Merging upstream version 1.76.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

45 files changed, 1590 insertions, 261 deletions

diff --git a/library/std/src/sys/common/alloc.rs b/library/std/src/sys/common/alloc.rs
index d58aa6c27..b7357460f 100644
--- a/library/std/src/sys/common/alloc.rs
+++ b/library/std/src/sys/common/alloc.rs
@@ -14,7 +14,6 @@ use crate::ptr;
     target_arch = "powerpc",
     target_arch = "powerpc64",
     target_arch = "sparc",
-    target_arch = "asmjs",
     target_arch = "wasm32",
     target_arch = "hexagon",
     all(target_arch = "riscv32", not(target_os = "espidf")),
diff --git a/library/std/src/sys/mod.rs b/library/std/src/sys/mod.rs
index 159ffe7ac..88420bd36 100644
--- a/library/std/src/sys/mod.rs
+++ b/library/std/src/sys/mod.rs
@@ -53,6 +53,9 @@ cfg_if::cfg_if! {
     } else if #[cfg(all(target_vendor = "fortanix", target_env = "sgx"))] {
         mod sgx;
         pub use self::sgx::*;
+    } else if #[cfg(target_os = "teeos")] {
+        mod teeos;
+        pub use self::teeos::*;
     } else {
         mod unsupported;
         pub use self::unsupported::*;
diff --git a/library/std/src/sys/personality/mod.rs b/library/std/src/sys/personality/mod.rs
index 386a399f5..d37b8ce63 100644
--- a/library/std/src/sys/personality/mod.rs
+++ b/library/std/src/sys/personality/mod.rs
@@ -12,7 +12,7 @@
 
 mod dwarf;
 
-#[cfg(not(test))]
+#[cfg(not(any(test, doctest)))]
 cfg_if::cfg_if! {
     if #[cfg(target_os = "emscripten")] {
         mod emcc;
@@ -28,6 +28,7 @@ cfg_if::cfg_if! {
     } else if #[cfg(any(
         all(target_family = "windows", target_env = "gnu"),
         target_os = "psp",
+        target_os = "xous",
         target_os = "solid_asp3",
         all(target_family = "unix", not(target_os = "espidf"), not(target_os = "l4re")),
         all(target_vendor = "fortanix", target_env = "sgx"),
diff --git a/library/std/src/sys/solid/net.rs b/library/std/src/sys/solid/net.rs
index 1eae0fc06..a768e2406 100644
--- a/library/std/src/sys/solid/net.rs
+++ b/library/std/src/sys/solid/net.rs
@@ -5,9 +5,10 @@ use crate::{
     io::{self, BorrowedBuf, BorrowedCursor, ErrorKind, IoSlice, IoSliceMut},
     mem,
     net::{Shutdown, SocketAddr},
+    os::solid::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd},
     ptr, str,
     sys_common::net::{getsockopt, setsockopt, sockaddr_to_addr},
-    sys_common::{AsInner, FromInner, IntoInner},
+    sys_common::{FromInner, IntoInner},
     time::Duration,
 };
 
@@ -28,102 +29,6 @@ const fn max_iov() -> usize {
     1024
 }
 
-/// A file descriptor.
-#[rustc_layout_scalar_valid_range_start(0)]
-// libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
-// 32-bit c_int. Below is -2, in two's complement, but that only works out
-// because c_int is 32 bits.
-#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
-struct FileDesc {
-    fd: c_int,
-}
-
-impl FileDesc {
-    #[inline]
-    fn new(fd: c_int) -> FileDesc {
-        assert_ne!(fd, -1i32);
-        // Safety: we just asserted that the value is in the valid range and
-        // isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
-        unsafe { FileDesc { fd } }
-    }
-
-    #[inline]
-    fn raw(&self) -> c_int {
-        self.fd
-    }
-
-    /// Extracts the actual file descriptor without closing it.
-    #[inline]
-    fn into_raw(self) -> c_int {
-        let fd = self.fd;
-        mem::forget(self);
-        fd
-    }
-
-    fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
-        let ret = cvt(unsafe {
-            netc::read(self.fd, buf.as_mut_ptr() as *mut c_void, cmp::min(buf.len(), READ_LIMIT))
-        })?;
-        Ok(ret as usize)
-    }
-
-    fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        let ret = cvt(unsafe {
-            netc::readv(
-                self.fd,
-                bufs.as_ptr() as *const netc::iovec,
-                cmp::min(bufs.len(), max_iov()) as c_int,
-            )
-        })?;
-        Ok(ret as usize)
-    }
-
-    #[inline]
-    fn is_read_vectored(&self) -> bool {
-        true
-    }
-
-    fn write(&self, buf: &[u8]) -> io::Result<usize> {
-        let ret = cvt(unsafe {
-            netc::write(self.fd, buf.as_ptr() as *const c_void, cmp::min(buf.len(), READ_LIMIT))
-        })?;
-        Ok(ret as usize)
-    }
-
-    fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        let ret = cvt(unsafe {
-            netc::writev(
-                self.fd,
-                bufs.as_ptr() as *const netc::iovec,
-                cmp::min(bufs.len(), max_iov()) as c_int,
-            )
-        })?;
-        Ok(ret as usize)
-    }
-
-    #[inline]
-    fn is_write_vectored(&self) -> bool {
-        true
-    }
-
-    fn duplicate(&self) -> io::Result<FileDesc> {
-        cvt(unsafe { netc::dup(self.fd) }).map(Self::new)
-    }
-}
-
-impl AsInner<c_int> for FileDesc {
-    #[inline]
-    fn as_inner(&self) -> &c_int {
-        &self.fd
-    }
-}
-
-impl Drop for FileDesc {
-    fn drop(&mut self) {
-        unsafe { netc::close(self.fd) };
-    }
-}
-
 #[doc(hidden)]
 pub trait IsMinusOne {
     fn is_minus_one(&self) -> bool;
@@ -212,7 +117,7 @@ pub(super) fn decode_error_kind(er: abi::ER) -> ErrorKind {
 
 pub fn init() {}
 
-pub struct Socket(FileDesc);
+pub struct Socket(OwnedFd);
 
 impl Socket {
     pub fn new(addr: &SocketAddr, ty: c_int) -> io::Result<Socket> {
@@ -226,16 +131,13 @@ impl Socket {
     pub fn new_raw(fam: c_int, ty: c_int) -> io::Result<Socket> {
         unsafe {
             let fd = cvt(netc::socket(fam, ty, 0))?;
-            let fd = FileDesc::new(fd);
-            let socket = Socket(fd);
-
-            Ok(socket)
+            Ok(Self::from_raw_fd(fd))
         }
     }
 
     pub fn connect(&self, addr: &SocketAddr) -> io::Result<()> {
         let (addr, len) = addr.into_inner();
-        cvt(unsafe { netc::connect(self.0.raw(), addr.as_ptr(), len) })?;
+        cvt(unsafe { netc::connect(self.as_raw_fd(), addr.as_ptr(), len) })?;
         Ok(())
     }
 
@@ -264,14 +166,14 @@ impl Socket {
             timeout.tv_usec = 1;
         }
 
-        let fds = netc::fd_set { num_fds: 1, fds: [self.0.raw()] };
+        let fds = netc::fd_set { num_fds: 1, fds: [self.as_raw_fd()] };
 
         let mut writefds = fds;
         let mut errorfds = fds;
 
         let n = unsafe {
             cvt(netc::select(
-                self.0.raw() + 1,
+                self.as_raw_fd() + 1,
                 ptr::null_mut(),
                 &mut writefds,
                 &mut errorfds,
@@ -294,18 +196,17 @@ impl Socket {
     }
 
     pub fn accept(&self, storage: *mut sockaddr, len: *mut socklen_t) -> io::Result<Socket> {
-        let fd = cvt_r(|| unsafe { netc::accept(self.0.raw(), storage, len) })?;
-        let fd = FileDesc::new(fd);
-        Ok(Socket(fd))
+        let fd = cvt_r(|| unsafe { netc::accept(self.as_raw_fd(), storage, len) })?;
+        unsafe { Ok(Self::from_raw_fd(fd)) }
     }
 
     pub fn duplicate(&self) -> io::Result<Socket> {
-        self.0.duplicate().map(Socket)
+        Ok(Self(self.0.try_clone()?))
     }
 
     fn recv_with_flags(&self, mut buf: BorrowedCursor<'_>, flags: c_int) -> io::Result<()> {
         let ret = cvt(unsafe {
-            netc::recv(self.0.raw(), buf.as_mut().as_mut_ptr().cast(), buf.capacity(), flags)
+            netc::recv(self.as_raw_fd(), buf.as_mut().as_mut_ptr().cast(), buf.capacity(), flags)
         })?;
         unsafe {
             buf.advance(ret as usize);
@@ -330,12 +231,19 @@ impl Socket {
     }
 
     pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        self.0.read_vectored(bufs)
+        let ret = cvt(unsafe {
+            netc::readv(
+                self.as_raw_fd(),
+                bufs.as_ptr() as *const netc::iovec,
+                cmp::min(bufs.len(), max_iov()) as c_int,
+            )
+        })?;
+        Ok(ret as usize)
     }
 
     #[inline]
     pub fn is_read_vectored(&self) -> bool {
-        self.0.is_read_vectored()
+        true
     }
 
     fn recv_from_with_flags(
@@ -348,7 +256,7 @@ impl Socket {
 
         let n = cvt(unsafe {
             netc::recvfrom(
-                self.0.raw(),
+                self.as_raw_fd(),
                 buf.as_mut_ptr() as *mut c_void,
                 buf.len(),
                 flags,
@@ -368,16 +276,30 @@ impl Socket {
     }
 
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
-        self.0.write(buf)
+        let ret = cvt(unsafe {
+            netc::write(
+                self.as_raw_fd(),
+                buf.as_ptr() as *const c_void,
+                cmp::min(buf.len(), READ_LIMIT),
+            )
+        })?;
+        Ok(ret as usize)
     }
 
     pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        self.0.write_vectored(bufs)
+        let ret = cvt(unsafe {
+            netc::writev(
+                self.as_raw_fd(),
+                bufs.as_ptr() as *const netc::iovec,
+                cmp::min(bufs.len(), max_iov()) as c_int,
+            )
+        })?;
+        Ok(ret as usize)
     }
 
     #[inline]
     pub fn is_write_vectored(&self) -> bool {
-        self.0.is_write_vectored()
+        true
     }
 
     pub fn set_timeout(&self, dur: Option<Duration>, kind: c_int) -> io::Result<()> {
@@ -423,7 +345,7 @@ impl Socket {
             Shutdown::Read => netc::SHUT_RD,
             Shutdown::Both => netc::SHUT_RDWR,
         };
-        cvt(unsafe { netc::shutdown(self.0.raw(), how) })?;
+        cvt(unsafe { netc::shutdown(self.as_raw_fd(), how) })?;
         Ok(())
     }
 
@@ -454,7 +376,7 @@ impl Socket {
     pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
         let mut nonblocking = nonblocking as c_int;
         cvt(unsafe {
-            netc::ioctl(*self.as_inner(), netc::FIONBIO, (&mut nonblocking) as *mut c_int as _)
+            netc::ioctl(self.as_raw_fd(), netc::FIONBIO, (&mut nonblocking) as *mut c_int as _)
         })
         .map(drop)
     }
@@ -466,25 +388,48 @@ impl Socket {
 
     // This method is used by sys_common code to abstract over targets.
     pub fn as_raw(&self) -> c_int {
-        *self.as_inner()
+        self.as_raw_fd()
     }
 }
 
-impl AsInner<c_int> for Socket {
+impl FromInner<OwnedFd> for Socket {
     #[inline]
-    fn as_inner(&self) -> &c_int {
-        self.0.as_inner()
+    fn from_inner(sock: OwnedFd) -> Socket {
+        Socket(sock)
     }
 }
 
-impl FromInner<c_int> for Socket {
-    fn from_inner(fd: c_int) -> Socket {
-        Socket(FileDesc::new(fd))
+impl IntoInner<OwnedFd> for Socket {
+    #[inline]
+    fn into_inner(self) -> OwnedFd {
+        self.0
     }
 }
 
-impl IntoInner<c_int> for Socket {
-    fn into_inner(self) -> c_int {
-        self.0.into_raw()
+impl AsFd for Socket {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.0.as_fd()
+    }
+}
+
+impl AsRawFd for Socket {
+    #[inline]
+    fn as_raw_fd(&self) -> c_int {
+        self.0.as_raw_fd()
+    }
+}
+
+impl FromRawFd for Socket {
+    #[inline]
+    unsafe fn from_raw_fd(fd: c_int) -> Socket {
+        unsafe { Self(FromRawFd::from_raw_fd(fd)) }
+    }
+}
+
+impl IntoRawFd for Socket {
+    #[inline]
+    fn into_raw_fd(self) -> c_int {
+        self.0.into_raw_fd()
     }
 }
diff --git a/library/std/src/sys/teeos/alloc.rs b/library/std/src/sys/teeos/alloc.rs
new file mode 100644
index 000000000..e236819aa
--- /dev/null
+++ b/library/std/src/sys/teeos/alloc.rs
@@ -0,0 +1,57 @@
+use crate::alloc::{GlobalAlloc, Layout, System};
+use crate::ptr;
+use crate::sys::common::alloc::{realloc_fallback, MIN_ALIGN};
+
+#[stable(feature = "alloc_system_type", since = "1.28.0")]
+unsafe impl GlobalAlloc for System {
+    #[inline]
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        // jemalloc provides alignment less than MIN_ALIGN for small allocations.
+        // So only rely on MIN_ALIGN if size >= align.
+        // Also see <https://github.com/rust-lang/rust/issues/45955> and
+        // <https://github.com/rust-lang/rust/issues/62251#issuecomment-507580914>.
+        if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
+            libc::malloc(layout.size()) as *mut u8
+        } else {
+            aligned_malloc(&layout)
+        }
+    }
+
+    #[inline]
+    unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
+        // See the comment above in `alloc` for why this check looks the way it does.
+        if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
+            libc::calloc(layout.size(), 1) as *mut u8
+        } else {
+            let ptr = self.alloc(layout);
+            if !ptr.is_null() {
+                ptr::write_bytes(ptr, 0, layout.size());
+            }
+            ptr
+        }
+    }
+
+    #[inline]
+    unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
+        libc::free(ptr as *mut libc::c_void)
+    }
+
+    #[inline]
+    unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
+        if layout.align() <= MIN_ALIGN && layout.align() <= new_size {
+            libc::realloc(ptr as *mut libc::c_void, new_size) as *mut u8
+        } else {
+            realloc_fallback(self, ptr, layout, new_size)
+        }
+    }
+}
+
+#[inline]
+unsafe fn aligned_malloc(layout: &Layout) -> *mut u8 {
+    let mut out = ptr::null_mut();
+    // posix_memalign requires that the alignment be a multiple of `sizeof(void*)`.
+    // Since these are all powers of 2, we can just use max.
+    let align = layout.align().max(crate::mem::size_of::<usize>());
+    let ret = libc::posix_memalign(&mut out, align, layout.size());
+    if ret != 0 { ptr::null_mut() } else { out as *mut u8 }
+}
diff --git a/library/std/src/sys/teeos/locks/condvar.rs b/library/std/src/sys/teeos/locks/condvar.rs
new file mode 100644
index 000000000..c08e8145b
--- /dev/null
+++ b/library/std/src/sys/teeos/locks/condvar.rs
@@ -0,0 +1,100 @@
+use crate::cell::UnsafeCell;
+use crate::ptr;
+use crate::sync::atomic::{AtomicPtr, Ordering::Relaxed};
+use crate::sys::locks::mutex::{self, Mutex};
+use crate::sys::time::TIMESPEC_MAX;
+use crate::sys_common::lazy_box::{LazyBox, LazyInit};
+use crate::time::Duration;
+
+extern "C" {
+    pub fn pthread_cond_timedwait(
+        cond: *mut libc::pthread_cond_t,
+        lock: *mut libc::pthread_mutex_t,
+        adstime: *const libc::timespec,
+    ) -> libc::c_int;
+}
+
+struct AllocatedCondvar(UnsafeCell<libc::pthread_cond_t>);
+
+pub struct Condvar {
+    inner: LazyBox<AllocatedCondvar>,
+    mutex: AtomicPtr<libc::pthread_mutex_t>,
+}
+
+#[inline]
+fn raw(c: &Condvar) -> *mut libc::pthread_cond_t {
+    c.inner.0.get()
+}
+
+unsafe impl Send for AllocatedCondvar {}
+unsafe impl Sync for AllocatedCondvar {}
+
+impl LazyInit for AllocatedCondvar {
+    fn init() -> Box<Self> {
+        let condvar = Box::new(AllocatedCondvar(UnsafeCell::new(libc::PTHREAD_COND_INITIALIZER)));
+
+        let r = unsafe { libc::pthread_cond_init(condvar.0.get(), crate::ptr::null()) };
+        assert_eq!(r, 0);
+
+        condvar
+    }
+}
+
+impl Drop for AllocatedCondvar {
+    #[inline]
+    fn drop(&mut self) {
+        let r = unsafe { libc::pthread_cond_destroy(self.0.get()) };
+        debug_assert_eq!(r, 0);
+    }
+}
+
+impl Condvar {
+    pub const fn new() -> Condvar {
+        Condvar { inner: LazyBox::new(), mutex: AtomicPtr::new(ptr::null_mut()) }
+    }
+
+    #[inline]
+    fn verify(&self, mutex: *mut libc::pthread_mutex_t) {
+        match self.mutex.compare_exchange(ptr::null_mut(), mutex, Relaxed, Relaxed) {
+            Ok(_) => {}                // Stored the address
+            Err(n) if n == mutex => {} // Lost a race to store the same address
+            _ => panic!("attempted to use a condition variable with two mutexes"),
+        }
+    }
+
+    #[inline]
+    pub fn notify_one(&self) {
+        let r = unsafe { libc::pthread_cond_signal(raw(self)) };
+        debug_assert_eq!(r, 0);
+    }
+
+    #[inline]
+    pub fn notify_all(&self) {
+        let r = unsafe { libc::pthread_cond_broadcast(raw(self)) };
+        debug_assert_eq!(r, 0);
+    }
+
+    #[inline]
+    pub unsafe fn wait(&self, mutex: &Mutex) {
+        let mutex = mutex::raw(mutex);
+        self.verify(mutex);
+        let r = libc::pthread_cond_wait(raw(self), mutex);
+        debug_assert_eq!(r, 0);
+    }
+
+    pub unsafe fn wait_timeout(&self, mutex: &Mutex, dur: Duration) -> bool {
+        use crate::sys::time::Timespec;
+
+        let mutex = mutex::raw(mutex);
+        self.verify(mutex);
+
+        let timeout = Timespec::now(libc::CLOCK_MONOTONIC)
+            .checked_add_duration(&dur)
+            .and_then(|t| t.to_timespec())
+            .unwrap_or(TIMESPEC_MAX);
+
+        let r = pthread_cond_timedwait(raw(self), mutex, &timeout);
+        assert!(r == libc::ETIMEDOUT || r == 0);
+        r == 0
+    }
+}
diff --git a/library/std/src/sys/teeos/locks/mod.rs b/library/std/src/sys/teeos/locks/mod.rs
new file mode 100644
index 000000000..c58e9c7fd
--- /dev/null
+++ b/library/std/src/sys/teeos/locks/mod.rs
@@ -0,0 +1,8 @@
+pub mod condvar;
+#[path = "../../unix/locks/pthread_mutex.rs"]
+pub mod mutex;
+pub mod rwlock;
+
+pub(crate) use condvar::Condvar;
+pub(crate) use mutex::Mutex;
+pub(crate) use rwlock::RwLock;
diff --git a/library/std/src/sys/teeos/locks/rwlock.rs b/library/std/src/sys/teeos/locks/rwlock.rs
new file mode 100644
index 000000000..27cdb8878
--- /dev/null
+++ b/library/std/src/sys/teeos/locks/rwlock.rs
@@ -0,0 +1,44 @@
+use crate::sys::locks::mutex::Mutex;
+
+/// we do not supported rwlock, so use mutex to simulate rwlock.
+/// it's useful because so many code in std will use rwlock.
+pub struct RwLock {
+    inner: Mutex,
+}
+
+impl RwLock {
+    #[inline]
+    pub const fn new() -> RwLock {
+        RwLock { inner: Mutex::new() }
+    }
+
+    #[inline]
+    pub fn read(&self) {
+        unsafe { self.inner.lock() };
+    }
+
+    #[inline]
+    pub fn try_read(&self) -> bool {
+        unsafe { self.inner.try_lock() }
+    }
+
+    #[inline]
+    pub fn write(&self) {
+        unsafe { self.inner.lock() };
+    }
+
+    #[inline]
+    pub unsafe fn try_write(&self) -> bool {
+        unsafe { self.inner.try_lock() }
+    }
+
+    #[inline]
+    pub unsafe fn read_unlock(&self) {
+        unsafe { self.inner.unlock() };
+    }
+
+    #[inline]
+    pub unsafe fn write_unlock(&self) {
+        unsafe { self.inner.unlock() };
+    }
+}
diff --git a/library/std/src/sys/teeos/mod.rs b/library/std/src/sys/teeos/mod.rs
new file mode 100644
index 000000000..ed8c54b2c
--- /dev/null
+++ b/library/std/src/sys/teeos/mod.rs
@@ -0,0 +1,167 @@
+//! System bindings for the Teeos platform
+//!
+//! This module contains the facade (aka platform-specific) implementations of
+//! OS level functionality for Teeos.
+#![allow(unsafe_op_in_unsafe_fn)]
+#![allow(unused_variables)]
+#![allow(dead_code)]
+
+pub use self::rand::hashmap_random_keys;
+
+pub mod alloc;
+#[path = "../unsupported/args.rs"]
+pub mod args;
+#[path = "../unix/cmath.rs"]
+pub mod cmath;
+#[path = "../unsupported/env.rs"]
+pub mod env;
+pub mod locks;
+//pub mod fd;
+#[path = "../unsupported/fs.rs"]
+pub mod fs;
+#[path = "../unsupported/io.rs"]
+pub mod io;
+#[path = "../unix/memchr.rs"]
+pub mod memchr;
+pub mod net;
+#[path = "../unsupported/once.rs"]
+pub mod once;
+pub mod os;
+#[path = "../unix/os_str.rs"]
+pub mod os_str;
+#[path = "../unix/path.rs"]
+pub mod path;
+#[path = "../unsupported/pipe.rs"]
+pub mod pipe;
+#[path = "../unsupported/process.rs"]
+pub mod process;
+mod rand;
+pub mod stdio;
+pub mod thread;
+pub mod thread_local_dtor;
+#[path = "../unix/thread_local_key.rs"]
+pub mod thread_local_key;
+#[path = "../unsupported/thread_parking.rs"]
+pub mod thread_parking;
+#[allow(non_upper_case_globals)]
+#[path = "../unix/time.rs"]
+pub mod time;
+
+use crate::io::ErrorKind;
+
+pub fn abort_internal() -> ! {
+    unsafe { libc::abort() }
+}
+
+// Trusted Applications are loaded as dynamic libraries on Teeos,
+// so this should never be called.
+pub fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {}
+
+// SAFETY: must be called only once during runtime cleanup.
+// this is not guaranteed to run, for example when the program aborts.
+pub unsafe fn cleanup() {
+    unimplemented!()
+    // We do NOT have stack overflow handler, because TEE OS will kill TA when it happens.
+    // So cleanup is commented
+    // stack_overflow::cleanup();
+}
+
+#[inline]
+pub(crate) fn is_interrupted(errno: i32) -> bool {
+    errno == libc::EINTR
+}
+
+// Note: code below is 1:1 copied from unix/mod.rs
+pub fn decode_error_kind(errno: i32) -> ErrorKind {
+    use ErrorKind::*;
+    match errno as libc::c_int {
+        libc::E2BIG => ArgumentListTooLong,
+        libc::EADDRINUSE => AddrInUse,
+        libc::EADDRNOTAVAIL => AddrNotAvailable,
+        libc::EBUSY => ResourceBusy,
+        libc::ECONNABORTED => ConnectionAborted,
+        libc::ECONNREFUSED => ConnectionRefused,
+        libc::ECONNRESET => ConnectionReset,
+        libc::EDEADLK => Deadlock,
+        libc::EDQUOT => FilesystemQuotaExceeded,
+        libc::EEXIST => AlreadyExists,
+        libc::EFBIG => FileTooLarge,
+        libc::EHOSTUNREACH => HostUnreachable,
+        libc::EINTR => Interrupted,
+        libc::EINVAL => InvalidInput,
+        libc::EISDIR => IsADirectory,
+        libc::ELOOP => FilesystemLoop,
+        libc::ENOENT => NotFound,
+        libc::ENOMEM => OutOfMemory,
+        libc::ENOSPC => StorageFull,
+        libc::ENOSYS => Unsupported,
+        libc::EMLINK => TooManyLinks,
+        libc::ENAMETOOLONG => InvalidFilename,
+        libc::ENETDOWN => NetworkDown,
+        libc::ENETUNREACH => NetworkUnreachable,
+        libc::ENOTCONN => NotConnected,
+        libc::ENOTDIR => NotADirectory,
+        libc::ENOTEMPTY => DirectoryNotEmpty,
+        libc::EPIPE => BrokenPipe,
+        libc::EROFS => ReadOnlyFilesystem,
+        libc::ESPIPE => NotSeekable,
+        libc::ESTALE => StaleNetworkFileHandle,
+        libc::ETIMEDOUT => TimedOut,
+        libc::ETXTBSY => ExecutableFileBusy,
+        libc::EXDEV => CrossesDevices,
+
+        libc::EACCES | libc::EPERM => PermissionDenied,
+
+        // These two constants can have the same value on some systems,
+        // but different values on others, so we can't use a match
+        // clause
+        x if x == libc::EAGAIN || x == libc::EWOULDBLOCK => WouldBlock,
+
+        _ => Uncategorized,
+    }
+}
+
+#[doc(hidden)]
+pub trait IsMinusOne {
+    fn is_minus_one(&self) -> bool;
+}
+
+macro_rules! impl_is_minus_one {
+    ($($t:ident)*) => ($(impl IsMinusOne for $t {
+        fn is_minus_one(&self) -> bool {
+            *self == -1
+        }
+    })*)
+}
+
+impl_is_minus_one! { i8 i16 i32 i64 isize }
+
+pub fn cvt<T: IsMinusOne>(t: T) -> crate::io::Result<T> {
+    if t.is_minus_one() { Err(crate::io::Error::last_os_error()) } else { Ok(t) }
+}
+
+pub fn cvt_r<T, F>(mut f: F) -> crate::io::Result<T>
+where
+    T: IsMinusOne,
+    F: FnMut() -> T,
+{
+    loop {
+        match cvt(f()) {
+            Err(ref e) if e.kind() == ErrorKind::Interrupted => {}
+            other => return other,
+        }
+    }
+}
+
+pub fn cvt_nz(error: libc::c_int) -> crate::io::Result<()> {
+    if error == 0 { Ok(()) } else { Err(crate::io::Error::from_raw_os_error(error)) }
+}
+
+use crate::io as std_io;
+pub fn unsupported<T>() -> std_io::Result<T> {
+    Err(unsupported_err())
+}
+
+pub fn unsupported_err() -> std_io::Error {
+    std_io::Error::new(std_io::ErrorKind::Unsupported, "operation not supported on this platform")
+}
diff --git a/library/std/src/sys/teeos/net.rs b/library/std/src/sys/teeos/net.rs
new file mode 100644
index 000000000..0df681dbf
--- /dev/null
+++ b/library/std/src/sys/teeos/net.rs
@@ -0,0 +1,372 @@
+use crate::fmt;
+use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut};
+use crate::net::{Ipv4Addr, Ipv6Addr, Shutdown, SocketAddr};
+use crate::sys::unsupported;
+use crate::time::Duration;
+
+pub struct TcpStream(!);
+
+impl TcpStream {
+    pub fn connect(_: io::Result<&SocketAddr>) -> io::Result<TcpStream> {
+        unsupported()
+    }
+
+    pub fn connect_timeout(_: &SocketAddr, _: Duration) -> io::Result<TcpStream> {
+        unsupported()
+    }
+
+    pub fn set_read_timeout(&self, _: Option<Duration>) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn set_write_timeout(&self, _: Option<Duration>) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
+        self.0
+    }
+
+    pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
+        self.0
+    }
+
+    pub fn peek(&self, _: &mut [u8]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn read(&self, _: &mut [u8]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn read_buf(&self, _buf: BorrowedCursor<'_>) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn read_vectored(&self, _: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn is_read_vectored(&self) -> bool {
+        self.0
+    }
+
+    pub fn write(&self, _: &[u8]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn write_vectored(&self, _: &[IoSlice<'_>]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn is_write_vectored(&self) -> bool {
+        self.0
+    }
+
+    pub fn peer_addr(&self) -> io::Result<SocketAddr> {
+        self.0
+    }
+
+    pub fn socket_addr(&self) -> io::Result<SocketAddr> {
+        self.0
+    }
+
+    pub fn shutdown(&self, _: Shutdown) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn duplicate(&self) -> io::Result<TcpStream> {
+        self.0
+    }
+
+    pub fn set_linger(&self, _: Option<Duration>) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn linger(&self) -> io::Result<Option<Duration>> {
+        self.0
+    }
+
+    pub fn set_nodelay(&self, _: bool) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn nodelay(&self) -> io::Result<bool> {
+        self.0
+    }
+
+    pub fn set_ttl(&self, _: u32) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn ttl(&self) -> io::Result<u32> {
+        self.0
+    }
+
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        self.0
+    }
+
+    pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
+        self.0
+    }
+}
+
+impl fmt::Debug for TcpStream {
+    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0
+    }
+}
+
+pub struct TcpListener(!);
+
+impl TcpListener {
+    pub fn bind(_: io::Result<&SocketAddr>) -> io::Result<TcpListener> {
+        unsupported()
+    }
+
+    pub fn socket_addr(&self) -> io::Result<SocketAddr> {
+        self.0
+    }
+
+    pub fn accept(&self) -> io::Result<(TcpStream, SocketAddr)> {
+        self.0
+    }
+
+    pub fn duplicate(&self) -> io::Result<TcpListener> {
+        self.0
+    }
+
+    pub fn set_ttl(&self, _: u32) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn ttl(&self) -> io::Result<u32> {
+        self.0
+    }
+
+    pub fn set_only_v6(&self, _: bool) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn only_v6(&self) -> io::Result<bool> {
+        self.0
+    }
+
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        self.0
+    }
+
+    pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
+        self.0
+    }
+}
+
+impl fmt::Debug for TcpListener {
+    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0
+    }
+}
+
+pub struct UdpSocket(!);
+
+impl UdpSocket {
+    pub fn bind(_: io::Result<&SocketAddr>) -> io::Result<UdpSocket> {
+        unsupported()
+    }
+
+    pub fn peer_addr(&self) -> io::Result<SocketAddr> {
+        self.0
+    }
+
+    pub fn socket_addr(&self) -> io::Result<SocketAddr> {
+        self.0
+    }
+
+    pub fn recv_from(&self, _: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
+        self.0
+    }
+
+    pub fn peek_from(&self, _: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
+        self.0
+    }
+
+    pub fn send_to(&self, _: &[u8], _: &SocketAddr) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn duplicate(&self) -> io::Result<UdpSocket> {
+        self.0
+    }
+
+    pub fn set_read_timeout(&self, _: Option<Duration>) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn set_write_timeout(&self, _: Option<Duration>) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
+        self.0
+    }
+
+    pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
+        self.0
+    }
+
+    pub fn set_broadcast(&self, _: bool) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn broadcast(&self) -> io::Result<bool> {
+        self.0
+    }
+
+    pub fn set_multicast_loop_v4(&self, _: bool) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn multicast_loop_v4(&self) -> io::Result<bool> {
+        self.0
+    }
+
+    pub fn set_multicast_ttl_v4(&self, _: u32) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn multicast_ttl_v4(&self) -> io::Result<u32> {
+        self.0
+    }
+
+    pub fn set_multicast_loop_v6(&self, _: bool) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn multicast_loop_v6(&self) -> io::Result<bool> {
+        self.0
+    }
+
+    pub fn join_multicast_v4(&self, _: &Ipv4Addr, _: &Ipv4Addr) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn join_multicast_v6(&self, _: &Ipv6Addr, _: u32) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn leave_multicast_v4(&self, _: &Ipv4Addr, _: &Ipv4Addr) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn leave_multicast_v6(&self, _: &Ipv6Addr, _: u32) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn set_ttl(&self, _: u32) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn ttl(&self) -> io::Result<u32> {
+        self.0
+    }
+
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        self.0
+    }
+
+    pub fn set_nonblocking(&self, _: bool) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn recv(&self, _: &mut [u8]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn peek(&self, _: &mut [u8]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn send(&self, _: &[u8]) -> io::Result<usize> {
+        self.0
+    }
+
+    pub fn connect(&self, _: io::Result<&SocketAddr>) -> io::Result<()> {
+        self.0
+    }
+}
+
+impl fmt::Debug for UdpSocket {
+    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0
+    }
+}
+
+pub struct LookupHost(!);
+
+impl LookupHost {
+    pub fn port(&self) -> u16 {
+        self.0
+    }
+}
+
+impl Iterator for LookupHost {
+    type Item = SocketAddr;
+    fn next(&mut self) -> Option<SocketAddr> {
+        self.0
+    }
+}
+
+impl TryFrom<&str> for LookupHost {
+    type Error = io::Error;
+
+    fn try_from(_v: &str) -> io::Result<LookupHost> {
+        unsupported()
+    }
+}
+
+impl<'a> TryFrom<(&'a str, u16)> for LookupHost {
+    type Error = io::Error;
+
+    fn try_from(_v: (&'a str, u16)) -> io::Result<LookupHost> {
+        unsupported()
+    }
+}
+
+#[allow(nonstandard_style)]
+pub mod netc {
+    pub const AF_INET: u8 = 0;
+    pub const AF_INET6: u8 = 1;
+    pub type sa_family_t = u8;
+
+    #[derive(Copy, Clone)]
+    pub struct in_addr {
+        pub s_addr: u32,
+    }
+
+    #[derive(Copy, Clone)]
+    pub struct sockaddr_in {
+        pub sin_family: sa_family_t,
+        pub sin_port: u16,
+        pub sin_addr: in_addr,
+    }
+
+    #[derive(Copy, Clone)]
+    pub struct in6_addr {
+        pub s6_addr: [u8; 16],
+    }
+
+    #[derive(Copy, Clone)]
+    pub struct sockaddr_in6 {
+        pub sin6_family: sa_family_t,
+        pub sin6_port: u16,
+        pub sin6_addr: in6_addr,
+        pub sin6_flowinfo: u32,
+        pub sin6_scope_id: u32,
+    }
+
+    #[derive(Copy, Clone)]
+    pub struct sockaddr {}
+}
+
+pub type Socket = UdpSocket;
diff --git a/library/std/src/sys/teeos/os.rs b/library/std/src/sys/teeos/os.rs
new file mode 100644
index 000000000..e54a92f01
--- /dev/null
+++ b/library/std/src/sys/teeos/os.rs
@@ -0,0 +1,134 @@
+//! Implementation of `std::os` functionality for teeos
+
+use core::marker::PhantomData;
+
+use crate::error::Error as StdError;
+use crate::ffi::{OsStr, OsString};
+use crate::fmt;
+use crate::io;
+use crate::path;
+use crate::path::PathBuf;
+
+use super::unsupported;
+
+pub fn errno() -> i32 {
+    unsafe { (*libc::__errno_location()) as i32 }
+}
+
+// Hardcoded to return 4096, since `sysconf` is only implemented as a stub.
+pub fn page_size() -> usize {
+    // unsafe { libc::sysconf(libc::_SC_PAGESIZE) as usize };
+    4096
+}
+
+// Everything below are stubs and copied from unsupported.rs
+
+pub fn error_string(_errno: i32) -> String {
+    "error string unimplemented".to_string()
+}
+
+pub fn getcwd() -> io::Result<PathBuf> {
+    unsupported()
+}
+
+pub fn chdir(_: &path::Path) -> io::Result<()> {
+    unsupported()
+}
+
+pub struct SplitPaths<'a>(!, PhantomData<&'a ()>);
+
+pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
+    panic!("unsupported")
+}
+
+impl<'a> Iterator for SplitPaths<'a> {
+    type Item = PathBuf;
+    fn next(&mut self) -> Option<PathBuf> {
+        self.0
+    }
+}
+
+#[derive(Debug)]
+pub struct JoinPathsError;
+
+pub fn join_paths<I, T>(_paths: I) -> Result<OsString, JoinPathsError>
+where
+    I: Iterator<Item = T>,
+    T: AsRef<OsStr>,
+{
+    Err(JoinPathsError)
+}
+
+impl fmt::Display for JoinPathsError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        "not supported on this platform yet".fmt(f)
+    }
+}
+
+impl StdError for JoinPathsError {
+    #[allow(deprecated)]
+    fn description(&self) -> &str {
+        "not supported on this platform yet"
+    }
+}
+
+pub fn current_exe() -> io::Result<PathBuf> {
+    unsupported()
+}
+
+pub struct Env(!);
+
+impl Env {
+    // FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when <OsStr as Debug>::fmt matches <str as Debug>::fmt.
+    pub fn str_debug(&self) -> impl fmt::Debug + '_ {
+        let Self(inner) = self;
+        match *inner {}
+    }
+}
+
+impl fmt::Debug for Env {
+    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Self(inner) = self;
+        match *inner {}
+    }
+}
+
+impl Iterator for Env {
+    type Item = (OsString, OsString);
+    fn next(&mut self) -> Option<(OsString, OsString)> {
+        let Self(inner) = self;
+        match *inner {}
+    }
+}
+
+pub fn env() -> Env {
+    panic!("not supported on this platform")
+}
+
+pub fn getenv(_: &OsStr) -> Option<OsString> {
+    None
+}
+
+pub fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> {
+    Err(io::Error::new(io::ErrorKind::Unsupported, "cannot set env vars on this platform"))
+}
+
+pub fn unsetenv(_: &OsStr) -> io::Result<()> {
+    Err(io::Error::new(io::ErrorKind::Unsupported, "cannot unset env vars on this platform"))
+}
+
+pub fn temp_dir() -> PathBuf {
+    panic!("no filesystem on this platform")
+}
+
+pub fn home_dir() -> Option<PathBuf> {
+    None
+}
+
+pub fn exit(_code: i32) -> ! {
+    panic!("TA should not call `exit`")
+}
+
+pub fn getpid() -> u32 {
+    panic!("no pids on this platform")
+}
diff --git a/library/std/src/sys/teeos/rand.rs b/library/std/src/sys/teeos/rand.rs
new file mode 100644
index 000000000..b45c3bb40
--- /dev/null
+++ b/library/std/src/sys/teeos/rand.rs
@@ -0,0 +1,21 @@
+pub fn hashmap_random_keys() -> (u64, u64) {
+    const KEY_LEN: usize = core::mem::size_of::<u64>();
+
+    let mut v = [0u8; KEY_LEN * 2];
+    imp::fill_bytes(&mut v);
+
+    let key1 = v[0..KEY_LEN].try_into().unwrap();
+    let key2 = v[KEY_LEN..].try_into().unwrap();
+
+    (u64::from_ne_bytes(key1), u64::from_ne_bytes(key2))
+}
+
+mod imp {
+    extern "C" {
+        fn TEE_GenerateRandom(randomBuffer: *mut core::ffi::c_void, randomBufferLen: libc::size_t);
+    }
+
+    pub fn fill_bytes(v: &mut [u8]) {
+        unsafe { TEE_GenerateRandom(v.as_mut_ptr() as _, v.len() * crate::mem::size_of::<u8>()) }
+    }
+}
diff --git a/library/std/src/sys/teeos/stdio.rs b/library/std/src/sys/teeos/stdio.rs
new file mode 100644
index 000000000..9ca04f292
--- /dev/null
+++ b/library/std/src/sys/teeos/stdio.rs
@@ -0,0 +1,88 @@
+#![deny(unsafe_op_in_unsafe_fn)]
+
+use crate::io;
+use core::arch::asm;
+
+pub struct Stdin;
+pub struct Stdout;
+pub struct Stderr;
+
+const KCALL_DEBUG_CMD_PUT_BYTES: i64 = 2;
+
+unsafe fn debug_call(cap_ref: u64, call_no: i64, arg1: u64, arg2: u64) -> i32 {
+    let ret: u64;
+    unsafe {
+        asm!(
+            "svc #99",
+            inout("x0") cap_ref => ret,
+            in("x1") call_no,
+            in("x2") arg1,
+            in("x3") arg2,
+        );
+    }
+
+    ret as i32
+}
+
+fn print_buf(s: &[u8]) -> io::Result<usize> {
+    // Corresponds to `HM_DEBUG_PUT_BYTES_LIMIT`.
+    const MAX_LEN: usize = 512;
+    let len = if s.len() > MAX_LEN { MAX_LEN } else { s.len() };
+    let result = unsafe { debug_call(0, KCALL_DEBUG_CMD_PUT_BYTES, s.as_ptr() as u64, len as u64) };
+
+    if result == 0 { Ok(len) } else { Err(io::Error::from(io::ErrorKind::InvalidInput)) }
+}
+
+impl Stdin {
+    pub const fn new() -> Stdin {
+        Stdin
+    }
+}
+
+impl io::Read for Stdin {
+    fn read(&mut self, _buf: &mut [u8]) -> io::Result<usize> {
+        Ok(0)
+    }
+}
+
+impl Stdout {
+    pub const fn new() -> Stdout {
+        Stdout
+    }
+}
+
+impl io::Write for Stdout {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        print_buf(buf)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl Stderr {
+    pub const fn new() -> Stderr {
+        Stderr
+    }
+}
+
+impl io::Write for Stderr {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        print_buf(buf)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+pub const STDIN_BUF_SIZE: usize = 0;
+
+pub fn is_ebadf(err: &io::Error) -> bool {
+    err.raw_os_error() == Some(libc::EBADF as i32)
+}
+
+pub fn panic_output() -> Option<impl io::Write> {
+    Some(Stderr::new())
+}
diff --git a/library/std/src/sys/teeos/thread.rs b/library/std/src/sys/teeos/thread.rs
new file mode 100644
index 000000000..155f333f9
--- /dev/null
+++ b/library/std/src/sys/teeos/thread.rs
@@ -0,0 +1,164 @@
+use core::convert::TryInto;
+
+use crate::cmp;
+use crate::ffi::CStr;
+use crate::io;
+use crate::mem;
+use crate::num::NonZeroUsize;
+use crate::ptr;
+use crate::sys::os;
+use crate::time::Duration;
+
+pub const DEFAULT_MIN_STACK_SIZE: usize = 8 * 1024;
+
+pub struct Thread {
+    id: libc::pthread_t,
+}
+
+// Some platforms may have pthread_t as a pointer in which case we still want
+// a thread to be Send/Sync
+unsafe impl Send for Thread {}
+unsafe impl Sync for Thread {}
+
+extern "C" {
+    pub fn TEE_Wait(timeout: u32) -> u32;
+}
+
+impl Thread {
+    // unsafe: see thread::Builder::spawn_unchecked for safety requirements
+    pub unsafe fn new(stack: usize, p: Box<dyn FnOnce()>) -> io::Result<Thread> {
+        let p = Box::into_raw(Box::new(p));
+        let mut native: libc::pthread_t = mem::zeroed();
+        let mut attr: libc::pthread_attr_t = mem::zeroed();
+        assert_eq!(libc::pthread_attr_init(&mut attr), 0);
+        assert_eq!(
+            libc::pthread_attr_settee(
+                &mut attr,
+                libc::TEESMP_THREAD_ATTR_CA_INHERIT,
+                libc::TEESMP_THREAD_ATTR_TASK_ID_INHERIT,
+                libc::TEESMP_THREAD_ATTR_HAS_SHADOW,
+            ),
+            0,
+        );
+
+        let stack_size = cmp::max(stack, min_stack_size(&attr));
+
+        match libc::pthread_attr_setstacksize(&mut attr, stack_size) {
+            0 => {}
+            n => {
+                assert_eq!(n, libc::EINVAL);
+                // EINVAL means |stack_size| is either too small or not a
+                // multiple of the system page size.  Because it's definitely
+                // >= PTHREAD_STACK_MIN, it must be an alignment issue.
+                // Round up to the nearest page and try again.
+                let page_size = os::page_size();
+                let stack_size =
+                    (stack_size + page_size - 1) & (-(page_size as isize - 1) as usize - 1);
+                assert_eq!(libc::pthread_attr_setstacksize(&mut attr, stack_size), 0);
+            }
+        };
+
+        let ret = libc::pthread_create(&mut native, &attr, thread_start, p as *mut _);
+        // Note: if the thread creation fails and this assert fails, then p will
+        // be leaked. However, an alternative design could cause double-free
+        // which is clearly worse.
+        assert_eq!(libc::pthread_attr_destroy(&mut attr), 0);
+
+        return if ret != 0 {
+            // The thread failed to start and as a result p was not consumed. Therefore, it is
+            // safe to reconstruct the box so that it gets deallocated.
+            drop(Box::from_raw(p));
+            Err(io::Error::from_raw_os_error(ret))
+        } else {
+            // The new thread will start running earliest after the next yield.
+            // We add a yield here, so that the user does not have to.
+            Thread::yield_now();
+            Ok(Thread { id: native })
+        };
+
+        extern "C" fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void {
+            unsafe {
+                // Next, set up our stack overflow handler which may get triggered if we run
+                // out of stack.
+                // this is not necessary in TEE.
+                //let _handler = stack_overflow::Handler::new();
+                // Finally, let's run some code.
+                Box::from_raw(main as *mut Box<dyn FnOnce()>)();
+            }
+            ptr::null_mut()
+        }
+    }
+
+    pub fn yield_now() {
+        let ret = unsafe { libc::sched_yield() };
+        debug_assert_eq!(ret, 0);
+    }
+
+    /// This does not do anything on teeos
+    pub fn set_name(_name: &CStr) {
+        // Both pthread_setname_np and prctl are not available to the TA,
+        // so we can't implement this currently. If the need arises please
+        // contact the teeos rustzone team.
+    }
+
+    /// only main thread could wait for sometime in teeos
+    pub fn sleep(dur: Duration) {
+        let sleep_millis = dur.as_millis();
+        let final_sleep: u32 =
+            if sleep_millis >= u32::MAX as u128 { u32::MAX } else { sleep_millis as u32 };
+        unsafe {
+            let _ = TEE_Wait(final_sleep);
+        }
+    }
+
+    /// must join, because no pthread_detach supported
+    pub fn join(self) {
+        unsafe {
+            let ret = libc::pthread_join(self.id, ptr::null_mut());
+            mem::forget(self);
+            assert!(ret == 0, "failed to join thread: {}", io::Error::from_raw_os_error(ret));
+        }
+    }
+
+    pub fn id(&self) -> libc::pthread_t {
+        self.id
+    }
+
+    pub fn into_id(self) -> libc::pthread_t {
+        let id = self.id;
+        mem::forget(self);
+        id
+    }
+}
+
+impl Drop for Thread {
+    fn drop(&mut self) {
+        // we can not call detach, so just panic if thread spawn without join
+        panic!("thread must join, detach is not supported!");
+    }
+}
+
+// Note: Both `sched_getaffinity` and `sysconf` are available but not functional on
+// teeos, so this function always returns an Error!
+pub fn available_parallelism() -> io::Result<NonZeroUsize> {
+    Err(io::Error::new(
+        io::ErrorKind::NotFound,
+        "The number of hardware threads is not known for the target platform",
+    ))
+}
+
+// stub
+pub mod guard {
+    use crate::ops::Range;
+    pub type Guard = Range<usize>;
+    pub unsafe fn current() -> Option<Guard> {
+        None
+    }
+    pub unsafe fn init() -> Option<Guard> {
+        None
+    }
+}
+
+fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
+    libc::PTHREAD_STACK_MIN.try_into().expect("Infallible")
+}
diff --git a/library/std/src/sys/teeos/thread_local_dtor.rs b/library/std/src/sys/teeos/thread_local_dtor.rs
new file mode 100644
index 000000000..5c6bc4d67
--- /dev/null
+++ b/library/std/src/sys/teeos/thread_local_dtor.rs
@@ -0,0 +1,4 @@
+pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
+    use crate::sys_common::thread_local_dtor::register_dtor_fallback;
+    register_dtor_fallback(t, dtor);
+}
diff --git a/library/std/src/sys/unix/args.rs b/library/std/src/sys/unix/args.rs
index 2da17fabc..9f7dcc041 100644
--- a/library/std/src/sys/unix/args.rs
+++ b/library/std/src/sys/unix/args.rs
@@ -244,13 +244,15 @@ mod imp {
         let mut res = Vec::new();
 
         unsafe {
-            let process_info_sel = sel_registerName("processInfo\0".as_ptr());
-            let arguments_sel = sel_registerName("arguments\0".as_ptr());
-            let utf8_sel = sel_registerName("UTF8String\0".as_ptr());
-            let count_sel = sel_registerName("count\0".as_ptr());
-            let object_at_sel = sel_registerName("objectAtIndex:\0".as_ptr());
-
-            let klass = objc_getClass("NSProcessInfo\0".as_ptr());
+            let process_info_sel =
+                sel_registerName(c"processInfo".as_ptr() as *const libc::c_uchar);
+            let arguments_sel = sel_registerName(c"arguments".as_ptr() as *const libc::c_uchar);
+            let utf8_sel = sel_registerName(c"UTF8String".as_ptr() as *const libc::c_uchar);
+            let count_sel = sel_registerName(c"count".as_ptr() as *const libc::c_uchar);
+            let object_at_sel =
+                sel_registerName(c"objectAtIndex:".as_ptr() as *const libc::c_uchar);
+
+            let klass = objc_getClass(c"NSProcessInfo".as_ptr() as *const libc::c_uchar);
             let info = objc_msgSend(klass, process_info_sel);
             let args = objc_msgSend(info, arguments_sel);
 
diff --git a/library/std/src/sys/unix/env.rs b/library/std/src/sys/unix/env.rs
index 3bb492fa9..3d4ba5098 100644
--- a/library/std/src/sys/unix/env.rs
+++ b/library/std/src/sys/unix/env.rs
@@ -174,17 +174,6 @@ pub mod os {
     pub const EXE_EXTENSION: &str = "elf";
 }
 
-#[cfg(all(target_os = "emscripten", target_arch = "asmjs"))]
-pub mod os {
-    pub const FAMILY: &str = "unix";
-    pub const OS: &str = "emscripten";
-    pub const DLL_PREFIX: &str = "lib";
-    pub const DLL_SUFFIX: &str = ".so";
-    pub const DLL_EXTENSION: &str = "so";
-    pub const EXE_SUFFIX: &str = ".js";
-    pub const EXE_EXTENSION: &str = "js";
-}
-
 #[cfg(all(target_os = "emscripten", target_arch = "wasm32"))]
 pub mod os {
     pub const FAMILY: &str = "unix";
diff --git a/library/std/src/sys/unix/fs.rs b/library/std/src/sys/unix/fs.rs
index 40eb910fd..72e7b1b1f 100644
--- a/library/std/src/sys/unix/fs.rs
+++ b/library/std/src/sys/unix/fs.rs
@@ -1140,7 +1140,7 @@ impl File {
         cfg_has_statx! {
             if let Some(ret) = unsafe { try_statx(
                 fd,
-                b"\0" as *const _ as *const c_char,
+                c"".as_ptr() as *const c_char,
                 libc::AT_EMPTY_PATH | libc::AT_STATX_SYNC_AS_STAT,
                 libc::STATX_ALL,
             ) } {
@@ -1300,13 +1300,17 @@ impl File {
 
     pub fn set_times(&self, times: FileTimes) -> io::Result<()> {
         #[cfg(not(any(target_os = "redox", target_os = "espidf", target_os = "horizon")))]
-        let to_timespec = |time: Option<SystemTime>| {
-            match time {
-                Some(time) if let Some(ts) = time.t.to_timespec() => Ok(ts),
-                Some(time) if time > crate::sys::time::UNIX_EPOCH => Err(io::const_io_error!(io::ErrorKind::InvalidInput, "timestamp is too large to set as a file time")),
-                Some(_) => Err(io::const_io_error!(io::ErrorKind::InvalidInput, "timestamp is too small to set as a file time")),
-                None => Ok(libc::timespec { tv_sec: 0, tv_nsec: libc::UTIME_OMIT as _ }),
-            }
+        let to_timespec = |time: Option<SystemTime>| match time {
+            Some(time) if let Some(ts) = time.t.to_timespec() => Ok(ts),
+            Some(time) if time > crate::sys::time::UNIX_EPOCH => Err(io::const_io_error!(
+                io::ErrorKind::InvalidInput,
+                "timestamp is too large to set as a file time"
+            )),
+            Some(_) => Err(io::const_io_error!(
+                io::ErrorKind::InvalidInput,
+                "timestamp is too small to set as a file time"
+            )),
+            None => Ok(libc::timespec { tv_sec: 0, tv_nsec: libc::UTIME_OMIT as _ }),
         };
         cfg_if::cfg_if! {
             if #[cfg(any(target_os = "redox", target_os = "espidf", target_os = "horizon"))] {
diff --git a/library/std/src/sys/unix/mod.rs b/library/std/src/sys/unix/mod.rs
index 4b28f6feb..b5da5f870 100644
--- a/library/std/src/sys/unix/mod.rs
+++ b/library/std/src/sys/unix/mod.rs
@@ -1,6 +1,5 @@
 #![allow(missing_docs, nonstandard_style)]
 
-use crate::ffi::CStr;
 use crate::io::ErrorKind;
 
 pub use self::rand::hashmap_random_keys;
@@ -75,7 +74,7 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
     // thread-id for the main thread and so renaming the main thread will rename the
     // process and we only want to enable this on platforms we've tested.
     if cfg!(target_os = "macos") {
-        thread::Thread::set_name(&CStr::from_bytes_with_nul_unchecked(b"main\0"));
+        thread::Thread::set_name(&c"main");
     }
 
     unsafe fn sanitize_standard_fds() {
@@ -127,7 +126,7 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
                 if pfd.revents & libc::POLLNVAL == 0 {
                     continue;
                 }
-                if open64("/dev/null\0".as_ptr().cast(), libc::O_RDWR, 0) == -1 {
+                if open64(c"/dev/null".as_ptr().cast(), libc::O_RDWR, 0) == -1 {
                     // If the stream is closed but we failed to reopen it, abort the
                     // process. Otherwise we wouldn't preserve the safety of
                     // operations on the corresponding Rust object Stdin, Stdout, or
@@ -157,7 +156,7 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
             use libc::open64;
             for fd in 0..3 {
                 if libc::fcntl(fd, libc::F_GETFD) == -1 && errno() == libc::EBADF {
-                    if open64("/dev/null\0".as_ptr().cast(), libc::O_RDWR, 0) == -1 {
+                    if open64(c"/dev/null".as_ptr().cast(), libc::O_RDWR, 0) == -1 {
                         // If the stream is closed but we failed to reopen it, abort the
                         // process. Otherwise we wouldn't preserve the safety of
                         // operations on the corresponding Rust object Stdin, Stdout, or
diff --git a/library/std/src/sys/unix/os.rs b/library/std/src/sys/unix/os.rs
index dc3c037c0..881b3a25c 100644
--- a/library/std/src/sys/unix/os.rs
+++ b/library/std/src/sys/unix/os.rs
@@ -180,7 +180,7 @@ pub fn getcwd() -> io::Result<PathBuf> {
 }
 
 #[cfg(target_os = "espidf")]
-pub fn chdir(p: &path::Path) -> io::Result<()> {
+pub fn chdir(_p: &path::Path) -> io::Result<()> {
     super::unsupported::unsupported()
 }
 
@@ -274,15 +274,19 @@ pub fn current_exe() -> io::Result<PathBuf> {
         return path.canonicalize();
     }
     // Search PWD to infer current_exe.
-    if let Some(pstr) = path.to_str() && pstr.contains("/") {
+    if let Some(pstr) = path.to_str()
+        && pstr.contains("/")
+    {
         return getcwd().map(|cwd| cwd.join(path))?.canonicalize();
     }
     // Search PATH to infer current_exe.
     if let Some(p) = getenv(OsStr::from_bytes("PATH".as_bytes())) {
         for search_path in split_paths(&p) {
             let pb = search_path.join(&path);
-            if pb.is_file() && let Ok(metadata) = crate::fs::metadata(&pb) &&
-               metadata.permissions().mode() & 0o111 != 0 {
+            if pb.is_file()
+                && let Ok(metadata) = crate::fs::metadata(&pb)
+                && metadata.permissions().mode() & 0o111 != 0
+            {
                 return pb.canonicalize();
             }
         }
diff --git a/library/std/src/sys/unix/process/process_common.rs b/library/std/src/sys/unix/process/process_common.rs
index bac32d9e6..c5f04fb8b 100644
--- a/library/std/src/sys/unix/process/process_common.rs
+++ b/library/std/src/sys/unix/process/process_common.rs
@@ -24,11 +24,11 @@ cfg_if::cfg_if! {
     if #[cfg(target_os = "fuchsia")] {
         // fuchsia doesn't have /dev/null
     } else if #[cfg(target_os = "redox")] {
-        const DEV_NULL: &str = "null:\0";
+        const DEV_NULL: &CStr = c"null:";
     } else if #[cfg(target_os = "vxworks")] {
-        const DEV_NULL: &str = "/null\0";
+        const DEV_NULL: &CStr = c"/null";
     } else {
-        const DEV_NULL: &str = "/dev/null\0";
+        const DEV_NULL: &CStr = c"/dev/null";
     }
 }
 
@@ -481,8 +481,7 @@ impl Stdio {
                 let mut opts = OpenOptions::new();
                 opts.read(readable);
                 opts.write(!readable);
-                let path = unsafe { CStr::from_ptr(DEV_NULL.as_ptr() as *const _) };
-                let fd = File::open_c(&path, &opts)?;
+                let fd = File::open_c(DEV_NULL, &opts)?;
                 Ok((ChildStdio::Owned(fd.into_inner()), None))
             }
 
diff --git a/library/std/src/sys/unix/process/process_unix.rs b/library/std/src/sys/unix/process/process_unix.rs
index 72aca4e66..ee86a5f88 100644
--- a/library/std/src/sys/unix/process/process_unix.rs
+++ b/library/std/src/sys/unix/process/process_unix.rs
@@ -9,6 +9,8 @@ use core::ffi::NonZero_c_int;
 
 #[cfg(target_os = "linux")]
 use crate::os::linux::process::PidFd;
+#[cfg(target_os = "linux")]
+use crate::os::unix::io::AsRawFd;
 
 #[cfg(any(
     target_os = "macos",
@@ -696,11 +698,12 @@ impl Command {
 
             msg.msg_iov = &mut iov as *mut _ as *mut _;
             msg.msg_iovlen = 1;
-            msg.msg_controllen = mem::size_of_val(&cmsg.buf) as _;
-            msg.msg_control = &mut cmsg.buf as *mut _ as *mut _;
 
             // only attach cmsg if we successfully acquired the pidfd
             if pidfd >= 0 {
+                msg.msg_controllen = mem::size_of_val(&cmsg.buf) as _;
+                msg.msg_control = &mut cmsg.buf as *mut _ as *mut _;
+
                 let hdr = CMSG_FIRSTHDR(&mut msg as *mut _ as *mut _);
                 (*hdr).cmsg_level = SOL_SOCKET;
                 (*hdr).cmsg_type = SCM_RIGHTS;
@@ -717,7 +720,7 @@ impl Command {
             // so we get a consistent SEQPACKET order
             match cvt_r(|| libc::sendmsg(sock.as_raw(), &msg, 0)) {
                 Ok(0) => {}
-                _ => rtabort!("failed to communicate with parent process"),
+                other => rtabort!("failed to communicate with parent process. {:?}", other),
             }
         }
     }
@@ -748,7 +751,7 @@ impl Command {
             msg.msg_controllen = mem::size_of::<Cmsg>() as _;
             msg.msg_control = &mut cmsg as *mut _ as *mut _;
 
-            match cvt_r(|| libc::recvmsg(sock.as_raw(), &mut msg, 0)) {
+            match cvt_r(|| libc::recvmsg(sock.as_raw(), &mut msg, libc::MSG_CMSG_CLOEXEC)) {
                 Err(_) => return -1,
                 Ok(_) => {}
             }
@@ -787,7 +790,7 @@ pub struct Process {
     // On Linux, stores the pidfd created for this child.
     // This is None if the user did not request pidfd creation,
     // or if the pidfd could not be created for some reason
-    // (e.g. the `clone3` syscall was not available).
+    // (e.g. the `pidfd_open` syscall was not available).
     #[cfg(target_os = "linux")]
     pidfd: Option<PidFd>,
 }
@@ -816,10 +819,23 @@ impl Process {
         // and used for another process, and we probably shouldn't be killing
         // random processes, so return Ok because the process has exited already.
         if self.status.is_some() {
-            Ok(())
-        } else {
-            cvt(unsafe { libc::kill(self.pid, libc::SIGKILL) }).map(drop)
+            return Ok(());
+        }
+        #[cfg(target_os = "linux")]
+        if let Some(pid_fd) = self.pidfd.as_ref() {
+            // pidfd_send_signal predates pidfd_open. so if we were able to get an fd then sending signals will work too
+            return cvt(unsafe {
+                libc::syscall(
+                    libc::SYS_pidfd_send_signal,
+                    pid_fd.as_raw_fd(),
+                    libc::SIGKILL,
+                    crate::ptr::null::<()>(),
+                    0,
+                )
+            })
+            .map(drop);
         }
+        cvt(unsafe { libc::kill(self.pid, libc::SIGKILL) }).map(drop)
     }
 
     pub fn wait(&mut self) -> io::Result<ExitStatus> {
@@ -827,6 +843,17 @@ impl Process {
         if let Some(status) = self.status {
             return Ok(status);
         }
+        #[cfg(target_os = "linux")]
+        if let Some(pid_fd) = self.pidfd.as_ref() {
+            let mut siginfo: libc::siginfo_t = unsafe { crate::mem::zeroed() };
+
+            cvt_r(|| unsafe {
+                libc::waitid(libc::P_PIDFD, pid_fd.as_raw_fd() as u32, &mut siginfo, libc::WEXITED)
+            })?;
+            let status = ExitStatus::from_waitid_siginfo(siginfo);
+            self.status = Some(status);
+            return Ok(status);
+        }
         let mut status = 0 as c_int;
         cvt_r(|| unsafe { libc::waitpid(self.pid, &mut status, 0) })?;
         self.status = Some(ExitStatus::new(status));
@@ -837,6 +864,25 @@ impl Process {
         if let Some(status) = self.status {
             return Ok(Some(status));
         }
+        #[cfg(target_os = "linux")]
+        if let Some(pid_fd) = self.pidfd.as_ref() {
+            let mut siginfo: libc::siginfo_t = unsafe { crate::mem::zeroed() };
+
+            cvt(unsafe {
+                libc::waitid(
+                    libc::P_PIDFD,
+                    pid_fd.as_raw_fd() as u32,
+                    &mut siginfo,
+                    libc::WEXITED | libc::WNOHANG,
+                )
+            })?;
+            if unsafe { siginfo.si_pid() } == 0 {
+                return Ok(None);
+            }
+            let status = ExitStatus::from_waitid_siginfo(siginfo);
+            self.status = Some(status);
+            return Ok(Some(status));
+        }
         let mut status = 0 as c_int;
         let pid = cvt(unsafe { libc::waitpid(self.pid, &mut status, libc::WNOHANG) })?;
         if pid == 0 {
@@ -866,6 +912,20 @@ impl ExitStatus {
         ExitStatus(status)
     }
 
+    #[cfg(target_os = "linux")]
+    pub fn from_waitid_siginfo(siginfo: libc::siginfo_t) -> ExitStatus {
+        let status = unsafe { siginfo.si_status() };
+
+        match siginfo.si_code {
+            libc::CLD_EXITED => ExitStatus((status & 0xff) << 8),
+            libc::CLD_KILLED => ExitStatus(status),
+            libc::CLD_DUMPED => ExitStatus(status | 0x80),
+            libc::CLD_CONTINUED => ExitStatus(0xffff),
+            libc::CLD_STOPPED | libc::CLD_TRAPPED => ExitStatus(((status & 0xff) << 8) | 0x7f),
+            _ => unreachable!("waitid() should only return the above codes"),
+        }
+    }
+
     fn exited(&self) -> bool {
         libc::WIFEXITED(self.0)
     }
diff --git a/library/std/src/sys/unix/process/process_unix/tests.rs b/library/std/src/sys/unix/process/process_unix/tests.rs
index 6aa79e7f9..6e952ed7c 100644
--- a/library/std/src/sys/unix/process/process_unix/tests.rs
+++ b/library/std/src/sys/unix/process/process_unix/tests.rs
@@ -64,7 +64,8 @@ fn test_command_fork_no_unwind() {
 #[test]
 #[cfg(target_os = "linux")]
 fn test_command_pidfd() {
-    use crate::os::fd::RawFd;
+    use crate::assert_matches::assert_matches;
+    use crate::os::fd::{AsRawFd, RawFd};
     use crate::os::linux::process::{ChildExt, CommandExt};
     use crate::process::Command;
 
@@ -78,10 +79,22 @@ fn test_command_pidfd() {
     };
 
     // always exercise creation attempts
-    let child = Command::new("echo").create_pidfd(true).spawn().unwrap();
+    let mut child = Command::new("false").create_pidfd(true).spawn().unwrap();
 
     // but only check if we know that the kernel supports pidfds
     if pidfd_open_available {
-        assert!(child.pidfd().is_ok())
+        assert!(child.pidfd().is_ok());
     }
+    if let Ok(pidfd) = child.pidfd() {
+        let flags = super::cvt(unsafe { libc::fcntl(pidfd.as_raw_fd(), libc::F_GETFD) }).unwrap();
+        assert!(flags & libc::FD_CLOEXEC != 0);
+    }
+    let status = child.wait().expect("error waiting on pidfd");
+    assert_eq!(status.code(), Some(1));
+
+    let mut child = Command::new("sleep").arg("1000").create_pidfd(true).spawn().unwrap();
+    assert_matches!(child.try_wait(), Ok(None));
+    child.kill().expect("failed to kill child");
+    let status = child.wait().expect("error waiting on pidfd");
+    assert_eq!(status.signal(), Some(libc::SIGKILL));
 }
diff --git a/library/std/src/sys/unix/thread.rs b/library/std/src/sys/unix/thread.rs
index 29db9468e..76b96bb37 100644
--- a/library/std/src/sys/unix/thread.rs
+++ b/library/std/src/sys/unix/thread.rs
@@ -163,10 +163,9 @@ impl Thread {
     #[cfg(target_os = "netbsd")]
     pub fn set_name(name: &CStr) {
         unsafe {
-            let cname = CStr::from_bytes_with_nul_unchecked(b"%s\0".as_slice());
             let res = libc::pthread_setname_np(
                 libc::pthread_self(),
-                cname.as_ptr(),
+                c"%s".as_ptr(),
                 name.as_ptr() as *mut libc::c_void,
             );
             debug_assert_eq!(res, 0);
diff --git a/library/std/src/sys/unix/thread_local_dtor.rs b/library/std/src/sys/unix/thread_local_dtor.rs
index 06399e8a2..ac85531c3 100644
--- a/library/std/src/sys/unix/thread_local_dtor.rs
+++ b/library/std/src/sys/unix/thread_local_dtor.rs
@@ -12,7 +12,13 @@
 // compiling from a newer linux to an older linux, so we also have a
 // fallback implementation to use as well.
 #[allow(unexpected_cfgs)]
-#[cfg(any(target_os = "linux", target_os = "fuchsia", target_os = "redox", target_os = "hurd"))]
+#[cfg(any(
+    target_os = "linux",
+    target_os = "android",
+    target_os = "fuchsia",
+    target_os = "redox",
+    target_os = "hurd"
+))]
 // FIXME: The Rust compiler currently omits weakly function definitions (i.e.,
 // __cxa_thread_atexit_impl) and its metadata from LLVM IR.
 #[no_sanitize(cfi, kcfi)]
@@ -23,6 +29,8 @@ pub unsafe fn register_dtor(t: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
     /// This is necessary because the __cxa_thread_atexit_impl implementation
     /// std links to by default may be a C or C++ implementation that was not
     /// compiled using the Clang integer normalization option.
+    #[cfg(sanitizer_cfi_normalize_integers)]
+    use core::ffi::c_int;
     #[cfg(not(sanitizer_cfi_normalize_integers))]
     #[cfi_encoding = "i"]
     #[repr(transparent)]
diff --git a/library/std/src/sys/unix/time.rs b/library/std/src/sys/unix/time.rs
index f2e86a4fb..f62eb828e 100644
--- a/library/std/src/sys/unix/time.rs
+++ b/library/std/src/sys/unix/time.rs
@@ -23,11 +23,11 @@ struct Nanoseconds(u32);
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct SystemTime {
-    pub(in crate::sys::unix) t: Timespec,
+    pub(crate) t: Timespec,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub(in crate::sys::unix) struct Timespec {
+pub(crate) struct Timespec {
     tv_sec: i64,
     tv_nsec: Nanoseconds,
 }
@@ -239,11 +239,11 @@ impl From<libc::timespec> for Timespec {
     not(target_arch = "riscv32")
 ))]
 #[repr(C)]
-pub(in crate::sys::unix) struct __timespec64 {
-    pub(in crate::sys::unix) tv_sec: i64,
+pub(crate) struct __timespec64 {
+    pub(crate) tv_sec: i64,
     #[cfg(target_endian = "big")]
     _padding: i32,
-    pub(in crate::sys::unix) tv_nsec: i32,
+    pub(crate) tv_nsec: i32,
     #[cfg(target_endian = "little")]
     _padding: i32,
 }
@@ -255,7 +255,7 @@ pub(in crate::sys::unix) struct __timespec64 {
     not(target_arch = "riscv32")
 ))]
 impl __timespec64 {
-    pub(in crate::sys::unix) fn new(tv_sec: i64, tv_nsec: i32) -> Self {
+    pub(crate) fn new(tv_sec: i64, tv_nsec: i32) -> Self {
         Self { tv_sec, tv_nsec, _padding: 0 }
     }
 }
diff --git a/library/std/src/sys/wasi/fs.rs b/library/std/src/sys/wasi/fs.rs
index 437aae3ae..e82386654 100644
--- a/library/std/src/sys/wasi/fs.rs
+++ b/library/std/src/sys/wasi/fs.rs
@@ -477,12 +477,13 @@ impl File {
     }
 
     pub fn set_times(&self, times: FileTimes) -> io::Result<()> {
-        let to_timestamp = |time: Option<SystemTime>| {
-            match time {
-                Some(time) if let Some(ts) = time.to_wasi_timestamp() => Ok(ts),
-                Some(_) => Err(io::const_io_error!(io::ErrorKind::InvalidInput, "timestamp is too large to set as a file time")),
-                None => Ok(0),
-            }
+        let to_timestamp = |time: Option<SystemTime>| match time {
+            Some(time) if let Some(ts) = time.to_wasi_timestamp() => Ok(ts),
+            Some(_) => Err(io::const_io_error!(
+                io::ErrorKind::InvalidInput,
+                "timestamp is too large to set as a file time"
+            )),
+            None => Ok(0),
         };
         self.fd.filestat_set_times(
             to_timestamp(times.accessed)?,
diff --git a/library/std/src/sys/windows/api.rs b/library/std/src/sys/windows/api.rs
index e9f0bbfbe..a7ea59e85 100644
--- a/library/std/src/sys/windows/api.rs
+++ b/library/std/src/sys/windows/api.rs
@@ -48,7 +48,7 @@ use super::c;
 /// converted to a `u32`. Clippy would warn about this but, alas, it's not run
 /// on the standard library.
 const fn win32_size_of<T: Sized>() -> u32 {
-    // Const assert that the size is less than u32::MAX.
+    // Const assert that the size does not exceed u32::MAX.
     // Uses a trait to workaround restriction on using generic types in inner items.
     trait Win32SizeOf: Sized {
         const WIN32_SIZE_OF: u32 = {
@@ -132,7 +132,7 @@ pub fn set_file_information_by_handle<T: SetFileInformation>(
         size: u32,
     ) -> Result<(), WinError> {
         let result = c::SetFileInformationByHandle(handle, class, info, size);
-        (result != 0).then_some(()).ok_or_else(|| get_last_error())
+        (result != 0).then_some(()).ok_or_else(get_last_error)
     }
     // SAFETY: The `SetFileInformation` trait ensures that this is safe.
     unsafe { set_info(handle, T::CLASS, info.as_ptr(), info.size()) }
diff --git a/library/std/src/sys/windows/c.rs b/library/std/src/sys/windows/c.rs
index a349e24b0..d55d9bace 100644
--- a/library/std/src/sys/windows/c.rs
+++ b/library/std/src/sys/windows/c.rs
@@ -3,6 +3,7 @@
 #![allow(nonstandard_style)]
 #![cfg_attr(test, allow(dead_code))]
 #![unstable(issue = "none", feature = "windows_c")]
+#![allow(clippy::style)]
 
 use crate::ffi::CStr;
 use crate::mem;
@@ -46,6 +47,8 @@ pub use FD_SET as fd_set;
 pub use LINGER as linger;
 pub use TIMEVAL as timeval;
 
+pub const INVALID_HANDLE_VALUE: HANDLE = ::core::ptr::invalid_mut(-1i32 as _);
+
 // https://learn.microsoft.com/en-us/cpp/c-runtime-library/exit-success-exit-failure?view=msvc-170
 pub const EXIT_SUCCESS: u32 = 0;
 pub const EXIT_FAILURE: u32 = 1;
@@ -81,7 +84,7 @@ pub fn nt_success(status: NTSTATUS) -> bool {
 
 impl UNICODE_STRING {
     pub fn from_ref(slice: &[u16]) -> Self {
-        let len = slice.len() * mem::size_of::<u16>();
+        let len = mem::size_of_val(slice);
         Self { Length: len as _, MaximumLength: len as _, Buffer: slice.as_ptr() as _ }
     }
 }
@@ -321,7 +324,7 @@ pub unsafe fn NtWriteFile(
 // Functions that aren't available on every version of Windows that we support,
 // but we still use them and just provide some form of a fallback implementation.
 compat_fn_with_fallback! {
-    pub static KERNEL32: &CStr = ansi_str!("kernel32");
+    pub static KERNEL32: &CStr = c"kernel32";
 
     // >= Win10 1607
     // https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-setthreaddescription
@@ -354,7 +357,7 @@ compat_fn_optional! {
 }
 
 compat_fn_with_fallback! {
-    pub static NTDLL: &CStr = ansi_str!("ntdll");
+    pub static NTDLL: &CStr = c"ntdll";
 
     pub fn NtCreateKeyedEvent(
         KeyedEventHandle: LPHANDLE,
diff --git a/library/std/src/sys/windows/c/windows_sys.lst b/library/std/src/sys/windows/c/windows_sys.lst
index 38bf15b7c..f91e1054a 100644
--- a/library/std/src/sys/windows/c/windows_sys.lst
+++ b/library/std/src/sys/windows/c/windows_sys.lst
@@ -2,6 +2,7 @@
 --config flatten std
 --filter
 // tidy-alphabetical-start
+!Windows.Win32.Foundation.INVALID_HANDLE_VALUE
 Windows.Wdk.Storage.FileSystem.FILE_COMPLETE_IF_OPLOCKED
 Windows.Wdk.Storage.FileSystem.FILE_CONTAINS_EXTENDED_CREATE_INFORMATION
 Windows.Wdk.Storage.FileSystem.FILE_CREATE
@@ -1923,7 +1924,6 @@ Windows.Win32.Foundation.HANDLE_FLAG_INHERIT
 Windows.Win32.Foundation.HANDLE_FLAG_PROTECT_FROM_CLOSE
 Windows.Win32.Foundation.HANDLE_FLAGS
 Windows.Win32.Foundation.HMODULE
-Windows.Win32.Foundation.INVALID_HANDLE_VALUE
 Windows.Win32.Foundation.MAX_PATH
 Windows.Win32.Foundation.NO_ERROR
 Windows.Win32.Foundation.NTSTATUS
@@ -2483,7 +2483,6 @@ Windows.Win32.System.SystemInformation.GetSystemTimeAsFileTime
 Windows.Win32.System.SystemInformation.GetWindowsDirectoryW
 Windows.Win32.System.SystemInformation.PROCESSOR_ARCHITECTURE
 Windows.Win32.System.SystemInformation.SYSTEM_INFO
-Windows.Win32.System.SystemServices.ALL_PROCESSOR_GROUPS
 Windows.Win32.System.SystemServices.DLL_PROCESS_DETACH
 Windows.Win32.System.SystemServices.DLL_THREAD_DETACH
 Windows.Win32.System.SystemServices.EXCEPTION_MAXIMUM_PARAMETERS
@@ -2492,6 +2491,7 @@ Windows.Win32.System.SystemServices.IO_REPARSE_TAG_SYMLINK
 Windows.Win32.System.Threading.ABOVE_NORMAL_PRIORITY_CLASS
 Windows.Win32.System.Threading.AcquireSRWLockExclusive
 Windows.Win32.System.Threading.AcquireSRWLockShared
+Windows.Win32.System.Threading.ALL_PROCESSOR_GROUPS
 Windows.Win32.System.Threading.BELOW_NORMAL_PRIORITY_CLASS
 Windows.Win32.System.Threading.CREATE_BREAKAWAY_FROM_JOB
 Windows.Win32.System.Threading.CREATE_DEFAULT_ERROR_MODE
diff --git a/library/std/src/sys/windows/c/windows_sys.rs b/library/std/src/sys/windows/c/windows_sys.rs
index e0509e6a5..b38b70c89 100644
--- a/library/std/src/sys/windows/c/windows_sys.rs
+++ b/library/std/src/sys/windows/c/windows_sys.rs
@@ -4,7 +4,7 @@
 // regenerate the bindings.
 //
 // ignore-tidy-filelength
-// Bindings generated by `windows-bindgen` 0.51.1
+// Bindings generated by `windows-bindgen` 0.52.0
 
 #![allow(non_snake_case, non_upper_case_globals, non_camel_case_types, dead_code, clippy::all)]
 #[link(name = "advapi32")]
@@ -63,7 +63,7 @@ extern "system" {
         lpnewfilename: PCWSTR,
         lpprogressroutine: LPPROGRESS_ROUTINE,
         lpdata: *const ::core::ffi::c_void,
-        pbcancel: *mut i32,
+        pbcancel: *mut BOOL,
         dwcopyflags: u32,
     ) -> BOOL;
 }
@@ -619,7 +619,7 @@ extern "system" {
         lpmultibytestr: PSTR,
         cbmultibyte: i32,
         lpdefaultchar: PCSTR,
-        lpuseddefaultchar: *mut i32,
+        lpuseddefaultchar: *mut BOOL,
     ) -> i32;
 }
 #[link(name = "kernel32")]
@@ -869,7 +869,7 @@ pub const AF_INET: ADDRESS_FAMILY = 2u16;
 pub const AF_INET6: ADDRESS_FAMILY = 23u16;
 pub const AF_UNIX: u16 = 1u16;
 pub const AF_UNSPEC: ADDRESS_FAMILY = 0u16;
-pub const ALL_PROCESSOR_GROUPS: u32 = 65535u32;
+pub const ALL_PROCESSOR_GROUPS: u16 = 65535u16;
 #[repr(C)]
 pub union ARM64_NT_NEON128 {
     pub Anonymous: ARM64_NT_NEON128_0,
@@ -3498,7 +3498,6 @@ impl ::core::clone::Clone for INIT_ONCE {
 }
 pub const INIT_ONCE_INIT_FAILED: u32 = 4u32;
 pub const INVALID_FILE_ATTRIBUTES: u32 = 4294967295u32;
-pub const INVALID_HANDLE_VALUE: HANDLE = ::core::ptr::invalid_mut(-1i32 as _);
 pub const INVALID_SOCKET: SOCKET = -1i32 as _;
 #[repr(C)]
 pub struct IN_ADDR {
diff --git a/library/std/src/sys/windows/compat.rs b/library/std/src/sys/windows/compat.rs
index e28dd4935..f60b3a2c7 100644
--- a/library/std/src/sys/windows/compat.rs
+++ b/library/std/src/sys/windows/compat.rs
@@ -225,9 +225,9 @@ macro_rules! compat_fn_optional {
 /// Load all needed functions from "api-ms-win-core-synch-l1-2-0".
 pub(super) fn load_synch_functions() {
     fn try_load() -> Option<()> {
-        const MODULE_NAME: &CStr = ansi_str!("api-ms-win-core-synch-l1-2-0");
-        const WAIT_ON_ADDRESS: &CStr = ansi_str!("WaitOnAddress");
-        const WAKE_BY_ADDRESS_SINGLE: &CStr = ansi_str!("WakeByAddressSingle");
+        const MODULE_NAME: &CStr = c"api-ms-win-core-synch-l1-2-0";
+        const WAIT_ON_ADDRESS: &CStr = c"WaitOnAddress";
+        const WAKE_BY_ADDRESS_SINGLE: &CStr = c"WakeByAddressSingle";
 
         // Try loading the library and all the required functions.
         // If any step fails, then they all fail.
diff --git a/library/std/src/sys/windows/fs.rs b/library/std/src/sys/windows/fs.rs
index d7e36b9a3..424845436 100644
--- a/library/std/src/sys/windows/fs.rs
+++ b/library/std/src/sys/windows/fs.rs
@@ -1,7 +1,7 @@
 use crate::os::windows::prelude::*;
 
 use crate::borrow::Cow;
-use crate::ffi::OsString;
+use crate::ffi::{c_void, OsString};
 use crate::fmt;
 use crate::io::{self, BorrowedCursor, Error, IoSlice, IoSliceMut, SeekFrom};
 use crate::mem::{self, MaybeUninit};
@@ -16,8 +16,6 @@ use crate::sys::{c, cvt, Align8};
 use crate::sys_common::{AsInner, FromInner, IntoInner};
 use crate::thread;
 
-use core::ffi::c_void;
-
 use super::path::maybe_verbatim;
 use super::{api, to_u16s, IoResult};
 
@@ -156,7 +154,7 @@ impl DirEntry {
     }
 
     pub fn path(&self) -> PathBuf {
-        self.root.join(&self.file_name())
+        self.root.join(self.file_name())
     }
 
     pub fn file_name(&self) -> OsString {
@@ -273,7 +271,9 @@ impl OpenOptions {
             (false, false, false) => c::OPEN_EXISTING,
             (true, false, false) => c::OPEN_ALWAYS,
             (false, true, false) => c::TRUNCATE_EXISTING,
-            (true, true, false) => c::CREATE_ALWAYS,
+            // `CREATE_ALWAYS` has weird semantics so we emulate it using
+            // `OPEN_ALWAYS` and a manual truncation step. See #115745.
+            (true, true, false) => c::OPEN_ALWAYS,
             (_, _, true) => c::CREATE_NEW,
         })
     }
@@ -289,19 +289,42 @@ impl OpenOptions {
 impl File {
     pub fn open(path: &Path, opts: &OpenOptions) -> io::Result<File> {
         let path = maybe_verbatim(path)?;
+        let creation = opts.get_creation_mode()?;
         let handle = unsafe {
             c::CreateFileW(
                 path.as_ptr(),
                 opts.get_access_mode()?,
                 opts.share_mode,
                 opts.security_attributes,
-                opts.get_creation_mode()?,
+                creation,
                 opts.get_flags_and_attributes(),
                 ptr::null_mut(),
             )
         };
         let handle = unsafe { HandleOrInvalid::from_raw_handle(handle) };
-        if let Ok(handle) = handle.try_into() {
+        if let Ok(handle) = OwnedHandle::try_from(handle) {
+            // Manual truncation. See #115745.
+            if opts.truncate
+                && creation == c::OPEN_ALWAYS
+                && unsafe { c::GetLastError() } == c::ERROR_ALREADY_EXISTS
+            {
+                unsafe {
+                    // This originally used `FileAllocationInfo` instead of
+                    // `FileEndOfFileInfo` but that wasn't supported by WINE.
+                    // It's arguable which fits the semantics of `OpenOptions`
+                    // better so let's just use the more widely supported method.
+                    let eof = c::FILE_END_OF_FILE_INFO { EndOfFile: 0 };
+                    let result = c::SetFileInformationByHandle(
+                        handle.as_raw_handle(),
+                        c::FileEndOfFileInfo,
+                        ptr::addr_of!(eof).cast::<c_void>(),
+                        mem::size_of::<c::FILE_END_OF_FILE_INFO>() as u32,
+                    );
+                    if result == 0 {
+                        return Err(io::Error::last_os_error());
+                    }
+                }
+            }
             Ok(File { handle: Handle::from_inner(handle) })
         } else {
             Err(Error::last_os_error())
@@ -548,7 +571,7 @@ impl File {
                 let user = super::args::from_wide_to_user_path(
                     subst.iter().copied().chain([0]).collect(),
                 )?;
-                Ok(PathBuf::from(OsString::from_wide(&user.strip_suffix(&[0]).unwrap_or(&user))))
+                Ok(PathBuf::from(OsString::from_wide(user.strip_suffix(&[0]).unwrap_or(&user))))
             } else {
                 Ok(PathBuf::from(OsString::from_wide(subst)))
             }
@@ -786,7 +809,7 @@ fn open_link_no_reparse(parent: &File, name: &[u16], access: u32) -> io::Result<
         // tricked into following a symlink. However, it may not be available in
         // earlier versions of Windows.
         static ATTRIBUTES: AtomicU32 = AtomicU32::new(c::OBJ_DONT_REPARSE);
-        let mut object = c::OBJECT_ATTRIBUTES {
+        let object = c::OBJECT_ATTRIBUTES {
             ObjectName: &mut name_str,
             RootDirectory: parent.as_raw_handle(),
             Attributes: ATTRIBUTES.load(Ordering::Relaxed),
@@ -795,7 +818,7 @@ fn open_link_no_reparse(parent: &File, name: &[u16], access: u32) -> io::Result<
         let status = c::NtCreateFile(
             &mut handle,
             access,
-            &mut object,
+            &object,
             &mut io_status,
             crate::ptr::null_mut(),
             0,
@@ -874,7 +897,7 @@ impl fmt::Debug for File {
         // FIXME(#24570): add more info here (e.g., mode)
         let mut b = f.debug_struct("File");
         b.field("handle", &self.handle.as_raw_handle());
-        if let Ok(path) = get_path(&self) {
+        if let Ok(path) = get_path(self) {
             b.field("path", &path);
         }
         b.finish()
@@ -1193,7 +1216,7 @@ pub fn readlink(path: &Path) -> io::Result<PathBuf> {
     let mut opts = OpenOptions::new();
     opts.access_mode(0);
     opts.custom_flags(c::FILE_FLAG_OPEN_REPARSE_POINT | c::FILE_FLAG_BACKUP_SEMANTICS);
-    let file = File::open(&path, &opts)?;
+    let file = File::open(path, &opts)?;
     file.readlink()
 }
 
@@ -1407,7 +1430,7 @@ pub fn symlink_junction<P: AsRef<Path>, Q: AsRef<Path>>(
 #[allow(dead_code)]
 fn symlink_junction_inner(original: &Path, junction: &Path) -> io::Result<()> {
     let d = DirBuilder::new();
-    d.mkdir(&junction)?;
+    d.mkdir(junction)?;
 
     let mut opts = OpenOptions::new();
     opts.write(true);
diff --git a/library/std/src/sys/windows/handle.rs b/library/std/src/sys/windows/handle.rs
index 56d0d6c08..c4495f81a 100644
--- a/library/std/src/sys/windows/handle.rs
+++ b/library/std/src/sys/windows/handle.rs
@@ -81,7 +81,7 @@ impl Handle {
         let res = unsafe { self.synchronous_read(buf.as_mut_ptr().cast(), buf.len(), None) };
 
         match res {
-            Ok(read) => Ok(read as usize),
+            Ok(read) => Ok(read),
 
             // The special treatment of BrokenPipe is to deal with Windows
             // pipe semantics, which yields this error when *reading* from
@@ -107,7 +107,7 @@ impl Handle {
             unsafe { self.synchronous_read(buf.as_mut_ptr().cast(), buf.len(), Some(offset)) };
 
         match res {
-            Ok(read) => Ok(read as usize),
+            Ok(read) => Ok(read),
             Err(ref e) if e.raw_os_error() == Some(c::ERROR_HANDLE_EOF as i32) => Ok(0),
             Err(e) => Err(e),
         }
@@ -121,7 +121,7 @@ impl Handle {
             Ok(read) => {
                 // Safety: `read` bytes were written to the initialized portion of the buffer
                 unsafe {
-                    cursor.advance(read as usize);
+                    cursor.advance(read);
                 }
                 Ok(())
             }
@@ -189,7 +189,7 @@ impl Handle {
     }
 
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
-        self.synchronous_write(&buf, None)
+        self.synchronous_write(buf, None)
     }
 
     pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
@@ -202,7 +202,7 @@ impl Handle {
     }
 
     pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
-        self.synchronous_write(&buf, Some(offset))
+        self.synchronous_write(buf, Some(offset))
     }
 
     pub fn try_clone(&self) -> io::Result<Self> {
diff --git a/library/std/src/sys/windows/io.rs b/library/std/src/sys/windows/io.rs
index 9b540ee07..649826d25 100644
--- a/library/std/src/sys/windows/io.rs
+++ b/library/std/src/sys/windows/io.rs
@@ -36,7 +36,7 @@ impl<'a> IoSlice<'a> {
 
     #[inline]
     pub fn as_slice(&self) -> &[u8] {
-        unsafe { slice::from_raw_parts(self.vec.buf as *mut u8, self.vec.len as usize) }
+        unsafe { slice::from_raw_parts(self.vec.buf, self.vec.len as usize) }
     }
 }
 
@@ -70,12 +70,12 @@ impl<'a> IoSliceMut<'a> {
 
     #[inline]
     pub fn as_slice(&self) -> &[u8] {
-        unsafe { slice::from_raw_parts(self.vec.buf as *mut u8, self.vec.len as usize) }
+        unsafe { slice::from_raw_parts(self.vec.buf, self.vec.len as usize) }
     }
 
     #[inline]
     pub fn as_mut_slice(&mut self) -> &mut [u8] {
-        unsafe { slice::from_raw_parts_mut(self.vec.buf as *mut u8, self.vec.len as usize) }
+        unsafe { slice::from_raw_parts_mut(self.vec.buf, self.vec.len as usize) }
     }
 }
 
diff --git a/library/std/src/sys/windows/mod.rs b/library/std/src/sys/windows/mod.rs
index c4e56e13b..8b722f01a 100644
--- a/library/std/src/sys/windows/mod.rs
+++ b/library/std/src/sys/windows/mod.rs
@@ -1,6 +1,6 @@
 #![allow(missing_docs, nonstandard_style)]
 
-use crate::ffi::{CStr, OsStr, OsString};
+use crate::ffi::{OsStr, OsString};
 use crate::io::ErrorKind;
 use crate::mem::MaybeUninit;
 use crate::os::windows::ffi::{OsStrExt, OsStringExt};
@@ -63,7 +63,7 @@ pub unsafe fn init(_argc: isize, _argv: *const *const u8, _sigpipe: u8) {
 
     // Normally, `thread::spawn` will call `Thread::set_name` but since this thread already
     // exists, we have to call it ourselves.
-    thread::Thread::set_name(&CStr::from_bytes_with_nul_unchecked(b"main\0"));
+    thread::Thread::set_name(&c"main");
 }
 
 // SAFETY: must be called only once during runtime cleanup.
@@ -150,7 +150,7 @@ pub fn decode_error_kind(errno: i32) -> ErrorKind {
 
 pub fn unrolled_find_u16s(needle: u16, haystack: &[u16]) -> Option<usize> {
     let ptr = haystack.as_ptr();
-    let mut start = &haystack[..];
+    let mut start = haystack;
 
     // For performance reasons unfold the loop eight times.
     while start.len() >= 8 {
diff --git a/library/std/src/sys/windows/net.rs b/library/std/src/sys/windows/net.rs
index c29b86366..6cd758ec5 100644
--- a/library/std/src/sys/windows/net.rs
+++ b/library/std/src/sys/windows/net.rs
@@ -162,7 +162,7 @@ impl Socket {
 
                 let mut timeout = c::timeval {
                     tv_sec: cmp::min(timeout.as_secs(), c_long::MAX as u64) as c_long,
-                    tv_usec: (timeout.subsec_nanos() / 1000) as c_long,
+                    tv_usec: timeout.subsec_micros() as c_long,
                 };
 
                 if timeout.tv_sec == 0 && timeout.tv_usec == 0 {
diff --git a/library/std/src/sys/windows/os.rs b/library/std/src/sys/windows/os.rs
index 8cc905101..829dd5eb9 100644
--- a/library/std/src/sys/windows/os.rs
+++ b/library/std/src/sys/windows/os.rs
@@ -297,7 +297,7 @@ pub fn getenv(k: &OsStr) -> Option<OsString> {
     let k = to_u16s(k).ok()?;
     super::fill_utf16_buf(
         |buf, sz| unsafe { c::GetEnvironmentVariableW(k.as_ptr(), buf, sz) },
-        |buf| OsStringExt::from_wide(buf),
+        OsStringExt::from_wide,
     )
     .ok()
 }
@@ -356,7 +356,7 @@ pub fn home_dir() -> Option<PathBuf> {
     crate::env::var_os("HOME")
         .or_else(|| crate::env::var_os("USERPROFILE"))
         .map(PathBuf::from)
-        .or_else(|| home_dir_crt())
+        .or_else(home_dir_crt)
 }
 
 pub fn exit(code: i32) -> ! {
@@ -364,5 +364,5 @@ pub fn exit(code: i32) -> ! {
 }
 
 pub fn getpid() -> u32 {
-    unsafe { c::GetCurrentProcessId() as u32 }
+    unsafe { c::GetCurrentProcessId() }
 }
diff --git a/library/std/src/sys/windows/path.rs b/library/std/src/sys/windows/path.rs
index 8c0e07b35..d9684f217 100644
--- a/library/std/src/sys/windows/path.rs
+++ b/library/std/src/sys/windows/path.rs
@@ -78,7 +78,7 @@ impl<'a> PrefixParserSlice<'a, '_> {
     fn strip_prefix(&self, prefix: &str) -> Option<Self> {
         self.prefix[self.index..]
             .starts_with(prefix.as_bytes())
-            .then(|| Self { index: self.index + prefix.len(), ..*self })
+            .then_some(Self { index: self.index + prefix.len(), ..*self })
     }
 
     fn prefix_bytes(&self) -> &'a [u8] {
@@ -104,7 +104,9 @@ pub fn parse_prefix(path: &OsStr) -> Option<Prefix<'_>> {
 
         // The meaning of verbatim paths can change when they use a different
         // separator.
-        if let Some(parser) = parser.strip_prefix(r"?\") && !parser.prefix_bytes().iter().any(|&x| x == b'/') {
+        if let Some(parser) = parser.strip_prefix(r"?\")
+            && !parser.prefix_bytes().iter().any(|&x| x == b'/')
+        {
             // \\?\
             if let Some(parser) = parser.strip_prefix(r"UNC\") {
                 // \\?\UNC\server\share
@@ -145,12 +147,10 @@ pub fn parse_prefix(path: &OsStr) -> Option<Prefix<'_>> {
                 None
             }
         }
-    } else if let Some(drive) = parse_drive(path) {
-        // C:
-        Some(Disk(drive))
     } else {
-        // no prefix
-        None
+        // If it has a drive like `C:` then it's a disk.
+        // Otherwise there is no prefix.
+        parse_drive(path).map(Disk)
     }
 }
 
@@ -250,7 +250,7 @@ pub(crate) fn get_long_path(mut path: Vec<u16>, prefer_verbatim: bool) -> io::Re
     // \\?\UNC\
     const UNC_PREFIX: &[u16] = &[SEP, SEP, QUERY, SEP, U, N, C, SEP];
 
-    if path.starts_with(VERBATIM_PREFIX) || path.starts_with(NT_PREFIX) || path == &[0] {
+    if path.starts_with(VERBATIM_PREFIX) || path.starts_with(NT_PREFIX) || path == [0] {
         // Early return for paths that are already verbatim or empty.
         return Ok(path);
     } else if path.len() < LEGACY_MAX_PATH {
diff --git a/library/std/src/sys/windows/process.rs b/library/std/src/sys/windows/process.rs
index f4078d359..9ec775959 100644
--- a/library/std/src/sys/windows/process.rs
+++ b/library/std/src/sys/windows/process.rs
@@ -245,7 +245,7 @@ impl Command {
     }
 
     pub fn get_current_dir(&self) -> Option<&Path> {
-        self.cwd.as_ref().map(|cwd| Path::new(cwd))
+        self.cwd.as_ref().map(Path::new)
     }
 
     pub unsafe fn raw_attribute<T: Copy + Send + Sync + 'static>(
@@ -463,7 +463,7 @@ fn resolve_exe<'a>(
 
         // Search the directories given by `search_paths`.
         let result = search_paths(parent_paths, child_paths, |mut path| {
-            path.push(&exe_path);
+            path.push(exe_path);
             if !has_extension {
                 path.set_extension(EXE_EXTENSION);
             }
@@ -597,7 +597,7 @@ impl Stdio {
                 opts.read(stdio_id == c::STD_INPUT_HANDLE);
                 opts.write(stdio_id != c::STD_INPUT_HANDLE);
                 opts.security_attributes(&mut sa);
-                File::open(Path::new("NUL"), &opts).map(|file| file.into_inner())
+                File::open(Path::new(r"\\.\NUL"), &opts).map(|file| file.into_inner())
             }
         }
     }
@@ -657,7 +657,7 @@ impl Process {
     }
 
     pub fn id(&self) -> u32 {
-        unsafe { c::GetProcessId(self.handle.as_raw_handle()) as u32 }
+        unsafe { c::GetProcessId(self.handle.as_raw_handle()) }
     }
 
     pub fn main_thread_handle(&self) -> BorrowedHandle<'_> {
@@ -917,9 +917,8 @@ fn make_proc_thread_attribute_list(
         )
     };
 
-    let mut proc_thread_attribute_list = ProcThreadAttributeList(
-        vec![MaybeUninit::uninit(); required_size as usize].into_boxed_slice(),
-    );
+    let mut proc_thread_attribute_list =
+        ProcThreadAttributeList(vec![MaybeUninit::uninit(); required_size].into_boxed_slice());
 
     // Once we've allocated the necessary memory, it's safe to invoke
     // `InitializeProcThreadAttributeList` to properly initialize the list.
diff --git a/library/std/src/sys/windows/stdio.rs b/library/std/src/sys/windows/stdio.rs
index a9ff909aa..819a48266 100644
--- a/library/std/src/sys/windows/stdio.rs
+++ b/library/std/src/sys/windows/stdio.rs
@@ -195,7 +195,7 @@ fn write_valid_utf8_to_console(handle: c::HANDLE, utf8: &str) -> io::Result<usiz
         MaybeUninit::slice_assume_init_ref(&utf16[..result as usize])
     };
 
-    let mut written = write_u16s(handle, &utf16)?;
+    let mut written = write_u16s(handle, utf16)?;
 
     // Figure out how many bytes of as UTF-8 were written away as UTF-16.
     if written == utf16.len() {
@@ -207,7 +207,7 @@ fn write_valid_utf8_to_console(handle: c::HANDLE, utf8: &str) -> io::Result<usiz
         // write the missing surrogate out now.
         // Buffering it would mean we have to lie about the number of bytes written.
         let first_code_unit_remaining = utf16[written];
-        if first_code_unit_remaining >= 0xDCEE && first_code_unit_remaining <= 0xDFFF {
+        if matches!(first_code_unit_remaining, 0xDCEE..=0xDFFF) {
             // low surrogate
             // We just hope this works, and give up otherwise
             let _ = write_u16s(handle, &utf16[written..written + 1]);
@@ -266,7 +266,7 @@ impl io::Read for Stdin {
         let mut bytes_copied = self.incomplete_utf8.read(buf);
 
         if bytes_copied == buf.len() {
-            return Ok(bytes_copied);
+            Ok(bytes_copied)
         } else if buf.len() - bytes_copied < 4 {
             // Not enough space to get a UTF-8 byte. We will use the incomplete UTF8.
             let mut utf16_buf = [MaybeUninit::new(0); 1];
@@ -332,7 +332,7 @@ fn read_u16s_fixup_surrogates(
         // and it is not 0, so we know that `buf[amount - 1]` have been
         // initialized.
         let last_char = unsafe { buf[amount - 1].assume_init() };
-        if last_char >= 0xD800 && last_char <= 0xDBFF {
+        if matches!(last_char, 0xD800..=0xDBFF) {
             // high surrogate
             *surrogate = last_char;
             amount -= 1;
diff --git a/library/std/src/sys/windows/time.rs b/library/std/src/sys/windows/time.rs
index bece48e79..09e78a293 100644
--- a/library/std/src/sys/windows/time.rs
+++ b/library/std/src/sys/windows/time.rs
@@ -1,7 +1,7 @@
 use crate::cmp::Ordering;
 use crate::fmt;
 use crate::mem;
-use crate::ptr::{null, null_mut};
+use crate::ptr::null;
 use crate::sys::c;
 use crate::sys_common::IntoInner;
 use crate::time::Duration;
@@ -240,7 +240,7 @@ impl WaitableTimer {
                 c::TIMER_ALL_ACCESS,
             )
         };
-        if handle != null_mut() { Ok(Self { handle }) } else { Err(()) }
+        if !handle.is_null() { Ok(Self { handle }) } else { Err(()) }
     }
     pub fn set(&self, duration: Duration) -> Result<(), ()> {
         // Convert the Duration to a format similar to FILETIME.
diff --git a/library/std/src/sys/xous/mod.rs b/library/std/src/sys/xous/mod.rs
index 6d5c218d1..c2550dcfd 100644
--- a/library/std/src/sys/xous/mod.rs
+++ b/library/std/src/sys/xous/mod.rs
@@ -28,7 +28,6 @@ pub mod process;
 pub mod stdio;
 pub mod thread;
 pub mod thread_local_key;
-#[path = "../unsupported/thread_parking.rs"]
 pub mod thread_parking;
 pub mod time;
 
diff --git a/library/std/src/sys/xous/os.rs b/library/std/src/sys/xous/os.rs
index 3d19fa4b3..8d2eaee8a 100644
--- a/library/std/src/sys/xous/os.rs
+++ b/library/std/src/sys/xous/os.rs
@@ -8,6 +8,28 @@ use crate::os::xous::ffi::Error as XousError;
 use crate::path::{self, PathBuf};
 
 #[cfg(not(test))]
+#[cfg(feature = "panic_unwind")]
+mod eh_unwinding {
+    pub(crate) struct EhFrameFinder(usize /* eh_frame */);
+    pub(crate) static mut EH_FRAME_SETTINGS: EhFrameFinder = EhFrameFinder(0);
+    impl EhFrameFinder {
+        pub(crate) unsafe fn init(&mut self, eh_frame: usize) {
+            unsafe {
+                EH_FRAME_SETTINGS.0 = eh_frame;
+            }
+        }
+    }
+    unsafe impl unwind::EhFrameFinder for EhFrameFinder {
+        fn find(&self, _pc: usize) -> Option<unwind::FrameInfo> {
+            Some(unwind::FrameInfo {
+                text_base: None,
+                kind: unwind::FrameInfoKind::EhFrame(self.0),
+            })
+        }
+    }
+}
+
+#[cfg(not(test))]
 mod c_compat {
     use crate::os::xous::ffi::exit;
     extern "C" {
@@ -20,7 +42,12 @@ mod c_compat {
     }
 
     #[no_mangle]
-    pub extern "C" fn _start() {
+    pub extern "C" fn _start(eh_frame: usize) {
+        #[cfg(feature = "panic_unwind")]
+        unsafe {
+            super::eh_unwinding::EH_FRAME_SETTINGS.init(eh_frame);
+            unwind::set_custom_eh_frame_finder(&super::eh_unwinding::EH_FRAME_SETTINGS).ok();
+        }
         exit(unsafe { main() });
     }
 
diff --git a/library/std/src/sys/xous/thread_parking.rs b/library/std/src/sys/xous/thread_parking.rs
new file mode 100644
index 000000000..aa39c6d27
--- /dev/null
+++ b/library/std/src/sys/xous/thread_parking.rs
@@ -0,0 +1,94 @@
+use crate::os::xous::ffi::{blocking_scalar, scalar};
+use crate::os::xous::services::{ticktimer_server, TicktimerScalar};
+use crate::pin::Pin;
+use crate::ptr;
+use crate::sync::atomic::{
+    AtomicI8,
+    Ordering::{Acquire, Release},
+};
+use crate::time::Duration;
+
+const NOTIFIED: i8 = 1;
+const EMPTY: i8 = 0;
+const PARKED: i8 = -1;
+
+pub struct Parker {
+    state: AtomicI8,
+}
+
+impl Parker {
+    pub unsafe fn new_in_place(parker: *mut Parker) {
+        unsafe { parker.write(Parker { state: AtomicI8::new(EMPTY) }) }
+    }
+
+    fn index(&self) -> usize {
+        ptr::from_ref(self).addr()
+    }
+
+    pub unsafe fn park(self: Pin<&Self>) {
+        // Change NOTIFIED to EMPTY and EMPTY to PARKED.
+        let state = self.state.fetch_sub(1, Acquire);
+        if state == NOTIFIED {
+            return;
+        }
+
+        // The state was set to PARKED. Wait until the `unpark` wakes us up.
+        blocking_scalar(
+            ticktimer_server(),
+            TicktimerScalar::WaitForCondition(self.index(), 0).into(),
+        )
+        .expect("failed to send WaitForCondition command");
+
+        self.state.swap(EMPTY, Acquire);
+    }
+
+    pub unsafe fn park_timeout(self: Pin<&Self>, timeout: Duration) {
+        // Change NOTIFIED to EMPTY and EMPTY to PARKED.
+        let state = self.state.fetch_sub(1, Acquire);
+        if state == NOTIFIED {
+            return;
+        }
+
+        // A value of zero indicates an indefinite wait. Clamp the number of
+        // milliseconds to the allowed range.
+        let millis = usize::max(timeout.as_millis().try_into().unwrap_or(usize::MAX), 1);
+
+        let was_timeout = blocking_scalar(
+            ticktimer_server(),
+            TicktimerScalar::WaitForCondition(self.index(), millis).into(),
+        )
+        .expect("failed to send WaitForCondition command")[0]
+            != 0;
+
+        let state = self.state.swap(EMPTY, Acquire);
+        if was_timeout && state == NOTIFIED {
+            // The state was set to NOTIFIED after we returned from the wait
+            // but before we reset the state. Therefore, a wakeup is on its
+            // way, which we need to consume here.
+            // NOTICE: this is a priority hole.
+            blocking_scalar(
+                ticktimer_server(),
+                TicktimerScalar::WaitForCondition(self.index(), 0).into(),
+            )
+            .expect("failed to send WaitForCondition command");
+        }
+    }
+
+    pub fn unpark(self: Pin<&Self>) {
+        let state = self.state.swap(NOTIFIED, Release);
+        if state == PARKED {
+            // The thread is parked, wake it up.
+            blocking_scalar(
+                ticktimer_server(),
+                TicktimerScalar::NotifyCondition(self.index(), 1).into(),
+            )
+            .expect("failed to send NotifyCondition command");
+        }
+    }
+}
+
+impl Drop for Parker {
+    fn drop(&mut self) {
+        scalar(ticktimer_server(), TicktimerScalar::FreeCondition(self.index()).into()).ok();
+    }
+}