diff --git a/library/std/src/io/stdio.rs b/library/std/src/io/stdio.rs
index 2d80fe49e80a7..3686b6673cc0f 100644
--- a/library/std/src/io/stdio.rs
+++ b/library/std/src/io/stdio.rs
@@ -12,11 +12,14 @@ use crate::io::{
 };
 use crate::panic::{RefUnwindSafe, UnwindSafe};
 use crate::sync::atomic::{Atomic, AtomicBool, Ordering};
-use crate::sync::{Arc, Mutex, MutexGuard, OnceLock, ReentrantLock, ReentrantLockGuard};
+use crate::sync::nonpoison::{Mutex, MutexGuard};
+use crate::sync::{Arc, OnceLock, ReentrantLock, ReentrantLockGuard, poison};
 use crate::sys::stdio;
 use crate::thread::AccessError;
 
-type LocalStream = Arc<Mutex<Vec<u8>>>;
+// This is explicitly using poisoning, as that affects what gets captured.
+// FIXME: maybe change this to a non-poisoning mutex regardless?
+type LocalStream = Arc<poison::Mutex<Vec<u8>>>;
 
 thread_local! {
     /// Used by the test crate to capture the output of the print macros and panics.
@@ -372,7 +375,7 @@ impl Stdin {
     pub fn lock(&self) -> StdinLock<'static> {
         // Locks this handle with 'static lifetime. This depends on the
         // implementation detail that the underlying `Mutex` is static.
-        StdinLock { inner: self.inner.lock().unwrap_or_else(|e| e.into_inner()) }
+        StdinLock { inner: self.inner.lock() }
     }
 
     /// Locks this handle and reads a line of input, appending it to the specified buffer.
@@ -434,6 +437,12 @@ impl Stdin {
     }
 }
 
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl UnwindSafe for Stdin {}
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl RefUnwindSafe for Stdin {}
+
 #[stable(feature = "std_debug", since = "1.16.0")]
 impl fmt::Debug for Stdin {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
@@ -507,6 +516,12 @@ impl StdinLock<'_> {
     }
 }
 
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl UnwindSafe for StdinLock<'_> {}
+
+#[stable(feature = "catch_unwind", since = "1.9.0")]
+impl RefUnwindSafe for StdinLock<'_> {}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl Read for StdinLock<'_> {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
diff --git a/library/std/src/io/stdio/tests.rs b/library/std/src/io/stdio/tests.rs
index e68d8c29fbce2..58f04720961eb 100644
--- a/library/std/src/io/stdio/tests.rs
+++ b/library/std/src/io/stdio/tests.rs
@@ -122,21 +122,21 @@ where
     let th1 = {
         let (log, tx) = (Arc::clone(&log), tx1);
         thread::spawn(move || {
-            log.lock().unwrap().push(Start1);
+            log.lock().push(Start1);
             let handle = get_handle();
             {
                 let locked = handle.lock();
-                log.lock().unwrap().push(Acquire1);
+                log.lock().push(Acquire1);
                 tx.send(Acquire1).unwrap(); // notify of acquisition
                 tx.send(Release1).unwrap(); // wait for release command
-                log.lock().unwrap().push(Release1);
+                log.lock().push(Release1);
             }
             tx.send(Acquire1).unwrap(); // wait for th2 acquire
             {
                 let locked = handle.lock();
-                log.lock().unwrap().push(Acquire1);
+                log.lock().push(Acquire1);
             }
-            log.lock().unwrap().push(Release1);
+            log.lock().push(Release1);
         })
     };
     let th2 = {
@@ -144,14 +144,14 @@ where
         thread::spawn(move || {
             tx.send(Start2).unwrap(); // wait for start command
             let locked = get_locked();
-            log.lock().unwrap().push(Acquire2);
+            log.lock().push(Acquire2);
             tx.send(Acquire2).unwrap(); // notify of acquisition
             tx.send(Release2).unwrap(); // wait for release command
-            log.lock().unwrap().push(Release2);
+            log.lock().push(Release2);
         })
     };
     assert_eq!(rx1.recv().unwrap(), Acquire1); // wait for th1 acquire
-    log.lock().unwrap().push(Start2);
+    log.lock().push(Start2);
     assert_eq!(rx2.recv().unwrap(), Start2); // block th2
     assert_eq!(rx1.recv().unwrap(), Release1); // release th1
     assert_eq!(rx2.recv().unwrap(), Acquire2); // wait for th2 acquire
@@ -160,7 +160,7 @@ where
     th2.join().unwrap();
     th1.join().unwrap();
     assert_eq!(
-        *log.lock().unwrap(),
+        *log.lock(),
         [Start1, Acquire1, Start2, Release1, Acquire2, Release2, Acquire1, Release1]
     );
 }
diff --git a/library/std/src/sync/mpmc/waker.rs b/library/std/src/sync/mpmc/waker.rs
index 4216fb7ac5902..219263b84bb03 100644
--- a/library/std/src/sync/mpmc/waker.rs
+++ b/library/std/src/sync/mpmc/waker.rs
@@ -3,8 +3,8 @@
 use super::context::Context;
 use super::select::{Operation, Selected};
 use crate::ptr;
-use crate::sync::Mutex;
 use crate::sync::atomic::{Atomic, AtomicBool, Ordering};
+use crate::sync::nonpoison::Mutex;
 
 /// Represents a thread blocked on a specific channel operation.
 pub(crate) struct Entry {
@@ -150,7 +150,7 @@ impl SyncWaker {
     /// Registers the current thread with an operation.
     #[inline]
     pub(crate) fn register(&self, oper: Operation, cx: &Context) {
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.lock();
         inner.register(oper, cx);
         self.is_empty
             .store(inner.selectors.is_empty() && inner.observers.is_empty(), Ordering::SeqCst);
@@ -159,7 +159,7 @@ impl SyncWaker {
     /// Unregisters an operation previously registered by the current thread.
     #[inline]
     pub(crate) fn unregister(&self, oper: Operation) -> Option<Entry> {
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.lock();
         let entry = inner.unregister(oper);
         self.is_empty
             .store(inner.selectors.is_empty() && inner.observers.is_empty(), Ordering::SeqCst);
@@ -170,7 +170,7 @@ impl SyncWaker {
     #[inline]
     pub(crate) fn notify(&self) {
         if !self.is_empty.load(Ordering::SeqCst) {
-            let mut inner = self.inner.lock().unwrap();
+            let mut inner = self.inner.lock();
             if !self.is_empty.load(Ordering::SeqCst) {
                 inner.try_select();
                 inner.notify();
@@ -185,7 +185,7 @@ impl SyncWaker {
     /// Notifies all threads that the channel is disconnected.
     #[inline]
     pub(crate) fn disconnect(&self) {
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.lock();
         inner.disconnect();
         self.is_empty
             .store(inner.selectors.is_empty() && inner.observers.is_empty(), Ordering::SeqCst);
diff --git a/library/std/src/sync/mpmc/zero.rs b/library/std/src/sync/mpmc/zero.rs
index f1ecf80fcb9f6..383961801a725 100644
--- a/library/std/src/sync/mpmc/zero.rs
+++ b/library/std/src/sync/mpmc/zero.rs
@@ -9,8 +9,8 @@ use super::utils::Backoff;
 use super::waker::Waker;
 use crate::cell::UnsafeCell;
 use crate::marker::PhantomData;
-use crate::sync::Mutex;
 use crate::sync::atomic::{Atomic, AtomicBool, Ordering};
+use crate::sync::nonpoison::Mutex;
 use crate::time::Instant;
 use crate::{fmt, ptr};
 
@@ -141,7 +141,7 @@ impl<T> Channel<T> {
     /// Attempts to send a message into the channel.
     pub(crate) fn try_send(&self, msg: T) -> Result<(), TrySendError<T>> {
         let token = &mut Token::default();
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.lock();
 
         // If there's a waiting receiver, pair up with it.
         if let Some(operation) = inner.receivers.try_select() {
@@ -165,7 +165,7 @@ impl<T> Channel<T> {
         deadline: Option<Instant>,
     ) -> Result<(), SendTimeoutError<T>> {
         let token = &mut Token::default();
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.lock();
 
         // If there's a waiting receiver, pair up with it.
         if let Some(operation) = inner.receivers.try_select() {
@@ -196,12 +196,12 @@ impl<T> Channel<T> {
             match sel {
                 Selected::Waiting => unreachable!(),
                 Selected::Aborted => {
-                    self.inner.lock().unwrap().senders.unregister(oper).unwrap();
+                    self.inner.lock().senders.unregister(oper).unwrap();
                     let msg = unsafe { packet.msg.get().replace(None).unwrap() };
                     Err(SendTimeoutError::Timeout(msg))
                 }
                 Selected::Disconnected => {
-                    self.inner.lock().unwrap().senders.unregister(oper).unwrap();
+                    self.inner.lock().senders.unregister(oper).unwrap();
                     let msg = unsafe { packet.msg.get().replace(None).unwrap() };
                     Err(SendTimeoutError::Disconnected(msg))
                 }
@@ -217,7 +217,7 @@ impl<T> Channel<T> {
     /// Attempts to receive a message without blocking.
     pub(crate) fn try_recv(&self) -> Result<T, TryRecvError> {
         let token = &mut Token::default();
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.lock();
 
         // If there's a waiting sender, pair up with it.
         if let Some(operation) = inner.senders.try_select() {
@@ -234,7 +234,7 @@ impl<T> Channel<T> {
     /// Receives a message from the channel.
     pub(crate) fn recv(&self, deadline: Option<Instant>) -> Result<T, RecvTimeoutError> {
         let token = &mut Token::default();
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.lock();
 
         // If there's a waiting sender, pair up with it.
         if let Some(operation) = inner.senders.try_select() {
@@ -264,11 +264,11 @@ impl<T> Channel<T> {
             match sel {
                 Selected::Waiting => unreachable!(),
                 Selected::Aborted => {
-                    self.inner.lock().unwrap().receivers.unregister(oper).unwrap();
+                    self.inner.lock().receivers.unregister(oper).unwrap();
                     Err(RecvTimeoutError::Timeout)
                 }
                 Selected::Disconnected => {
-                    self.inner.lock().unwrap().receivers.unregister(oper).unwrap();
+                    self.inner.lock().receivers.unregister(oper).unwrap();
                     Err(RecvTimeoutError::Disconnected)
                 }
                 Selected::Operation(_) => {
@@ -284,7 +284,7 @@ impl<T> Channel<T> {
     ///
     /// Returns `true` if this call disconnected the channel.
     pub(crate) fn disconnect(&self) -> bool {
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.lock();
 
         if !inner.is_disconnected {
             inner.is_disconnected = true;
diff --git a/library/std/src/sys/backtrace.rs b/library/std/src/sys/backtrace.rs
index 57682207e078e..e5084c15b80ca 100644
--- a/library/std/src/sys/backtrace.rs
+++ b/library/std/src/sys/backtrace.rs
@@ -5,7 +5,7 @@ use crate::backtrace_rs::{self, BacktraceFmt, BytesOrWideString, PrintFmt};
 use crate::borrow::Cow;
 use crate::io::prelude::*;
 use crate::path::{self, Path, PathBuf};
-use crate::sync::{Mutex, MutexGuard, PoisonError};
+use crate::sync::nonpoison::{Mutex, MutexGuard};
 use crate::{env, fmt, io};
 
 /// Max number of frames to print.
@@ -15,7 +15,7 @@ pub(crate) struct BacktraceLock<'a>(#[allow(dead_code)] MutexGuard<'a, ()>);
 
 pub(crate) fn lock<'a>() -> BacktraceLock<'a> {
     static LOCK: Mutex<()> = Mutex::new(());
-    BacktraceLock(LOCK.lock().unwrap_or_else(PoisonError::into_inner))
+    BacktraceLock(LOCK.lock())
 }
 
 impl BacktraceLock<'_> {
diff --git a/library/std/src/sys/env/hermit.rs b/library/std/src/sys/env/hermit.rs
index 445ecdeb6a39f..488f194a0aec4 100644
--- a/library/std/src/sys/env/hermit.rs
+++ b/library/std/src/sys/env/hermit.rs
@@ -5,12 +5,12 @@ use crate::collections::HashMap;
 use crate::ffi::{CStr, OsStr, OsString, c_char};
 use crate::io;
 use crate::os::hermit::ffi::OsStringExt;
-use crate::sync::Mutex;
+use crate::sync::nonpoison::Mutex;
 
 static ENV: Mutex<Option<HashMap<OsString, OsString>>> = Mutex::new(None);
 
 pub fn init(env: *const *const c_char) {
-    let mut guard = ENV.lock().unwrap();
+    let mut guard = ENV.lock();
     let map = guard.insert(HashMap::new());
 
     if env.is_null() {
@@ -48,7 +48,7 @@ pub fn init(env: *const *const c_char) {
 /// Returns a vector of (variable, value) byte-vector pairs for all the
 /// environment variables of the current process.
 pub fn env() -> Env {
-    let guard = ENV.lock().unwrap();
+    let guard = ENV.lock();
     let env = guard.as_ref().unwrap();
 
     let result = env.iter().map(|(key, value)| (key.clone(), value.clone())).collect();
@@ -57,16 +57,16 @@ pub fn env() -> Env {
 }
 
 pub fn getenv(k: &OsStr) -> Option<OsString> {
-    ENV.lock().unwrap().as_ref().unwrap().get(k).cloned()
+    ENV.lock().as_ref().unwrap().get(k).cloned()
 }
 
 pub unsafe fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {
     let (k, v) = (k.to_owned(), v.to_owned());
-    ENV.lock().unwrap().as_mut().unwrap().insert(k, v);
+    ENV.lock().as_mut().unwrap().insert(k, v);
     Ok(())
 }
 
 pub unsafe fn unsetenv(k: &OsStr) -> io::Result<()> {
-    ENV.lock().unwrap().as_mut().unwrap().remove(k);
+    ENV.lock().as_mut().unwrap().remove(k);
     Ok(())
 }
diff --git a/library/std/src/sys/pal/unix/stack_overflow/thread_info.rs b/library/std/src/sys/pal/unix/stack_overflow/thread_info.rs
index e81429b98a6c7..2a8878c569184 100644
--- a/library/std/src/sys/pal/unix/stack_overflow/thread_info.rs
+++ b/library/std/src/sys/pal/unix/stack_overflow/thread_info.rs
@@ -27,8 +27,8 @@
 use crate::collections::BTreeMap;
 use crate::hint::spin_loop;
 use crate::ops::Range;
-use crate::sync::Mutex;
 use crate::sync::atomic::{AtomicUsize, Ordering};
+use crate::sync::nonpoison::Mutex;
 use crate::sys::os::errno_location;
 
 pub struct ThreadInfo {
diff --git a/library/std/src/sys/process/windows.rs b/library/std/src/sys/process/windows.rs
index 7d58093c54bbf..3c79283c12ceb 100644
--- a/library/std/src/sys/process/windows.rs
+++ b/library/std/src/sys/process/windows.rs
@@ -16,7 +16,7 @@ use crate::os::windows::io::{AsHandle, AsRawHandle, BorrowedHandle, FromRawHandl
 use crate::os::windows::process::ProcThreadAttributeList;
 use crate::path::{Path, PathBuf};
 use crate::process::StdioPipes;
-use crate::sync::Mutex;
+use crate::sync::nonpoison::Mutex;
 use crate::sys::args::{self, Arg};
 use crate::sys::c::{self, EXIT_FAILURE, EXIT_SUCCESS};
 use crate::sys::fs::{File, OpenOptions};
diff --git a/library/std/src/sys/thread/sgx.rs b/library/std/src/sys/thread/sgx.rs
index f20ef7d86b9c7..c0fb33e0edef8 100644
--- a/library/std/src/sys/thread/sgx.rs
+++ b/library/std/src/sys/thread/sgx.rs
@@ -12,7 +12,7 @@ pub use self::task_queue::JoinNotifier;
 
 mod task_queue {
     use super::wait_notify;
-    use crate::sync::{Mutex, MutexGuard};
+    use crate::sync::nonpoison::{Mutex, MutexGuard};
 
     pub type JoinHandle = wait_notify::Waiter;
 
@@ -48,7 +48,7 @@ mod task_queue {
     static TASK_QUEUE: Mutex<Vec<Task>> = Mutex::new(Vec::new());
 
     pub(super) fn lock() -> MutexGuard<'static, Vec<Task>> {
-        TASK_QUEUE.lock().unwrap()
+        TASK_QUEUE.lock()
     }
 }
 
diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index 16313da8e178c..89a828181e960 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -1257,11 +1257,11 @@ impl ThreadId {
                 }
             }
             _ => {
-                use crate::sync::{Mutex, PoisonError};
+                use crate::sync::nonpoison::Mutex;
 
                 static COUNTER: Mutex<u64> = Mutex::new(0);
 
-                let mut counter = COUNTER.lock().unwrap_or_else(PoisonError::into_inner);
+                let mut counter = COUNTER.lock();
                 let Some(id) = counter.checked_add(1) else {
                     // in case the panic handler ends up calling `ThreadId::new()`,
                     // avoid reentrant lock acquire.