Use rustix to replace some unsafe calls

userspace/ksud/Cargo.lock

@@ -256,9 +256,9 @@ dependencies = [
 
 [[package]]
 name = "clang-sys"
-version = "1.4.0"
+version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa2e27ae6ab525c3d369ded447057bca5438d86dc3a68f6faafb8269ba82ebf3"
+checksum = "67523a3b4be3ce1989d607a828d036249522dd9c1c8de7f4dd2dae43a37369d1"
 dependencies = [
  "glob",
  "libc",
@@ -858,6 +858,7 @@ dependencies = [
  "regex",
  "retry",
  "rust-embed",
+ "rustix 0.38.30",
  "serde",
  "serde_json",
  "sha256",
@@ -908,12 +909,12 @@ dependencies = [
 
 [[package]]
 name = "libloading"
-version = "0.7.4"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b67380fd3b2fbe7527a606e18729d21c6f3951633d0500574c4dc22d2d638b9f"
+checksum = "c571b676ddfc9a8c12f1f3d3085a7b163966a8fd8098a90640953ce5f6170161"
 dependencies = [
  "cfg-if 1.0.0",
- "winapi",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -1376,8 +1377,10 @@ checksum = "322394588aaf33c24007e8bb3238ee3e4c5c09c084ab32bc73890b99ff326bca"
 dependencies = [
  "bitflags 2.4.1",
  "errno 0.3.8",
+ "itoa",
  "libc",
  "linux-raw-sys 0.4.13",
+ "once_cell",
  "windows-sys 0.52.0",
 ]
 
@@ -1456,9 +1459,9 @@ dependencies = [
 
 [[package]]
 name = "shlex"
-version = "1.1.0"
+version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "43b2853a4d09f215c24cc5489c992ce46052d359b5109343cbafbf26bc62f8a3"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
 [[package]]
 name = "smart-default"
@@ -1598,11 +1601,10 @@ dependencies = [
 
 [[package]]
 name = "tracing"
-version = "0.1.37"
+version = "0.1.40"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8ce8c33a8d48bd45d624a6e523445fd21ec13d3653cd51f681abf67418f54eb8"
+checksum = "c3523ab5a71916ccf420eebdf5521fcef02141234bbc0b8a49f2fdc4544364ef"
 dependencies = [
- "cfg-if 1.0.0",
  "pin-project-lite",
  "tracing-attributes",
  "tracing-core",
@@ -1610,20 +1612,20 @@ dependencies = [
 
 [[package]]
 name = "tracing-attributes"
-version = "0.1.23"
+version = "0.1.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4017f8f45139870ca7e672686113917c71c7a6e02d4924eda67186083c03081a"
+checksum = "34704c8d6ebcbc939824180af020566b01a7c01f80641264eba0999f6c2b6be7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 1.0.107",
+ "syn 2.0.48",
 ]
 
 [[package]]
 name = "tracing-core"
-version = "0.1.30"
+version = "0.1.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "24eb03ba0eab1fd845050058ce5e616558e8f8d8fca633e6b163fe25c797213a"
+checksum = "c06d3da6113f116aaee68e4d601191614c9053067f9ab7f6edbcb161237daa54"
 dependencies = [
  "once_cell",
 ]

userspace/ksud/Cargo.toml

@@ -40,6 +40,7 @@ hole-punch = { git = "https://github.com/tiann/hole-punch" }
 
 [target.'cfg(any(target_os = "android", target_os = "linux"))'.dependencies]
 sys-mount = { git = "https://github.com/tiann/sys-mount", branch = "loopfix" }
+rustix = { version = "0.38", features = ["all-apis"] }
 # some android specific dependencies which compiles under unix are also listed here for convenience of coding
 android-properties = { version = "0.2.2", features = ["bionic-deprecated"] }
 procfs = "0.16"

userspace/ksud/src/event.rs

@@ -1,6 +1,5 @@
 use anyhow::{bail, Context, Result};
 use log::{info, warn};
-use std::path::PathBuf;
 use std::{collections::HashMap, path::Path};
 
 use crate::module::prune_modules;

userspace/ksud/src/ksu.rs

@@ -14,6 +14,12 @@ use crate::{
     utils::{self, umask},
 };
 
+#[cfg(any(target_os = "linux", target_os = "android"))]
+use rustix::{
+    process::getuid,
+    thread::{set_thread_res_gid, set_thread_res_uid, Gid, Uid},
+};
+
 pub const KERNEL_SU_OPTION: u32 = 0xDEAD_BEEF;
 
 const CMD_GRANT_ROOT: u64 = 0;
@@ -65,8 +71,13 @@ fn set_identity(uid: u32, gid: u32, groups: &[u32]) {
         if !groups.is_empty() {
             libc::setgroups(groups.len(), groups.as_ptr());
         }
-        libc::setresgid(gid, gid, gid);
+    }
-        libc::setresuid(uid, uid, uid);
+    #[cfg(any(target_os = "linux", target_os = "android"))]
+    {
+        let gid = unsafe { Gid::from_raw(gid) };
+        let uid = unsafe { Uid::from_raw(uid) };
+        set_thread_res_gid(gid, gid, gid).ok();
+        set_thread_res_uid(uid, uid, uid).ok();
     }
 }
 
@@ -203,7 +214,7 @@ pub fn root_shell() -> Result<()> {
     }
 
     // use current uid if no user specified, these has been done in kernel!
-    let mut uid = unsafe { libc::getuid() };
+    let mut uid = getuid().as_raw();
     if free_idx < matches.free.len() {
         let name = &matches.free[free_idx];
         uid = unsafe {

userspace/ksud/src/utils.rs

@@ -15,6 +15,12 @@ use std::os::unix::prelude::PermissionsExt;
 use hole_punch::*;
 use std::io::{Read, Seek, SeekFrom};
 
+#[cfg(any(target_os = "linux", target_os = "android"))]
+use rustix::{
+    process,
+    thread::{move_into_link_name_space, unshare, LinkNameSpaceType, UnshareFlags},
+};
+
 pub fn ensure_clean_dir(dir: &str) -> Result<()> {
     let path = Path::new(dir);
     log::debug!("ensure_clean_dir: {}", path.display());
@@ -115,24 +121,23 @@ pub fn get_zip_uncompressed_size(zip_path: &str) -> Result<u64> {
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
 pub fn switch_mnt_ns(pid: i32) -> Result<()> {
-    use anyhow::ensure;
+    use rustix::{
-    use std::os::fd::AsRawFd;
+        fd::AsFd,
+        fs::{open, Mode, OFlags},
+    };
     let path = format!("/proc/{pid}/ns/mnt");
-    let fd = std::fs::File::open(path)?;
+    let fd = open(path, OFlags::RDONLY, Mode::from_raw_mode(0))?;
     let current_dir = std::env::current_dir();
-    let ret = unsafe { libc::setns(fd.as_raw_fd(), libc::CLONE_NEWNS) };
+    move_into_link_name_space(fd.as_fd(), Some(LinkNameSpaceType::Mount))?;
     if let std::result::Result::Ok(current_dir) = current_dir {
         let _ = std::env::set_current_dir(current_dir);
     }
-    ensure!(ret == 0, "switch mnt ns failed");
     Ok(())
 }
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
 pub fn unshare_mnt_ns() -> Result<()> {
-    use anyhow::ensure;
+    unshare(UnshareFlags::NEWNS)?;
-    let ret = unsafe { libc::unshare(libc::CLONE_NEWNS) };
-    ensure!(ret == 0, "unshare mnt ns failed");
     Ok(())
 }
 
@@ -164,7 +169,7 @@ pub fn switch_cgroups() {
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
 pub fn umask(mask: u32) {
-    unsafe { libc::umask(mask) };
+    process::umask(rustix::fs::Mode::from_raw_mode(mask));
 }
 
 #[cfg(not(any(target_os = "linux", target_os = "android")))]