Overhaul DLL injection

zluda_dump/src/os_win.rs

@@ -18,7 +18,6 @@ const GET_PROC_ADDRESS_NO_REDIRECT: &'static [u8] = b"ZludaGetProcAddress_NoRedi
 lazy_static! {
     static ref PLATFORM_LIBRARY: PlatformLibrary = unsafe { PlatformLibrary::new() };
 }
-include!("../../zluda_redirect/src/payload_guid.rs");
 
 #[allow(non_snake_case)]
 struct PlatformLibrary {

zluda_inject/Cargo.toml

@@ -10,6 +10,8 @@ path = "src/main.rs"
 
 [target.'cfg(windows)'.dependencies]
 winapi = { version = "0.3", features = ["jobapi2", "processthreadsapi", "synchapi", "winbase", "std"] }
+tempfile = "3"
+argh = "0.1"
 detours-sys = { path = "../detours-sys" }
 
 [dev-dependencies]

zluda_inject/build.rs

@@ -43,6 +43,8 @@ fn main() -> Result<(), VarError> {
             .arg("-ldylib=nvcuda")
             .arg("-C")
             .arg(format!("opt-level={}", opt_level))
+            .arg("-L")
+            .arg(format!("{}", out_dir))
             .arg("--out-dir")
             .arg(format!("{}", out_dir))
             .arg("--target")
@@ -52,11 +54,11 @@ fn main() -> Result<(), VarError> {
     }
     std::fs::copy(
         format!(
-            "{}{}do_cuinit_main_clr.exe",
+            "{}{}do_cuinit_late_clr.exe",
             helpers_dir_as_string,
             path::MAIN_SEPARATOR
         ),
-        format!("{}{}do_cuinit_main_clr.exe", out_dir, path::MAIN_SEPARATOR),
+        format!("{}{}do_cuinit_late_clr.exe", out_dir, path::MAIN_SEPARATOR),
     )
     .unwrap();
     println!("cargo:rustc-env=HELPERS_OUT_DIR={}", &out_dir);

zluda_inject/src/bin.rs

@@ -1,11 +1,14 @@
+use std::env;
+use std::os::windows;
 use std::os::windows::ffi::OsStrExt;
-use std::path::Path;
-use std::ptr;
-use std::{env, ops::Deref};
 use std::{error::Error, process};
+use std::{fs, io, ptr};
 use std::{mem, path::PathBuf};
 
+use argh::FromArgs;
 use mem::size_of_val;
+use tempfile::TempDir;
+use winapi::um::processenv::SearchPathW;
 use winapi::um::{
     jobapi2::{AssignProcessToJobObject, SetInformationJobObject},
     processthreadsapi::{GetExitCodeProcess, ResumeThread},
@@ -20,28 +23,46 @@ use winapi::um::{
 use winapi::um::winbase::{INFINITE, WAIT_FAILED};
 
 static REDIRECT_DLL: &'static str = "zluda_redirect.dll";
-static ZLUDA_DLL: &'static str = "nvcuda.dll";
+static NVCUDA_DLL: &'static str = "nvcuda.dll";
-static ZLUDA_ML_DLL: &'static str = "nvml.dll";
+static NVML_DLL: &'static str = "nvml.dll";
 
 include!("../../zluda_redirect/src/payload_guid.rs");
 
+#[derive(FromArgs)]
+/// Launch application with custom CUDA libraries
+struct ProgramArguments {
+    /// DLL to be injected instead of system nvcuda.dll. If not provided {0} will use nvcuda.dll from its directory
+    #[argh(option)]
+    nvcuda: Option<PathBuf>,
+
+    /// DLL to be injected instead of system nvml.dll. If not provided {0} will use nvml.dll from its directory
+    #[argh(option)]
+    nvml: Option<PathBuf>,
+
+    /// executable to be injected with custom CUDA libraries
+    #[argh(positional)]
+    exe: String,
+
+    /// arguments to the executable
+    #[argh(positional)]
+    args: Vec<String>,
+}
+
 pub fn main_impl() -> Result<(), Box<dyn Error>> {
-    let args = env::args().collect::<Vec<_>>();
+    let raw_args = argh::from_env::<ProgramArguments>();
-    if args.len() <= 1 {
+    let normalized_args = NormalizedArguments::new(raw_args)?;
-        print_help_and_exit();
+    let mut environment = Environment::setup(normalized_args)?;
-    }
-    let injector_path = env::current_exe()?;
-    let injector_dir = injector_path.parent().unwrap();
-    let redirect_path = create_redirect_path(injector_dir);
-    let (mut inject_nvcuda_path, mut inject_nvml_path, cmd) =
-        create_inject_path(&args[1..], injector_dir)?;
-    let mut cmd_line = construct_command_line(cmd);
     let mut startup_info = unsafe { mem::zeroed::<detours_sys::_STARTUPINFOW>() };
     let mut proc_info = unsafe { mem::zeroed::<detours_sys::_PROCESS_INFORMATION>() };
+    let mut dlls_to_inject = [
+        environment.nvml_path_zero_terminated.as_ptr() as *const i8,
+        environment.nvcuda_path_zero_terminated.as_ptr() as _,
+        environment.redirect_path_zero_terminated.as_ptr() as _,
+    ];
     os_call!(
-        detours_sys::DetourCreateProcessWithDllExW(
+        detours_sys::DetourCreateProcessWithDllsW(
             ptr::null(),
-            cmd_line.as_mut_ptr(),
+            environment.winapi_command_line_zero_terminated.as_mut_ptr(),
             ptr::null_mut(),
             ptr::null_mut(),
             0,
@@ -50,7 +71,8 @@ pub fn main_impl() -> Result<(), Box<dyn Error>> {
             ptr::null(),
             &mut startup_info as *mut _,
             &mut proc_info as *mut _,
-            redirect_path.as_ptr() as *const i8,
+            dlls_to_inject.len() as u32,
+            dlls_to_inject.as_mut_ptr(),
             Option::None
         ),
         |x| x != 0
@@ -60,8 +82,8 @@ pub fn main_impl() -> Result<(), Box<dyn Error>> {
         detours_sys::DetourCopyPayloadToProcess(
             proc_info.hProcess,
             &PAYLOAD_NVCUDA_GUID,
-            inject_nvcuda_path.as_mut_ptr() as *mut _,
+            environment.nvcuda_path_zero_terminated.as_ptr() as *mut _,
-            (inject_nvcuda_path.len() * mem::size_of::<u16>()) as u32
+            environment.nvcuda_path_zero_terminated.len() as u32
         ),
         |x| x != 0
     );
@@ -69,8 +91,8 @@ pub fn main_impl() -> Result<(), Box<dyn Error>> {
         detours_sys::DetourCopyPayloadToProcess(
             proc_info.hProcess,
             &PAYLOAD_NVML_GUID,
-            inject_nvml_path.as_mut_ptr() as *mut _,
+            environment.nvml_path_zero_terminated.as_ptr() as *mut _,
-            (inject_nvml_path.len() * mem::size_of::<u16>()) as u32
+            environment.nvml_path_zero_terminated.len() as u32
         ),
         |x| x != 0
     );
@@ -85,6 +107,135 @@ pub fn main_impl() -> Result<(), Box<dyn Error>> {
     process::exit(child_exit_code as i32)
 }
 
+struct NormalizedArguments {
+    nvml_path: PathBuf,
+    nvcuda_path: PathBuf,
+    redirect_path: PathBuf,
+    winapi_command_line_zero_terminated: Vec<u16>,
+}
+
+impl NormalizedArguments {
+    fn new(prog_args: ProgramArguments) -> Result<Self, Box<dyn Error>> {
+        let current_exe = env::current_exe()?;
+        let nvml_path = Self::get_absolute_path(&current_exe, prog_args.nvml, NVML_DLL)?;
+        let nvcuda_path = Self::get_absolute_path(&current_exe, prog_args.nvcuda, NVCUDA_DLL)?;
+        let winapi_command_line_zero_terminated =
+            construct_command_line(std::iter::once(prog_args.exe).chain(prog_args.args));
+        let mut redirect_path = current_exe.parent().unwrap().to_path_buf();
+        redirect_path.push(REDIRECT_DLL);
+        Ok(Self {
+            nvml_path,
+            nvcuda_path,
+            redirect_path,
+            winapi_command_line_zero_terminated,
+        })
+    }
+
+    const WIN_MAX_PATH: usize = 260;
+
+    fn get_absolute_path(
+        current_exe: &PathBuf,
+        dll: Option<PathBuf>,
+        default: &str,
+    ) -> Result<PathBuf, Box<dyn Error>> {
+        Ok(if let Some(dll) = dll {
+            if dll.is_absolute() {
+                dll
+            } else {
+                let mut full_dll_path = vec![0; Self::WIN_MAX_PATH];
+                let mut dll_utf16 = dll.as_os_str().encode_wide().collect::<Vec<_>>();
+                dll_utf16.push(0);
+                loop {
+                    let copied_len = os_call!(
+                        SearchPathW(
+                            ptr::null_mut(),
+                            dll_utf16.as_ptr(),
+                            ptr::null(),
+                            full_dll_path.len() as u32,
+                            full_dll_path.as_mut_ptr(),
+                            ptr::null_mut()
+                        ),
+                        |x| x != 0
+                    ) as usize;
+                    if copied_len > full_dll_path.len() {
+                        full_dll_path.resize(copied_len + 1, 0);
+                    } else {
+                        full_dll_path.truncate(copied_len);
+                        break;
+                    }
+                }
+                PathBuf::from(String::from_utf16_lossy(&full_dll_path))
+            }
+        } else {
+            let mut dll_path = current_exe.parent().unwrap().to_path_buf();
+            dll_path.push(default);
+            dll_path
+        })
+    }
+}
+
+struct Environment {
+    nvml_path_zero_terminated: String,
+    nvcuda_path_zero_terminated: String,
+    redirect_path_zero_terminated: String,
+    winapi_command_line_zero_terminated: Vec<u16>,
+    _temp_dir: TempDir,
+}
+
+// This structs represents "enviroment". By environment we mean all paths
+// (nvcuda.dll, nvml.dll, etc.) and all related resources like the temporary
+// directory which contains nvcuda.dll
+impl Environment {
+    fn setup(args: NormalizedArguments) -> io::Result<Self> {
+        let _temp_dir = TempDir::new()?;
+        let nvml_path_zero_terminated = Self::zero_terminate(Self::copy_to_correct_name(
+            args.nvml_path,
+            &_temp_dir,
+            NVML_DLL,
+        )?);
+        let nvcuda_path_zero_terminated = Self::zero_terminate(Self::copy_to_correct_name(
+            args.nvcuda_path,
+            &_temp_dir,
+            NVCUDA_DLL,
+        )?);
+        let redirect_path_zero_terminated = Self::zero_terminate(args.redirect_path);
+        Ok(Self {
+            nvml_path_zero_terminated,
+            nvcuda_path_zero_terminated,
+            redirect_path_zero_terminated,
+            winapi_command_line_zero_terminated: args.winapi_command_line_zero_terminated,
+            _temp_dir,
+        })
+    }
+
+    fn copy_to_correct_name(
+        path_buf: PathBuf,
+        temp_dir: &TempDir,
+        correct_name: &str,
+    ) -> io::Result<PathBuf> {
+        let file_name = path_buf.file_name().unwrap();
+        if file_name == correct_name {
+            Ok(path_buf)
+        } else {
+            let mut temp_file_path = temp_dir.path().to_path_buf();
+            temp_file_path.push(correct_name);
+            match windows::fs::symlink_file(&path_buf, &temp_file_path) {
+                Ok(()) => {}
+                Err(_) => {
+                    fs::copy(&path_buf, &temp_file_path)?;
+                }
+            }
+            Ok(temp_file_path)
+        }
+    }
+
+    fn zero_terminate(p: PathBuf) -> String {
+        let mut s = p.to_string_lossy().to_string();
+        s.push('\0');
+        s
+    }
+}
+
 fn kill_child_on_process_exit(child: HANDLE) -> Result<(), Box<dyn Error>> {
     let job_handle = os_call!(CreateJobObjectA(ptr::null_mut(), ptr::null()), |x| x
         != ptr::null_mut());
@@ -103,29 +254,11 @@ fn kill_child_on_process_exit(child: HANDLE) -> Result<(), Box<dyn Error>> {
     Ok(())
 }
 
-fn print_help_and_exit() -> ! {
-    let current_exe = env::current_exe().unwrap();
-    let exe_name = current_exe.file_name().unwrap().to_string_lossy();
-    println!(
-        "USAGE:
-    {0} -- <EXE> [ARGS]...
-    {0} <DLL> -- <EXE> [ARGS]...
-ARGS:
-    <DLL>        DLL to be injected instead of system nvcuda.dll, if not provided
-                 will use nvcuda.dll from the directory where {0} is located
-    <EXE>        Path to the executable to be injected with <DLL>
-    <ARGS>...    Arguments that will be passed to <EXE>
-",
-        exe_name
-    );
-    process::exit(1)
-}
-
 // Adapted from https://docs.microsoft.com/en-us/archive/blogs/twistylittlepassagesallalike/everyone-quotes-command-line-arguments-the-wrong-way
-fn construct_command_line(args: &[String]) -> Vec<u16> {
+fn construct_command_line(args: impl Iterator<Item = String>) -> Vec<u16> {
     let mut cmd_line = Vec::new();
-    let args_len = args.len();
+    let args_len = args.size_hint().0;
-    for (idx, arg) in args.iter().enumerate() {
+    for (idx, arg) in args.enumerate() {
         if !arg.contains(&[' ', '\t', '\n', '\u{2B7F}', '\"'][..]) {
             cmd_line.extend(arg.encode_utf16());
         } else {
@@ -176,55 +309,3 @@ fn construct_command_line(args: &[String]) -> Vec<u16> {
     cmd_line.push(0);
     cmd_line
 }
-
-fn create_redirect_path(injector_dir: &Path) -> Vec<u8> {
-    let mut injector_dir = injector_dir.to_path_buf();
-    injector_dir.push(REDIRECT_DLL);
-    let mut result = injector_dir.to_string_lossy().into_owned().into_bytes();
-    result.push(0);
-    result
-}
-
-fn create_inject_path<'a>(
-    args: &'a [String],
-    injector_dir: &Path,
-) -> std::io::Result<(Vec<u16>, Vec<u16>, &'a [String])> {
-    let injector_dir = injector_dir.to_path_buf();
-    let (nvcuda_path, unparsed_args) = if args.get(0).map(Deref::deref) == Some("--") {
-        (
-            encode_file_in_directory_raw(injector_dir.clone(), ZLUDA_DLL),
-            &args[1..],
-        )
-    } else if args.get(1).map(Deref::deref) == Some("--") {
-        let dll_path = make_absolute_and_encode(&args[0])?;
-        (dll_path, &args[2..])
-    } else {
-        print_help_and_exit()
-    };
-    let nvml_path = encode_file_in_directory_raw(injector_dir, ZLUDA_ML_DLL);
-    Ok((nvcuda_path, nvml_path, unparsed_args))
-}
-
-fn encode_file_in_directory_raw(mut dir: PathBuf, file: &'static str) -> Vec<u16> {
-    dir.push(file);
-    let mut result = dir
-        .to_string_lossy()
-        .as_ref()
-        .encode_utf16()
-        .collect::<Vec<_>>();
-    result.push(0);
-    result
-}
-
-fn make_absolute_and_encode(maybe_path: &str) -> std::io::Result<Vec<u16>> {
-    let path = Path::new(maybe_path);
-    let mut encoded_path = if path.is_relative() {
-        let mut current_dir = env::current_dir()?;
-        current_dir.push(path);
-        current_dir.as_os_str().encode_wide().collect::<Vec<_>>()
-    } else {
-        maybe_path.encode_utf16().collect::<Vec<_>>()
-    };
-    encoded_path.push(0);
-    Ok(encoded_path)
-}

zluda_inject/tests/helpers/do_cuinit_early.rs

@@ -0,0 +1,10 @@
+#![crate_type = "bin"]
+
+#[link(name = "do_cuinit")]
+extern "system" {
+    fn do_cuinit(flags: u32) -> u32;
+}
+
+fn main() {
+    unsafe { do_cuinit(0) };
+}

zluda_inject/tests/helpers/subprocess.rs

@@ -0,0 +1,10 @@
+#![crate_type = "bin"]
+
+use std::io;
+use std::process::Command;
+
+fn main() -> io::Result<()> {
+    let status = Command::new("direct_cuinit.exe").status()?;
+    assert!(status.success());
+    Ok(())
+}

zluda_inject/tests/inject.rs

@@ -5,19 +5,29 @@ fn direct_cuinit() -> io::Result<()> {
     run_process_and_check_for_zluda_dump("direct_cuinit")
 }
 
+#[test]
+fn do_cuinit_early() -> io::Result<()> {
+    run_process_and_check_for_zluda_dump("do_cuinit_early")
+}
+
+#[test]
+fn do_cuinit_late() -> io::Result<()> {
+    run_process_and_check_for_zluda_dump("do_cuinit_late")
+}
+
+#[test]
+fn do_cuinit_late_clr() -> io::Result<()> {
+    run_process_and_check_for_zluda_dump("do_cuinit_late_clr")
+}
+
 #[test]
 fn indirect_cuinit() -> io::Result<()> {
     run_process_and_check_for_zluda_dump("indirect_cuinit")
 }
 
 #[test]
-fn do_cuinit() -> io::Result<()> {
+fn subprocess() -> io::Result<()> {
-    run_process_and_check_for_zluda_dump("do_cuinit_main")
+    run_process_and_check_for_zluda_dump("subprocess")
-}
-
-#[test]
-fn do_cuinit_clr() -> io::Result<()> {
-    run_process_and_check_for_zluda_dump("do_cuinit_main_clr")
 }
 
 fn run_process_and_check_for_zluda_dump(name: &'static str) -> io::Result<()> {
@@ -27,7 +37,11 @@ fn run_process_and_check_for_zluda_dump(name: &'static str) -> io::Result<()> {
     let helpers_dir = env!("HELPERS_OUT_DIR");
     let exe_under_test = format!("{}{}{}.exe", helpers_dir, std::path::MAIN_SEPARATOR, name);
     let mut test_cmd = Command::new(&zluda_with_exe);
-    let test_cmd = test_cmd.arg(&zluda_dump_dll).arg("--").arg(&exe_under_test);
+    let test_cmd = test_cmd
+        .arg("--nvcuda")
+        .arg(&zluda_dump_dll)
+        .arg("--")
+        .arg(&exe_under_test);
     let test_output = test_cmd.output()?;
     assert!(test_output.status.success());
     let stderr_text = String::from_utf8(test_output.stderr).unwrap();

zluda_ml/src/impl.rs

@@ -1,5 +1,3 @@
-use std::io::Write;
-use std::slice;
 use std::{
     os::raw::{c_char, c_uint},
     ptr,

zluda_redirect/Cargo.toml

@@ -11,6 +11,3 @@ crate-type = ["cdylib"]
 detours-sys = { path = "../detours-sys" }
 wchar = "0.6"
 winapi = { version = "0.3", features = [ "sysinfoapi", "memoryapi", "processthreadsapi", "winbase", "winnt", "winerror", "libloaderapi", "tlhelp32", "handleapi", "std"] }
-tempfile = "3"
-goblin = { version = "0.4", default-features = false, features = ["pe64"] }
-memoffset = "0.6"

zluda_redirect/src/lib.rs

@@ -6,32 +6,35 @@ extern crate winapi;
 use std::{
     collections::HashMap,
     ffi::{c_void, CStr},
-    io, mem,
+    mem, ptr, slice, usize,
-    os::raw::c_uint,
-    ptr, slice, usize,
 };
 
 use detours_sys::{
-    DetourAllocateRegionWithinJumpBounds, DetourAttach, DetourEnumerateExports,
+    DetourAttach, DetourRestoreAfterWith, DetourTransactionAbort, DetourTransactionBegin,
-    DetourRestoreAfterWith, DetourTransactionAbort, DetourTransactionBegin,
     DetourTransactionCommit, DetourUpdateProcessWithDll, DetourUpdateThread,
 };
-use goblin::pe::{
-    self,
-    header::{CoffHeader, DOS_MAGIC, PE_MAGIC, PE_POINTER_OFFSET},
-    optional_header::StandardFields64,
-};
-use memoffset::offset_of;
-use tempfile::TempDir;
 use wchar::wch;
+use winapi::{
+    shared::minwindef::{BOOL, LPVOID},
+    um::{
+        handleapi::{CloseHandle, INVALID_HANDLE_VALUE},
+        minwinbase::LPSECURITY_ATTRIBUTES,
+        processthreadsapi::{
+            CreateProcessA, GetCurrentProcessId, GetCurrentThreadId, OpenThread, ResumeThread,
+            SuspendThread, TerminateProcess, LPPROCESS_INFORMATION, LPSTARTUPINFOA, LPSTARTUPINFOW,
+        },
+        tlhelp32::{
+            CreateToolhelp32Snapshot, Thread32First, Thread32Next, TH32CS_SNAPTHREAD, THREADENTRY32,
+        },
+        winbase::CREATE_SUSPENDED,
+        winnt::{LPSTR, LPWSTR, THREAD_SUSPEND_RESUME},
+    },
+};
 use winapi::{
     shared::minwindef::{DWORD, FALSE, HMODULE, TRUE},
     um::{
         libloaderapi::{GetModuleHandleA, LoadLibraryExA},
-        memoryapi::VirtualProtect,
+        winnt::LPCSTR,
-        processthreadsapi::{FlushInstructionCache, GetCurrentProcess},
-        sysinfoapi::GetSystemInfo,
-        winnt::{LPCSTR, PAGE_READWRITE},
     },
 };
 use winapi::{
@@ -47,26 +50,6 @@ use winapi::{
     shared::winerror::NO_ERROR,
     um::libloaderapi::{LoadLibraryA, LoadLibraryExW, LoadLibraryW},
 };
-use winapi::{
-    shared::{
-        minwindef::{BOOL, LPVOID},
-        winerror::E_UNEXPECTED,
-    },
-    um::{
-        handleapi::{CloseHandle, INVALID_HANDLE_VALUE},
-        libloaderapi::GetModuleHandleW,
-        minwinbase::LPSECURITY_ATTRIBUTES,
-        processthreadsapi::{
-            CreateProcessA, GetCurrentProcessId, GetCurrentThreadId, OpenThread, ResumeThread,
-            SuspendThread, TerminateProcess, LPPROCESS_INFORMATION, LPSTARTUPINFOA, LPSTARTUPINFOW,
-        },
-        tlhelp32::{
-            CreateToolhelp32Snapshot, Thread32First, Thread32Next, TH32CS_SNAPTHREAD, THREADENTRY32,
-        },
-        winbase::{CopyFileW, CreateSymbolicLinkW, CREATE_SUSPENDED},
-        winnt::{LPSTR, LPWSTR, THREAD_SUSPEND_RESUME},
-    },
-};
 
 include!("payload_guid.rs");
 
@@ -74,13 +57,12 @@ const NVCUDA_UTF8: &'static str = "NVCUDA.DLL";
 const NVCUDA_UTF16: &[u16] = wch!("NVCUDA.DLL");
 const NVML_UTF8: &'static str = "NVML.DLL";
 const NVML_UTF16: &[u16] = wch!("NVML.DLL");
-static mut ZLUDA_PATH_UTF8: Vec<u8> = Vec::new();
+static mut ZLUDA_PATH_UTF8: Option<&'static [u8]> = None;
-static mut ZLUDA_PATH_UTF16: Option<&'static [u16]> = None;
+static mut ZLUDA_PATH_UTF16: Vec<u16> = Vec::new();
-static mut ZLUDA_ML_PATH_UTF8: Vec<u8> = Vec::new();
+static mut ZLUDA_ML_PATH_UTF8: Option<&'static [u8]> = None;
-static mut ZLUDA_ML_PATH_UTF16: Option<&'static [u16]> = None;
+static mut ZLUDA_ML_PATH_UTF16: Vec<u16> = Vec::new();
 static mut CURRENT_MODULE_FILENAME: Vec<u8> = Vec::new();
 static mut DETOUR_STATE: Option<DetourDetachGuard> = None;
-const CUDA_ERROR_NOT_SUPPORTED: c_uint = 801;
 
 #[no_mangle]
 #[used]
@@ -197,9 +179,9 @@ unsafe extern "system" fn ZludaLoadLibraryW_NoRedirect(lpLibFileName: LPCWSTR) -
 #[allow(non_snake_case)]
 unsafe extern "system" fn ZludaLoadLibraryA(lpLibFileName: LPCSTR) -> HMODULE {
     let nvcuda_file_name = if is_nvcuda_dll_utf8(lpLibFileName as *const _) {
-        ZLUDA_PATH_UTF8.as_ptr() as *const _
+        ZLUDA_PATH_UTF8.unwrap().as_ptr() as *const _
     } else if is_nvml_dll_utf8(lpLibFileName as *const _) {
-        ZLUDA_ML_PATH_UTF8.as_ptr() as *const _
+        ZLUDA_ML_PATH_UTF8.unwrap().as_ptr() as *const _
     } else {
         lpLibFileName
     };
@@ -209,9 +191,9 @@ unsafe extern "system" fn ZludaLoadLibraryA(lpLibFileName: LPCSTR) -> HMODULE {
 #[allow(non_snake_case)]
 unsafe extern "system" fn ZludaLoadLibraryW(lpLibFileName: LPCWSTR) -> HMODULE {
     let nvcuda_file_name = if is_nvcuda_dll_utf16(lpLibFileName) {
-        ZLUDA_PATH_UTF16.unwrap().as_ptr()
+        ZLUDA_PATH_UTF16.as_ptr()
     } else if is_nvml_dll_utf16(lpLibFileName as *const _) {
-        ZLUDA_ML_PATH_UTF16.unwrap().as_ptr()
+        ZLUDA_ML_PATH_UTF16.as_ptr()
     } else {
         lpLibFileName
     };
@@ -225,9 +207,9 @@ unsafe extern "system" fn ZludaLoadLibraryExA(
     dwFlags: DWORD,
 ) -> HMODULE {
     let nvcuda_file_name = if is_nvcuda_dll_utf8(lpLibFileName as *const _) {
-        ZLUDA_PATH_UTF8.as_ptr() as *const _
+        ZLUDA_PATH_UTF8.unwrap().as_ptr() as *const _
     } else if is_nvml_dll_utf8(lpLibFileName as *const _) {
-        ZLUDA_ML_PATH_UTF8.as_ptr() as *const _
+        ZLUDA_ML_PATH_UTF8.unwrap().as_ptr() as *const _
     } else {
         lpLibFileName
     };
@@ -241,9 +223,9 @@ unsafe extern "system" fn ZludaLoadLibraryExW(
     dwFlags: DWORD,
 ) -> HMODULE {
     let nvcuda_file_name = if is_nvcuda_dll_utf16(lpLibFileName) {
-        ZLUDA_PATH_UTF16.unwrap().as_ptr()
+        ZLUDA_PATH_UTF16.as_ptr()
     } else if is_nvml_dll_utf16(lpLibFileName as *const _) {
-        ZLUDA_ML_PATH_UTF16.unwrap().as_ptr()
+        ZLUDA_ML_PATH_UTF16.as_ptr()
     } else {
         lpLibFileName
     };
@@ -392,67 +374,6 @@ unsafe extern "system" fn ZludaCreateProcessWithTokenW(
     continue_create_process_hook(create_proc_result, dwCreationFlags, lpProcessInformation)
 }
 
-static mut MAIN: unsafe extern "system" fn() -> DWORD = zluda_main;
-static mut COR_EXE_MAIN: unsafe extern "system" fn() -> DWORD = zluda_main_clr;
-
-// https://docs.microsoft.com/en-us/windows/win32/dlls/dynamic-link-library-search-order#search-order-for-desktop-applications
-// "If a DLL with the same module name is already loaded in memory, the system
-// uses the loaded DLL, no matter which directory it is in. The system does not
-// search for the DLL."
-unsafe extern "system" fn zluda_main() -> DWORD {
-    zluda_main_impl(MAIN)
-}
-
-unsafe extern "system" fn zluda_main_clr() -> DWORD {
-    zluda_main_impl(COR_EXE_MAIN)
-}
-
-unsafe fn zluda_main_impl(original: unsafe extern "system" fn() -> DWORD) -> DWORD {
-    let temp_dir = match do_zluda_preload() {
-        Ok(f) => f,
-        Err(e) => return e.raw_os_error().unwrap_or(E_UNEXPECTED) as DWORD,
-    };
-    let result = original();
-    drop(temp_dir);
-    result
-}
-
-unsafe fn do_zluda_preload() -> std::io::Result<TempDir> {
-    let temp_dir = tempfile::tempdir()?;
-    do_single_zluda_preload(&temp_dir, ZLUDA_PATH_UTF16.unwrap().as_ptr(), NVCUDA_UTF8)?;
-    do_single_zluda_preload(&temp_dir, ZLUDA_ML_PATH_UTF16.unwrap().as_ptr(), NVML_UTF8)?;
-    Ok(temp_dir)
-}
-
-unsafe fn do_single_zluda_preload(
-    temp_dir: &TempDir,
-    full_path: *const u16,
-    file_name: &'static str,
-) -> io::Result<()> {
-    let mut temp_file_path = temp_dir.path().to_path_buf();
-    temp_file_path.push(file_name);
-    let mut temp_file_path_utf16 = temp_file_path
-        .into_os_string()
-        .to_string_lossy()
-        .encode_utf16()
-        .collect::<Vec<_>>();
-    temp_file_path_utf16.push(0);
-    // Probably we are not in developer mode, do a copty then
-    if 0 == CreateSymbolicLinkW(
-        temp_file_path_utf16.as_ptr(),
-        full_path,
-        0x2, //SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE
-    ) {
-        if 0 == CopyFileW(full_path, temp_file_path_utf16.as_ptr(), 1) {
-            return Err(io::Error::last_os_error());
-        }
-    }
-    if ptr::null_mut() == ZludaLoadLibraryW_NoRedirect(temp_file_path_utf16.as_ptr()) {
-        return Err(io::Error::last_os_error());
-    }
-    Ok(())
-}
-
 // This type encapsulates typical calling sequence of detours and cleanup.
 // We have two ways we do detours:
 // * If we are loaded before nvcuda.dll, we hook LoadLibrary*
@@ -633,21 +554,31 @@ unsafe fn continue_create_process_hook(
     // continues uninjected than to break the parent
     if DetourUpdateProcessWithDll(
         (*process_information).hProcess,
-        &mut CURRENT_MODULE_FILENAME.as_ptr() as *mut _ as *mut _,
+        &mut ZLUDA_ML_PATH_UTF8.unwrap().as_ptr() as *mut _ as *mut _,
         1,
     ) != FALSE
+        && DetourUpdateProcessWithDll(
+            (*process_information).hProcess,
+            &mut ZLUDA_PATH_UTF8.unwrap().as_ptr() as *mut _ as *mut _,
+            1,
+        ) != FALSE
+        && DetourUpdateProcessWithDll(
+            (*process_information).hProcess,
+            &mut CURRENT_MODULE_FILENAME.as_ptr() as *mut _ as *mut _,
+            1,
+        ) != FALSE
     {
         detours_sys::DetourCopyPayloadToProcess(
             (*process_information).hProcess,
             &PAYLOAD_NVML_GUID,
-            ZLUDA_ML_PATH_UTF16.unwrap().as_ptr() as *mut _,
+            ZLUDA_ML_PATH_UTF16.as_ptr() as *mut _,
-            (ZLUDA_ML_PATH_UTF16.unwrap().len() * mem::size_of::<u16>()) as u32,
+            (ZLUDA_ML_PATH_UTF16.len() * mem::size_of::<u16>()) as u32,
         );
         detours_sys::DetourCopyPayloadToProcess(
             (*process_information).hProcess,
             &PAYLOAD_NVCUDA_GUID,
-            ZLUDA_PATH_UTF16.unwrap().as_ptr() as *mut _,
+            ZLUDA_PATH_UTF16.as_ptr() as *mut _,
-            (ZLUDA_PATH_UTF16.unwrap().len() * mem::size_of::<u16>()) as u32,
+            (ZLUDA_PATH_UTF16.len() * mem::size_of::<u16>()) as u32,
         );
     }
     if original_creation_flags & CREATE_SUSPENDED == 0 {
@@ -733,23 +664,18 @@ unsafe extern "system" fn DllMain(instDLL: HINSTANCE, dwReason: u32, _: *const u
         }
         match get_zluda_dlls_paths() {
             Some((nvcuda_path, nvml_path)) => {
-                ZLUDA_PATH_UTF16 = Some(nvcuda_path);
+                ZLUDA_PATH_UTF8 = Some(nvcuda_path);
-                ZLUDA_ML_PATH_UTF16 = Some(nvml_path);
+                ZLUDA_ML_PATH_UTF8 = Some(nvml_path);
-                // from_utf16_lossy(...) handles terminating NULL correctly
+                ZLUDA_PATH_UTF16 = std::str::from_utf8_unchecked(nvcuda_path)
-                ZLUDA_PATH_UTF8 = String::from_utf16_lossy(nvcuda_path).into_bytes();
+                    .encode_utf16()
-                ZLUDA_ML_PATH_UTF8 = String::from_utf16_lossy(nvml_path).into_bytes();
+                    .collect::<Vec<_>>();
+                ZLUDA_ML_PATH_UTF16 = std::str::from_utf8_unchecked(nvml_path)
+                    .encode_utf16()
+                    .collect::<Vec<_>>();
             }
             None => return FALSE,
         }
-        // If the application (directly or not) links to nvcuda.dll, nvcuda.dll
+        match detour_already_loaded_nvcuda() {
-        // will get loaded before we can act. In this case, instead of
-        // redirecting LoadLibrary* to load ZLUDA, we override already loaded
-        // functions
-        let detach_guard = match get_cuinit() {
-            Some((nvcuda_mod, _)) => detour_already_loaded_nvcuda(nvcuda_mod),
-            None => detour_main(),
-        };
-        match detach_guard {
             Some(g) => {
                 DETOUR_STATE = Some(g);
                 TRUE
@@ -787,42 +713,9 @@ unsafe fn initialize_current_module_name(current_module: HINSTANCE) -> bool {
     }
 }
 
-unsafe fn get_cuinit() -> Option<(HMODULE, FARPROC)> {
-    let nvcuda = GetModuleHandleA(b"nvcuda\0".as_ptr() as _);
-    if nvcuda == ptr::null_mut() {
-        return None;
-    }
-    let cuinit_addr = GetProcAddress(nvcuda, b"cuInit\0".as_ptr() as _);
-    if cuinit_addr == ptr::null_mut() {
-        return None;
-    }
-    Some((nvcuda as *mut _, cuinit_addr))
-}
-
 #[must_use]
-unsafe fn detour_already_loaded_nvcuda(nvcuda_mod: HMODULE) -> Option<DetourDetachGuard> {
+unsafe fn detour_already_loaded_nvcuda() -> Option<DetourDetachGuard> {
-    let zluda_module = LoadLibraryW(ZLUDA_PATH_UTF16.unwrap().as_ptr());
+    let nvcuda_mod = GetModuleHandleA(b"nvcuda\0".as_ptr() as _);
-    if zluda_module == ptr::null_mut() {
-        return None;
-    }
-    let original_functions = gather_imports(nvcuda_mod);
-    let override_functions = gather_imports(zluda_module);
-    let mut override_fn_pairs = HashMap::with_capacity(original_functions.len());
-    // TODO: optimize
-    for (original_fn_name, original_fn_address) in original_functions {
-        let override_fn_address =
-            match override_functions.binary_search_by_key(&original_fn_name, |(name, _)| *name) {
-                Ok(x) => override_functions[x].1,
-                Err(_) => {
-                    // TODO: print a warning in debug
-                    cuda_unsupported as _
-                }
-            };
-        override_fn_pairs.insert(
-            original_fn_name,
-            (original_fn_address as _, override_fn_address),
-        );
-    }
     let detour_functions = vec![
         (
             &mut LOAD_LIBRARY_A as *mut _ as *mut *mut c_void,
@@ -838,146 +731,10 @@ unsafe fn detour_already_loaded_nvcuda(nvcuda_mod: HMODULE) -> Option<DetourDeta
             ZludaLoadLibraryExW as _,
         ),
     ];
-    DetourDetachGuard::detour_functions(nvcuda_mod, detour_functions, override_fn_pairs)
+    DetourDetachGuard::detour_functions(nvcuda_mod, detour_functions, HashMap::new())
 }
 
-unsafe extern "system" fn cuda_unsupported() -> c_uint {
+fn get_zluda_dlls_paths() -> Option<(&'static [u8], &'static [u8])> {
-    CUDA_ERROR_NOT_SUPPORTED
-}
-
-unsafe fn gather_imports(module: HINSTANCE) -> Vec<(&'static CStr, *mut c_void)> {
-    let mut result = Vec::new();
-    DetourEnumerateExports(
-        module as _,
-        &mut result as *mut _ as *mut _,
-        Some(gather_imports_impl),
-    );
-    result
-}
-
-unsafe extern "stdcall" fn gather_imports_impl(
-    context: *mut c_void,
-    _: u32,
-    name: LPCSTR,
-    code: *mut c_void,
-) -> i32 {
-    let result: &mut Vec<(&'static CStr, *mut c_void)> = &mut *(context as *mut Vec<_>);
-    result.push((CStr::from_ptr(name), code));
-    TRUE
-}
-
-#[must_use]
-unsafe fn detour_main() -> Option<DetourDetachGuard> {
-    if !override_entry_point() {
-        return None;
-    }
-    let mut detour_functions = vec![
-        (
-            &mut LOAD_LIBRARY_A as *mut _ as *mut *mut c_void,
-            ZludaLoadLibraryA as *mut c_void,
-        ),
-        (&mut LOAD_LIBRARY_W as *mut _ as _, ZludaLoadLibraryW as _),
-        (
-            &mut LOAD_LIBRARY_EX_A as *mut _ as _,
-            ZludaLoadLibraryExA as _,
-        ),
-        (
-            &mut LOAD_LIBRARY_EX_W as *mut _ as _,
-            ZludaLoadLibraryExW as _,
-        ),
-    ];
-    detour_functions.extend(get_clr_entry_point());
-    DetourDetachGuard::detour_functions(ptr::null_mut(), detour_functions, HashMap::new())
-}
-
-unsafe fn override_entry_point() -> bool {
-    let exe_handle = GetModuleHandleW(ptr::null());
-    let dos_signature = exe_handle as *mut u16;
-    if *dos_signature != DOS_MAGIC {
-        return false;
-    }
-    let pe_offset = *((exe_handle as *mut u8).add(PE_POINTER_OFFSET as usize) as *mut u32);
-    let pe_sig = (exe_handle as *mut u8).add(pe_offset as usize) as *mut u32;
-    if (*pe_sig) != PE_MAGIC {
-        return false;
-    }
-    let coff_header = pe_sig.add(1) as *mut CoffHeader;
-    let standard_coff_fields = coff_header.add(1) as *mut StandardFields64;
-    if (*standard_coff_fields).magic != pe::optional_header::MAGIC_64 {
-        return false;
-    }
-    let entry_point = mem::transmute::<_, unsafe extern "system" fn() -> DWORD>(
-        (exe_handle as *mut u8).add((*standard_coff_fields).address_of_entry_point as usize),
-    );
-    let mut allocated_size = 0;
-    let exe_region = DetourAllocateRegionWithinJumpBounds(exe_handle as _, &mut allocated_size);
-    if (allocated_size as usize) < mem::size_of::<JmpThunk64>() || exe_region == ptr::null_mut() {
-        return false;
-    }
-    MAIN = entry_point;
-    *(exe_region as *mut JmpThunk64) = JmpThunk64::new(zluda_main);
-    FlushInstructionCache(
-        GetCurrentProcess(),
-        exe_region,
-        mem::size_of::<JmpThunk64>(),
-    );
-    let new_address_of_entry_point = (exe_region as *mut u8).offset_from(exe_handle as *mut u8);
-    let entry_point_offset = offset_of!(StandardFields64, address_of_entry_point);
-    let mut system_info = mem::zeroed();
-    GetSystemInfo(&mut system_info);
-    let pointer_to_address_of_entry_point =
-        (standard_coff_fields as *mut u8).add(entry_point_offset) as *mut i32;
-    let page_size = system_info.dwPageSize as usize;
-    let page_start = (((pointer_to_address_of_entry_point as usize) / page_size) * page_size) as _;
-    let mut old_protect = 0;
-    if VirtualProtect(page_start, page_size, PAGE_READWRITE, &mut old_protect) == 0 {
-        return false;
-    }
-    *pointer_to_address_of_entry_point = new_address_of_entry_point as i32;
-    if VirtualProtect(page_start, page_size, old_protect, &mut old_protect) == 0 {
-        return false;
-    }
-    true
-}
-
-// mov rax, $address;
-// jmp rax;
-// int 3;
-#[repr(packed)]
-#[allow(dead_code)]
-#[cfg(target_pointer_width = "64")]
-struct JmpThunk64 {
-    mov_rax: [u8; 2],
-    address: u64,
-    jmp_rax: [u8; 2],
-    int3: u8,
-}
-
-impl JmpThunk64 {
-    fn new<T: Sized>(target: unsafe extern "system" fn() -> T) -> Self {
-        JmpThunk64 {
-            mov_rax: [0x48, 0xB8],
-            address: target as u64,
-            jmp_rax: [0xFF, 0xE0],
-            int3: 0xcc,
-        }
-    }
-}
-
-unsafe fn get_clr_entry_point() -> Option<(*mut *mut c_void, *mut c_void)> {
-    let mscoree = GetModuleHandleA(b"mscoree\0".as_ptr() as _);
-    if mscoree == ptr::null_mut() {
-        return None;
-    }
-    let proc = GetProcAddress(mscoree, b"_CorExeMain\0".as_ptr() as _);
-    if proc == ptr::null_mut() {
-        return None;
-    }
-    COR_EXE_MAIN = mem::transmute(proc);
-    Some((&mut COR_EXE_MAIN as *mut _ as _, zluda_main_clr as _))
-}
-
-fn get_zluda_dlls_paths() -> Option<(&'static [u16], &'static [u16])> {
     match get_payload(&PAYLOAD_NVCUDA_GUID) {
         None => None,
         Some(nvcuda_payload) => match get_payload(&PAYLOAD_NVML_GUID) {
@@ -987,22 +744,17 @@ fn get_zluda_dlls_paths() -> Option<(&'static [u16], &'static [u16])> {
     }
 }
 
-fn get_payload(guid: &detours_sys::GUID) -> Option<&'static [u16]> {
+fn get_payload(guid: &detours_sys::GUID) -> Option<&'static [u8]> {
-    let mut module = ptr::null_mut();
+    let mut size = 0;
-    loop {
+    let payload_ptr = unsafe { detours_sys::DetourFindPayloadEx(guid, &mut size) };
-        module = unsafe { detours_sys::DetourEnumerateModules(module) };
+    if payload_ptr != ptr::null_mut() {
-        if module == ptr::null_mut() {
+        Some(unsafe {
-            return None;
+            slice::from_raw_parts(
-        }
+                payload_ptr as *const _,
-        let mut size = 0;
+                (size as usize) / mem::size_of::<u16>(),
-        let payload_ptr = unsafe { detours_sys::DetourFindPayload(module, guid, &mut size) };
+            )
-        if payload_ptr != ptr::null_mut() {
+        })
-            return Some(unsafe {
+    } else {
-                slice::from_raw_parts(
+        None
-                    payload_ptr as *const _,
-                    (size as usize) / mem::size_of::<u16>(),
-                )
-            });
-        }
     }
 }