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authorBenno Lossin <benno.lossin@proton.me>2023-08-14 11:47:32 +0300
committerMiguel Ojeda <ojeda@kernel.org>2023-08-21 15:31:49 +0300
commit2e704f1883f5dd2f1380944c7d969c817fcd189e (patch)
treea1fdc5b19b6b24890542983a3033093f8a450a84 /rust
parent674b1c7aed6082e1ce329bb3bcb49e7eb9913e79 (diff)
downloadlinux-2e704f1883f5dd2f1380944c7d969c817fcd189e.tar.xz
rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>`
`UnsafeCell<T>` and `T` have the same layout so if `T` is `Zeroable` then so should `UnsafeCell<T>` be. This allows using the derive macro for `Zeroable` on types that contain an `UnsafeCell<T>`. Since `Opaque<T>` contains a `MaybeUninit<T>`, all bytes zero is a valid bit pattern for that type. Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230814084602.25699-11-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'rust')
-rw-r--r--rust/kernel/init.rs8
1 files changed, 7 insertions, 1 deletions
diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index 429b485d8825..0e44b3cc2eed 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -202,11 +202,12 @@
use crate::{
error::{self, Error},
sync::UniqueArc,
- types::ScopeGuard,
+ types::{Opaque, ScopeGuard},
};
use alloc::boxed::Box;
use core::{
alloc::AllocError,
+ cell::UnsafeCell,
convert::Infallible,
marker::PhantomData,
mem::MaybeUninit,
@@ -1151,6 +1152,11 @@ impl_zeroable! {
// SAFETY: Type is allowed to take any value, including all zeros.
{<T>} MaybeUninit<T>,
+ // SAFETY: Type is allowed to take any value, including all zeros.
+ {<T>} Opaque<T>,
+
+ // SAFETY: `T: Zeroable` and `UnsafeCell` is `repr(transparent)`.
+ {<T: ?Sized + Zeroable>} UnsafeCell<T>,
// SAFETY: All zeros is equivalent to `None` (option layout optimization guarantee).
Option<NonZeroU8>, Option<NonZeroU16>, Option<NonZeroU32>, Option<NonZeroU64>,