diff options
| -rw-r--r-- | rust/kernel/lib.rs | 1 | ||||
| -rw-r--r-- | rust/kernel/sync/arc.rs | 16 |
2 files changed, 13 insertions, 4 deletions
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 821bd067151c..2d7606135ef6 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -28,7 +28,6 @@ #[cfg(not(CONFIG_RUST))] compile_error!("Missing kernel configuration for conditional compilation"); -#[allow(unused_extern_crates)] // Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate). extern crate self as kernel; diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs index b45769a29541..de36d55e81d8 100644 --- a/rust/kernel/sync/arc.rs +++ b/rust/kernel/sync/arc.rs @@ -18,7 +18,8 @@ use crate::{ bindings, error::{self, Error}, - init::{InPlaceInit, Init, PinInit}, + init::{self, InPlaceInit, Init, PinInit}, + try_init, types::{ForeignOwnable, Opaque}, }; use alloc::boxed::Box; @@ -31,6 +32,7 @@ use core::{ pin::Pin, ptr::NonNull, }; +use macros::pin_data; mod std_vendor; @@ -125,6 +127,7 @@ pub struct Arc<T: ?Sized> { _p: PhantomData<ArcInner<T>>, } +#[pin_data] #[repr(C)] struct ArcInner<T: ?Sized> { refcount: Opaque<bindings::refcount_t>, @@ -505,9 +508,16 @@ impl<T> UniqueArc<T> { /// Tries to allocate a new [`UniqueArc`] instance whose contents are not initialised yet. pub fn try_new_uninit() -> Result<UniqueArc<MaybeUninit<T>>, AllocError> { - Ok(UniqueArc::<MaybeUninit<T>> { + // INVARIANT: The refcount is initialised to a non-zero value. + let inner = Box::try_init::<AllocError>(try_init!(ArcInner { + // SAFETY: There are no safety requirements for this FFI call. + refcount: Opaque::new(unsafe { bindings::REFCOUNT_INIT(1) }), + data <- init::uninit::<T, AllocError>(), + }? AllocError))?; + Ok(UniqueArc { // INVARIANT: The newly-created object has a ref-count of 1. - inner: Arc::try_new(MaybeUninit::uninit())?, + // SAFETY: The pointer from the `Box` is valid. + inner: unsafe { Arc::from_inner(Box::leak(inner).into()) }, }) } } |