/ksud/src/su.rs

@@ -11,6 +11,8 @@ 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,
@@ -138,6 +140,7 @@ 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
@@ -265,6 +268,13 @@ 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);