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-rw-r--r--rust/kernel/types.rs27
1 files changed, 27 insertions, 0 deletions
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index bd189d646adb..132ca1113083 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -9,6 +9,7 @@ use core::{
marker::{PhantomData, PhantomPinned},
mem::MaybeUninit,
ops::{Deref, DerefMut},
+ pin::Pin,
ptr::NonNull,
};
@@ -89,6 +90,32 @@ impl<T: 'static> ForeignOwnable for Box<T> {
}
}
+impl<T: 'static> ForeignOwnable for Pin<Box<T>> {
+ type Borrowed<'a> = Pin<&'a T>;
+
+ fn into_foreign(self) -> *const core::ffi::c_void {
+ // SAFETY: We are still treating the box as pinned.
+ Box::into_raw(unsafe { Pin::into_inner_unchecked(self) }) as _
+ }
+
+ unsafe fn borrow<'a>(ptr: *const core::ffi::c_void) -> Pin<&'a T> {
+ // SAFETY: The safety requirements for this function ensure that the object is still alive,
+ // so it is safe to dereference the raw pointer.
+ // The safety requirements of `from_foreign` also ensure that the object remains alive for
+ // the lifetime of the returned value.
+ let r = unsafe { &*ptr.cast() };
+
+ // SAFETY: This pointer originates from a `Pin<Box<T>>`.
+ unsafe { Pin::new_unchecked(r) }
+ }
+
+ unsafe fn from_foreign(ptr: *const core::ffi::c_void) -> Self {
+ // SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
+ // call to `Self::into_foreign`.
+ unsafe { Pin::new_unchecked(Box::from_raw(ptr as _)) }
+ }
+}
+
impl ForeignOwnable for () {
type Borrowed<'a> = ();