From e8474426d8c0ca60ac222845b9c6f7befe3f6a4a Mon Sep 17 00:00:00 2001
From: Dario Nieuwenhuis <dirbaio@dirbaio.net>
Date: Tue, 20 Feb 2024 01:02:15 +0100
Subject: hal-internal: remove impl DerefMut for PeripheralRef.

if you have `PeripheralRef<'a, AnyPIn>` for pin A, and `AnyPin` (owned) for pin B, you can `mem::swap` them.
so, getting access forever to pin A, just by "sacrificing" pin B

this defeats the point of PeripheralRef, which is if you got a `PeripheralRef<'a, T>` then you're only allowed to use the peripheral for `'a`.

Also some drivers rely on the fact only one instance of a singleton exists for soundness, so this is a soundness fix for those.
---
 embassy-hal-internal/src/peripheral.rs | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

(limited to 'embassy-hal-internal/src')

diff --git a/embassy-hal-internal/src/peripheral.rs b/embassy-hal-internal/src/peripheral.rs
index 16d49edfb..f03f41507 100644
--- a/embassy-hal-internal/src/peripheral.rs
+++ b/embassy-hal-internal/src/peripheral.rs
@@ -1,5 +1,5 @@
 use core::marker::PhantomData;
-use core::ops::{Deref, DerefMut};
+use core::ops::Deref;
 
 /// An exclusive reference to a peripheral.
 ///
@@ -86,13 +86,6 @@ impl<'a, T> Deref for PeripheralRef<'a, T> {
     }
 }
 
-impl<'a, T> DerefMut for PeripheralRef<'a, T> {
-    #[inline]
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        &mut self.inner
-    }
-}
-
 /// Trait for any type that can be used as a peripheral of type `P`.
 ///
 /// This is used in driver constructors, to allow passing either owned peripherals (e.g. `TWISPI0`),
@@ -162,7 +155,7 @@ pub trait Peripheral: Sized {
     }
 }
 
-impl<'b, T: DerefMut> Peripheral for T
+impl<'b, T: Deref> Peripheral for T
 where
     T::Target: Peripheral,
 {
-- 
cgit 


From 1f17fdf84ee30f989a1a5bd8945a76a9f5edac4b Mon Sep 17 00:00:00 2001
From: Dario Nieuwenhuis <dirbaio@dirbaio.net>
Date: Wed, 21 Feb 2024 21:51:43 +0100
Subject: nrf/buffered_uart: refactor so rx/tx halves are independent.

---
 embassy-hal-internal/src/atomic_ring_buffer.rs | 33 +++++++++++++++++++++++---
 1 file changed, 30 insertions(+), 3 deletions(-)

(limited to 'embassy-hal-internal/src')

diff --git a/embassy-hal-internal/src/atomic_ring_buffer.rs b/embassy-hal-internal/src/atomic_ring_buffer.rs
index b4f2cec28..34ceac852 100644
--- a/embassy-hal-internal/src/atomic_ring_buffer.rs
+++ b/embassy-hal-internal/src/atomic_ring_buffer.rs
@@ -1,6 +1,6 @@
 //! Atomic reusable ringbuffer.
-use core::slice;
 use core::sync::atomic::{AtomicPtr, AtomicUsize, Ordering};
+use core::{ptr, slice};
 
 /// Atomic reusable ringbuffer
 ///
@@ -73,6 +73,7 @@ impl RingBuffer {
     pub unsafe fn deinit(&self) {
         // Ordering: it's OK to use `Relaxed` because this is not called
         // concurrently with other methods.
+        self.buf.store(ptr::null_mut(), Ordering::Relaxed);
         self.len.store(0, Ordering::Relaxed);
         self.start.store(0, Ordering::Relaxed);
         self.end.store(0, Ordering::Relaxed);
@@ -82,20 +83,46 @@ impl RingBuffer {
     ///
     /// # Safety
     ///
-    /// Only one reader can exist at a time.
+    /// - Only one reader can exist at a time.
+    /// - Ringbuffer must be initialized.
     pub unsafe fn reader(&self) -> Reader<'_> {
         Reader(self)
     }
 
+    /// Try creating a reader, fails if not initialized.
+    ///
+    /// # Safety
+    ///
+    /// Only one reader can exist at a time.
+    pub unsafe fn try_reader(&self) -> Option<Reader<'_>> {
+        if self.buf.load(Ordering::Relaxed).is_null() {
+            return None;
+        }
+        Some(Reader(self))
+    }
+
     /// Create a writer.
     ///
     /// # Safety
     ///
-    /// Only one writer can exist at a time.
+    /// - Only one writer can exist at a time.
+    /// - Ringbuffer must be initialized.
     pub unsafe fn writer(&self) -> Writer<'_> {
         Writer(self)
     }
 
+    /// Try creating a writer, fails if not initialized.
+    ///
+    /// # Safety
+    ///
+    /// Only one writer can exist at a time.
+    pub unsafe fn try_writer(&self) -> Option<Writer<'_>> {
+        if self.buf.load(Ordering::Relaxed).is_null() {
+            return None;
+        }
+        Some(Writer(self))
+    }
+
     /// Return length of buffer.
     pub fn len(&self) -> usize {
         self.len.load(Ordering::Relaxed)
-- 
cgit