Merging upstream version 1.68.2+dfsg1.

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

89 files changed, 1174 insertions, 694 deletions

diff --git a/library/std/src/alloc.rs b/library/std/src/alloc.rs
index 61c1ff578..c5a5991cc 100644
--- a/library/std/src/alloc.rs
+++ b/library/std/src/alloc.rs
@@ -338,7 +338,7 @@ fn default_alloc_error_hook(layout: Layout) {
 
     #[allow(unused_unsafe)]
     if unsafe { __rust_alloc_error_handler_should_panic != 0 } {
-        panic!("memory allocation of {} bytes failed\n", layout.size());
+        panic!("memory allocation of {} bytes failed", layout.size());
     } else {
         rtprintpanic!("memory allocation of {} bytes failed\n", layout.size());
     }
diff --git a/library/std/src/backtrace.rs b/library/std/src/backtrace.rs
index 9cb74f951..7543ffadd 100644
--- a/library/std/src/backtrace.rs
+++ b/library/std/src/backtrace.rs
@@ -23,10 +23,10 @@
 //!
 //! ## Platform support
 //!
-//! Not all platforms that libstd compiles for support capturing backtraces.
-//! Some platforms simply do nothing when capturing a backtrace. To check
-//! whether the platform supports capturing backtraces you can consult the
-//! `BacktraceStatus` enum as a result of `Backtrace::status`.
+//! Not all platforms that std compiles for support capturing backtraces. Some
+//! platforms simply do nothing when capturing a backtrace. To check whether the
+//! platform supports capturing backtraces you can consult the `BacktraceStatus`
+//! enum as a result of `Backtrace::status`.
 //!
 //! Like above with accuracy platform support is done on a best effort basis.
 //! Sometimes libraries might not be available at runtime or something may go
diff --git a/library/std/src/collections/hash/map/tests.rs b/library/std/src/collections/hash/map/tests.rs
index 65634f206..6b89518e2 100644
--- a/library/std/src/collections/hash/map/tests.rs
+++ b/library/std/src/collections/hash/map/tests.rs
@@ -3,7 +3,8 @@ use super::HashMap;
 use super::RandomState;
 use crate::assert_matches::assert_matches;
 use crate::cell::RefCell;
-use rand::{thread_rng, Rng};
+use crate::test_helpers::test_rng;
+use rand::Rng;
 use realstd::collections::TryReserveErrorKind::*;
 
 // https://github.com/rust-lang/rust/issues/62301
@@ -710,16 +711,16 @@ fn test_entry_take_doesnt_corrupt() {
     }
 
     let mut m = HashMap::new();
-    let mut rng = thread_rng();
+    let mut rng = test_rng();
 
     // Populate the map with some items.
     for _ in 0..50 {
-        let x = rng.gen_range(-10, 10);
+        let x = rng.gen_range(-10..10);
         m.insert(x, ());
     }
 
     for _ in 0..1000 {
-        let x = rng.gen_range(-10, 10);
+        let x = rng.gen_range(-10..10);
         match m.entry(x) {
             Vacant(_) => {}
             Occupied(e) => {
diff --git a/library/std/src/collections/hash/set.rs b/library/std/src/collections/hash/set.rs
index cee884145..b59f89d32 100644
--- a/library/std/src/collections/hash/set.rs
+++ b/library/std/src/collections/hash/set.rs
@@ -317,7 +317,7 @@ impl<T, S> HashSet<T, S> {
     ///
     /// let mut set = HashSet::from([1, 2, 3, 4, 5, 6]);
     /// set.retain(|&k| k % 2 == 0);
-    /// assert_eq!(set.len(), 3);
+    /// assert_eq!(set, HashSet::from([2, 4, 6]));
     /// ```
     ///
     /// # Performance
diff --git a/library/std/src/env.rs b/library/std/src/env.rs
index 6eb7cbea6..183f9ab3b 100644
--- a/library/std/src/env.rs
+++ b/library/std/src/env.rs
@@ -570,6 +570,13 @@ impl Error for JoinPathsError {
 ///
 /// [msdn]: https://docs.microsoft.com/en-us/windows/win32/api/userenv/nf-userenv-getuserprofiledirectorya
 ///
+/// # Deprecation
+///
+/// This function is deprecated because the behaviour on Windows is not correct.
+/// The 'HOME' environment variable is not standard on Windows, and may not produce
+/// desired results; for instance, under Cygwin or Mingw it will return `/home/you`
+/// when it should return `C:\Users\you`.
+///
 /// # Examples
 ///
 /// ```
@@ -582,7 +589,7 @@ impl Error for JoinPathsError {
 /// ```
 #[deprecated(
     since = "1.29.0",
-    note = "This function's behavior is unexpected and probably not what you want. \
+    note = "This function's behavior may be unexpected on Windows. \
             Consider using a crate from crates.io instead."
 )]
 #[must_use]
diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs
index f357d505f..286ad68fd 100644
--- a/library/std/src/fs.rs
+++ b/library/std/src/fs.rs
@@ -249,8 +249,9 @@ pub struct DirBuilder {
 pub fn read<P: AsRef<Path>>(path: P) -> io::Result<Vec<u8>> {
     fn inner(path: &Path) -> io::Result<Vec<u8>> {
         let mut file = File::open(path)?;
-        let mut bytes = Vec::new();
-        file.read_to_end(&mut bytes)?;
+        let size = file.metadata().map(|m| m.len()).unwrap_or(0);
+        let mut bytes = Vec::with_capacity(size as usize);
+        io::default_read_to_end(&mut file, &mut bytes)?;
         Ok(bytes)
     }
     inner(path.as_ref())
@@ -288,8 +289,9 @@ pub fn read<P: AsRef<Path>>(path: P) -> io::Result<Vec<u8>> {
 pub fn read_to_string<P: AsRef<Path>>(path: P) -> io::Result<String> {
     fn inner(path: &Path) -> io::Result<String> {
         let mut file = File::open(path)?;
-        let mut string = String::new();
-        file.read_to_string(&mut string)?;
+        let size = file.metadata().map(|m| m.len()).unwrap_or(0);
+        let mut string = String::with_capacity(size as usize);
+        io::default_read_to_string(&mut file, &mut string)?;
         Ok(string)
     }
     inner(path.as_ref())
@@ -1510,7 +1512,7 @@ impl FileType {
     }
 
     /// Tests whether this file type represents a regular file.
-    /// The result is  mutually exclusive to the results of
+    /// The result is mutually exclusive to the results of
     /// [`is_dir`] and [`is_symlink`]; only zero or one of these
     /// tests may pass.
     ///
diff --git a/library/std/src/fs/tests.rs b/library/std/src/fs/tests.rs
index b8959316d..eb582be01 100644
--- a/library/std/src/fs/tests.rs
+++ b/library/std/src/fs/tests.rs
@@ -10,7 +10,7 @@ use crate::sys_common::io::test::{tmpdir, TempDir};
 use crate::thread;
 use crate::time::{Duration, Instant};
 
-use rand::{rngs::StdRng, RngCore, SeedableRng};
+use rand::RngCore;
 
 #[cfg(unix)]
 use crate::os::unix::fs::symlink as symlink_dir;
@@ -1181,7 +1181,7 @@ fn _assert_send_sync() {
 #[test]
 fn binary_file() {
     let mut bytes = [0; 1024];
-    StdRng::from_entropy().fill_bytes(&mut bytes);
+    crate::test_helpers::test_rng().fill_bytes(&mut bytes);
 
     let tmpdir = tmpdir();
 
@@ -1194,7 +1194,7 @@ fn binary_file() {
 #[test]
 fn write_then_read() {
     let mut bytes = [0; 1024];
-    StdRng::from_entropy().fill_bytes(&mut bytes);
+    crate::test_helpers::test_rng().fill_bytes(&mut bytes);
 
     let tmpdir = tmpdir();
 
@@ -1551,3 +1551,47 @@ fn hiberfil_sys() {
     fs::metadata(hiberfil).unwrap();
     assert_eq!(true, hiberfil.exists());
 }
+
+/// Test that two different ways of obtaining the FileType give the same result.
+/// Cf. https://github.com/rust-lang/rust/issues/104900
+#[test]
+fn test_eq_direntry_metadata() {
+    let tmpdir = tmpdir();
+    let file_path = tmpdir.join("file");
+    File::create(file_path).unwrap();
+    for e in fs::read_dir(tmpdir.path()).unwrap() {
+        let e = e.unwrap();
+        let p = e.path();
+        let ft1 = e.file_type().unwrap();
+        let ft2 = p.metadata().unwrap().file_type();
+        assert_eq!(ft1, ft2);
+    }
+}
+
+/// Regression test for https://github.com/rust-lang/rust/issues/50619.
+#[test]
+#[cfg(target_os = "linux")]
+fn test_read_dir_infinite_loop() {
+    use crate::io::ErrorKind;
+    use crate::process::Command;
+
+    // Create a zombie child process
+    let Ok(mut child) = Command::new("echo").spawn() else { return };
+
+    // Make sure the process is (un)dead
+    match child.kill() {
+        // InvalidInput means the child already exited
+        Err(e) if e.kind() != ErrorKind::InvalidInput => return,
+        _ => {}
+    }
+
+    // open() on this path will succeed, but readdir() will fail
+    let id = child.id();
+    let path = format!("/proc/{id}/net");
+
+    // Skip the test if we can't open the directory in the first place
+    let Ok(dir) = fs::read_dir(path) else { return };
+
+    // Check for duplicate errors
+    assert!(dir.filter(|e| e.is_err()).take(2).count() < 2);
+}
diff --git a/library/std/src/io/buffered/tests.rs b/library/std/src/io/buffered/tests.rs
index f4e688eb9..4c1b7d576 100644
--- a/library/std/src/io/buffered/tests.rs
+++ b/library/std/src/io/buffered/tests.rs
@@ -288,8 +288,8 @@ fn test_buffered_reader_seek_underflow_discard_buffer_between_seeks() {
     let mut reader = BufReader::with_capacity(5, ErrAfterFirstSeekReader { first_seek: true });
     assert_eq!(reader.fill_buf().ok(), Some(&[0, 0, 0, 0, 0][..]));
 
-    // The following seek will require two underlying seeks.  The first will
-    // succeed but the second will fail.  This should still invalidate the
+    // The following seek will require two underlying seeks. The first will
+    // succeed but the second will fail. This should still invalidate the
     // buffer.
     assert!(reader.seek(SeekFrom::Current(i64::MIN)).is_err());
     assert_eq!(reader.buffer().len(), 0);
diff --git a/library/std/src/io/error/repr_bitpacked.rs b/library/std/src/io/error/repr_bitpacked.rs
index 781ae03ad..358148405 100644
--- a/library/std/src/io/error/repr_bitpacked.rs
+++ b/library/std/src/io/error/repr_bitpacked.rs
@@ -166,7 +166,7 @@ impl Repr {
         // `new_unchecked` is safe.
         let res = Self(unsafe { NonNull::new_unchecked(tagged) }, PhantomData);
         // quickly smoke-check we encoded the right thing (This generally will
-        // only run in libstd's tests, unless the user uses -Zbuild-std)
+        // only run in std's tests, unless the user uses -Zbuild-std)
         debug_assert!(matches!(res.data(), ErrorData::Custom(_)), "repr(custom) encoding failed");
         res
     }
@@ -177,7 +177,7 @@ impl Repr {
         // Safety: `TAG_OS` is not zero, so the result of the `|` is not 0.
         let res = Self(unsafe { NonNull::new_unchecked(ptr::invalid_mut(utagged)) }, PhantomData);
         // quickly smoke-check we encoded the right thing (This generally will
-        // only run in libstd's tests, unless the user uses -Zbuild-std)
+        // only run in std's tests, unless the user uses -Zbuild-std)
         debug_assert!(
             matches!(res.data(), ErrorData::Os(c) if c == code),
             "repr(os) encoding failed for {code}"
@@ -191,7 +191,7 @@ impl Repr {
         // Safety: `TAG_SIMPLE` is not zero, so the result of the `|` is not 0.
         let res = Self(unsafe { NonNull::new_unchecked(ptr::invalid_mut(utagged)) }, PhantomData);
         // quickly smoke-check we encoded the right thing (This generally will
-        // only run in libstd's tests, unless the user uses -Zbuild-std)
+        // only run in std's tests, unless the user uses -Zbuild-std)
         debug_assert!(
             matches!(res.data(), ErrorData::Simple(k) if k == kind),
             "repr(simple) encoding failed {:?}",
@@ -348,7 +348,7 @@ fn kind_from_prim(ek: u32) -> Option<ErrorKind> {
 // that our encoding relies on for correctness and soundness. (Some of these are
 // a bit overly thorough/cautious, admittedly)
 //
-// If any of these are hit on a platform that libstd supports, we should likely
+// If any of these are hit on a platform that std supports, we should likely
 // just use `repr_unpacked.rs` there instead (unless the fix is easy).
 macro_rules! static_assert {
     ($condition:expr) => {
@@ -374,10 +374,10 @@ static_assert!((TAG_MASK + 1).is_power_of_two());
 static_assert!(align_of::<SimpleMessage>() >= TAG_MASK + 1);
 static_assert!(align_of::<Custom>() >= TAG_MASK + 1);
 
-static_assert!(@usize_eq: (TAG_MASK & TAG_SIMPLE_MESSAGE), TAG_SIMPLE_MESSAGE);
-static_assert!(@usize_eq: (TAG_MASK & TAG_CUSTOM), TAG_CUSTOM);
-static_assert!(@usize_eq: (TAG_MASK & TAG_OS), TAG_OS);
-static_assert!(@usize_eq: (TAG_MASK & TAG_SIMPLE), TAG_SIMPLE);
+static_assert!(@usize_eq: TAG_MASK & TAG_SIMPLE_MESSAGE, TAG_SIMPLE_MESSAGE);
+static_assert!(@usize_eq: TAG_MASK & TAG_CUSTOM, TAG_CUSTOM);
+static_assert!(@usize_eq: TAG_MASK & TAG_OS, TAG_OS);
+static_assert!(@usize_eq: TAG_MASK & TAG_SIMPLE, TAG_SIMPLE);
 
 // This is obviously true (`TAG_CUSTOM` is `0b01`), but in `Repr::new_custom` we
 // offset a pointer by this value, and expect it to both be within the same
diff --git a/library/std/src/io/mod.rs b/library/std/src/io/mod.rs
index 23a13523f..de528e853 100644
--- a/library/std/src/io/mod.rs
+++ b/library/std/src/io/mod.rs
@@ -2137,8 +2137,10 @@ pub trait BufRead: Read {
     }
 
     /// Read all bytes until a newline (the `0xA` byte) is reached, and append
-    /// them to the provided buffer. You do not need to clear the buffer before
-    /// appending.
+    /// them to the provided `String` buffer.
+    ///
+    /// Previous content of the buffer will be preserved. To avoid appending to
+    /// the buffer, you need to [`clear`] it first.
     ///
     /// This function will read bytes from the underlying stream until the
     /// newline delimiter (the `0xA` byte) or EOF is found. Once found, all bytes
@@ -2151,9 +2153,11 @@ pub trait BufRead: Read {
     ///
     /// This function is blocking and should be used carefully: it is possible for
     /// an attacker to continuously send bytes without ever sending a newline
-    /// or EOF.
+    /// or EOF. You can use [`take`] to limit the maximum number of bytes read.
     ///
     /// [`Ok(0)`]: Ok
+    /// [`clear`]: String::clear
+    /// [`take`]: crate::io::Read::take
     ///
     /// # Errors
     ///
diff --git a/library/std/src/io/stdio.rs b/library/std/src/io/stdio.rs
index 1141a957d..14bfef4c7 100644
--- a/library/std/src/io/stdio.rs
+++ b/library/std/src/io/stdio.rs
@@ -10,9 +10,8 @@ use crate::fmt;
 use crate::fs::File;
 use crate::io::{self, BufReader, IoSlice, IoSliceMut, LineWriter, Lines};
 use crate::sync::atomic::{AtomicBool, Ordering};
-use crate::sync::{Arc, Mutex, MutexGuard, OnceLock};
+use crate::sync::{Arc, Mutex, MutexGuard, OnceLock, ReentrantMutex, ReentrantMutexGuard};
 use crate::sys::stdio;
-use crate::sys_common::remutex::{ReentrantMutex, ReentrantMutexGuard};
 
 type LocalStream = Arc<Mutex<Vec<u8>>>;
 
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 65d4c3c89..a7e13f5b8 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -14,7 +14,7 @@
 //! # How to read this documentation
 //!
 //! If you already know the name of what you are looking for, the fastest way to
-//! find it is to use the <a href="#" onclick="focusSearchBar();">search
+//! find it is to use the <a href="#" onclick="window.searchState.focus();">search
 //! bar</a> at the top of the page.
 //!
 //! Otherwise, you may want to jump to one of these useful sections:
@@ -202,7 +202,7 @@
     no_global_oom_handling,
     not(no_global_oom_handling)
 ))]
-// To run libstd tests without x.py without ending up with two copies of libstd, Miri needs to be
+// To run std tests without x.py without ending up with two copies of std, Miri needs to be
 // able to "empty" this crate. See <https://github.com/rust-lang/miri-test-libstd/issues/4>.
 // rustc itself never sets the feature, so this line has no affect there.
 #![cfg(any(not(feature = "miri-test-libstd"), test, doctest))]
@@ -532,7 +532,7 @@ pub mod process;
 pub mod sync;
 pub mod time;
 
-// Pull in `std_float` crate  into libstd. The contents of
+// Pull in `std_float` crate  into std. The contents of
 // `std_float` are in a different repository: rust-lang/portable-simd.
 #[path = "../../portable-simd/crates/std_float/src/lib.rs"]
 #[allow(missing_debug_implementations, dead_code, unsafe_op_in_unsafe_fn, unused_unsafe)]
@@ -602,7 +602,7 @@ mod personality;
 #[allow(dead_code, unused_attributes, fuzzy_provenance_casts)]
 mod backtrace_rs;
 
-// Re-export macros defined in libcore.
+// Re-export macros defined in core.
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow(deprecated, deprecated_in_future)]
 pub use core::{
@@ -610,7 +610,7 @@ pub use core::{
     unimplemented, unreachable, write, writeln,
 };
 
-// Re-export built-in macros defined through libcore.
+// Re-export built-in macros defined through core.
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow(deprecated)]
 pub use core::{
@@ -652,3 +652,30 @@ mod sealed {
     #[unstable(feature = "sealed", issue = "none")]
     pub trait Sealed {}
 }
+
+#[cfg(test)]
+#[allow(dead_code)] // Not used in all configurations.
+pub(crate) mod test_helpers {
+    /// Test-only replacement for `rand::thread_rng()`, which is unusable for
+    /// us, as we want to allow running stdlib tests on tier-3 targets which may
+    /// not have `getrandom` support.
+    ///
+    /// Does a bit of a song and dance to ensure that the seed is different on
+    /// each call (as some tests sadly rely on this), but doesn't try that hard.
+    ///
+    /// This is duplicated in the `core`, `alloc` test suites (as well as
+    /// `std`'s integration tests), but figuring out a mechanism to share these
+    /// seems far more painful than copy-pasting a 7 line function a couple
+    /// times, given that even under a perma-unstable feature, I don't think we
+    /// want to expose types from `rand` from `std`.
+    #[track_caller]
+    pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng {
+        use core::hash::{BuildHasher, Hash, Hasher};
+        let mut hasher = crate::collections::hash_map::RandomState::new().build_hasher();
+        core::panic::Location::caller().hash(&mut hasher);
+        let hc64 = hasher.finish();
+        let seed_vec = hc64.to_le_bytes().into_iter().chain(0u8..8).collect::<Vec<u8>>();
+        let seed: [u8; 16] = seed_vec.as_slice().try_into().unwrap();
+        rand::SeedableRng::from_seed(seed)
+    }
+}
diff --git a/library/std/src/macros.rs b/library/std/src/macros.rs
index 6e4ba1404..fcc5cfafd 100644
--- a/library/std/src/macros.rs
+++ b/library/std/src/macros.rs
@@ -3,6 +3,7 @@
 //! This module contains a set of macros which are exported from the standard
 //! library. Each macro is available for use when linking against the standard
 //! library.
+// ignore-tidy-dbg
 
 #[doc = include_str!("../../core/src/macros/panic.md")]
 #[macro_export]
diff --git a/library/std/src/net/ip_addr.rs b/library/std/src/net/ip_addr.rs
index 5453853e1..07f08c1b5 100644
--- a/library/std/src/net/ip_addr.rs
+++ b/library/std/src/net/ip_addr.rs
@@ -1195,6 +1195,9 @@ impl Ipv6Addr {
 
     /// An IPv6 address representing localhost: `::1`.
     ///
+    /// This corresponds to constant `IN6ADDR_LOOPBACK_INIT` or `in6addr_loopback` in other
+    /// languages.
+    ///
     /// # Examples
     ///
     /// ```
@@ -1203,11 +1206,15 @@ impl Ipv6Addr {
     /// let addr = Ipv6Addr::LOCALHOST;
     /// assert_eq!(addr, Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1));
     /// ```
+    #[doc(alias = "IN6ADDR_LOOPBACK_INIT")]
+    #[doc(alias = "in6addr_loopback")]
     #[stable(feature = "ip_constructors", since = "1.30.0")]
     pub const LOCALHOST: Self = Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 1);
 
     /// An IPv6 address representing the unspecified address: `::`
     ///
+    /// This corresponds to constant `IN6ADDR_ANY_INIT` or `in6addr_any` in other languages.
+    ///
     /// # Examples
     ///
     /// ```
@@ -1216,6 +1223,8 @@ impl Ipv6Addr {
     /// let addr = Ipv6Addr::UNSPECIFIED;
     /// assert_eq!(addr, Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0));
     /// ```
+    #[doc(alias = "IN6ADDR_ANY_INIT")]
+    #[doc(alias = "in6addr_any")]
     #[stable(feature = "ip_constructors", since = "1.30.0")]
     pub const UNSPECIFIED: Self = Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0);
 
diff --git a/library/std/src/os/fd/mod.rs b/library/std/src/os/fd/mod.rs
index c6aa7c77d..35de4860f 100644
--- a/library/std/src/os/fd/mod.rs
+++ b/library/std/src/os/fd/mod.rs
@@ -3,7 +3,7 @@
 //! This module is supported on Unix platforms and WASI, which both use a
 //! similar file descriptor system for referencing OS resources.
 
-#![stable(feature = "io_safety", since = "1.63.0")]
+#![stable(feature = "os_fd", since = "1.66.0")]
 #![deny(unsafe_op_in_unsafe_fn)]
 
 // `RawFd`, `AsRawFd`, etc.
@@ -19,7 +19,7 @@ mod net;
 mod tests;
 
 // Export the types and traits for the public API.
-#[unstable(feature = "os_fd", issue = "98699")]
+#[stable(feature = "os_fd", since = "1.66.0")]
 pub use owned::*;
-#[unstable(feature = "os_fd", issue = "98699")]
+#[stable(feature = "os_fd", since = "1.66.0")]
 pub use raw::*;
diff --git a/library/std/src/os/fd/owned.rs b/library/std/src/os/fd/owned.rs
index c16518577..c41e093a7 100644
--- a/library/std/src/os/fd/owned.rs
+++ b/library/std/src/os/fd/owned.rs
@@ -100,7 +100,7 @@ impl BorrowedFd<'_> {
 
         // For ESP-IDF, F_DUPFD is used instead, because the CLOEXEC semantics
         // will never be supported, as this is a bare metal framework with
-        // no capabilities for multi-process execution.  While F_DUPFD is also
+        // no capabilities for multi-process execution. While F_DUPFD is also
         // not supported yet, it might be (currently it returns ENOSYS).
         #[cfg(target_os = "espidf")]
         let cmd = libc::F_DUPFD;
diff --git a/library/std/src/os/net/linux_ext/addr.rs b/library/std/src/os/net/linux_ext/addr.rs
index df3fc8e6a..85065984f 100644
--- a/library/std/src/os/net/linux_ext/addr.rs
+++ b/library/std/src/os/net/linux_ext/addr.rs
@@ -38,7 +38,7 @@ pub trait SocketAddrExt: Sealed {
     ///     Ok(())
     /// }
     /// ```
-    fn from_abstract_name<N>(name: &N) -> crate::io::Result<SocketAddr>
+    fn from_abstract_name<N>(name: N) -> crate::io::Result<SocketAddr>
     where
         N: AsRef<[u8]>;
 
diff --git a/library/std/src/os/unix/net/addr.rs b/library/std/src/os/unix/net/addr.rs
index 81ac829d2..ece2b33bd 100644
--- a/library/std/src/os/unix/net/addr.rs
+++ b/library/std/src/os/unix/net/addr.rs
@@ -256,7 +256,7 @@ impl linux_ext::addr::SocketAddrExt for SocketAddr {
         if let AddressKind::Abstract(name) = self.address() { Some(name) } else { None }
     }
 
-    fn from_abstract_name<N>(name: &N) -> crate::io::Result<Self>
+    fn from_abstract_name<N>(name: N) -> crate::io::Result<Self>
     where
         N: AsRef<[u8]>,
     {
diff --git a/library/std/src/panic.rs b/library/std/src/panic.rs
index c4f022de0..9fa8f5702 100644
--- a/library/std/src/panic.rs
+++ b/library/std/src/panic.rs
@@ -114,6 +114,9 @@ where
 /// aborting the process as well. This function *only* catches unwinding panics,
 /// not those that abort the process.
 ///
+/// Note that if a custom panic hook has been set, it will be invoked before
+/// the panic is caught, before unwinding.
+///
 /// Also note that unwinding into Rust code with a foreign exception (e.g.
 /// an exception thrown from C++ code) is undefined behavior.
 ///
diff --git a/library/std/src/panicking.rs b/library/std/src/panicking.rs
index 1039835bb..b0db3112e 100644
--- a/library/std/src/panicking.rs
+++ b/library/std/src/panicking.rs
@@ -306,11 +306,11 @@ pub mod panic_count {
     // and after increase and decrease, but not necessarily during their execution.
     //
     // Additionally, the top bit of GLOBAL_PANIC_COUNT (GLOBAL_ALWAYS_ABORT_FLAG)
-    // records whether panic::always_abort() has been called.  This can only be
+    // records whether panic::always_abort() has been called. This can only be
     // set, never cleared.
     // panic::always_abort() is usually called to prevent memory allocations done by
     // the panic handling in the child created by `libc::fork`.
-    // Memory allocations performed in  a child created with `libc::fork` are undefined
+    // Memory allocations performed in a child created with `libc::fork` are undefined
     // behavior in most operating systems.
     // Accessing LOCAL_PANIC_COUNT in a child created by `libc::fork` would lead to a memory
     // allocation. Only GLOBAL_PANIC_COUNT can be accessed in this situation. This is
@@ -517,7 +517,7 @@ pub fn panicking() -> bool {
     !panic_count::count_is_zero()
 }
 
-/// Entry point of panics from the libcore crate (`panic_impl` lang item).
+/// Entry point of panics from the core crate (`panic_impl` lang item).
 #[cfg(not(test))]
 #[panic_handler]
 pub fn begin_panic_handler(info: &PanicInfo<'_>) -> ! {
@@ -699,7 +699,11 @@ fn rust_panic_with_hook(
         // have limited options. Currently our preference is to
         // just abort. In the future we may consider resuming
         // unwinding or otherwise exiting the thread cleanly.
-        rtprintpanic!("thread panicked while panicking. aborting.\n");
+        if !can_unwind {
+            rtprintpanic!("thread caused non-unwinding panic. aborting.\n");
+        } else {
+            rtprintpanic!("thread panicked while panicking. aborting.\n");
+        }
         crate::sys::abort_internal();
     }
 
diff --git a/library/std/src/path.rs b/library/std/src/path.rs
index 6c957c2fa..4778114b4 100644
--- a/library/std/src/path.rs
+++ b/library/std/src/path.rs
@@ -271,7 +271,7 @@ pub const MAIN_SEPARATOR: char = crate::sys::path::MAIN_SEP;
 /// The primary separator of path components for the current platform.
 ///
 /// For example, `/` on Unix and `\` on Windows.
-#[unstable(feature = "main_separator_str", issue = "94071")]
+#[stable(feature = "main_separator_str", since = "1.68.0")]
 pub const MAIN_SEPARATOR_STR: &str = crate::sys::path::MAIN_SEP_STR;
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -306,7 +306,7 @@ unsafe fn u8_slice_as_os_str(s: &[u8]) -> &OsStr {
     // This casts are safe as OsStr is internally a wrapper around [u8] on all
     // platforms.
     //
-    // Note that currently this relies on the special knowledge that libstd has;
+    // Note that currently this relies on the special knowledge that std has;
     // these types are single-element structs but are not marked
     // repr(transparent) or repr(C) which would make these casts not allowable
     // outside std.
@@ -607,7 +607,7 @@ pub struct Components<'a> {
 
     // true if path *physically* has a root separator; for most Windows
     // prefixes, it may have a "logical" root separator for the purposes of
-    // normalization, e.g.,  \\server\share == \\server\share\.
+    // normalization, e.g., \\server\share == \\server\share\.
     has_physical_root: bool,
 
     // The iterator is double-ended, and these two states keep track of what has
@@ -1246,6 +1246,9 @@ impl PathBuf {
     ///   and `path` is not empty, the new path is normalized: all references
     ///   to `.` and `..` are removed.
     ///
+    /// Consider using [`Path::join`] if you need a new `PathBuf` instead of
+    /// using this function on a cloned `PathBuf`.
+    ///
     /// # Examples
     ///
     /// Pushing a relative path extends the existing path:
@@ -1411,7 +1414,8 @@ impl PathBuf {
         self.push(file_name);
     }
 
-    /// Updates [`self.extension`] to `extension`.
+    /// Updates [`self.extension`] to `Some(extension)` or to `None` if
+    /// `extension` is empty.
     ///
     /// Returns `false` and does nothing if [`self.file_name`] is [`None`],
     /// returns `true` and updates the extension otherwise.
@@ -1419,6 +1423,20 @@ impl PathBuf {
     /// If [`self.extension`] is [`None`], the extension is added; otherwise
     /// it is replaced.
     ///
+    /// If `extension` is the empty string, [`self.extension`] will be [`None`]
+    /// afterwards, not `Some("")`.
+    ///
+    /// # Caveats
+    ///
+    /// The new `extension` may contain dots and will be used in its entirety,
+    /// but only the part after the final dot will be reflected in
+    /// [`self.extension`].
+    ///
+    /// If the file stem contains internal dots and `extension` is empty, part
+    /// of the old file stem will be considered the new [`self.extension`].
+    ///
+    /// See the examples below.
+    ///
     /// [`self.file_name`]: Path::file_name
     /// [`self.extension`]: Path::extension
     ///
@@ -1432,8 +1450,20 @@ impl PathBuf {
     /// p.set_extension("force");
     /// assert_eq!(Path::new("/feel/the.force"), p.as_path());
     ///
-    /// p.set_extension("dark_side");
-    /// assert_eq!(Path::new("/feel/the.dark_side"), p.as_path());
+    /// p.set_extension("dark.side");
+    /// assert_eq!(Path::new("/feel/the.dark.side"), p.as_path());
+    ///
+    /// p.set_extension("cookie");
+    /// assert_eq!(Path::new("/feel/the.dark.cookie"), p.as_path());
+    ///
+    /// p.set_extension("");
+    /// assert_eq!(Path::new("/feel/the.dark"), p.as_path());
+    ///
+    /// p.set_extension("");
+    /// assert_eq!(Path::new("/feel/the"), p.as_path());
+    ///
+    /// p.set_extension("");
+    /// assert_eq!(Path::new("/feel/the"), p.as_path());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn set_extension<S: AsRef<OsStr>>(&mut self, extension: S) -> bool {
@@ -1748,6 +1778,14 @@ impl ops::Deref for PathBuf {
     }
 }
 
+#[stable(feature = "path_buf_deref_mut", since = "1.68.0")]
+impl ops::DerefMut for PathBuf {
+    #[inline]
+    fn deref_mut(&mut self) -> &mut Path {
+        Path::from_inner_mut(&mut self.inner)
+    }
+}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Borrow<Path> for PathBuf {
     #[inline]
@@ -2000,6 +2038,12 @@ impl Path {
         unsafe { &*(s.as_ref() as *const OsStr as *const Path) }
     }
 
+    fn from_inner_mut(inner: &mut OsStr) -> &mut Path {
+        // SAFETY: Path is just a wrapper around OsStr,
+        // therefore converting &mut OsStr to &mut Path is safe.
+        unsafe { &mut *(inner as *mut OsStr as *mut Path) }
+    }
+
     /// Yields the underlying [`OsStr`] slice.
     ///
     /// # Examples
@@ -2025,12 +2069,12 @@ impl Path {
     /// #![feature(path_as_mut_os_str)]
     /// use std::path::{Path, PathBuf};
     ///
-    /// let mut path = PathBuf::from("/Foo.TXT").into_boxed_path();
+    /// let mut path = PathBuf::from("Foo.TXT");
     ///
-    /// assert_ne!(&*path, Path::new("/foo.txt"));
+    /// assert_ne!(path, Path::new("foo.txt"));
     ///
     /// path.as_mut_os_str().make_ascii_lowercase();
-    /// assert_eq!(&*path, Path::new("/foo.txt"));
+    /// assert_eq!(path, Path::new("foo.txt"));
     /// ```
     #[unstable(feature = "path_as_mut_os_str", issue = "105021")]
     #[must_use]
@@ -3133,9 +3177,9 @@ impl<'a> IntoIterator for &'a Path {
 }
 
 macro_rules! impl_cmp {
-    ($lhs:ty, $rhs: ty) => {
+    (<$($life:lifetime),*> $lhs:ty, $rhs: ty) => {
         #[stable(feature = "partialeq_path", since = "1.6.0")]
-        impl<'a, 'b> PartialEq<$rhs> for $lhs {
+        impl<$($life),*> PartialEq<$rhs> for $lhs {
             #[inline]
             fn eq(&self, other: &$rhs) -> bool {
                 <Path as PartialEq>::eq(self, other)
@@ -3143,7 +3187,7 @@ macro_rules! impl_cmp {
         }
 
         #[stable(feature = "partialeq_path", since = "1.6.0")]
-        impl<'a, 'b> PartialEq<$lhs> for $rhs {
+        impl<$($life),*> PartialEq<$lhs> for $rhs {
             #[inline]
             fn eq(&self, other: &$lhs) -> bool {
                 <Path as PartialEq>::eq(self, other)
@@ -3151,7 +3195,7 @@ macro_rules! impl_cmp {
         }
 
         #[stable(feature = "cmp_path", since = "1.8.0")]
-        impl<'a, 'b> PartialOrd<$rhs> for $lhs {
+        impl<$($life),*> PartialOrd<$rhs> for $lhs {
             #[inline]
             fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
                 <Path as PartialOrd>::partial_cmp(self, other)
@@ -3159,7 +3203,7 @@ macro_rules! impl_cmp {
         }
 
         #[stable(feature = "cmp_path", since = "1.8.0")]
-        impl<'a, 'b> PartialOrd<$lhs> for $rhs {
+        impl<$($life),*> PartialOrd<$lhs> for $rhs {
             #[inline]
             fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
                 <Path as PartialOrd>::partial_cmp(self, other)
@@ -3168,16 +3212,16 @@ macro_rules! impl_cmp {
     };
 }
 
-impl_cmp!(PathBuf, Path);
-impl_cmp!(PathBuf, &'a Path);
-impl_cmp!(Cow<'a, Path>, Path);
-impl_cmp!(Cow<'a, Path>, &'b Path);
-impl_cmp!(Cow<'a, Path>, PathBuf);
+impl_cmp!(<> PathBuf, Path);
+impl_cmp!(<'a> PathBuf, &'a Path);
+impl_cmp!(<'a> Cow<'a, Path>, Path);
+impl_cmp!(<'a, 'b> Cow<'a, Path>, &'b Path);
+impl_cmp!(<'a> Cow<'a, Path>, PathBuf);
 
 macro_rules! impl_cmp_os_str {
-    ($lhs:ty, $rhs: ty) => {
+    (<$($life:lifetime),*> $lhs:ty, $rhs: ty) => {
         #[stable(feature = "cmp_path", since = "1.8.0")]
-        impl<'a, 'b> PartialEq<$rhs> for $lhs {
+        impl<$($life),*> PartialEq<$rhs> for $lhs {
             #[inline]
             fn eq(&self, other: &$rhs) -> bool {
                 <Path as PartialEq>::eq(self, other.as_ref())
@@ -3185,7 +3229,7 @@ macro_rules! impl_cmp_os_str {
         }
 
         #[stable(feature = "cmp_path", since = "1.8.0")]
-        impl<'a, 'b> PartialEq<$lhs> for $rhs {
+        impl<$($life),*> PartialEq<$lhs> for $rhs {
             #[inline]
             fn eq(&self, other: &$lhs) -> bool {
                 <Path as PartialEq>::eq(self.as_ref(), other)
@@ -3193,7 +3237,7 @@ macro_rules! impl_cmp_os_str {
         }
 
         #[stable(feature = "cmp_path", since = "1.8.0")]
-        impl<'a, 'b> PartialOrd<$rhs> for $lhs {
+        impl<$($life),*> PartialOrd<$rhs> for $lhs {
             #[inline]
             fn partial_cmp(&self, other: &$rhs) -> Option<cmp::Ordering> {
                 <Path as PartialOrd>::partial_cmp(self, other.as_ref())
@@ -3201,7 +3245,7 @@ macro_rules! impl_cmp_os_str {
         }
 
         #[stable(feature = "cmp_path", since = "1.8.0")]
-        impl<'a, 'b> PartialOrd<$lhs> for $rhs {
+        impl<$($life),*> PartialOrd<$lhs> for $rhs {
             #[inline]
             fn partial_cmp(&self, other: &$lhs) -> Option<cmp::Ordering> {
                 <Path as PartialOrd>::partial_cmp(self.as_ref(), other)
@@ -3210,20 +3254,20 @@ macro_rules! impl_cmp_os_str {
     };
 }
 
-impl_cmp_os_str!(PathBuf, OsStr);
-impl_cmp_os_str!(PathBuf, &'a OsStr);
-impl_cmp_os_str!(PathBuf, Cow<'a, OsStr>);
-impl_cmp_os_str!(PathBuf, OsString);
-impl_cmp_os_str!(Path, OsStr);
-impl_cmp_os_str!(Path, &'a OsStr);
-impl_cmp_os_str!(Path, Cow<'a, OsStr>);
-impl_cmp_os_str!(Path, OsString);
-impl_cmp_os_str!(&'a Path, OsStr);
-impl_cmp_os_str!(&'a Path, Cow<'b, OsStr>);
-impl_cmp_os_str!(&'a Path, OsString);
-impl_cmp_os_str!(Cow<'a, Path>, OsStr);
-impl_cmp_os_str!(Cow<'a, Path>, &'b OsStr);
-impl_cmp_os_str!(Cow<'a, Path>, OsString);
+impl_cmp_os_str!(<> PathBuf, OsStr);
+impl_cmp_os_str!(<'a> PathBuf, &'a OsStr);
+impl_cmp_os_str!(<'a> PathBuf, Cow<'a, OsStr>);
+impl_cmp_os_str!(<> PathBuf, OsString);
+impl_cmp_os_str!(<> Path, OsStr);
+impl_cmp_os_str!(<'a> Path, &'a OsStr);
+impl_cmp_os_str!(<'a> Path, Cow<'a, OsStr>);
+impl_cmp_os_str!(<> Path, OsString);
+impl_cmp_os_str!(<'a> &'a Path, OsStr);
+impl_cmp_os_str!(<'a, 'b> &'a Path, Cow<'b, OsStr>);
+impl_cmp_os_str!(<'a> &'a Path, OsString);
+impl_cmp_os_str!(<'a> Cow<'a, Path>, OsStr);
+impl_cmp_os_str!(<'a, 'b> Cow<'a, Path>, &'b OsStr);
+impl_cmp_os_str!(<'a> Cow<'a, Path>, OsString);
 
 #[stable(since = "1.7.0", feature = "strip_prefix")]
 impl fmt::Display for StripPrefixError {
diff --git a/library/std/src/personality/dwarf/eh.rs b/library/std/src/personality/dwarf/eh.rs
index a783e1870..87585a8fc 100644
--- a/library/std/src/personality/dwarf/eh.rs
+++ b/library/std/src/personality/dwarf/eh.rs
@@ -84,7 +84,7 @@ pub unsafe fn find_eh_action(lsda: *const u8, context: &EHContext<'_>) -> Result
             let cs_start = read_encoded_pointer(&mut reader, context, call_site_encoding)?;
             let cs_len = read_encoded_pointer(&mut reader, context, call_site_encoding)?;
             let cs_lpad = read_encoded_pointer(&mut reader, context, call_site_encoding)?;
-            let cs_action = reader.read_uleb128();
+            let cs_action_entry = reader.read_uleb128();
             // Callsite table is sorted by cs_start, so if we've passed the ip, we
             // may stop searching.
             if ip < func_start + cs_start {
@@ -95,7 +95,7 @@ pub unsafe fn find_eh_action(lsda: *const u8, context: &EHContext<'_>) -> Result
                     return Ok(EHAction::None);
                 } else {
                     let lpad = lpad_base + cs_lpad;
-                    return Ok(interpret_cs_action(cs_action, lpad));
+                    return Ok(interpret_cs_action(action_table as *mut u8, cs_action_entry, lpad));
                 }
             }
         }
@@ -113,26 +113,39 @@ pub unsafe fn find_eh_action(lsda: *const u8, context: &EHContext<'_>) -> Result
         let mut idx = ip;
         loop {
             let cs_lpad = reader.read_uleb128();
-            let cs_action = reader.read_uleb128();
+            let cs_action_entry = reader.read_uleb128();
             idx -= 1;
             if idx == 0 {
                 // Can never have null landing pad for sjlj -- that would have
                 // been indicated by a -1 call site index.
                 let lpad = (cs_lpad + 1) as usize;
-                return Ok(interpret_cs_action(cs_action, lpad));
+                return Ok(interpret_cs_action(action_table as *mut u8, cs_action_entry, lpad));
             }
         }
     }
 }
 
-fn interpret_cs_action(cs_action: u64, lpad: usize) -> EHAction {
-    if cs_action == 0 {
-        // If cs_action is 0 then this is a cleanup (Drop::drop). We run these
+unsafe fn interpret_cs_action(
+    action_table: *mut u8,
+    cs_action_entry: u64,
+    lpad: usize,
+) -> EHAction {
+    if cs_action_entry == 0 {
+        // If cs_action_entry is 0 then this is a cleanup (Drop::drop). We run these
         // for both Rust panics and foreign exceptions.
         EHAction::Cleanup(lpad)
     } else {
-        // Stop unwinding Rust panics at catch_unwind.
-        EHAction::Catch(lpad)
+        // If lpad != 0 and cs_action_entry != 0, we have to check ttype_index.
+        // If ttype_index == 0 under the condition, we take cleanup action.
+        let action_record = (action_table as *mut u8).offset(cs_action_entry as isize - 1);
+        let mut action_reader = DwarfReader::new(action_record);
+        let ttype_index = action_reader.read_sleb128();
+        if ttype_index == 0 {
+            EHAction::Cleanup(lpad)
+        } else {
+            // Stop unwinding Rust panics at catch_unwind.
+            EHAction::Catch(lpad)
+        }
     }
 }
 
diff --git a/library/std/src/prelude/v1.rs b/library/std/src/prelude/v1.rs
index a5a798078..2aefd7c51 100644
--- a/library/std/src/prelude/v1.rs
+++ b/library/std/src/prelude/v1.rs
@@ -59,14 +59,12 @@ pub use core::prelude::v1::{RustcDecodable, RustcEncodable};
 
 // Do not `doc(no_inline)` so that they become doc items on their own
 // (no public module for them to be re-exported from).
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
-pub use core::prelude::v1::alloc_error_handler;
-#[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
-pub use core::prelude::v1::{bench, derive, global_allocator, test, test_case};
+pub use core::prelude::v1::{
+    alloc_error_handler, bench, derive, global_allocator, test, test_case,
+};
 
 #[unstable(feature = "derive_const", issue = "none")]
-#[cfg(not(bootstrap))]
 pub use core::prelude::v1::derive_const;
 
 // Do not `doc(no_inline)` either.
@@ -91,7 +89,6 @@ pub use core::prelude::v1::cfg_eval;
     issue = "23416",
     reason = "placeholder syntax for type ascription"
 )]
-#[cfg(not(bootstrap))]
 pub use core::prelude::v1::type_ascribe;
 
 // The file so far is equivalent to src/libcore/prelude/v1.rs,
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index 400d25beb..62ce2cb33 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -362,6 +362,10 @@ impl Read for ChildStdout {
     fn is_read_vectored(&self) -> bool {
         self.inner.is_read_vectored()
     }
+
+    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        self.inner.read_to_end(buf)
+    }
 }
 
 impl AsInner<AnonPipe> for ChildStdout {
@@ -907,10 +911,8 @@ impl Command {
     /// ```
     #[stable(feature = "process", since = "1.0.0")]
     pub fn output(&mut self) -> io::Result<Output> {
-        self.inner
-            .spawn(imp::Stdio::MakePipe, false)
-            .map(Child::from_inner)
-            .and_then(|p| p.wait_with_output())
+        let (status, stdout, stderr) = self.inner.output()?;
+        Ok(Output { status: ExitStatus(status), stdout, stderr })
     }
 
     /// Executes a command as a child process, waiting for it to finish and
@@ -1036,6 +1038,15 @@ impl fmt::Debug for Command {
     /// Format the program and arguments of a Command for display. Any
     /// non-utf8 data is lossily converted using the utf8 replacement
     /// character.
+    ///
+    /// The default format approximates a shell invocation of the program along with its
+    /// arguments. It does not include most of the other command properties. The output is not guaranteed to work
+    /// (e.g. due to lack of shell-escaping or differences in path resolution)
+    /// On some platforms you can use [the alternate syntax] to show more fields.
+    ///
+    /// Note that the debug implementation is platform-specific.
+    ///
+    /// [the alternate syntax]: fmt#sign0
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.inner.fmt(f)
     }
@@ -2153,18 +2164,11 @@ pub fn id() -> u32 {
 /// to provide similar functionality.
 #[cfg_attr(not(test), lang = "termination")]
 #[stable(feature = "termination_trait_lib", since = "1.61.0")]
-#[rustc_on_unimplemented(
-    on(
-        all(not(bootstrap), cause = "MainFunctionType"),
-        message = "`main` has invalid return type `{Self}`",
-        label = "`main` can only return types that implement `{Termination}`"
-    ),
-    on(
-        bootstrap,
-        message = "`main` has invalid return type `{Self}`",
-        label = "`main` can only return types that implement `{Termination}`"
-    )
-)]
+#[rustc_on_unimplemented(on(
+    cause = "MainFunctionType",
+    message = "`main` has invalid return type `{Self}`",
+    label = "`main` can only return types that implement `{Termination}`"
+))]
 pub trait Termination {
     /// Is called to get the representation of the value as status code.
     /// This status code is returned to the operating system.
diff --git a/library/std/src/process/tests.rs b/library/std/src/process/tests.rs
index 955ad6891..b4f6cc2da 100644
--- a/library/std/src/process/tests.rs
+++ b/library/std/src/process/tests.rs
@@ -417,6 +417,100 @@ fn env_empty() {
     assert!(p.is_ok());
 }
 
+#[test]
+#[cfg(not(windows))]
+#[cfg_attr(any(target_os = "emscripten", target_env = "sgx"), ignore)]
+fn main() {
+    const PIDFD: &'static str =
+        if cfg!(target_os = "linux") { "    create_pidfd: false,\n" } else { "" };
+
+    let mut command = Command::new("some-boring-name");
+
+    assert_eq!(format!("{command:?}"), format!(r#""some-boring-name""#));
+
+    assert_eq!(
+        format!("{command:#?}"),
+        format!(
+            r#"Command {{
+    program: "some-boring-name",
+    args: [
+        "some-boring-name",
+    ],
+{PIDFD}}}"#
+        )
+    );
+
+    command.args(&["1", "2", "3"]);
+
+    assert_eq!(format!("{command:?}"), format!(r#""some-boring-name" "1" "2" "3""#));
+
+    assert_eq!(
+        format!("{command:#?}"),
+        format!(
+            r#"Command {{
+    program: "some-boring-name",
+    args: [
+        "some-boring-name",
+        "1",
+        "2",
+        "3",
+    ],
+{PIDFD}}}"#
+        )
+    );
+
+    crate::os::unix::process::CommandExt::arg0(&mut command, "exciting-name");
+
+    assert_eq!(
+        format!("{command:?}"),
+        format!(r#"["some-boring-name"] "exciting-name" "1" "2" "3""#)
+    );
+
+    assert_eq!(
+        format!("{command:#?}"),
+        format!(
+            r#"Command {{
+    program: "some-boring-name",
+    args: [
+        "exciting-name",
+        "1",
+        "2",
+        "3",
+    ],
+{PIDFD}}}"#
+        )
+    );
+
+    let mut command_with_env_and_cwd = Command::new("boring-name");
+    command_with_env_and_cwd.current_dir("/some/path").env("FOO", "bar");
+    assert_eq!(
+        format!("{command_with_env_and_cwd:?}"),
+        r#"cd "/some/path" && FOO="bar" "boring-name""#
+    );
+    assert_eq!(
+        format!("{command_with_env_and_cwd:#?}"),
+        format!(
+            r#"Command {{
+    program: "boring-name",
+    args: [
+        "boring-name",
+    ],
+    env: CommandEnv {{
+        clear: false,
+        vars: {{
+            "FOO": Some(
+                "bar",
+            ),
+        }},
+    }},
+    cwd: Some(
+        "/some/path",
+    ),
+{PIDFD}}}"#
+        )
+    );
+}
+
 // See issue #91991
 #[test]
 #[cfg(windows)]
diff --git a/library/std/src/rt.rs b/library/std/src/rt.rs
index 9c2f0c1dd..f1eeb75be 100644
--- a/library/std/src/rt.rs
+++ b/library/std/src/rt.rs
@@ -139,9 +139,9 @@ fn lang_start_internal(
     // mechanism itself.
     //
     // There are a couple of instances where unwinding can begin. First is inside of the
-    // `rt::init`, `rt::cleanup` and similar functions controlled by libstd. In those instances a
-    // panic is a libstd implementation bug. A quite likely one too, as there isn't any way to
-    // prevent libstd from accidentally introducing a panic to these functions. Another is from
+    // `rt::init`, `rt::cleanup` and similar functions controlled by bstd. In those instances a
+    // panic is a std implementation bug. A quite likely one too, as there isn't any way to
+    // prevent std from accidentally introducing a panic to these functions. Another is from
     // user code from `main` or, more nefariously, as described in e.g. issue #86030.
     // SAFETY: Only called once during runtime initialization.
     panic::catch_unwind(move || unsafe { init(argc, argv, sigpipe) }).map_err(rt_abort)?;
diff --git a/library/std/src/sync/lazy_lock.rs b/library/std/src/sync/lazy_lock.rs
index c8d3289ca..4a1530530 100644
--- a/library/std/src/sync/lazy_lock.rs
+++ b/library/std/src/sync/lazy_lock.rs
@@ -46,17 +46,15 @@ pub struct LazyLock<T, F = fn() -> T> {
     cell: OnceLock<T>,
     init: Cell<Option<F>>,
 }
-
-impl<T, F> LazyLock<T, F> {
+impl<T, F: FnOnce() -> T> LazyLock<T, F> {
     /// Creates a new lazy value with the given initializing
     /// function.
+    #[inline]
     #[unstable(feature = "once_cell", issue = "74465")]
     pub const fn new(f: F) -> LazyLock<T, F> {
         LazyLock { cell: OnceLock::new(), init: Cell::new(Some(f)) }
     }
-}
 
-impl<T, F: FnOnce() -> T> LazyLock<T, F> {
     /// Forces the evaluation of this lazy value and
     /// returns a reference to result. This is equivalent
     /// to the `Deref` impl, but is explicit.
@@ -73,6 +71,7 @@ impl<T, F: FnOnce() -> T> LazyLock<T, F> {
     /// assert_eq!(LazyLock::force(&lazy), &92);
     /// assert_eq!(&*lazy, &92);
     /// ```
+    #[inline]
     #[unstable(feature = "once_cell", issue = "74465")]
     pub fn force(this: &LazyLock<T, F>) -> &T {
         this.cell.get_or_init(|| match this.init.take() {
@@ -85,6 +84,8 @@ impl<T, F: FnOnce() -> T> LazyLock<T, F> {
 #[unstable(feature = "once_cell", issue = "74465")]
 impl<T, F: FnOnce() -> T> Deref for LazyLock<T, F> {
     type Target = T;
+
+    #[inline]
     fn deref(&self) -> &T {
         LazyLock::force(self)
     }
@@ -93,6 +94,7 @@ impl<T, F: FnOnce() -> T> Deref for LazyLock<T, F> {
 #[unstable(feature = "once_cell", issue = "74465")]
 impl<T: Default> Default for LazyLock<T> {
     /// Creates a new lazy value using `Default` as the initializing function.
+    #[inline]
     fn default() -> LazyLock<T> {
         LazyLock::new(T::default)
     }
diff --git a/library/std/src/sync/lazy_lock/tests.rs b/library/std/src/sync/lazy_lock/tests.rs
index f11b66bfc..a5d4e25c5 100644
--- a/library/std/src/sync/lazy_lock/tests.rs
+++ b/library/std/src/sync/lazy_lock/tests.rs
@@ -136,6 +136,12 @@ fn sync_lazy_poisoning() {
     }
 }
 
+// Check that we can infer `T` from closure's type.
+#[test]
+fn lazy_type_inference() {
+    let _ = LazyCell::new(|| ());
+}
+
 #[test]
 fn is_sync_send() {
     fn assert_traits<T: Send + Sync>() {}
diff --git a/library/std/src/sync/mod.rs b/library/std/src/sync/mod.rs
index 4fee8d3e9..ba20bab87 100644
--- a/library/std/src/sync/mod.rs
+++ b/library/std/src/sync/mod.rs
@@ -177,6 +177,8 @@ pub use self::lazy_lock::LazyLock;
 #[unstable(feature = "once_cell", issue = "74465")]
 pub use self::once_lock::OnceLock;
 
+pub(crate) use self::remutex::{ReentrantMutex, ReentrantMutexGuard};
+
 pub mod mpsc;
 
 mod barrier;
@@ -187,4 +189,5 @@ mod mutex;
 mod once;
 mod once_lock;
 mod poison;
+mod remutex;
 mod rwlock;
diff --git a/library/std/src/sync/mutex/tests.rs b/library/std/src/sync/mutex/tests.rs
index 93900566f..1786a3c09 100644
--- a/library/std/src/sync/mutex/tests.rs
+++ b/library/std/src/sync/mutex/tests.rs
@@ -181,7 +181,7 @@ fn test_mutex_arc_poison() {
     let arc2 = arc.clone();
     let _ = thread::spawn(move || {
         let lock = arc2.lock().unwrap();
-        assert_eq!(*lock, 2);
+        assert_eq!(*lock, 2); // deliberate assertion failure to poison the mutex
     })
     .join();
     assert!(arc.lock().is_err());
diff --git a/library/std/src/sync/once_lock.rs b/library/std/src/sync/once_lock.rs
index 16d1fd2a5..ed339ca5d 100644
--- a/library/std/src/sync/once_lock.rs
+++ b/library/std/src/sync/once_lock.rs
@@ -61,8 +61,9 @@ pub struct OnceLock<T> {
 
 impl<T> OnceLock<T> {
     /// Creates a new empty cell.
-    #[unstable(feature = "once_cell", issue = "74465")]
+    #[inline]
     #[must_use]
+    #[unstable(feature = "once_cell", issue = "74465")]
     pub const fn new() -> OnceLock<T> {
         OnceLock {
             once: Once::new(),
@@ -75,6 +76,7 @@ impl<T> OnceLock<T> {
     ///
     /// Returns `None` if the cell is empty, or being initialized. This
     /// method never blocks.
+    #[inline]
     #[unstable(feature = "once_cell", issue = "74465")]
     pub fn get(&self) -> Option<&T> {
         if self.is_initialized() {
@@ -88,6 +90,7 @@ impl<T> OnceLock<T> {
     /// Gets the mutable reference to the underlying value.
     ///
     /// Returns `None` if the cell is empty. This method never blocks.
+    #[inline]
     #[unstable(feature = "once_cell", issue = "74465")]
     pub fn get_mut(&mut self) -> Option<&mut T> {
         if self.is_initialized() {
@@ -125,6 +128,7 @@ impl<T> OnceLock<T> {
     ///     assert_eq!(CELL.get(), Some(&92));
     /// }
     /// ```
+    #[inline]
     #[unstable(feature = "once_cell", issue = "74465")]
     pub fn set(&self, value: T) -> Result<(), T> {
         let mut value = Some(value);
@@ -164,6 +168,7 @@ impl<T> OnceLock<T> {
     /// let value = cell.get_or_init(|| unreachable!());
     /// assert_eq!(value, &92);
     /// ```
+    #[inline]
     #[unstable(feature = "once_cell", issue = "74465")]
     pub fn get_or_init<F>(&self, f: F) -> &T
     where
@@ -203,6 +208,7 @@ impl<T> OnceLock<T> {
     /// assert_eq!(value, Ok(&92));
     /// assert_eq!(cell.get(), Some(&92))
     /// ```
+    #[inline]
     #[unstable(feature = "once_cell", issue = "74465")]
     pub fn get_or_try_init<F, E>(&self, f: F) -> Result<&T, E>
     where
@@ -241,6 +247,7 @@ impl<T> OnceLock<T> {
     /// cell.set("hello".to_string()).unwrap();
     /// assert_eq!(cell.into_inner(), Some("hello".to_string()));
     /// ```
+    #[inline]
     #[unstable(feature = "once_cell", issue = "74465")]
     pub fn into_inner(mut self) -> Option<T> {
         self.take()
@@ -267,6 +274,7 @@ impl<T> OnceLock<T> {
     /// assert_eq!(cell.take(), Some("hello".to_string()));
     /// assert_eq!(cell.get(), None);
     /// ```
+    #[inline]
     #[unstable(feature = "once_cell", issue = "74465")]
     pub fn take(&mut self) -> Option<T> {
         if self.is_initialized() {
@@ -315,6 +323,7 @@ impl<T> OnceLock<T> {
     /// # Safety
     ///
     /// The value must be initialized
+    #[inline]
     unsafe fn get_unchecked(&self) -> &T {
         debug_assert!(self.is_initialized());
         (&*self.value.get()).assume_init_ref()
@@ -323,6 +332,7 @@ impl<T> OnceLock<T> {
     /// # Safety
     ///
     /// The value must be initialized
+    #[inline]
     unsafe fn get_unchecked_mut(&mut self) -> &mut T {
         debug_assert!(self.is_initialized());
         (&mut *self.value.get()).assume_init_mut()
@@ -360,6 +370,7 @@ impl<T> const Default for OnceLock<T> {
     ///     assert_eq!(OnceLock::<()>::new(), OnceLock::default());
     /// }
     /// ```
+    #[inline]
     fn default() -> OnceLock<T> {
         OnceLock::new()
     }
@@ -377,6 +388,7 @@ impl<T: fmt::Debug> fmt::Debug for OnceLock<T> {
 
 #[unstable(feature = "once_cell", issue = "74465")]
 impl<T: Clone> Clone for OnceLock<T> {
+    #[inline]
     fn clone(&self) -> OnceLock<T> {
         let cell = Self::new();
         if let Some(value) = self.get() {
@@ -408,6 +420,7 @@ impl<T> From<T> for OnceLock<T> {
     /// Ok(())
     /// # }
     /// ```
+    #[inline]
     fn from(value: T) -> Self {
         let cell = Self::new();
         match cell.set(value) {
@@ -419,6 +432,7 @@ impl<T> From<T> for OnceLock<T> {
 
 #[unstable(feature = "once_cell", issue = "74465")]
 impl<T: PartialEq> PartialEq for OnceLock<T> {
+    #[inline]
     fn eq(&self, other: &OnceLock<T>) -> bool {
         self.get() == other.get()
     }
@@ -429,6 +443,7 @@ impl<T: Eq> Eq for OnceLock<T> {}
 
 #[unstable(feature = "once_cell", issue = "74465")]
 unsafe impl<#[may_dangle] T> Drop for OnceLock<T> {
+    #[inline]
     fn drop(&mut self) {
         if self.is_initialized() {
             // SAFETY: The cell is initialized and being dropped, so it can't
diff --git a/library/std/src/sys_common/remutex.rs b/library/std/src/sync/remutex.rs
index 4c054da64..4c054da64 100644
--- a/library/std/src/sys_common/remutex.rs
+++ b/library/std/src/sync/remutex.rs
diff --git a/library/std/src/sys_common/remutex/tests.rs b/library/std/src/sync/remutex/tests.rs
index 8e97ce11c..fc553081d 100644
--- a/library/std/src/sys_common/remutex/tests.rs
+++ b/library/std/src/sync/remutex/tests.rs
@@ -1,6 +1,6 @@
+use super::{ReentrantMutex, ReentrantMutexGuard};
 use crate::cell::RefCell;
 use crate::sync::Arc;
-use crate::sys_common::remutex::{ReentrantMutex, ReentrantMutexGuard};
 use crate::thread;
 
 #[test]
diff --git a/library/std/src/sync/rwlock/tests.rs b/library/std/src/sync/rwlock/tests.rs
index b5b3ad989..1a9d3d3f1 100644
--- a/library/std/src/sync/rwlock/tests.rs
+++ b/library/std/src/sync/rwlock/tests.rs
@@ -2,7 +2,7 @@ use crate::sync::atomic::{AtomicUsize, Ordering};
 use crate::sync::mpsc::channel;
 use crate::sync::{Arc, RwLock, RwLockReadGuard, TryLockError};
 use crate::thread;
-use rand::{self, Rng};
+use rand::Rng;
 
 #[derive(Eq, PartialEq, Debug)]
 struct NonCopy(i32);
@@ -28,7 +28,7 @@ fn frob() {
         let tx = tx.clone();
         let r = r.clone();
         thread::spawn(move || {
-            let mut rng = rand::thread_rng();
+            let mut rng = crate::test_helpers::test_rng();
             for _ in 0..M {
                 if rng.gen_bool(1.0 / (N as f64)) {
                     drop(r.write().unwrap());
diff --git a/library/std/src/sys/itron/thread.rs b/library/std/src/sys/itron/thread.rs
index c2b366808..19350b83f 100644
--- a/library/std/src/sys/itron/thread.rs
+++ b/library/std/src/sys/itron/thread.rs
@@ -119,7 +119,7 @@ impl Thread {
 
             let old_lifecycle = inner
                 .lifecycle
-                .swap(LIFECYCLE_EXITED_OR_FINISHED_OR_JOIN_FINALIZE, Ordering::Release);
+                .swap(LIFECYCLE_EXITED_OR_FINISHED_OR_JOIN_FINALIZE, Ordering::AcqRel);
 
             match old_lifecycle {
                 LIFECYCLE_DETACHED => {
@@ -129,9 +129,9 @@ impl Thread {
 
                     // In this case, `*p_inner`'s ownership has been moved to
                     // us, and we are responsible for dropping it. The acquire
-                    // ordering is not necessary because the parent thread made
-                    // no memory access needing synchronization since the call
-                    // to `acre_tsk`.
+                    // ordering ensures that the swap operation that wrote
+                    // `LIFECYCLE_DETACHED` happens-before `Box::from_raw(
+                    // p_inner)`.
                     // Safety: See above.
                     let _ = unsafe { Box::from_raw(p_inner) };
 
@@ -151,6 +151,9 @@ impl Thread {
                     // Since the parent might drop `*inner` and terminate us as
                     // soon as it sees `JOIN_FINALIZE`, the release ordering
                     // must be used in the above `swap` call.
+                    //
+                    // To make the task referred to by `parent_tid` visible, we
+                    // must use the acquire ordering in the above `swap` call.
 
                     // [JOINING → JOIN_FINALIZE]
                     // Wake up the parent task.
@@ -218,11 +221,15 @@ impl Thread {
 
         let current_task = current_task as usize;
 
-        match inner.lifecycle.swap(current_task, Ordering::Acquire) {
+        match inner.lifecycle.swap(current_task, Ordering::AcqRel) {
             LIFECYCLE_INIT => {
                 // [INIT → JOINING]
                 // The child task will transition the state to `JOIN_FINALIZE`
                 // and wake us up.
+                //
+                // To make the task referred to by `current_task` visible from
+                // the child task's point of view, we must use the release
+                // ordering in the above `swap` call.
                 loop {
                     expect_success_aborting(unsafe { abi::slp_tsk() }, &"slp_tsk");
                     // To synchronize with the child task's memory accesses to
@@ -267,15 +274,15 @@ impl Drop for Thread {
         let inner = unsafe { self.p_inner.as_ref() };
 
         // Detach the thread.
-        match inner.lifecycle.swap(LIFECYCLE_DETACHED_OR_JOINED, Ordering::Acquire) {
+        match inner.lifecycle.swap(LIFECYCLE_DETACHED_OR_JOINED, Ordering::AcqRel) {
             LIFECYCLE_INIT => {
                 // [INIT → DETACHED]
                 // When the time comes, the child will figure out that no
                 // one will ever join it.
                 // The ownership of `*p_inner` is moved to the child thread.
-                // However, the release ordering is not necessary because we
-                // made no memory access needing synchronization since the call
-                // to `acre_tsk`.
+                // The release ordering ensures that the above swap operation on
+                // `lifecycle` happens-before the child thread's
+                // `Box::from_raw(p_inner)`.
             }
             LIFECYCLE_FINISHED => {
                 // [FINISHED → JOINED]
@@ -287,7 +294,7 @@ impl Drop for Thread {
                 // Terminate and delete the task
                 // Safety: `self.task` still represents a task we own (because
                 //         this method or `join_inner` is called only once for
-                //         each `Thread`). The task  indicated that it's safe to
+                //         each `Thread`). The task indicated that it's safe to
                 //         delete by entering the `FINISHED` state.
                 unsafe { terminate_and_delete_task(self.task) };
 
diff --git a/library/std/src/sys/sgx/mod.rs b/library/std/src/sys/sgx/mod.rs
index 01e4ffe3d..9865a945b 100644
--- a/library/std/src/sys/sgx/mod.rs
+++ b/library/std/src/sys/sgx/mod.rs
@@ -34,6 +34,7 @@ pub mod process;
 pub mod stdio;
 pub mod thread;
 pub mod thread_local_key;
+pub mod thread_parking;
 pub mod time;
 
 mod condvar;
diff --git a/library/std/src/sys/sgx/thread.rs b/library/std/src/sys/sgx/thread.rs
index d745a6196..1608b8cb6 100644
--- a/library/std/src/sys/sgx/thread.rs
+++ b/library/std/src/sys/sgx/thread.rs
@@ -65,39 +65,36 @@ mod task_queue {
 /// execution. The signal is sent once all TLS destructors have finished at
 /// which point no new thread locals should be created.
 pub mod wait_notify {
-    use super::super::waitqueue::{SpinMutex, WaitQueue, WaitVariable};
+    use crate::pin::Pin;
     use crate::sync::Arc;
+    use crate::sys_common::thread_parking::Parker;
 
-    pub struct Notifier(Arc<SpinMutex<WaitVariable<bool>>>);
+    pub struct Notifier(Arc<Parker>);
 
     impl Notifier {
         /// Notify the waiter. The waiter is either notified right away (if
         /// currently blocked in `Waiter::wait()`) or later when it calls the
         /// `Waiter::wait()` method.
         pub fn notify(self) {
-            let mut guard = self.0.lock();
-            *guard.lock_var_mut() = true;
-            let _ = WaitQueue::notify_one(guard);
+            Pin::new(&*self.0).unpark()
         }
     }
 
-    pub struct Waiter(Arc<SpinMutex<WaitVariable<bool>>>);
+    pub struct Waiter(Arc<Parker>);
 
     impl Waiter {
         /// Wait for a notification. If `Notifier::notify()` has already been
         /// called, this will return immediately, otherwise the current thread
         /// is blocked until notified.
         pub fn wait(self) {
-            let guard = self.0.lock();
-            if *guard.lock_var() {
-                return;
-            }
-            WaitQueue::wait(guard, || {});
+            // SAFETY:
+            // This is only ever called on one thread.
+            unsafe { Pin::new(&*self.0).park() }
         }
     }
 
     pub fn new() -> (Notifier, Waiter) {
-        let inner = Arc::new(SpinMutex::new(WaitVariable::new(false)));
+        let inner = Arc::new(Parker::new());
         (Notifier(inner.clone()), Waiter(inner))
     }
 }
diff --git a/library/std/src/sys/sgx/thread_parking.rs b/library/std/src/sys/sgx/thread_parking.rs
new file mode 100644
index 000000000..0006cd4f1
--- /dev/null
+++ b/library/std/src/sys/sgx/thread_parking.rs
@@ -0,0 +1,23 @@
+use super::abi::usercalls;
+use crate::io::ErrorKind;
+use crate::time::Duration;
+use fortanix_sgx_abi::{EV_UNPARK, WAIT_INDEFINITE};
+
+pub type ThreadId = fortanix_sgx_abi::Tcs;
+
+pub use super::abi::thread::current;
+
+pub fn park(_hint: usize) {
+    usercalls::wait(EV_UNPARK, WAIT_INDEFINITE).unwrap();
+}
+
+pub fn park_timeout(dur: Duration, _hint: usize) {
+    let timeout = u128::min(dur.as_nanos(), WAIT_INDEFINITE as u128 - 1) as u64;
+    if let Err(e) = usercalls::wait(EV_UNPARK, timeout) {
+        assert!(matches!(e.kind(), ErrorKind::TimedOut | ErrorKind::WouldBlock))
+    }
+}
+
+pub fn unpark(tid: ThreadId, _hint: usize) {
+    let _ = usercalls::send(EV_UNPARK, Some(tid));
+}
diff --git a/library/std/src/sys/unix/android.rs b/library/std/src/sys/unix/android.rs
index 73ff10ab8..0f704994f 100644
--- a/library/std/src/sys/unix/android.rs
+++ b/library/std/src/sys/unix/android.rs
@@ -1,7 +1,7 @@
 //! Android ABI-compatibility module
 //!
-//! The ABI of Android has changed quite a bit over time, and libstd attempts to
-//! be both forwards and backwards compatible as much as possible. We want to
+//! The ABI of Android has changed quite a bit over time, and std attempts to be
+//! both forwards and backwards compatible as much as possible. We want to
 //! always work with the most recent version of Android, but we also want to
 //! work with older versions of Android for whenever projects need to.
 //!
diff --git a/library/std/src/sys/unix/fs.rs b/library/std/src/sys/unix/fs.rs
index 37a49f2d7..8e1f35d6c 100644
--- a/library/std/src/sys/unix/fs.rs
+++ b/library/std/src/sys/unix/fs.rs
@@ -149,12 +149,13 @@ cfg_has_statx! {{
     ) -> Option<io::Result<FileAttr>> {
         use crate::sync::atomic::{AtomicU8, Ordering};
 
-        // Linux kernel prior to 4.11 or glibc prior to glibc 2.28 don't support `statx`
-        // We store the availability in global to avoid unnecessary syscalls.
-        // 0: Unknown
-        // 1: Not available
-        // 2: Available
-        static STATX_STATE: AtomicU8 = AtomicU8::new(0);
+        // Linux kernel prior to 4.11 or glibc prior to glibc 2.28 don't support `statx`.
+        // We check for it on first failure and remember availability to avoid having to
+        // do it again.
+        #[repr(u8)]
+        enum STATX_STATE{ Unknown = 0, Present, Unavailable }
+        static STATX_SAVED_STATE: AtomicU8 = AtomicU8::new(STATX_STATE::Unknown as u8);
+
         syscall! {
             fn statx(
                 fd: c_int,
@@ -165,31 +166,44 @@ cfg_has_statx! {{
             ) -> c_int
         }
 
-        match STATX_STATE.load(Ordering::Relaxed) {
-            0 => {
-                // It is a trick to call `statx` with null pointers to check if the syscall
-                // is available. According to the manual, it is expected to fail with EFAULT.
-                // We do this mainly for performance, since it is nearly hundreds times
-                // faster than a normal successful call.
-                let err = cvt(statx(0, ptr::null(), 0, libc::STATX_ALL, ptr::null_mut()))
-                    .err()
-                    .and_then(|e| e.raw_os_error());
-                // We don't check `err == Some(libc::ENOSYS)` because the syscall may be limited
-                // and returns `EPERM`. Listing all possible errors seems not a good idea.
-                // See: https://github.com/rust-lang/rust/issues/65662
-                if err != Some(libc::EFAULT) {
-                    STATX_STATE.store(1, Ordering::Relaxed);
-                    return None;
-                }
-                STATX_STATE.store(2, Ordering::Relaxed);
-            }
-            1 => return None,
-            _ => {}
+        if STATX_SAVED_STATE.load(Ordering::Relaxed) == STATX_STATE::Unavailable as u8 {
+            return None;
         }
 
         let mut buf: libc::statx = mem::zeroed();
         if let Err(err) = cvt(statx(fd, path, flags, mask, &mut buf)) {
-            return Some(Err(err));
+            if STATX_SAVED_STATE.load(Ordering::Relaxed) == STATX_STATE::Present as u8 {
+                return Some(Err(err));
+            }
+
+            // Availability not checked yet.
+            //
+            // First try the cheap way.
+            if err.raw_os_error() == Some(libc::ENOSYS) {
+                STATX_SAVED_STATE.store(STATX_STATE::Unavailable as u8, Ordering::Relaxed);
+                return None;
+            }
+
+            // Error other than `ENOSYS` is not a good enough indicator -- it is
+            // known that `EPERM` can be returned as a result of using seccomp to
+            // block the syscall.
+            // Availability is checked by performing a call which expects `EFAULT`
+            // if the syscall is usable.
+            // See: https://github.com/rust-lang/rust/issues/65662
+            // FIXME this can probably just do the call if `EPERM` was received, but
+            // previous iteration of the code checked it for all errors and for now
+            // this is retained.
+            // FIXME what about transient conditions like `ENOMEM`?
+            let err2 = cvt(statx(0, ptr::null(), 0, libc::STATX_ALL, ptr::null_mut()))
+                .err()
+                .and_then(|e| e.raw_os_error());
+            if err2 == Some(libc::EFAULT) {
+                STATX_SAVED_STATE.store(STATX_STATE::Present as u8, Ordering::Relaxed);
+                return Some(Err(err));
+            } else {
+                STATX_SAVED_STATE.store(STATX_STATE::Unavailable as u8, Ordering::Relaxed);
+                return None;
+            }
         }
 
         // We cannot fill `stat64` exhaustively because of private padding fields.
@@ -243,17 +257,15 @@ struct InnerReadDir {
 
 pub struct ReadDir {
     inner: Arc<InnerReadDir>,
-    #[cfg(not(any(
-        target_os = "android",
-        target_os = "linux",
-        target_os = "solaris",
-        target_os = "illumos",
-        target_os = "fuchsia",
-        target_os = "redox",
-    )))]
     end_of_stream: bool,
 }
 
+impl ReadDir {
+    fn new(inner: InnerReadDir) -> Self {
+        Self { inner: Arc::new(inner), end_of_stream: false }
+    }
+}
+
 struct Dir(*mut libc::DIR);
 
 unsafe impl Send for Dir {}
@@ -332,11 +344,23 @@ pub struct FileTimes {
     modified: Option<SystemTime>,
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, Eq, Debug)]
 pub struct FileType {
     mode: mode_t,
 }
 
+impl PartialEq for FileType {
+    fn eq(&self, other: &Self) -> bool {
+        self.masked() == other.masked()
+    }
+}
+
+impl core::hash::Hash for FileType {
+    fn hash<H: core::hash::Hasher>(&self, state: &mut H) {
+        self.masked().hash(state);
+    }
+}
+
 #[derive(Debug)]
 pub struct DirBuilder {
     mode: mode_t,
@@ -548,7 +572,11 @@ impl FileType {
     }
 
     pub fn is(&self, mode: mode_t) -> bool {
-        self.mode & libc::S_IFMT == mode
+        self.masked() == mode
+    }
+
+    fn masked(&self) -> mode_t {
+        self.mode & libc::S_IFMT
     }
 }
 
@@ -578,18 +606,26 @@ impl Iterator for ReadDir {
         target_os = "illumos"
     ))]
     fn next(&mut self) -> Option<io::Result<DirEntry>> {
+        if self.end_of_stream {
+            return None;
+        }
+
         unsafe {
             loop {
                 // As of POSIX.1-2017, readdir() is not required to be thread safe; only
                 // readdir_r() is. However, readdir_r() cannot correctly handle platforms
-                // with unlimited or variable NAME_MAX.  Many modern platforms guarantee
+                // with unlimited or variable NAME_MAX. Many modern platforms guarantee
                 // thread safety for readdir() as long an individual DIR* is not accessed
                 // concurrently, which is sufficient for Rust.
                 super::os::set_errno(0);
                 let entry_ptr = readdir64(self.inner.dirp.0);
                 if entry_ptr.is_null() {
-                    // null can mean either the end is reached or an error occurred.
-                    // So we had to clear errno beforehand to check for an error now.
+                    // We either encountered an error, or reached the end. Either way,
+                    // the next call to next() should return None.
+                    self.end_of_stream = true;
+
+                    // To distinguish between errors and end-of-directory, we had to clear
+                    // errno beforehand to check for an error now.
                     return match super::os::errno() {
                         0 => None,
                         e => Some(Err(Error::from_raw_os_error(e))),
@@ -1347,18 +1383,7 @@ pub fn readdir(path: &Path) -> io::Result<ReadDir> {
     } else {
         let root = path.to_path_buf();
         let inner = InnerReadDir { dirp: Dir(ptr), root };
-        Ok(ReadDir {
-            inner: Arc::new(inner),
-            #[cfg(not(any(
-                target_os = "android",
-                target_os = "linux",
-                target_os = "solaris",
-                target_os = "illumos",
-                target_os = "fuchsia",
-                target_os = "redox",
-            )))]
-            end_of_stream: false,
-        })
+        Ok(ReadDir::new(inner))
     }
 }
 
@@ -1739,12 +1764,16 @@ mod remove_dir_impl {
     use crate::os::unix::io::{AsRawFd, FromRawFd, IntoRawFd};
     use crate::os::unix::prelude::{OwnedFd, RawFd};
     use crate::path::{Path, PathBuf};
-    use crate::sync::Arc;
     use crate::sys::common::small_c_string::run_path_with_cstr;
     use crate::sys::{cvt, cvt_r};
 
-    #[cfg(not(all(target_os = "macos", not(target_arch = "aarch64")),))]
+    #[cfg(not(any(
+        all(target_os = "linux", target_env = "gnu"),
+        all(target_os = "macos", not(target_arch = "aarch64"))
+    )))]
     use libc::{fdopendir, openat, unlinkat};
+    #[cfg(all(target_os = "linux", target_env = "gnu"))]
+    use libc::{fdopendir, openat64 as openat, unlinkat};
     #[cfg(all(target_os = "macos", not(target_arch = "aarch64")))]
     use macos_weak::{fdopendir, openat, unlinkat};
 
@@ -1811,21 +1840,8 @@ mod remove_dir_impl {
         // a valid root is not needed because we do not call any functions involving the full path
         // of the DirEntrys.
         let dummy_root = PathBuf::new();
-        Ok((
-            ReadDir {
-                inner: Arc::new(InnerReadDir { dirp, root: dummy_root }),
-                #[cfg(not(any(
-                    target_os = "android",
-                    target_os = "linux",
-                    target_os = "solaris",
-                    target_os = "illumos",
-                    target_os = "fuchsia",
-                    target_os = "redox",
-                )))]
-                end_of_stream: false,
-            },
-            new_parent_fd,
-        ))
+        let inner = InnerReadDir { dirp, root: dummy_root };
+        Ok((ReadDir::new(inner), new_parent_fd))
     }
 
     #[cfg(any(
diff --git a/library/std/src/sys/unix/kernel_copy.rs b/library/std/src/sys/unix/kernel_copy.rs
index 94546ca09..73b9bef7e 100644
--- a/library/std/src/sys/unix/kernel_copy.rs
+++ b/library/std/src/sys/unix/kernel_copy.rs
@@ -61,6 +61,10 @@ use crate::ptr;
 use crate::sync::atomic::{AtomicBool, AtomicU8, Ordering};
 use crate::sys::cvt;
 use crate::sys::weak::syscall;
+#[cfg(not(all(target_os = "linux", target_env = "gnu")))]
+use libc::sendfile as sendfile64;
+#[cfg(all(target_os = "linux", target_env = "gnu"))]
+use libc::sendfile64;
 use libc::{EBADF, EINVAL, ENOSYS, EOPNOTSUPP, EOVERFLOW, EPERM, EXDEV};
 
 #[cfg(test)]
@@ -583,7 +587,7 @@ pub(super) fn copy_regular_files(reader: RawFd, writer: RawFd, max_len: u64) ->
                         // - copy_file_range file is immutable or syscall is blocked by seccomp¹ (EPERM)
                         // - copy_file_range cannot be used with pipes or device nodes (EINVAL)
                         // - the writer fd was opened with O_APPEND (EBADF²)
-                        // and no bytes were written successfully yet.  (All these errnos should
+                        // and no bytes were written successfully yet. (All these errnos should
                         // not be returned if something was already written, but they happen in
                         // the wild, see #91152.)
                         //
@@ -647,7 +651,7 @@ fn sendfile_splice(mode: SpliceMode, reader: RawFd, writer: RawFd, len: u64) ->
 
         let result = match mode {
             SpliceMode::Sendfile => {
-                cvt(unsafe { libc::sendfile(writer, reader, ptr::null_mut(), chunk_size) })
+                cvt(unsafe { sendfile64(writer, reader, ptr::null_mut(), chunk_size) })
             }
             SpliceMode::Splice => cvt(unsafe {
                 splice(reader, ptr::null_mut(), writer, ptr::null_mut(), chunk_size, 0)
diff --git a/library/std/src/sys/unix/locks/pthread_condvar.rs b/library/std/src/sys/unix/locks/pthread_condvar.rs
index 1ddb09905..6be1abc2b 100644
--- a/library/std/src/sys/unix/locks/pthread_condvar.rs
+++ b/library/std/src/sys/unix/locks/pthread_condvar.rs
@@ -2,6 +2,7 @@ use crate::cell::UnsafeCell;
 use crate::ptr;
 use crate::sync::atomic::{AtomicPtr, Ordering::Relaxed};
 use crate::sys::locks::{pthread_mutex, Mutex};
+use crate::sys::time::TIMESPEC_MAX;
 use crate::sys_common::lazy_box::{LazyBox, LazyInit};
 use crate::time::Duration;
 
@@ -12,13 +13,6 @@ pub struct Condvar {
     mutex: AtomicPtr<libc::pthread_mutex_t>,
 }
 
-const TIMESPEC_MAX: libc::timespec =
-    libc::timespec { tv_sec: <libc::time_t>::MAX, tv_nsec: 1_000_000_000 - 1 };
-
-fn saturating_cast_to_time_t(value: u64) -> libc::time_t {
-    if value > <libc::time_t>::MAX as u64 { <libc::time_t>::MAX } else { value as libc::time_t }
-}
-
 #[inline]
 fn raw(c: &Condvar) -> *mut libc::pthread_cond_t {
     c.inner.0.get()
@@ -133,26 +127,15 @@ impl Condvar {
         target_os = "horizon"
     )))]
     pub unsafe fn wait_timeout(&self, mutex: &Mutex, dur: Duration) -> bool {
-        use crate::mem;
+        use crate::sys::time::Timespec;
 
         let mutex = pthread_mutex::raw(mutex);
         self.verify(mutex);
 
-        let mut now: libc::timespec = mem::zeroed();
-        let r = libc::clock_gettime(libc::CLOCK_MONOTONIC, &mut now);
-        assert_eq!(r, 0);
-
-        // Nanosecond calculations can't overflow because both values are below 1e9.
-        let nsec = dur.subsec_nanos() + now.tv_nsec as u32;
-
-        let sec = saturating_cast_to_time_t(dur.as_secs())
-            .checked_add((nsec / 1_000_000_000) as libc::time_t)
-            .and_then(|s| s.checked_add(now.tv_sec));
-        let nsec = nsec % 1_000_000_000;
-
-        let timeout =
-            sec.map(|s| libc::timespec { tv_sec: s, tv_nsec: nsec as _ }).unwrap_or(TIMESPEC_MAX);
-
+        let timeout = Timespec::now(libc::CLOCK_MONOTONIC)
+            .checked_add_duration(&dur)
+            .and_then(|t| t.to_timespec())
+            .unwrap_or(TIMESPEC_MAX);
         let r = libc::pthread_cond_timedwait(raw(self), mutex, &timeout);
         assert!(r == libc::ETIMEDOUT || r == 0);
         r == 0
@@ -169,57 +152,41 @@ impl Condvar {
         target_os = "espidf",
         target_os = "horizon"
     ))]
-    pub unsafe fn wait_timeout(&self, mutex: &Mutex, mut dur: Duration) -> bool {
+    pub unsafe fn wait_timeout(&self, mutex: &Mutex, dur: Duration) -> bool {
+        use crate::sys::time::SystemTime;
         use crate::time::Instant;
 
         let mutex = pthread_mutex::raw(mutex);
         self.verify(mutex);
 
-        // 1000 years
-        let max_dur = Duration::from_secs(1000 * 365 * 86400);
-
-        if dur > max_dur {
-            // OSX implementation of `pthread_cond_timedwait` is buggy
-            // with super long durations. When duration is greater than
-            // 0x100_0000_0000_0000 seconds, `pthread_cond_timedwait`
-            // in macOS Sierra return error 316.
-            //
-            // This program demonstrates the issue:
-            // https://gist.github.com/stepancheg/198db4623a20aad2ad7cddb8fda4a63c
-            //
-            // To work around this issue, and possible bugs of other OSes, timeout
-            // is clamped to 1000 years, which is allowable per the API of `wait_timeout`
-            // because of spurious wakeups.
-
-            dur = max_dur;
-        }
-
-        // First, figure out what time it currently is, in both system and
-        // stable time.  pthread_cond_timedwait uses system time, but we want to
-        // report timeout based on stable time.
-        let mut sys_now = libc::timeval { tv_sec: 0, tv_usec: 0 };
-        let stable_now = Instant::now();
-        let r = libc::gettimeofday(&mut sys_now, ptr::null_mut());
-        assert_eq!(r, 0, "unexpected error: {:?}", crate::io::Error::last_os_error());
-
-        let nsec = dur.subsec_nanos() as libc::c_long + (sys_now.tv_usec * 1000) as libc::c_long;
-        let extra = (nsec / 1_000_000_000) as libc::time_t;
-        let nsec = nsec % 1_000_000_000;
-        let seconds = saturating_cast_to_time_t(dur.as_secs());
-
-        let timeout = sys_now
-            .tv_sec
-            .checked_add(extra)
-            .and_then(|s| s.checked_add(seconds))
-            .map(|s| libc::timespec { tv_sec: s, tv_nsec: nsec })
+        // OSX implementation of `pthread_cond_timedwait` is buggy
+        // with super long durations. When duration is greater than
+        // 0x100_0000_0000_0000 seconds, `pthread_cond_timedwait`
+        // in macOS Sierra returns error 316.
+        //
+        // This program demonstrates the issue:
+        // https://gist.github.com/stepancheg/198db4623a20aad2ad7cddb8fda4a63c
+        //
+        // To work around this issue, and possible bugs of other OSes, timeout
+        // is clamped to 1000 years, which is allowable per the API of `wait_timeout`
+        // because of spurious wakeups.
+        let dur = Duration::min(dur, Duration::from_secs(1000 * 365 * 86400));
+
+        // pthread_cond_timedwait uses system time, but we want to report timeout
+        // based on stable time.
+        let now = Instant::now();
+
+        let timeout = SystemTime::now()
+            .t
+            .checked_add_duration(&dur)
+            .and_then(|t| t.to_timespec())
             .unwrap_or(TIMESPEC_MAX);
 
-        // And wait!
         let r = libc::pthread_cond_timedwait(raw(self), mutex, &timeout);
         debug_assert!(r == libc::ETIMEDOUT || r == 0);
 
         // ETIMEDOUT is not a totally reliable method of determining timeout due
         // to clock shifts, so do the check ourselves
-        stable_now.elapsed() < dur
+        now.elapsed() < dur
     }
 }
diff --git a/library/std/src/sys/unix/mod.rs b/library/std/src/sys/unix/mod.rs
index 9055a011c..30a96be14 100644
--- a/library/std/src/sys/unix/mod.rs
+++ b/library/std/src/sys/unix/mod.rs
@@ -40,7 +40,7 @@ pub mod stdio;
 pub mod thread;
 pub mod thread_local_dtor;
 pub mod thread_local_key;
-pub mod thread_parker;
+pub mod thread_parking;
 pub mod time;
 
 #[cfg(target_os = "espidf")]
@@ -95,6 +95,10 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
         )))]
         'poll: {
             use crate::sys::os::errno;
+            #[cfg(not(all(target_os = "linux", target_env = "gnu")))]
+            use libc::open as open64;
+            #[cfg(all(target_os = "linux", target_env = "gnu"))]
+            use libc::open64;
             let pfds: &mut [_] = &mut [
                 libc::pollfd { fd: 0, events: 0, revents: 0 },
                 libc::pollfd { fd: 1, events: 0, revents: 0 },
@@ -116,7 +120,7 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
                 if pfd.revents & libc::POLLNVAL == 0 {
                     continue;
                 }
-                if libc::open("/dev/null\0".as_ptr().cast(), libc::O_RDWR, 0) == -1 {
+                if open64("/dev/null\0".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
@@ -139,9 +143,13 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
         )))]
         {
             use crate::sys::os::errno;
+            #[cfg(not(all(target_os = "linux", target_env = "gnu")))]
+            use libc::open as open64;
+            #[cfg(all(target_os = "linux", target_env = "gnu"))]
+            use libc::open64;
             for fd in 0..3 {
                 if libc::fcntl(fd, libc::F_GETFD) == -1 && errno() == libc::EBADF {
-                    if libc::open("/dev/null\0".as_ptr().cast(), libc::O_RDWR, 0) == -1 {
+                    if open64("/dev/null\0".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
@@ -156,7 +164,7 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
     unsafe fn reset_sigpipe(#[allow(unused_variables)] sigpipe: u8) {
         #[cfg(not(any(target_os = "emscripten", target_os = "fuchsia", target_os = "horizon")))]
         {
-            // We don't want to add this as a public type to libstd, nor do we
+            // We don't want to add this as a public type to std, nor do we
             // want to `include!` a file from the compiler (which would break
             // Miri and xargo for example), so we choose to duplicate these
             // constants from `compiler/rustc_session/src/config/sigpipe.rs`.
@@ -176,12 +184,7 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
                 sigpipe::SIG_DFL => (true, Some(libc::SIG_DFL)),
                 _ => unreachable!(),
             };
-            // The bootstrap compiler doesn't know about sigpipe::DEFAULT, and always passes in
-            // SIG_IGN. This causes some tests to fail because they expect SIGPIPE to be reset to
-            // default on process spawning (which doesn't happen if #[unix_sigpipe] is specified).
-            // Since we can't differentiate between the cases here, treat SIG_IGN as DEFAULT
-            // unconditionally.
-            if sigpipe_attr_specified && !(cfg!(bootstrap) && sigpipe == sigpipe::SIG_IGN) {
+            if sigpipe_attr_specified {
                 UNIX_SIGPIPE_ATTR_SPECIFIED.store(true, crate::sync::atomic::Ordering::Relaxed);
             }
             if let Some(handler) = handler {
diff --git a/library/std/src/sys/unix/net.rs b/library/std/src/sys/unix/net.rs
index b84bf8f92..c86f80972 100644
--- a/library/std/src/sys/unix/net.rs
+++ b/library/std/src/sys/unix/net.rs
@@ -512,7 +512,7 @@ impl FromRawFd for Socket {
 // A workaround for this bug is to call the res_init libc function, to clear
 // the cached configs. Unfortunately, while we believe glibc's implementation
 // of res_init is thread-safe, we know that other implementations are not
-// (https://github.com/rust-lang/rust/issues/43592). Code here in libstd could
+// (https://github.com/rust-lang/rust/issues/43592). Code here in std could
 // try to synchronize its res_init calls with a Mutex, but that wouldn't
 // protect programs that call into libc in other ways. So instead of calling
 // res_init unconditionally, we call it only when we detect we're linking
diff --git a/library/std/src/sys/unix/pipe.rs b/library/std/src/sys/unix/pipe.rs
index a56c275c9..a744d0ab6 100644
--- a/library/std/src/sys/unix/pipe.rs
+++ b/library/std/src/sys/unix/pipe.rs
@@ -58,6 +58,10 @@ impl AnonPipe {
         self.0.is_read_vectored()
     }
 
+    pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        self.0.read_to_end(buf)
+    }
+
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
         self.0.write(buf)
     }
diff --git a/library/std/src/sys/unix/process/process_common.rs b/library/std/src/sys/unix/process/process_common.rs
index 848adca78..afd03d79c 100644
--- a/library/std/src/sys/unix/process/process_common.rs
+++ b/library/std/src/sys/unix/process/process_common.rs
@@ -144,6 +144,7 @@ pub enum ChildStdio {
     Null,
 }
 
+#[derive(Debug)]
 pub enum Stdio {
     Inherit,
     Null,
@@ -510,16 +511,68 @@ impl ChildStdio {
 }
 
 impl fmt::Debug for Command {
+    // show all attributes but `self.closures` which does not implement `Debug`
+    // and `self.argv` which is not useful for debugging
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        if self.program != self.args[0] {
-            write!(f, "[{:?}] ", self.program)?;
-        }
-        write!(f, "{:?}", self.args[0])?;
+        if f.alternate() {
+            let mut debug_command = f.debug_struct("Command");
+            debug_command.field("program", &self.program).field("args", &self.args);
+            if !self.env.is_unchanged() {
+                debug_command.field("env", &self.env);
+            }
+
+            if self.cwd.is_some() {
+                debug_command.field("cwd", &self.cwd);
+            }
+            if self.uid.is_some() {
+                debug_command.field("uid", &self.uid);
+            }
+            if self.gid.is_some() {
+                debug_command.field("gid", &self.gid);
+            }
+
+            if self.groups.is_some() {
+                debug_command.field("groups", &self.groups);
+            }
+
+            if self.stdin.is_some() {
+                debug_command.field("stdin", &self.stdin);
+            }
+            if self.stdout.is_some() {
+                debug_command.field("stdout", &self.stdout);
+            }
+            if self.stderr.is_some() {
+                debug_command.field("stderr", &self.stderr);
+            }
+            if self.pgroup.is_some() {
+                debug_command.field("pgroup", &self.pgroup);
+            }
+
+            #[cfg(target_os = "linux")]
+            {
+                debug_command.field("create_pidfd", &self.create_pidfd);
+            }
 
-        for arg in &self.args[1..] {
-            write!(f, " {:?}", arg)?;
+            debug_command.finish()
+        } else {
+            if let Some(ref cwd) = self.cwd {
+                write!(f, "cd {cwd:?} && ")?;
+            }
+            for (key, value_opt) in self.get_envs() {
+                if let Some(value) = value_opt {
+                    write!(f, "{}={value:?} ", key.to_string_lossy())?;
+                }
+            }
+            if self.program != self.args[0] {
+                write!(f, "[{:?}] ", self.program)?;
+            }
+            write!(f, "{:?}", self.args[0])?;
+
+            for arg in &self.args[1..] {
+                write!(f, " {:?}", arg)?;
+            }
+            Ok(())
         }
-        Ok(())
     }
 }
 
diff --git a/library/std/src/sys/unix/process/process_fuchsia.rs b/library/std/src/sys/unix/process/process_fuchsia.rs
index 66ea3db20..d4c7e58b3 100644
--- a/library/std/src/sys/unix/process/process_fuchsia.rs
+++ b/library/std/src/sys/unix/process/process_fuchsia.rs
@@ -35,6 +35,11 @@ impl Command {
         Ok((Process { handle: Handle::new(process_handle) }, ours))
     }
 
+    pub fn output(&mut self) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
+        let (proc, pipes) = self.spawn(Stdio::MakePipe, false)?;
+        crate::sys_common::process::wait_with_output(proc, pipes)
+    }
+
     pub fn exec(&mut self, default: Stdio) -> io::Error {
         if self.saw_nul() {
             return io::const_io_error!(
@@ -257,7 +262,7 @@ impl ExitStatus {
     // available on Fuchsia.
     //
     // It does not appear that Fuchsia is Unix-like enough to implement ExitStatus (or indeed many
-    // other things from std::os::unix) properly.  This veneer is always going to be a bodge.  So
+    // other things from std::os::unix) properly. This veneer is always going to be a bodge. So
     // while I don't know if these implementations are actually correct, I think they will do for
     // now at least.
     pub fn core_dumped(&self) -> bool {
@@ -272,9 +277,9 @@ impl ExitStatus {
 
     pub fn into_raw(&self) -> c_int {
         // We don't know what someone who calls into_raw() will do with this value, but it should
-        // have the conventional Unix representation.  Despite the fact that this is not
+        // have the conventional Unix representation. Despite the fact that this is not
         // standardised in SuS or POSIX, all Unix systems encode the signal and exit status the
-        // same way.  (Ie the WIFEXITED, WEXITSTATUS etc. macros have identical behaviour on every
+        // same way. (Ie the WIFEXITED, WEXITSTATUS etc. macros have identical behaviour on every
         // Unix.)
         //
         // The caller of `std::os::unix::into_raw` is probably wanting a Unix exit status, and may
@@ -282,14 +287,14 @@ impl ExitStatus {
         // different Unix variant.
         //
         // The other view would be to say that the caller on Fuchsia ought to know that `into_raw`
-        // will give a raw Fuchsia status (whatever that is - I don't know, personally).  That is
+        // will give a raw Fuchsia status (whatever that is - I don't know, personally). That is
         // not possible here because we must return a c_int because that's what Unix (including
         // SuS and POSIX) say a wait status is, but Fuchsia apparently uses a u64, so it won't
         // necessarily fit.
         //
         // It seems to me that the right answer would be to provide std::os::fuchsia with its
         // own ExitStatusExt, rather that trying to provide a not very convincing imitation of
-        // Unix.  Ie, std::os::unix::process:ExitStatusExt ought not to exist on Fuchsia.  But
+        // Unix. Ie, std::os::unix::process:ExitStatusExt ought not to exist on Fuchsia. But
         // fixing this up that is beyond the scope of my efforts now.
         let exit_status_as_if_unix: u8 = self.0.try_into().expect("Fuchsia process return code bigger than 8 bits, but std::os::unix::ExitStatusExt::into_raw() was called to try to convert the value into a traditional Unix-style wait status, which cannot represent values greater than 255.");
         let wait_status_as_if_unix = (exit_status_as_if_unix as c_int) << 8;
diff --git a/library/std/src/sys/unix/process/process_unix.rs b/library/std/src/sys/unix/process/process_unix.rs
index 56a805cef..3bc17b775 100644
--- a/library/std/src/sys/unix/process/process_unix.rs
+++ b/library/std/src/sys/unix/process/process_unix.rs
@@ -66,14 +66,15 @@ impl Command {
         //
         // Note that as soon as we're done with the fork there's no need to hold
         // a lock any more because the parent won't do anything and the child is
-        // in its own process. Thus the parent drops the lock guard while the child
-        // forgets it to avoid unlocking it on a new thread, which would be invalid.
+        // in its own process. Thus the parent drops the lock guard immediately.
+        // The child calls `mem::forget` to leak the lock, which is crucial because
+        // releasing a lock is not async-signal-safe.
         let env_lock = sys::os::env_read_lock();
         let (pid, pidfd) = unsafe { self.do_fork()? };
 
         if pid == 0 {
             crate::panic::always_abort();
-            mem::forget(env_lock);
+            mem::forget(env_lock); // avoid non-async-signal-safe unlocking
             drop(input);
             let Err(err) = unsafe { self.do_exec(theirs, envp.as_ref()) };
             let errno = err.raw_os_error().unwrap_or(libc::EINVAL) as u32;
@@ -132,6 +133,11 @@ impl Command {
         }
     }
 
+    pub fn output(&mut self) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
+        let (proc, pipes) = self.spawn(Stdio::MakePipe, false)?;
+        crate::sys_common::process::wait_with_output(proc, pipes)
+    }
+
     // Attempts to fork the process. If successful, returns Ok((0, -1))
     // in the child, and Ok((child_pid, -1)) in the parent.
     #[cfg(not(target_os = "linux"))]
@@ -660,11 +666,11 @@ impl ExitStatus {
     }
 
     pub fn exit_ok(&self) -> Result<(), ExitStatusError> {
-        // This assumes that WIFEXITED(status) && WEXITSTATUS==0 corresponds to status==0.  This is
+        // This assumes that WIFEXITED(status) && WEXITSTATUS==0 corresponds to status==0. This is
         // true on all actual versions of Unix, is widely assumed, and is specified in SuS
-        // https://pubs.opengroup.org/onlinepubs/9699919799/functions/wait.html .  If it is not
+        // https://pubs.opengroup.org/onlinepubs/9699919799/functions/wait.html. If it is not
         // true for a platform pretending to be Unix, the tests (our doctests, and also
-        // procsss_unix/tests.rs) will spot it.  `ExitStatusError::code` assumes this too.
+        // procsss_unix/tests.rs) will spot it. `ExitStatusError::code` assumes this too.
         match NonZero_c_int::try_from(self.0) {
             /* was nonzero */ Ok(failure) => Err(ExitStatusError(failure)),
             /* was zero, couldn't convert */ Err(_) => Ok(()),
@@ -740,6 +746,8 @@ fn signal_string(signal: i32) -> &'static str {
         libc::SIGWINCH => " (SIGWINCH)",
         #[cfg(not(target_os = "haiku"))]
         libc::SIGIO => " (SIGIO)",
+        #[cfg(target_os = "haiku")]
+        libc::SIGPOLL => " (SIGPOLL)",
         libc::SIGSYS => " (SIGSYS)",
         // For information on Linux signals, run `man 7 signal`
         #[cfg(all(
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 e0e2d478f..e5e1f956b 100644
--- a/library/std/src/sys/unix/process/process_unix/tests.rs
+++ b/library/std/src/sys/unix/process/process_unix/tests.rs
@@ -3,7 +3,7 @@ use crate::panic::catch_unwind;
 use crate::process::Command;
 
 // Many of the other aspects of this situation, including heap alloc concurrency
-// safety etc., are tested in src/test/ui/process/process-panic-after-fork.rs
+// safety etc., are tested in tests/ui/process/process-panic-after-fork.rs
 
 #[test]
 fn exitstatus_display_tests() {
@@ -19,17 +19,17 @@ fn exitstatus_display_tests() {
     t(0x00000, "exit status: 0");
     t(0x0ff00, "exit status: 255");
 
-    // On MacOS, 0x0137f is WIFCONTINUED, not WIFSTOPPED.  Probably *BSD is similar.
+    // On MacOS, 0x0137f is WIFCONTINUED, not WIFSTOPPED. Probably *BSD is similar.
     //   https://github.com/rust-lang/rust/pull/82749#issuecomment-790525956
     // The purpose of this test is to test our string formatting, not our understanding of the wait
-    // status magic numbers.  So restrict these to Linux.
+    // status magic numbers. So restrict these to Linux.
     if cfg!(target_os = "linux") {
         t(0x0137f, "stopped (not terminated) by signal: 19 (SIGSTOP)");
         t(0x0ffff, "continued (WIFCONTINUED)");
     }
 
     // Testing "unrecognised wait status" is hard because the wait.h macros typically
-    // assume that the value came from wait and isn't mad.  With the glibc I have here
+    // assume that the value came from wait and isn't mad. With the glibc I have here
     // this works:
     if cfg!(all(target_os = "linux", target_env = "gnu")) {
         t(0x000ff, "unrecognised wait status: 255 0xff");
diff --git a/library/std/src/sys/unix/process/process_unsupported.rs b/library/std/src/sys/unix/process/process_unsupported.rs
index 72f9f3f9c..f28ca58d0 100644
--- a/library/std/src/sys/unix/process/process_unsupported.rs
+++ b/library/std/src/sys/unix/process/process_unsupported.rs
@@ -20,6 +20,10 @@ impl Command {
         unsupported()
     }
 
+    pub fn output(&mut self) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
+        unsupported()
+    }
+
     pub fn exec(&mut self, _default: Stdio) -> io::Error {
         unsupported_err()
     }
diff --git a/library/std/src/sys/unix/process/process_vxworks.rs b/library/std/src/sys/unix/process/process_vxworks.rs
index 200ef6719..569a4b149 100644
--- a/library/std/src/sys/unix/process/process_vxworks.rs
+++ b/library/std/src/sys/unix/process/process_vxworks.rs
@@ -108,6 +108,11 @@ impl Command {
         }
     }
 
+    pub fn output(&mut self) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
+        let (proc, pipes) = self.spawn(Stdio::MakePipe, false)?;
+        crate::sys_common::process::wait_with_output(proc, pipes)
+    }
+
     pub fn exec(&mut self, default: Stdio) -> io::Error {
         let ret = Command::spawn(self, default, false);
         match ret {
@@ -190,11 +195,11 @@ impl ExitStatus {
     }
 
     pub fn exit_ok(&self) -> Result<(), ExitStatusError> {
-        // This assumes that WIFEXITED(status) && WEXITSTATUS==0 corresponds to status==0.  This is
+        // This assumes that WIFEXITED(status) && WEXITSTATUS==0 corresponds to status==0. This is
         // true on all actual versions of Unix, is widely assumed, and is specified in SuS
-        // https://pubs.opengroup.org/onlinepubs/9699919799/functions/wait.html .  If it is not
+        // https://pubs.opengroup.org/onlinepubs/9699919799/functions/wait.html. If it is not
         // true for a platform pretending to be Unix, the tests (our doctests, and also
-        // procsss_unix/tests.rs) will spot it.  `ExitStatusError::code` assumes this too.
+        // procsss_unix/tests.rs) will spot it. `ExitStatusError::code` assumes this too.
         match NonZero_c_int::try_from(self.0) {
             Ok(failure) => Err(ExitStatusError(failure)),
             Err(_) => Ok(()),
diff --git a/library/std/src/sys/unix/stack_overflow.rs b/library/std/src/sys/unix/stack_overflow.rs
index 75a5c0f92..b59d4ba26 100644
--- a/library/std/src/sys/unix/stack_overflow.rs
+++ b/library/std/src/sys/unix/stack_overflow.rs
@@ -45,7 +45,10 @@ mod imp {
     use crate::thread;
 
     use libc::MAP_FAILED;
-    use libc::{mmap, munmap};
+    #[cfg(not(all(target_os = "linux", target_env = "gnu")))]
+    use libc::{mmap as mmap64, munmap};
+    #[cfg(all(target_os = "linux", target_env = "gnu"))]
+    use libc::{mmap64, munmap};
     use libc::{sigaction, sighandler_t, SA_ONSTACK, SA_SIGINFO, SIGBUS, SIG_DFL};
     use libc::{sigaltstack, SIGSTKSZ, SS_DISABLE};
     use libc::{MAP_ANON, MAP_PRIVATE, PROT_NONE, PROT_READ, PROT_WRITE, SIGSEGV};
@@ -135,7 +138,7 @@ mod imp {
         #[cfg(not(any(target_os = "openbsd", target_os = "netbsd", target_os = "linux",)))]
         let flags = MAP_PRIVATE | MAP_ANON;
         let stackp =
-            mmap(ptr::null_mut(), SIGSTKSZ + page_size(), PROT_READ | PROT_WRITE, flags, -1, 0);
+            mmap64(ptr::null_mut(), SIGSTKSZ + page_size(), PROT_READ | PROT_WRITE, flags, -1, 0);
         if stackp == MAP_FAILED {
             panic!("failed to allocate an alternative stack: {}", io::Error::last_os_error());
         }
diff --git a/library/std/src/sys/unix/thread.rs b/library/std/src/sys/unix/thread.rs
index c1d30dd9d..2a1830d06 100644
--- a/library/std/src/sys/unix/thread.rs
+++ b/library/std/src/sys/unix/thread.rs
@@ -73,7 +73,7 @@ impl Thread {
                 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
+                    // 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();
@@ -136,7 +136,7 @@ impl Thread {
 
         unsafe {
             // Available since glibc 2.12, musl 1.1.16, and uClibc 1.0.20.
-            let name = truncate_cstr(name, TASK_COMM_LEN);
+            let name = truncate_cstr::<{ TASK_COMM_LEN }>(name);
             let res = libc::pthread_setname_np(libc::pthread_self(), name.as_ptr());
             // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked.
             debug_assert_eq!(res, 0);
@@ -153,7 +153,7 @@ impl Thread {
     #[cfg(any(target_os = "macos", target_os = "ios", target_os = "watchos"))]
     pub fn set_name(name: &CStr) {
         unsafe {
-            let name = truncate_cstr(name, libc::MAXTHREADNAMESIZE);
+            let name = truncate_cstr::<{ libc::MAXTHREADNAMESIZE }>(name);
             let res = libc::pthread_setname_np(name.as_ptr());
             // We have no good way of propagating errors here, but in debug-builds let's check that this actually worked.
             debug_assert_eq!(res, 0);
@@ -285,17 +285,12 @@ impl Drop for Thread {
 }
 
 #[cfg(any(target_os = "linux", target_os = "macos", target_os = "ios", target_os = "watchos"))]
-fn truncate_cstr(cstr: &CStr, max_with_nul: usize) -> crate::borrow::Cow<'_, CStr> {
-    use crate::{borrow::Cow, ffi::CString};
-
-    if cstr.to_bytes_with_nul().len() > max_with_nul {
-        let bytes = cstr.to_bytes()[..max_with_nul - 1].to_vec();
-        // SAFETY: the non-nul bytes came straight from a CStr.
-        // (CString will add the terminating nul.)
-        Cow::Owned(unsafe { CString::from_vec_unchecked(bytes) })
-    } else {
-        Cow::Borrowed(cstr)
+fn truncate_cstr<const MAX_WITH_NUL: usize>(cstr: &CStr) -> [libc::c_char; MAX_WITH_NUL] {
+    let mut result = [0; MAX_WITH_NUL];
+    for (src, dst) in cstr.to_bytes().iter().zip(&mut result[..MAX_WITH_NUL - 1]) {
+        *dst = *src as libc::c_char;
     }
+    result
 }
 
 pub fn available_parallelism() -> io::Result<NonZeroUsize> {
@@ -510,7 +505,7 @@ mod cgroups {
                     let limit = raw_quota.next()?;
                     let period = raw_quota.next()?;
                     match (limit.parse::<usize>(), period.parse::<usize>()) {
-                        (Ok(limit), Ok(period)) => {
+                        (Ok(limit), Ok(period)) if period > 0 => {
                             quota = quota.min(limit / period);
                         }
                         _ => {}
@@ -570,7 +565,7 @@ mod cgroups {
                 let period = parse_file("cpu.cfs_period_us");
 
                 match (limit, period) {
-                    (Some(limit), Some(period)) => quota = quota.min(limit / period),
+                    (Some(limit), Some(period)) if period > 0 => quota = quota.min(limit / period),
                     _ => {}
                 }
 
@@ -658,7 +653,10 @@ pub mod guard {
 ))]
 #[cfg_attr(test, allow(dead_code))]
 pub mod guard {
-    use libc::{mmap, mprotect};
+    #[cfg(not(all(target_os = "linux", target_env = "gnu")))]
+    use libc::{mmap as mmap64, mprotect};
+    #[cfg(all(target_os = "linux", target_env = "gnu"))]
+    use libc::{mmap64, mprotect};
     use libc::{MAP_ANON, MAP_FAILED, MAP_FIXED, MAP_PRIVATE, PROT_NONE, PROT_READ, PROT_WRITE};
 
     use crate::io;
@@ -757,10 +755,10 @@ pub mod guard {
         if cfg!(all(target_os = "linux", not(target_env = "musl"))) {
             // Linux doesn't allocate the whole stack right away, and
             // the kernel has its own stack-guard mechanism to fault
-            // when growing too close to an existing mapping.  If we map
+            // when growing too close to an existing mapping. If we map
             // our own guard, then the kernel starts enforcing a rather
             // large gap above that, rendering much of the possible
-            // stack space useless.  See #43052.
+            // stack space useless. See #43052.
             //
             // Instead, we'll just note where we expect rlimit to start
             // faulting, so our handler can report "stack overflow", and
@@ -776,14 +774,14 @@ pub mod guard {
             None
         } else if cfg!(target_os = "freebsd") {
             // FreeBSD's stack autogrows, and optionally includes a guard page
-            // at the bottom.  If we try to remap the bottom of the stack
-            // ourselves, FreeBSD's guard page moves upwards.  So we'll just use
+            // at the bottom. If we try to remap the bottom of the stack
+            // ourselves, FreeBSD's guard page moves upwards. So we'll just use
             // the builtin guard page.
             let stackptr = get_stack_start_aligned()?;
             let guardaddr = stackptr.addr();
             // Technically the number of guard pages is tunable and controlled
             // by the security.bsd.stack_guard_page sysctl, but there are
-            // few reasons to change it from the default.  The default value has
+            // few reasons to change it from the default. The default value has
             // been 1 ever since FreeBSD 11.1 and 10.4.
             const GUARD_PAGES: usize = 1;
             let guard = guardaddr..guardaddr + GUARD_PAGES * page_size;
@@ -808,7 +806,7 @@ pub mod guard {
             // read/write permissions and only then mprotect() it to
             // no permissions at all. See issue #50313.
             let stackptr = get_stack_start_aligned()?;
-            let result = mmap(
+            let result = mmap64(
                 stackptr,
                 page_size,
                 PROT_READ | PROT_WRITE,
@@ -879,9 +877,9 @@ pub mod guard {
             } else if cfg!(all(target_os = "linux", any(target_env = "gnu", target_env = "uclibc")))
             {
                 // glibc used to include the guard area within the stack, as noted in the BUGS
-                // section of `man pthread_attr_getguardsize`.  This has been corrected starting
+                // section of `man pthread_attr_getguardsize`. This has been corrected starting
                 // with glibc 2.27, and in some distro backports, so the guard is now placed at the
-                // end (below) the stack.  There's no easy way for us to know which we have at
+                // end (below) the stack. There's no easy way for us to know which we have at
                 // runtime, so we'll just match any fault in the range right above or below the
                 // stack base to call that fault a stack overflow.
                 Some(stackaddr - guardsize..stackaddr + guardsize)
diff --git a/library/std/src/sys/unix/thread_parker/netbsd.rs b/library/std/src/sys/unix/thread_parker/netbsd.rs
deleted file mode 100644
index 7657605b5..000000000
--- a/library/std/src/sys/unix/thread_parker/netbsd.rs
+++ /dev/null
@@ -1,113 +0,0 @@
-use crate::ffi::{c_int, c_void};
-use crate::pin::Pin;
-use crate::ptr::{null, null_mut};
-use crate::sync::atomic::{
-    AtomicU64,
-    Ordering::{Acquire, Relaxed, Release},
-};
-use crate::time::Duration;
-use libc::{_lwp_self, clockid_t, lwpid_t, time_t, timespec, CLOCK_MONOTONIC};
-
-extern "C" {
-    fn ___lwp_park60(
-        clock_id: clockid_t,
-        flags: c_int,
-        ts: *mut timespec,
-        unpark: lwpid_t,
-        hint: *const c_void,
-        unparkhint: *const c_void,
-    ) -> c_int;
-    fn _lwp_unpark(lwp: lwpid_t, hint: *const c_void) -> c_int;
-}
-
-/// The thread is not parked and the token is not available.
-///
-/// Zero cannot be a valid LWP id, since it is used as empty value for the unpark
-/// argument in _lwp_park.
-const EMPTY: u64 = 0;
-/// The token is available. Do not park anymore.
-const NOTIFIED: u64 = u64::MAX;
-
-pub struct Parker {
-    /// The parker state. Contains either one of the two state values above or the LWP
-    /// id of the parked thread.
-    state: AtomicU64,
-}
-
-impl Parker {
-    pub unsafe fn new(parker: *mut Parker) {
-        parker.write(Parker { state: AtomicU64::new(EMPTY) })
-    }
-
-    // Does not actually need `unsafe` or `Pin`, but the pthread implementation does.
-    pub unsafe fn park(self: Pin<&Self>) {
-        // If the token has already been made available, we can skip
-        // a bit of work, so check for it here.
-        if self.state.load(Acquire) != NOTIFIED {
-            let parked = _lwp_self() as u64;
-            let hint = self.state.as_mut_ptr().cast();
-            if self.state.compare_exchange(EMPTY, parked, Relaxed, Acquire).is_ok() {
-                // Loop to guard against spurious wakeups.
-                loop {
-                    ___lwp_park60(0, 0, null_mut(), 0, hint, null());
-                    if self.state.load(Acquire) == NOTIFIED {
-                        break;
-                    }
-                }
-            }
-        }
-
-        // At this point, the change to NOTIFIED has always been observed with acquire
-        // ordering, so we can just use a relaxed store here (instead of a swap).
-        self.state.store(EMPTY, Relaxed);
-    }
-
-    // Does not actually need `unsafe` or `Pin`, but the pthread implementation does.
-    pub unsafe fn park_timeout(self: Pin<&Self>, dur: Duration) {
-        if self.state.load(Acquire) != NOTIFIED {
-            let parked = _lwp_self() as u64;
-            let hint = self.state.as_mut_ptr().cast();
-            let mut timeout = timespec {
-                // Saturate so that the operation will definitely time out
-                // (even if it is after the heat death of the universe).
-                tv_sec: dur.as_secs().try_into().ok().unwrap_or(time_t::MAX),
-                tv_nsec: dur.subsec_nanos().into(),
-            };
-
-            if self.state.compare_exchange(EMPTY, parked, Relaxed, Acquire).is_ok() {
-                // Timeout needs to be mutable since it is modified on NetBSD 9.0 and
-                // above.
-                ___lwp_park60(CLOCK_MONOTONIC, 0, &mut timeout, 0, hint, null());
-                // Use a swap to get acquire ordering even if the token was set after
-                // the timeout occurred.
-                self.state.swap(EMPTY, Acquire);
-                return;
-            }
-        }
-
-        self.state.store(EMPTY, Relaxed);
-    }
-
-    // Does not actually need `Pin`, but the pthread implementation does.
-    pub fn unpark(self: Pin<&Self>) {
-        let state = self.state.swap(NOTIFIED, Release);
-        if !matches!(state, EMPTY | NOTIFIED) {
-            let lwp = state as lwpid_t;
-            let hint = self.state.as_mut_ptr().cast();
-
-            // If the parking thread terminated and did not actually park, this will
-            // probably return an error, which is OK. In the worst case, another
-            // thread has received the same LWP id. It will then receive a spurious
-            // wakeup, but those are allowable per the API contract. The same reasoning
-            // applies if a timeout occurred before this call, but the state was not
-            // yet reset.
-
-            // SAFETY:
-            // The syscall has no invariants to hold. Only unsafe because it is an
-            // extern function.
-            unsafe {
-                _lwp_unpark(lwp, hint);
-            }
-        }
-    }
-}
diff --git a/library/std/src/sys/unix/thread_parker/darwin.rs b/library/std/src/sys/unix/thread_parking/darwin.rs
index 2f5356fe2..b709fada3 100644
--- a/library/std/src/sys/unix/thread_parker/darwin.rs
+++ b/library/std/src/sys/unix/thread_parking/darwin.rs
@@ -46,7 +46,7 @@ unsafe impl Sync for Parker {}
 unsafe impl Send for Parker {}
 
 impl Parker {
-    pub unsafe fn new(parker: *mut Parker) {
+    pub unsafe fn new_in_place(parker: *mut Parker) {
         let semaphore = dispatch_semaphore_create(0);
         assert!(
             !semaphore.is_null(),
diff --git a/library/std/src/sys/unix/thread_parker/mod.rs b/library/std/src/sys/unix/thread_parking/mod.rs
index 35f1e68a8..185333c07 100644
--- a/library/std/src/sys/unix/thread_parker/mod.rs
+++ b/library/std/src/sys/unix/thread_parking/mod.rs
@@ -24,7 +24,7 @@ cfg_if::cfg_if! {
         pub use darwin::Parker;
     } else if #[cfg(target_os = "netbsd")] {
         mod netbsd;
-        pub use netbsd::Parker;
+        pub use netbsd::{current, park, park_timeout, unpark, ThreadId};
     } else {
         mod pthread;
         pub use pthread::Parker;
diff --git a/library/std/src/sys/unix/thread_parking/netbsd.rs b/library/std/src/sys/unix/thread_parking/netbsd.rs
new file mode 100644
index 000000000..3be081221
--- /dev/null
+++ b/library/std/src/sys/unix/thread_parking/netbsd.rs
@@ -0,0 +1,52 @@
+use crate::ffi::{c_int, c_void};
+use crate::ptr;
+use crate::time::Duration;
+use libc::{_lwp_self, clockid_t, lwpid_t, time_t, timespec, CLOCK_MONOTONIC};
+
+extern "C" {
+    fn ___lwp_park60(
+        clock_id: clockid_t,
+        flags: c_int,
+        ts: *mut timespec,
+        unpark: lwpid_t,
+        hint: *const c_void,
+        unparkhint: *const c_void,
+    ) -> c_int;
+    fn _lwp_unpark(lwp: lwpid_t, hint: *const c_void) -> c_int;
+}
+
+pub type ThreadId = lwpid_t;
+
+#[inline]
+pub fn current() -> ThreadId {
+    unsafe { _lwp_self() }
+}
+
+#[inline]
+pub fn park(hint: usize) {
+    unsafe {
+        ___lwp_park60(0, 0, ptr::null_mut(), 0, ptr::invalid(hint), ptr::null());
+    }
+}
+
+pub fn park_timeout(dur: Duration, hint: usize) {
+    let mut timeout = timespec {
+        // Saturate so that the operation will definitely time out
+        // (even if it is after the heat death of the universe).
+        tv_sec: dur.as_secs().try_into().ok().unwrap_or(time_t::MAX),
+        tv_nsec: dur.subsec_nanos().into(),
+    };
+
+    // Timeout needs to be mutable since it is modified on NetBSD 9.0 and
+    // above.
+    unsafe {
+        ___lwp_park60(CLOCK_MONOTONIC, 0, &mut timeout, 0, ptr::invalid(hint), ptr::null());
+    }
+}
+
+#[inline]
+pub fn unpark(tid: ThreadId, hint: usize) {
+    unsafe {
+        _lwp_unpark(tid, ptr::invalid(hint));
+    }
+}
diff --git a/library/std/src/sys/unix/thread_parker/pthread.rs b/library/std/src/sys/unix/thread_parking/pthread.rs
index 3dfc0026e..082d25e68 100644
--- a/library/std/src/sys/unix/thread_parker/pthread.rs
+++ b/library/std/src/sys/unix/thread_parking/pthread.rs
@@ -6,6 +6,7 @@ use crate::pin::Pin;
 use crate::ptr::addr_of_mut;
 use crate::sync::atomic::AtomicUsize;
 use crate::sync::atomic::Ordering::SeqCst;
+use crate::sys::time::TIMESPEC_MAX;
 use crate::time::Duration;
 
 const EMPTY: usize = 0;
@@ -32,9 +33,6 @@ unsafe fn wait(cond: *mut libc::pthread_cond_t, lock: *mut libc::pthread_mutex_t
     debug_assert_eq!(r, 0);
 }
 
-const TIMESPEC_MAX: libc::timespec =
-    libc::timespec { tv_sec: <libc::time_t>::MAX, tv_nsec: 1_000_000_000 - 1 };
-
 unsafe fn wait_timeout(
     cond: *mut libc::pthread_cond_t,
     lock: *mut libc::pthread_mutex_t,
@@ -46,7 +44,8 @@ unsafe fn wait_timeout(
         target_os = "macos",
         target_os = "ios",
         target_os = "watchos",
-        target_os = "espidf"
+        target_os = "espidf",
+        target_os = "horizon",
     ))]
     let (now, dur) = {
         use crate::cmp::min;
@@ -72,7 +71,8 @@ unsafe fn wait_timeout(
         target_os = "macos",
         target_os = "ios",
         target_os = "watchos",
-        target_os = "espidf"
+        target_os = "espidf",
+        target_os = "horizon",
     )))]
     let (now, dur) = {
         use crate::sys::time::Timespec;
@@ -99,7 +99,7 @@ impl Parker {
     ///
     /// # Safety
     /// The constructed parker must never be moved.
-    pub unsafe fn new(parker: *mut Parker) {
+    pub unsafe fn new_in_place(parker: *mut Parker) {
         // Use the default mutex implementation to allow for simpler initialization.
         // This could lead to undefined behaviour when deadlocking. This is avoided
         // by not deadlocking. Note in particular the unlocking operation before any
diff --git a/library/std/src/sys/unix/time.rs b/library/std/src/sys/unix/time.rs
index d5abd9b58..2daad981b 100644
--- a/library/std/src/sys/unix/time.rs
+++ b/library/std/src/sys/unix/time.rs
@@ -5,6 +5,9 @@ pub use self::inner::Instant;
 
 const NSEC_PER_SEC: u64 = 1_000_000_000;
 pub const UNIX_EPOCH: SystemTime = SystemTime { t: Timespec::zero() };
+#[allow(dead_code)] // Used for pthread condvar timeouts
+pub const TIMESPEC_MAX: libc::timespec =
+    libc::timespec { tv_sec: <libc::time_t>::MAX, tv_nsec: 1_000_000_000 - 1 };
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[repr(transparent)]
diff --git a/library/std/src/sys/unix/weak.rs b/library/std/src/sys/unix/weak.rs
index f5a4ce929..62ffee70b 100644
--- a/library/std/src/sys/unix/weak.rs
+++ b/library/std/src/sys/unix/weak.rs
@@ -1,9 +1,8 @@
 //! Support for "weak linkage" to symbols on Unix
 //!
-//! Some I/O operations we do in libstd require newer versions of OSes but we
-//! need to maintain binary compatibility with older releases for now. In order
-//! to use the new functionality when available we use this module for
-//! detection.
+//! Some I/O operations we do in std require newer versions of OSes but we need
+//! to maintain binary compatibility with older releases for now. In order to
+//! use the new functionality when available we use this module for detection.
 //!
 //! One option to use here is weak linkage, but that is unfortunately only
 //! really workable with ELF. Otherwise, use dlsym to get the symbol value at
@@ -29,7 +28,7 @@ use crate::ptr;
 use crate::sync::atomic::{self, AtomicPtr, Ordering};
 
 // We can use true weak linkage on ELF targets.
-#[cfg(all(not(any(target_os = "macos", target_os = "ios")), not(bootstrap)))]
+#[cfg(not(any(target_os = "macos", target_os = "ios")))]
 pub(crate) macro weak {
     (fn $name:ident($($t:ty),*) -> $ret:ty) => (
         let ref $name: ExternWeak<unsafe extern "C" fn($($t),*) -> $ret> = {
@@ -43,30 +42,14 @@ pub(crate) macro weak {
     )
 }
 
-#[cfg(all(not(any(target_os = "macos", target_os = "ios")), bootstrap))]
-pub(crate) macro weak {
-    (fn $name:ident($($t:ty),*) -> $ret:ty) => (
-        let ref $name: ExternWeak<unsafe extern "C" fn($($t),*) -> $ret> = {
-            extern "C" {
-                #[linkage = "extern_weak"]
-                static $name: *const libc::c_void;
-            }
-            #[allow(unused_unsafe)]
-            ExternWeak::new(unsafe { $name })
-        };
-    )
-}
-
 // On non-ELF targets, use the dlsym approximation of weak linkage.
 #[cfg(any(target_os = "macos", target_os = "ios"))]
 pub(crate) use self::dlsym as weak;
 
-#[cfg(not(bootstrap))]
 pub(crate) struct ExternWeak<F: Copy> {
     weak_ptr: Option<F>,
 }
 
-#[cfg(not(bootstrap))]
 impl<F: Copy> ExternWeak<F> {
     #[inline]
     pub(crate) fn new(weak_ptr: Option<F>) -> Self {
@@ -79,34 +62,6 @@ impl<F: Copy> ExternWeak<F> {
     }
 }
 
-#[cfg(bootstrap)]
-pub(crate) struct ExternWeak<F> {
-    weak_ptr: *const libc::c_void,
-    _marker: PhantomData<F>,
-}
-
-#[cfg(bootstrap)]
-impl<F> ExternWeak<F> {
-    #[inline]
-    pub(crate) fn new(weak_ptr: *const libc::c_void) -> Self {
-        ExternWeak { weak_ptr, _marker: PhantomData }
-    }
-}
-
-#[cfg(bootstrap)]
-impl<F> ExternWeak<F> {
-    #[inline]
-    pub(crate) fn get(&self) -> Option<F> {
-        unsafe {
-            if self.weak_ptr.is_null() {
-                None
-            } else {
-                Some(mem::transmute_copy::<*const libc::c_void, F>(&self.weak_ptr))
-            }
-        }
-    }
-}
-
 pub(crate) macro dlsym {
     (fn $name:ident($($t:ty),*) -> $ret:ty) => (
          dlsym!(fn $name($($t),*) -> $ret, stringify!($name));
diff --git a/library/std/src/sys/unsupported/mod.rs b/library/std/src/sys/unsupported/mod.rs
index 7bf6d40b7..15b22c620 100644
--- a/library/std/src/sys/unsupported/mod.rs
+++ b/library/std/src/sys/unsupported/mod.rs
@@ -9,6 +9,7 @@ pub mod fs;
 pub mod io;
 pub mod locks;
 pub mod net;
+pub mod once;
 pub mod os;
 #[path = "../unix/os_str.rs"]
 pub mod os_str;
diff --git a/library/std/src/sys/unsupported/once.rs b/library/std/src/sys/unsupported/once.rs
new file mode 100644
index 000000000..b4bb4975f
--- /dev/null
+++ b/library/std/src/sys/unsupported/once.rs
@@ -0,0 +1,89 @@
+use crate::cell::Cell;
+use crate::sync as public;
+
+pub struct Once {
+    state: Cell<State>,
+}
+
+pub struct OnceState {
+    poisoned: bool,
+    set_state_to: Cell<State>,
+}
+
+#[derive(Clone, Copy, PartialEq, Eq)]
+enum State {
+    Incomplete,
+    Poisoned,
+    Running,
+    Complete,
+}
+
+struct CompletionGuard<'a> {
+    state: &'a Cell<State>,
+    set_state_on_drop_to: State,
+}
+
+impl<'a> Drop for CompletionGuard<'a> {
+    fn drop(&mut self) {
+        self.state.set(self.set_state_on_drop_to);
+    }
+}
+
+// Safety: threads are not supported on this platform.
+unsafe impl Sync for Once {}
+
+impl Once {
+    #[inline]
+    #[rustc_const_stable(feature = "const_once_new", since = "1.32.0")]
+    pub const fn new() -> Once {
+        Once { state: Cell::new(State::Incomplete) }
+    }
+
+    #[inline]
+    pub fn is_completed(&self) -> bool {
+        self.state.get() == State::Complete
+    }
+
+    #[cold]
+    #[track_caller]
+    pub fn call(&self, ignore_poisoning: bool, f: &mut impl FnMut(&public::OnceState)) {
+        let state = self.state.get();
+        match state {
+            State::Poisoned if !ignore_poisoning => {
+                // Panic to propagate the poison.
+                panic!("Once instance has previously been poisoned");
+            }
+            State::Incomplete | State::Poisoned => {
+                self.state.set(State::Running);
+                // `guard` will set the new state on drop.
+                let mut guard =
+                    CompletionGuard { state: &self.state, set_state_on_drop_to: State::Poisoned };
+                // Run the function, letting it know if we're poisoned or not.
+                let f_state = public::OnceState {
+                    inner: OnceState {
+                        poisoned: state == State::Poisoned,
+                        set_state_to: Cell::new(State::Complete),
+                    },
+                };
+                f(&f_state);
+                guard.set_state_on_drop_to = f_state.inner.set_state_to.get();
+            }
+            State::Running => {
+                panic!("one-time initialization may not be performed recursively");
+            }
+            State::Complete => {}
+        }
+    }
+}
+
+impl OnceState {
+    #[inline]
+    pub fn is_poisoned(&self) -> bool {
+        self.poisoned
+    }
+
+    #[inline]
+    pub fn poison(&self) {
+        self.set_state_to.set(State::Poisoned)
+    }
+}
diff --git a/library/std/src/sys/unsupported/pipe.rs b/library/std/src/sys/unsupported/pipe.rs
index 25514c232..0bba673b4 100644
--- a/library/std/src/sys/unsupported/pipe.rs
+++ b/library/std/src/sys/unsupported/pipe.rs
@@ -15,6 +15,10 @@ impl AnonPipe {
         self.0
     }
 
+    pub fn read_to_end(&self, _buf: &mut Vec<u8>) -> io::Result<usize> {
+        self.0
+    }
+
     pub fn write(&self, _buf: &[u8]) -> io::Result<usize> {
         self.0
     }
diff --git a/library/std/src/sys/unsupported/process.rs b/library/std/src/sys/unsupported/process.rs
index 633f17c05..a494f2d6b 100644
--- a/library/std/src/sys/unsupported/process.rs
+++ b/library/std/src/sys/unsupported/process.rs
@@ -75,6 +75,10 @@ impl Command {
     ) -> io::Result<(Process, StdioPipes)> {
         unsupported()
     }
+
+    pub fn output(&mut self) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
+        unsupported()
+    }
 }
 
 impl From<AnonPipe> for Stdio {
diff --git a/library/std/src/sys/wasi/mod.rs b/library/std/src/sys/wasi/mod.rs
index c8c47763a..1dc3f2b20 100644
--- a/library/std/src/sys/wasi/mod.rs
+++ b/library/std/src/sys/wasi/mod.rs
@@ -32,6 +32,8 @@ pub mod io;
 #[path = "../unsupported/locks/mod.rs"]
 pub mod locks;
 pub mod net;
+#[path = "../unsupported/once.rs"]
+pub mod once;
 pub mod os;
 #[path = "../unix/os_str.rs"]
 pub mod os_str;
diff --git a/library/std/src/sys/wasm/mod.rs b/library/std/src/sys/wasm/mod.rs
index d68c3e5f1..77ebe3c4a 100644
--- a/library/std/src/sys/wasm/mod.rs
+++ b/library/std/src/sys/wasm/mod.rs
@@ -66,6 +66,8 @@ cfg_if::cfg_if! {
     } else {
         #[path = "../unsupported/locks/mod.rs"]
         pub mod locks;
+        #[path = "../unsupported/once.rs"]
+        pub mod once;
         #[path = "../unsupported/thread.rs"]
         pub mod thread;
     }
diff --git a/library/std/src/sys/windows/c.rs b/library/std/src/sys/windows/c.rs
index 81461de4f..f58dcf128 100644
--- a/library/std/src/sys/windows/c.rs
+++ b/library/std/src/sys/windows/c.rs
@@ -295,8 +295,6 @@ pub fn nt_success(status: NTSTATUS) -> bool {
     status >= 0
 }
 
-// "RNG\0"
-pub const BCRYPT_RNG_ALGORITHM: &[u16] = &[b'R' as u16, b'N' as u16, b'G' as u16, 0];
 pub const BCRYPT_USE_SYSTEM_PREFERRED_RNG: DWORD = 0x00000002;
 
 #[repr(C)]
@@ -834,6 +832,10 @@ if #[cfg(not(target_vendor = "uwp"))] {
 
     #[link(name = "advapi32")]
     extern "system" {
+        // Forbidden when targeting UWP
+        #[link_name = "SystemFunction036"]
+        pub fn RtlGenRandom(RandomBuffer: *mut u8, RandomBufferLength: ULONG) -> BOOLEAN;
+
         // Allowed but unused by UWP
         pub fn OpenProcessToken(
             ProcessHandle: HANDLE,
@@ -1258,13 +1260,6 @@ extern "system" {
         cbBuffer: ULONG,
         dwFlags: ULONG,
     ) -> NTSTATUS;
-    pub fn BCryptOpenAlgorithmProvider(
-        phalgorithm: *mut BCRYPT_ALG_HANDLE,
-        pszAlgId: LPCWSTR,
-        pszimplementation: LPCWSTR,
-        dwflags: ULONG,
-    ) -> NTSTATUS;
-    pub fn BCryptCloseAlgorithmProvider(hAlgorithm: BCRYPT_ALG_HANDLE, dwFlags: ULONG) -> NTSTATUS;
 }
 
 // Functions that aren't available on every version of Windows that we support,
diff --git a/library/std/src/sys/windows/mod.rs b/library/std/src/sys/windows/mod.rs
index e67411e16..77359abe4 100644
--- a/library/std/src/sys/windows/mod.rs
+++ b/library/std/src/sys/windows/mod.rs
@@ -33,7 +33,7 @@ pub mod stdio;
 pub mod thread;
 pub mod thread_local_dtor;
 pub mod thread_local_key;
-pub mod thread_parker;
+pub mod thread_parking;
 pub mod time;
 cfg_if::cfg_if! {
     if #[cfg(not(target_vendor = "uwp"))] {
diff --git a/library/std/src/sys/windows/os.rs b/library/std/src/sys/windows/os.rs
index 352337ba3..d7adeb266 100644
--- a/library/std/src/sys/windows/os.rs
+++ b/library/std/src/sys/windows/os.rs
@@ -157,7 +157,7 @@ impl<'a> Iterator for SplitPaths<'a> {
         // Double quotes are used as a way of introducing literal semicolons
         // (since c:\some;dir is a valid Windows path). Double quotes are not
         // themselves permitted in path names, so there is no way to escape a
-        // double quote.  Quoted regions can appear in arbitrary locations, so
+        // double quote. Quoted regions can appear in arbitrary locations, so
         //
         //   c:\foo;c:\som"e;di"r;c:\bar
         //
diff --git a/library/std/src/sys/windows/pipe.rs b/library/std/src/sys/windows/pipe.rs
index 9f26acc45..7b25edaa5 100644
--- a/library/std/src/sys/windows/pipe.rs
+++ b/library/std/src/sys/windows/pipe.rs
@@ -1,7 +1,7 @@
 use crate::os::windows::prelude::*;
 
 use crate::ffi::OsStr;
-use crate::io::{self, IoSlice, IoSliceMut};
+use crate::io::{self, IoSlice, IoSliceMut, Read};
 use crate::mem;
 use crate::path::Path;
 use crate::ptr;
@@ -261,6 +261,10 @@ impl AnonPipe {
         self.inner.is_read_vectored()
     }
 
+    pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        self.handle().read_to_end(buf)
+    }
+
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
         unsafe {
             let len = crate::cmp::min(buf.len(), c::DWORD::MAX as usize) as c::DWORD;
diff --git a/library/std/src/sys/windows/process.rs b/library/std/src/sys/windows/process.rs
index 31e9b34fb..10bc949e1 100644
--- a/library/std/src/sys/windows/process.rs
+++ b/library/std/src/sys/windows/process.rs
@@ -351,6 +351,11 @@ impl Command {
             ))
         }
     }
+
+    pub fn output(&mut self) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
+        let (proc, pipes) = self.spawn(Stdio::MakePipe, false)?;
+        crate::sys_common::process::wait_with_output(proc, pipes)
+    }
 }
 
 impl fmt::Debug for Command {
diff --git a/library/std/src/sys/windows/rand.rs b/library/std/src/sys/windows/rand.rs
index b5a49489d..cdf37cfe9 100644
--- a/library/std/src/sys/windows/rand.rs
+++ b/library/std/src/sys/windows/rand.rs
@@ -1,106 +1,39 @@
-//! # Random key generation
-//!
-//! This module wraps the RNG provided by the OS. There are a few different
-//! ways to interface with the OS RNG so it's worth exploring each of the options.
-//! Note that at the time of writing these all go through the (undocumented)
-//! `bcryptPrimitives.dll` but they use different route to get there.
-//!
-//! Originally we were using [`RtlGenRandom`], however that function is
-//! deprecated and warns it "may be altered or unavailable in subsequent versions".
-//!
-//! So we switched to [`BCryptGenRandom`] with the `BCRYPT_USE_SYSTEM_PREFERRED_RNG`
-//! flag to query and find the system configured RNG. However, this change caused a small
-//! but significant number of users to experience panics caused by a failure of
-//! this function. See [#94098].
-//!
-//! The current version falls back to using `BCryptOpenAlgorithmProvider` if
-//! `BCRYPT_USE_SYSTEM_PREFERRED_RNG` fails for any reason.
-//!
-//! [#94098]: https://github.com/rust-lang/rust/issues/94098
-//! [`RtlGenRandom`]: https://docs.microsoft.com/en-us/windows/win32/api/ntsecapi/nf-ntsecapi-rtlgenrandom
-//! [`BCryptGenRandom`]: https://docs.microsoft.com/en-us/windows/win32/api/bcrypt/nf-bcrypt-bcryptgenrandom
+use crate::io;
 use crate::mem;
 use crate::ptr;
 use crate::sys::c;
 
-/// Generates high quality secure random keys for use by [`HashMap`].
-///
-/// This is used to seed the default [`RandomState`].
-///
-/// [`HashMap`]: crate::collections::HashMap
-/// [`RandomState`]: crate::collections::hash_map::RandomState
 pub fn hashmap_random_keys() -> (u64, u64) {
-    Rng::SYSTEM.gen_random_keys().unwrap_or_else(fallback_rng)
+    let mut v = (0, 0);
+    let ret = unsafe {
+        c::BCryptGenRandom(
+            ptr::null_mut(),
+            &mut v as *mut _ as *mut u8,
+            mem::size_of_val(&v) as c::ULONG,
+            c::BCRYPT_USE_SYSTEM_PREFERRED_RNG,
+        )
+    };
+    if c::nt_success(ret) { v } else { fallback_rng() }
 }
 
-struct Rng {
-    algorithm: c::BCRYPT_ALG_HANDLE,
-    flags: u32,
-}
-impl Rng {
-    const SYSTEM: Self = unsafe { Self::new(ptr::null_mut(), c::BCRYPT_USE_SYSTEM_PREFERRED_RNG) };
-
-    /// Create the RNG from an existing algorithm handle.
-    ///
-    /// # Safety
-    ///
-    /// The handle must either be null or a valid algorithm handle.
-    const unsafe fn new(algorithm: c::BCRYPT_ALG_HANDLE, flags: u32) -> Self {
-        Self { algorithm, flags }
-    }
-
-    /// Open a handle to the RNG algorithm.
-    fn open() -> Result<Self, c::NTSTATUS> {
-        use crate::sync::atomic::AtomicPtr;
-        use crate::sync::atomic::Ordering::{Acquire, Release};
-
-        // An atomic is used so we don't need to reopen the handle every time.
-        static HANDLE: AtomicPtr<crate::ffi::c_void> = AtomicPtr::new(ptr::null_mut());
-
-        let mut handle = HANDLE.load(Acquire);
-        if handle.is_null() {
-            let status = unsafe {
-                c::BCryptOpenAlgorithmProvider(
-                    &mut handle,
-                    c::BCRYPT_RNG_ALGORITHM.as_ptr(),
-                    ptr::null(),
-                    0,
-                )
-            };
-            if c::nt_success(status) {
-                // If another thread opens a handle first then use that handle instead.
-                let result = HANDLE.compare_exchange(ptr::null_mut(), handle, Release, Acquire);
-                if let Err(previous_handle) = result {
-                    // Close our handle and return the previous one.
-                    unsafe { c::BCryptCloseAlgorithmProvider(handle, 0) };
-                    handle = previous_handle;
-                }
-                Ok(unsafe { Self::new(handle, 0) })
-            } else {
-                Err(status)
-            }
-        } else {
-            Ok(unsafe { Self::new(handle, 0) })
-        }
-    }
+/// Generate random numbers using the fallback RNG function (RtlGenRandom)
+///
+/// This is necessary because of a failure to load the SysWOW64 variant of the
+/// bcryptprimitives.dll library from code that lives in bcrypt.dll
+/// See <https://bugzilla.mozilla.org/show_bug.cgi?id=1788004#c9>
+#[cfg(not(target_vendor = "uwp"))]
+#[inline(never)]
+fn fallback_rng() -> (u64, u64) {
+    let mut v = (0, 0);
+    let ret =
+        unsafe { c::RtlGenRandom(&mut v as *mut _ as *mut u8, mem::size_of_val(&v) as c::ULONG) };
 
-    fn gen_random_keys(self) -> Result<(u64, u64), c::NTSTATUS> {
-        let mut v = (0, 0);
-        let status = unsafe {
-            let size = mem::size_of_val(&v).try_into().unwrap();
-            c::BCryptGenRandom(self.algorithm, ptr::addr_of_mut!(v).cast(), size, self.flags)
-        };
-        if c::nt_success(status) { Ok(v) } else { Err(status) }
-    }
+    if ret != 0 { v } else { panic!("fallback RNG broken: {}", io::Error::last_os_error()) }
 }
 
-/// Generate random numbers using the fallback RNG function
+/// We can't use RtlGenRandom with UWP, so there is no fallback
+#[cfg(target_vendor = "uwp")]
 #[inline(never)]
-fn fallback_rng(rng_status: c::NTSTATUS) -> (u64, u64) {
-    match Rng::open().and_then(|rng| rng.gen_random_keys()) {
-        Ok(keys) => keys,
-        Err(status) => {
-            panic!("RNG broken: {rng_status:#x}, fallback RNG broken: {status:#x}")
-        }
-    }
+fn fallback_rng() -> (u64, u64) {
+    panic!("fallback RNG broken: RtlGenRandom() not supported on UWP");
 }
diff --git a/library/std/src/sys/windows/thread.rs b/library/std/src/sys/windows/thread.rs
index c5c9e97e6..1cb576c95 100644
--- a/library/std/src/sys/windows/thread.rs
+++ b/library/std/src/sys/windows/thread.rs
@@ -26,7 +26,7 @@ impl Thread {
 
         // FIXME On UNIX, we guard against stack sizes that are too small but
         // that's because pthreads enforces that stacks are at least
-        // PTHREAD_STACK_MIN bytes big.  Windows has no such lower limit, it's
+        // PTHREAD_STACK_MIN bytes big. Windows has no such lower limit, it's
         // just that below a certain threshold you can't do anything useful.
         // That threshold is application and architecture-specific, however.
         let ret = c::CreateThread(
diff --git a/library/std/src/sys/windows/thread_parker.rs b/library/std/src/sys/windows/thread_parking.rs
index 2f7ae863b..5d43676ad 100644
--- a/library/std/src/sys/windows/thread_parker.rs
+++ b/library/std/src/sys/windows/thread_parking.rs
@@ -97,7 +97,7 @@ const NOTIFIED: i8 = 1;
 impl Parker {
     /// Construct the Windows parker. The UNIX parker implementation
     /// requires this to happen in-place.
-    pub unsafe fn new(parker: *mut Parker) {
+    pub unsafe fn new_in_place(parker: *mut Parker) {
         parker.write(Self { state: AtomicI8::new(EMPTY) });
     }
 
diff --git a/library/std/src/sys_common/backtrace.rs b/library/std/src/sys_common/backtrace.rs
index 8807077cb..f1d804ef4 100644
--- a/library/std/src/sys_common/backtrace.rs
+++ b/library/std/src/sys_common/backtrace.rs
@@ -20,7 +20,7 @@ pub fn lock() -> impl Drop {
 /// Prints the current backtrace.
 pub fn print(w: &mut dyn Write, format: PrintFmt) -> io::Result<()> {
     // There are issues currently linking libbacktrace into tests, and in
-    // general during libstd's own unit tests we're not testing this path. In
+    // general during std's own unit tests we're not testing this path. In
     // test mode immediately return here to optimize away any references to the
     // libbacktrace symbols
     if cfg!(test) {
@@ -111,7 +111,7 @@ unsafe fn _print_fmt(fmt: &mut fmt::Formatter<'_>, print_fmt: PrintFmt) -> fmt::
 }
 
 /// Fixed frame used to clean the backtrace with `RUST_BACKTRACE=1`. Note that
-/// this is only inline(never) when backtraces in libstd are enabled, otherwise
+/// this is only inline(never) when backtraces in std are enabled, otherwise
 /// it's fine to optimize away.
 #[cfg_attr(feature = "backtrace", inline(never))]
 pub fn __rust_begin_short_backtrace<F, T>(f: F) -> T
@@ -127,7 +127,7 @@ where
 }
 
 /// Fixed frame used to clean the backtrace with `RUST_BACKTRACE=1`. Note that
-/// this is only inline(never) when backtraces in libstd are enabled, otherwise
+/// this is only inline(never) when backtraces in std are enabled, otherwise
 /// it's fine to optimize away.
 #[cfg_attr(feature = "backtrace", inline(never))]
 pub fn __rust_end_short_backtrace<F, T>(f: F) -> T
diff --git a/library/std/src/sys_common/io.rs b/library/std/src/sys_common/io.rs
index d1e9fed41..4a42ff3c6 100644
--- a/library/std/src/sys_common/io.rs
+++ b/library/std/src/sys_common/io.rs
@@ -39,9 +39,10 @@ pub mod test {
         }
     }
 
+    #[track_caller] // for `test_rng`
     pub fn tmpdir() -> TempDir {
         let p = env::temp_dir();
-        let mut r = rand::thread_rng();
+        let mut r = crate::test_helpers::test_rng();
         let ret = p.join(&format!("rust-{}", r.next_u32()));
         fs::create_dir(&ret).unwrap();
         TempDir(ret)
diff --git a/library/std/src/sys_common/mod.rs b/library/std/src/sys_common/mod.rs
index b1987aa0f..6b24b0e9a 100644
--- a/library/std/src/sys_common/mod.rs
+++ b/library/std/src/sys_common/mod.rs
@@ -27,11 +27,10 @@ pub mod lazy_box;
 pub mod memchr;
 pub mod once;
 pub mod process;
-pub mod remutex;
 pub mod thread;
 pub mod thread_info;
 pub mod thread_local_dtor;
-pub mod thread_parker;
+pub mod thread_parking;
 pub mod wstr;
 pub mod wtf8;
 
diff --git a/library/std/src/sys_common/once/mod.rs b/library/std/src/sys_common/once/mod.rs
index 8742e68cc..359697d83 100644
--- a/library/std/src/sys_common/once/mod.rs
+++ b/library/std/src/sys_common/once/mod.rs
@@ -6,22 +6,6 @@
 // As a result, we end up implementing it ourselves in the standard library.
 // This also gives us the opportunity to optimize the implementation a bit which
 // should help the fast path on call sites.
-//
-// So to recap, the guarantees of a Once are that it will call the
-// initialization closure at most once, and it will never return until the one
-// that's running has finished running. This means that we need some form of
-// blocking here while the custom callback is running at the very least.
-// Additionally, we add on the restriction of **poisoning**. Whenever an
-// initialization closure panics, the Once enters a "poisoned" state which means
-// that all future calls will immediately panic as well.
-//
-// So to implement this, one might first reach for a `Mutex`, but those cannot
-// be put into a `static`. It also gets a lot harder with poisoning to figure
-// out when the mutex needs to be deallocated because it's not after the closure
-// finishes, but after the first successful closure finishes.
-//
-// All in all, this is instead implemented with atomics and lock-free
-// operations! Whee!
 
 cfg_if::cfg_if! {
     if #[cfg(any(
@@ -36,8 +20,15 @@ cfg_if::cfg_if! {
     ))] {
         mod futex;
         pub use futex::{Once, OnceState};
+    } else if #[cfg(any(
+        windows,
+        target_family = "unix",
+        all(target_vendor = "fortanix", target_env = "sgx"),
+        target_os = "solid_asp3",
+    ))] {
+        mod queue;
+        pub use queue::{Once, OnceState};
     } else {
-        mod generic;
-        pub use generic::{Once, OnceState};
+        pub use crate::sys::once::{Once, OnceState};
     }
 }
diff --git a/library/std/src/sys_common/once/generic.rs b/library/std/src/sys_common/once/queue.rs
index d953a6745..d953a6745 100644
--- a/library/std/src/sys_common/once/generic.rs
+++ b/library/std/src/sys_common/once/queue.rs
diff --git a/library/std/src/sys_common/process.rs b/library/std/src/sys_common/process.rs
index 9f978789a..18883048d 100644
--- a/library/std/src/sys_common/process.rs
+++ b/library/std/src/sys_common/process.rs
@@ -4,10 +4,13 @@
 use crate::collections::BTreeMap;
 use crate::env;
 use crate::ffi::{OsStr, OsString};
-use crate::sys::process::EnvKey;
+use crate::fmt;
+use crate::io;
+use crate::sys::pipe::read2;
+use crate::sys::process::{EnvKey, ExitStatus, Process, StdioPipes};
 
 // Stores a set of changes to an environment
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub struct CommandEnv {
     clear: bool,
     saw_path: bool,
@@ -20,6 +23,14 @@ impl Default for CommandEnv {
     }
 }
 
+impl fmt::Debug for CommandEnv {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut debug_command_env = f.debug_struct("CommandEnv");
+        debug_command_env.field("clear", &self.clear).field("vars", &self.vars);
+        debug_command_env.finish()
+    }
+}
+
 impl CommandEnv {
     // Capture the current environment with these changes applied
     pub fn capture(&self) -> BTreeMap<EnvKey, OsString> {
@@ -117,3 +128,30 @@ impl<'a> ExactSizeIterator for CommandEnvs<'a> {
         self.iter.is_empty()
     }
 }
+
+pub fn wait_with_output(
+    mut process: Process,
+    mut pipes: StdioPipes,
+) -> io::Result<(ExitStatus, Vec<u8>, Vec<u8>)> {
+    drop(pipes.stdin.take());
+
+    let (mut stdout, mut stderr) = (Vec::new(), Vec::new());
+    match (pipes.stdout.take(), pipes.stderr.take()) {
+        (None, None) => {}
+        (Some(out), None) => {
+            let res = out.read_to_end(&mut stdout);
+            res.unwrap();
+        }
+        (None, Some(err)) => {
+            let res = err.read_to_end(&mut stderr);
+            res.unwrap();
+        }
+        (Some(out), Some(err)) => {
+            let res = read2(out, &mut stdout, err, &mut stderr);
+            res.unwrap();
+        }
+    }
+
+    let status = process.wait()?;
+    Ok((status, stdout, stderr))
+}
diff --git a/library/std/src/sys_common/thread_local_key.rs b/library/std/src/sys_common/thread_local_key.rs
index 747579f17..2672a2a75 100644
--- a/library/std/src/sys_common/thread_local_key.rs
+++ b/library/std/src/sys_common/thread_local_key.rs
@@ -117,10 +117,14 @@ pub struct Key {
 /// This value specifies no destructor by default.
 pub const INIT: StaticKey = StaticKey::new(None);
 
+// Define a sentinel value that is unlikely to be returned
+// as a TLS key (but it may be returned).
+const KEY_SENTVAL: usize = 0;
+
 impl StaticKey {
     #[rustc_const_unstable(feature = "thread_local_internals", issue = "none")]
     pub const fn new(dtor: Option<unsafe extern "C" fn(*mut u8)>) -> StaticKey {
-        StaticKey { key: atomic::AtomicUsize::new(0), dtor }
+        StaticKey { key: atomic::AtomicUsize::new(KEY_SENTVAL), dtor }
     }
 
     /// Gets the value associated with this TLS key
@@ -144,31 +148,36 @@ impl StaticKey {
     #[inline]
     unsafe fn key(&self) -> imp::Key {
         match self.key.load(Ordering::Relaxed) {
-            0 => self.lazy_init() as imp::Key,
+            KEY_SENTVAL => self.lazy_init() as imp::Key,
             n => n as imp::Key,
         }
     }
 
     unsafe fn lazy_init(&self) -> usize {
-        // POSIX allows the key created here to be 0, but the compare_exchange
-        // below relies on using 0 as a sentinel value to check who won the
+        // POSIX allows the key created here to be KEY_SENTVAL, but the compare_exchange
+        // below relies on using KEY_SENTVAL as a sentinel value to check who won the
         // race to set the shared TLS key. As far as I know, there is no
         // guaranteed value that cannot be returned as a posix_key_create key,
         // so there is no value we can initialize the inner key with to
         // prove that it has not yet been set. As such, we'll continue using a
-        // value of 0, but with some gyrations to make sure we have a non-0
+        // value of KEY_SENTVAL, but with some gyrations to make sure we have a non-KEY_SENTVAL
         // value returned from the creation routine.
         // FIXME: this is clearly a hack, and should be cleaned up.
         let key1 = imp::create(self.dtor);
-        let key = if key1 != 0 {
+        let key = if key1 as usize != KEY_SENTVAL {
             key1
         } else {
             let key2 = imp::create(self.dtor);
             imp::destroy(key1);
             key2
         };
-        rtassert!(key != 0);
-        match self.key.compare_exchange(0, key as usize, Ordering::SeqCst, Ordering::SeqCst) {
+        rtassert!(key as usize != KEY_SENTVAL);
+        match self.key.compare_exchange(
+            KEY_SENTVAL,
+            key as usize,
+            Ordering::SeqCst,
+            Ordering::SeqCst,
+        ) {
             // The CAS succeeded, so we've created the actual key
             Ok(_) => key as usize,
             // If someone beat us to the punch, use their key instead
diff --git a/library/std/src/sys_common/thread_parker/futex.rs b/library/std/src/sys_common/thread_parking/futex.rs
index d9e2f39e3..588e7b278 100644
--- a/library/std/src/sys_common/thread_parker/futex.rs
+++ b/library/std/src/sys_common/thread_parking/futex.rs
@@ -35,7 +35,7 @@ pub struct Parker {
 impl Parker {
     /// Construct the futex parker. The UNIX parker implementation
     /// requires this to happen in-place.
-    pub unsafe fn new(parker: *mut Parker) {
+    pub unsafe fn new_in_place(parker: *mut Parker) {
         parker.write(Self { state: AtomicU32::new(EMPTY) });
     }
 
diff --git a/library/std/src/sys_common/thread_parker/generic.rs b/library/std/src/sys_common/thread_parking/generic.rs
index f3d8b34d3..3209bffe3 100644
--- a/library/std/src/sys_common/thread_parker/generic.rs
+++ b/library/std/src/sys_common/thread_parking/generic.rs
@@ -19,7 +19,7 @@ pub struct Parker {
 impl Parker {
     /// Construct the generic parker. The UNIX parker implementation
     /// requires this to happen in-place.
-    pub unsafe fn new(parker: *mut Parker) {
+    pub unsafe fn new_in_place(parker: *mut Parker) {
         parker.write(Parker {
             state: AtomicUsize::new(EMPTY),
             lock: Mutex::new(()),
diff --git a/library/std/src/sys_common/thread_parking/id.rs b/library/std/src/sys_common/thread_parking/id.rs
new file mode 100644
index 000000000..e98169597
--- /dev/null
+++ b/library/std/src/sys_common/thread_parking/id.rs
@@ -0,0 +1,108 @@
+//! Thread parking using thread ids.
+//!
+//! Some platforms (notably NetBSD) have thread parking primitives whose semantics
+//! match those offered by `thread::park`, with the difference that the thread to
+//! be unparked is referenced by a platform-specific thread id. Since the thread
+//! parker is constructed before that id is known, an atomic state variable is used
+//! to manage the park state and propagate the thread id. This also avoids platform
+//! calls in the case where `unpark` is called before `park`.
+
+use crate::cell::UnsafeCell;
+use crate::pin::Pin;
+use crate::sync::atomic::{
+    fence, AtomicI8,
+    Ordering::{Acquire, Relaxed, Release},
+};
+use crate::sys::thread_parking::{current, park, park_timeout, unpark, ThreadId};
+use crate::time::Duration;
+
+pub struct Parker {
+    state: AtomicI8,
+    tid: UnsafeCell<Option<ThreadId>>,
+}
+
+const PARKED: i8 = -1;
+const EMPTY: i8 = 0;
+const NOTIFIED: i8 = 1;
+
+impl Parker {
+    pub fn new() -> Parker {
+        Parker { state: AtomicI8::new(EMPTY), tid: UnsafeCell::new(None) }
+    }
+
+    /// Create a new thread parker. UNIX requires this to happen in-place.
+    pub unsafe fn new_in_place(parker: *mut Parker) {
+        parker.write(Parker::new())
+    }
+
+    /// # Safety
+    /// * must always be called from the same thread
+    /// * must be called before the state is set to PARKED
+    unsafe fn init_tid(&self) {
+        // The field is only ever written to from this thread, so we don't need
+        // synchronization to read it here.
+        if self.tid.get().read().is_none() {
+            // Because this point is only reached once, before the state is set
+            // to PARKED for the first time, the non-atomic write here can not
+            // conflict with reads by other threads.
+            self.tid.get().write(Some(current()));
+            // Ensure that the write can be observed by all threads reading the
+            // state. Synchronizes with the acquire barrier in `unpark`.
+            fence(Release);
+        }
+    }
+
+    pub unsafe fn park(self: Pin<&Self>) {
+        self.init_tid();
+
+        // Changes NOTIFIED to EMPTY and EMPTY to PARKED.
+        let mut state = self.state.fetch_sub(1, Acquire).wrapping_sub(1);
+        if state == PARKED {
+            // Loop to guard against spurious wakeups.
+            while state == PARKED {
+                park(self.state.as_mut_ptr().addr());
+                state = self.state.load(Acquire);
+            }
+
+            // Since the state change has already been observed with acquire
+            // ordering, the state can be reset with a relaxed store instead
+            // of a swap.
+            self.state.store(EMPTY, Relaxed);
+        }
+    }
+
+    pub unsafe fn park_timeout(self: Pin<&Self>, dur: Duration) {
+        self.init_tid();
+
+        let state = self.state.fetch_sub(1, Acquire).wrapping_sub(1);
+        if state == PARKED {
+            park_timeout(dur, self.state.as_mut_ptr().addr());
+            // Swap to ensure that we observe all state changes with acquire
+            // ordering, even if the state has been changed after the timeout
+            // occured.
+            self.state.swap(EMPTY, Acquire);
+        }
+    }
+
+    pub fn unpark(self: Pin<&Self>) {
+        let state = self.state.swap(NOTIFIED, Release);
+        if state == PARKED {
+            // Synchronize with the release fence in `init_tid` to observe the
+            // write to `tid`.
+            fence(Acquire);
+            // # Safety
+            // The thread id is initialized before the state is set to `PARKED`
+            // for the first time and is not written to from that point on
+            // (negating the need for an atomic read).
+            let tid = unsafe { self.tid.get().read().unwrap_unchecked() };
+            // It is possible that the waiting thread woke up because of a timeout
+            // and terminated before this call is made. This call then returns an
+            // error or wakes up an unrelated thread. The platform API and
+            // environment does allow this, however.
+            unpark(tid, self.state.as_mut_ptr().addr());
+        }
+    }
+}
+
+unsafe impl Send for Parker {}
+unsafe impl Sync for Parker {}
diff --git a/library/std/src/sys_common/thread_parker/mod.rs b/library/std/src/sys_common/thread_parking/mod.rs
index f86a9a555..0ead6633c 100644
--- a/library/std/src/sys_common/thread_parker/mod.rs
+++ b/library/std/src/sys_common/thread_parking/mod.rs
@@ -11,11 +11,17 @@ cfg_if::cfg_if! {
     ))] {
         mod futex;
         pub use futex::Parker;
+    } else if #[cfg(any(
+        target_os = "netbsd",
+        all(target_vendor = "fortanix", target_env = "sgx"),
+    ))] {
+        mod id;
+        pub use id::Parker;
     } else if #[cfg(target_os = "solid_asp3")] {
         mod wait_flag;
         pub use wait_flag::Parker;
     } else if #[cfg(any(windows, target_family = "unix"))] {
-        pub use crate::sys::thread_parker::Parker;
+        pub use crate::sys::thread_parking::Parker;
     } else {
         mod generic;
         pub use generic::Parker;
diff --git a/library/std/src/sys_common/thread_parker/wait_flag.rs b/library/std/src/sys_common/thread_parking/wait_flag.rs
index 6561c1866..d0f8899a9 100644
--- a/library/std/src/sys_common/thread_parker/wait_flag.rs
+++ b/library/std/src/sys_common/thread_parking/wait_flag.rs
@@ -41,7 +41,7 @@ pub struct Parker {
 impl Parker {
     /// Construct a parker for the current thread. The UNIX parker
     /// implementation requires this to happen in-place.
-    pub unsafe fn new(parker: *mut Parker) {
+    pub unsafe fn new_in_place(parker: *mut Parker) {
         parker.write(Parker { state: AtomicI8::new(EMPTY), wait_flag: WaitFlag::new() })
     }
 
diff --git a/library/std/src/thread/local.rs b/library/std/src/thread/local.rs
index 5d267891b..b30bb7b77 100644
--- a/library/std/src/thread/local.rs
+++ b/library/std/src/thread/local.rs
@@ -905,9 +905,8 @@ pub mod statik {
 pub mod fast {
     use super::lazy::LazyKeyInner;
     use crate::cell::Cell;
-    use crate::fmt;
-    use crate::mem;
     use crate::sys::thread_local_dtor::register_dtor;
+    use crate::{fmt, mem, panic};
 
     #[derive(Copy, Clone)]
     enum DtorState {
@@ -950,7 +949,7 @@ pub mod fast {
 
         // note that this is just a publicly-callable function only for the
         // const-initialized form of thread locals, basically a way to call the
-        // free `register_dtor` function defined elsewhere in libstd.
+        // free `register_dtor` function defined elsewhere in std.
         pub unsafe fn register_dtor(a: *mut u8, dtor: unsafe extern "C" fn(*mut u8)) {
             unsafe {
                 register_dtor(a, dtor);
@@ -1028,10 +1027,15 @@ pub mod fast {
         // `Option<T>` to `None`, and `dtor_state` to `RunningOrHasRun`. This
         // causes future calls to `get` to run `try_initialize_drop` again,
         // which will now fail, and return `None`.
-        unsafe {
+        //
+        // Wrap the call in a catch to ensure unwinding is caught in the event
+        // a panic takes place in a destructor.
+        if let Err(_) = panic::catch_unwind(panic::AssertUnwindSafe(|| unsafe {
             let value = (*ptr).inner.take();
             (*ptr).dtor_state.set(DtorState::RunningOrHasRun);
             drop(value);
+        })) {
+            rtabort!("thread local panicked on drop");
         }
     }
 }
@@ -1044,10 +1048,8 @@ pub mod fast {
 pub mod os {
     use super::lazy::LazyKeyInner;
     use crate::cell::Cell;
-    use crate::fmt;
-    use crate::marker;
-    use crate::ptr;
     use crate::sys_common::thread_local_key::StaticKey as OsStaticKey;
+    use crate::{fmt, marker, panic, ptr};
 
     /// Use a regular global static to store this key; the state provided will then be
     /// thread-local.
@@ -1137,12 +1139,17 @@ pub mod os {
         //
         // Note that to prevent an infinite loop we reset it back to null right
         // before we return from the destructor ourselves.
-        unsafe {
+        //
+        // Wrap the call in a catch to ensure unwinding is caught in the event
+        // a panic takes place in a destructor.
+        if let Err(_) = panic::catch_unwind(|| unsafe {
             let ptr = Box::from_raw(ptr as *mut Value<T>);
             let key = ptr.key;
             key.os.set(ptr::invalid_mut(1));
             drop(ptr);
             key.os.set(ptr::null_mut());
+        }) {
+            rtabort!("thread local panicked on drop");
         }
     }
 }
diff --git a/library/std/src/thread/local/tests.rs b/library/std/src/thread/local/tests.rs
index 80dc4c038..964c7fc5b 100644
--- a/library/std/src/thread/local/tests.rs
+++ b/library/std/src/thread/local/tests.rs
@@ -23,11 +23,11 @@ impl Signal {
     }
 }
 
-struct Foo(Signal);
+struct NotifyOnDrop(Signal);
 
-impl Drop for Foo {
+impl Drop for NotifyOnDrop {
     fn drop(&mut self) {
-        let Foo(ref f) = *self;
+        let NotifyOnDrop(ref f) = *self;
         f.notify();
     }
 }
@@ -82,18 +82,18 @@ fn states() {
 
 #[test]
 fn smoke_dtor() {
-    thread_local!(static FOO: UnsafeCell<Option<Foo>> = UnsafeCell::new(None));
+    thread_local!(static FOO: UnsafeCell<Option<NotifyOnDrop>> = UnsafeCell::new(None));
     run(&FOO);
-    thread_local!(static FOO2: UnsafeCell<Option<Foo>> = const { UnsafeCell::new(None) });
+    thread_local!(static FOO2: UnsafeCell<Option<NotifyOnDrop>> = const { UnsafeCell::new(None) });
     run(&FOO2);
 
-    fn run(key: &'static LocalKey<UnsafeCell<Option<Foo>>>) {
+    fn run(key: &'static LocalKey<UnsafeCell<Option<NotifyOnDrop>>>) {
         let signal = Signal::default();
         let signal2 = signal.clone();
         let t = thread::spawn(move || unsafe {
             let mut signal = Some(signal2);
             key.with(|f| {
-                *f.get() = Some(Foo(signal.take().unwrap()));
+                *f.get() = Some(NotifyOnDrop(signal.take().unwrap()));
             });
         });
         signal.wait();
@@ -187,13 +187,13 @@ fn self_referential() {
 fn dtors_in_dtors_in_dtors() {
     struct S1(Signal);
     thread_local!(static K1: UnsafeCell<Option<S1>> = UnsafeCell::new(None));
-    thread_local!(static K2: UnsafeCell<Option<Foo>> = UnsafeCell::new(None));
+    thread_local!(static K2: UnsafeCell<Option<NotifyOnDrop>> = UnsafeCell::new(None));
 
     impl Drop for S1 {
         fn drop(&mut self) {
             let S1(ref signal) = *self;
             unsafe {
-                let _ = K2.try_with(|s| *s.get() = Some(Foo(signal.clone())));
+                let _ = K2.try_with(|s| *s.get() = Some(NotifyOnDrop(signal.clone())));
             }
         }
     }
@@ -211,13 +211,13 @@ fn dtors_in_dtors_in_dtors() {
 fn dtors_in_dtors_in_dtors_const_init() {
     struct S1(Signal);
     thread_local!(static K1: UnsafeCell<Option<S1>> = const { UnsafeCell::new(None) });
-    thread_local!(static K2: UnsafeCell<Option<Foo>> = const { UnsafeCell::new(None) });
+    thread_local!(static K2: UnsafeCell<Option<NotifyOnDrop>> = const { UnsafeCell::new(None) });
 
     impl Drop for S1 {
         fn drop(&mut self) {
             let S1(ref signal) = *self;
             unsafe {
-                let _ = K2.try_with(|s| *s.get() = Some(Foo(signal.clone())));
+                let _ = K2.try_with(|s| *s.get() = Some(NotifyOnDrop(signal.clone())));
             }
         }
     }
diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index 34bdb8bd4..692ff0cbc 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -173,10 +173,16 @@ use crate::sync::Arc;
 use crate::sys::thread as imp;
 use crate::sys_common::thread;
 use crate::sys_common::thread_info;
-use crate::sys_common::thread_parker::Parker;
+use crate::sys_common::thread_parking::Parker;
 use crate::sys_common::{AsInner, IntoInner};
 use crate::time::Duration;
 
+#[stable(feature = "scoped_threads", since = "1.63.0")]
+mod scoped;
+
+#[stable(feature = "scoped_threads", since = "1.63.0")]
+pub use scoped::{scope, Scope, ScopedJoinHandle};
+
 ////////////////////////////////////////////////////////////////////////////////
 // Thread-local storage
 ////////////////////////////////////////////////////////////////////////////////
@@ -184,12 +190,6 @@ use crate::time::Duration;
 #[macro_use]
 mod local;
 
-#[stable(feature = "scoped_threads", since = "1.63.0")]
-mod scoped;
-
-#[stable(feature = "scoped_threads", since = "1.63.0")]
-pub use scoped::{scope, Scope, ScopedJoinHandle};
-
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::local::{AccessError, LocalKey};
 
@@ -209,7 +209,6 @@ pub use self::local::{AccessError, LocalKey};
 ))]
 #[doc(hidden)]
 pub use self::local::fast::Key as __FastLocalKeyInner;
-
 // when building for tests, use real std's type
 #[unstable(feature = "libstd_thread_internals", issue = "none")]
 #[cfg(test)]
@@ -220,12 +219,21 @@ pub use self::local::fast::Key as __FastLocalKeyInner;
 pub use realstd::thread::__FastLocalKeyInner;
 
 #[unstable(feature = "libstd_thread_internals", issue = "none")]
+#[cfg(not(test))]
 #[cfg(all(
     not(target_thread_local),
     not(all(target_family = "wasm", not(target_feature = "atomics"))),
 ))]
 #[doc(hidden)]
 pub use self::local::os::Key as __OsLocalKeyInner;
+// when building for tests, use real std's type
+#[unstable(feature = "libstd_thread_internals", issue = "none")]
+#[cfg(test)]
+#[cfg(all(
+    not(target_thread_local),
+    not(all(target_family = "wasm", not(target_feature = "atomics"))),
+))]
+pub use realstd::thread::__OsLocalKeyInner;
 
 #[unstable(feature = "libstd_thread_internals", issue = "none")]
 #[cfg(all(target_family = "wasm", not(target_feature = "atomics")))]
@@ -1216,7 +1224,7 @@ impl Thread {
             let ptr = Arc::get_mut_unchecked(&mut arc).as_mut_ptr();
             addr_of_mut!((*ptr).name).write(name);
             addr_of_mut!((*ptr).id).write(ThreadId::new());
-            Parker::new(addr_of_mut!((*ptr).parker));
+            Parker::new_in_place(addr_of_mut!((*ptr).parker));
             Pin::new_unchecked(arc.assume_init())
         };