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Remove critical sections from PeripheralMutex interrupt handler by checking the interrupt's priority on startup.

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Since `PeripheralMutex` is the only way to safely maintain state across interrupts, and it no longer allows setting the interrupt's priority, the priority changing isn't a concern.

This also prevents other causes of UB due to the interrupt being exposed during `with`, and allowing enabling the interrupt and setting its context to a bogus pointer.
This commit is contained in:
Liam Murphy
2021-07-27 17:28:52 +10:00
parent 1b7ad7080e
commit 079526559f
5 changed files with 187 additions and 48 deletions
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20
embassy-nrf/src/buffered_uarte.rs
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@ -176,7 +176,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> BufferedUarte<'d, U, T> {
pub fn set_baudrate(self: Pin<&mut Self>, baudrate: Baudrate) {
let mut inner = self.inner();
inner.as_mut().register_interrupt();
inner.with(|state, _irq| {
inner.with(|state| {
let r = U::regs();
let timeout = 0x8000_0000 / (baudrate as u32 / 40);
@ -196,7 +196,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> AsyncBufRead for BufferedUarte<'d,
fn poll_fill_buf(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Result<&[u8]>> {
let mut inner = self.inner();
inner.as_mut().register_interrupt();
inner.with(|state, _irq| {
inner.with(|state| {
// Conservative compiler fence to prevent optimizations that do not
// take in to account actions by DMA. The fence has been placed here,
// before any DMA action has started
@ -221,11 +221,11 @@ impl<'d, U: UarteInstance, T: TimerInstance> AsyncBufRead for BufferedUarte<'d,
fn consume(self: Pin<&mut Self>, amt: usize) {
let mut inner = self.inner();
inner.as_mut().register_interrupt();
inner.with(|state, irq| {
inner.as_mut().with(|state| {
trace!("consume {:?}", amt);
state.rx.pop(amt);
irq.pend();
})
});
inner.pend();
}
}
@ -233,7 +233,7 @@ impl<'d, U: UarteInstance, T: TimerInstance> AsyncWrite for BufferedUarte<'d, U,
fn poll_write(self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8]) -> Poll<Result<usize>> {
let mut inner = self.inner();
inner.as_mut().register_interrupt();
inner.with(|state, irq| {
let poll = inner.as_mut().with(|state| {
trace!("poll_write: {:?}", buf.len());
let tx_buf = state.tx.push_buf();
@ -254,10 +254,12 @@ impl<'d, U: UarteInstance, T: TimerInstance> AsyncWrite for BufferedUarte<'d, U,
// before any DMA action has started
compiler_fence(Ordering::SeqCst);
irq.pend();
Poll::Ready(Ok(n))
})
});
inner.pend();
poll
}
}