It is slightly more convenient to operate on mut pointers, and this also
properly conveys the desired ownership semantics of the trait.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
---
rust/kernel/alloc/kbox.rs | 16 ++++++++--------
rust/kernel/miscdevice.rs | 2 +-
rust/kernel/sync/arc.rs | 10 +++++-----
rust/kernel/types.rs | 14 +++++++-------
4 files changed, 21 insertions(+), 21 deletions(-)
diff --git a/rust/kernel/alloc/kbox.rs b/rust/kernel/alloc/kbox.rs
index 3f0b04609bd487e3f50247f9f1abd5394b749c7e..e00c14053efbfb08d053e0f0b11247fa25d9d516 100644
--- a/rust/kernel/alloc/kbox.rs
+++ b/rust/kernel/alloc/kbox.rs
@@ -355,17 +355,17 @@ impl<T: 'static, A> ForeignOwnable for Box<T, A>
{
type Borrowed<'a> = &'a T;
- fn into_foreign(self) -> *const crate::ffi::c_void {
+ fn into_foreign(self) -> *mut crate::ffi::c_void {
Box::into_raw(self).cast()
}
- unsafe fn from_foreign(ptr: *const crate::ffi::c_void) -> Self {
+ unsafe fn from_foreign(ptr: *mut crate::ffi::c_void) -> Self {
// SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
// call to `Self::into_foreign`.
- unsafe { Box::from_raw(ptr.cast_mut().cast()) }
+ unsafe { Box::from_raw(ptr.cast()) }
}
- unsafe fn borrow<'a>(ptr: *const crate::ffi::c_void) -> &'a T {
+ unsafe fn borrow<'a>(ptr: *mut crate::ffi::c_void) -> &'a T {
// SAFETY: The safety requirements of this method ensure that the object remains alive and
// immutable for the duration of 'a.
unsafe { &*ptr.cast() }
@@ -378,18 +378,18 @@ impl<T: 'static, A> ForeignOwnable for Pin<Box<T, A>>
{
type Borrowed<'a> = Pin<&'a T>;
- fn into_foreign(self) -> *const crate::ffi::c_void {
+ fn into_foreign(self) -> *mut crate::ffi::c_void {
// SAFETY: We are still treating the box as pinned.
Box::into_raw(unsafe { Pin::into_inner_unchecked(self) }).cast()
}
- unsafe fn from_foreign(ptr: *const crate::ffi::c_void) -> Self {
+ unsafe fn from_foreign(ptr: *mut crate::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.cast_mut().cast())) }
+ unsafe { Pin::new_unchecked(Box::from_raw(ptr.cast())) }
}
- unsafe fn borrow<'a>(ptr: *const crate::ffi::c_void) -> Pin<&'a T> {
+ unsafe fn borrow<'a>(ptr: *mut crate::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
diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs
index 7e2a79b3ae263659b7e0781c05cb130d10c8accb..e58807ad28dc644fa384e9c1fb41fd6e53abea7a 100644
--- a/rust/kernel/miscdevice.rs
+++ b/rust/kernel/miscdevice.rs
@@ -193,7 +193,7 @@ impl<T: MiscDevice> VtableHelper<T> {
};
// SAFETY: The open call of a file owns the private data.
- unsafe { (*file).private_data = ptr.into_foreign().cast_mut() };
+ unsafe { (*file).private_data = ptr.into_foreign() };
0
}
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index a11f267ce5d40b987f1f3c459271e5317ea0bae8..01d85da799d77127fc99a9b270b8a7b1ef435b6f 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -333,24 +333,24 @@ pub fn into_unique_or_drop(self) -> Option<Pin<UniqueArc<T>>> {
impl<T: 'static> ForeignOwnable for Arc<T> {
type Borrowed<'a> = ArcBorrow<'a, T>;
- fn into_foreign(self) -> *const crate::ffi::c_void {
+ fn into_foreign(self) -> *mut crate::ffi::c_void {
ManuallyDrop::new(self).ptr.as_ptr().cast()
}
- unsafe fn borrow<'a>(ptr: *const crate::ffi::c_void) -> ArcBorrow<'a, T> {
+ unsafe fn borrow<'a>(ptr: *mut crate::ffi::c_void) -> ArcBorrow<'a, T> {
// SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
// call to `Self::into_foreign`.
- let inner = unsafe { NonNull::new_unchecked(ptr.cast_mut().cast::<ArcInner<T>>()) };
+ let inner = unsafe { NonNull::new_unchecked(ptr.cast::<ArcInner<T>>()) };
// SAFETY: The safety requirements of `from_foreign` ensure that the object remains alive
// for the lifetime of the returned value.
unsafe { ArcBorrow::new(inner) }
}
- unsafe fn from_foreign(ptr: *const crate::ffi::c_void) -> Self {
+ unsafe fn from_foreign(ptr: *mut crate::ffi::c_void) -> Self {
// SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
// call to `Self::into_foreign`.
- let inner = unsafe { NonNull::new_unchecked(ptr.cast_mut().cast::<ArcInner<T>>()) };
+ let inner = unsafe { NonNull::new_unchecked(ptr.cast::<ArcInner<T>>()) };
// SAFETY: By the safety requirement of this function, we know that `ptr` came from
// a previous call to `Arc::into_foreign`, which guarantees that `ptr` is valid and
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index 318d2140470a90568100f86fd8c6d8084031f556..f9b398ee31fd5303f0224995f51d314a0c4ecbf2 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -29,7 +29,7 @@ pub trait ForeignOwnable: Sized {
/// For example, it might be invalid, dangling or pointing to uninitialized memory. Using it in
/// any way except for [`ForeignOwnable::from_foreign`], [`ForeignOwnable::borrow`],
/// [`ForeignOwnable::try_from_foreign`] can result in undefined behavior.
- fn into_foreign(self) -> *const crate::ffi::c_void;
+ fn into_foreign(self) -> *mut crate::ffi::c_void;
/// Borrows a foreign-owned object.
///
@@ -37,7 +37,7 @@ pub trait ForeignOwnable: Sized {
///
/// `ptr` must have been returned by a previous call to [`ForeignOwnable::into_foreign`] for
/// which a previous matching [`ForeignOwnable::from_foreign`] hasn't been called yet.
- unsafe fn borrow<'a>(ptr: *const crate::ffi::c_void) -> Self::Borrowed<'a>;
+ unsafe fn borrow<'a>(ptr: *mut crate::ffi::c_void) -> Self::Borrowed<'a>;
/// Converts a foreign-owned object back to a Rust-owned one.
///
@@ -47,7 +47,7 @@ pub trait ForeignOwnable: Sized {
/// which a previous matching [`ForeignOwnable::from_foreign`] hasn't been called yet.
/// Additionally, all instances (if any) of values returned by [`ForeignOwnable::borrow`] for
/// this object must have been dropped.
- unsafe fn from_foreign(ptr: *const crate::ffi::c_void) -> Self;
+ unsafe fn from_foreign(ptr: *mut crate::ffi::c_void) -> Self;
/// Tries to convert a foreign-owned object back to a Rust-owned one.
///
@@ -58,7 +58,7 @@ pub trait ForeignOwnable: Sized {
///
/// `ptr` must either be null or satisfy the safety requirements for
/// [`ForeignOwnable::from_foreign`].
- unsafe fn try_from_foreign(ptr: *const crate::ffi::c_void) -> Option<Self> {
+ unsafe fn try_from_foreign(ptr: *mut crate::ffi::c_void) -> Option<Self> {
if ptr.is_null() {
None
} else {
@@ -72,13 +72,13 @@ unsafe fn try_from_foreign(ptr: *const crate::ffi::c_void) -> Option<Self> {
impl ForeignOwnable for () {
type Borrowed<'a> = ();
- fn into_foreign(self) -> *const crate::ffi::c_void {
+ fn into_foreign(self) -> *mut crate::ffi::c_void {
core::ptr::NonNull::dangling().as_ptr()
}
- unsafe fn borrow<'a>(_: *const crate::ffi::c_void) -> Self::Borrowed<'a> {}
+ unsafe fn borrow<'a>(_: *mut crate::ffi::c_void) -> Self::Borrowed<'a> {}
- unsafe fn from_foreign(_: *const crate::ffi::c_void) -> Self {}
+ unsafe fn from_foreign(_: *mut crate::ffi::c_void) -> Self {}
}
/// Runs a cleanup function/closure when dropped.
--
2.47.0On 20.11.2024 12:46, Tamir Duberstein wrote:
> It is slightly more convenient to operate on mut pointers, and this also
> properly conveys the desired ownership semantics of the trait.
>
> Reviewed-by: Alice Ryhl <aliceryhl@google.com>
> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
> Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
> ---
> rust/kernel/alloc/kbox.rs | 16 ++++++++--------
> rust/kernel/miscdevice.rs | 2 +-
> rust/kernel/sync/arc.rs | 10 +++++-----
> rust/kernel/types.rs | 14 +++++++-------
> 4 files changed, 21 insertions(+), 21 deletions(-)
>
> diff --git a/rust/kernel/alloc/kbox.rs b/rust/kernel/alloc/kbox.rs
> index 3f0b04609bd487e3f50247f9f1abd5394b749c7e..e00c14053efbfb08d053e0f0b11247fa25d9d516 100644
> --- a/rust/kernel/alloc/kbox.rs
> +++ b/rust/kernel/alloc/kbox.rs
> @@ -355,17 +355,17 @@ impl<T: 'static, A> ForeignOwnable for Box<T, A>
> {
> type Borrowed<'a> = &'a T;
>
> - fn into_foreign(self) -> *const crate::ffi::c_void {
> + fn into_foreign(self) -> *mut crate::ffi::c_void {
> Box::into_raw(self).cast()
> }
>
> - unsafe fn from_foreign(ptr: *const crate::ffi::c_void) -> Self {
> + unsafe fn from_foreign(ptr: *mut crate::ffi::c_void) -> Self {
> // SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
> // call to `Self::into_foreign`.
> - unsafe { Box::from_raw(ptr.cast_mut().cast()) }
> + unsafe { Box::from_raw(ptr.cast()) }
> }
>
> - unsafe fn borrow<'a>(ptr: *const crate::ffi::c_void) -> &'a T {
> + unsafe fn borrow<'a>(ptr: *mut crate::ffi::c_void) -> &'a T {
> // SAFETY: The safety requirements of this method ensure that the object remains alive and
> // immutable for the duration of 'a.
> unsafe { &*ptr.cast() }
> @@ -378,18 +378,18 @@ impl<T: 'static, A> ForeignOwnable for Pin<Box<T, A>>
> {
> type Borrowed<'a> = Pin<&'a T>;
>
> - fn into_foreign(self) -> *const crate::ffi::c_void {
> + fn into_foreign(self) -> *mut crate::ffi::c_void {
> // SAFETY: We are still treating the box as pinned.
> Box::into_raw(unsafe { Pin::into_inner_unchecked(self) }).cast()
> }
>
> - unsafe fn from_foreign(ptr: *const crate::ffi::c_void) -> Self {
> + unsafe fn from_foreign(ptr: *mut crate::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.cast_mut().cast())) }
> + unsafe { Pin::new_unchecked(Box::from_raw(ptr.cast())) }
> }
>
> - unsafe fn borrow<'a>(ptr: *const crate::ffi::c_void) -> Pin<&'a T> {
> + unsafe fn borrow<'a>(ptr: *mut crate::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
> diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs
> index 7e2a79b3ae263659b7e0781c05cb130d10c8accb..e58807ad28dc644fa384e9c1fb41fd6e53abea7a 100644
> --- a/rust/kernel/miscdevice.rs
> +++ b/rust/kernel/miscdevice.rs
> @@ -193,7 +193,7 @@ impl<T: MiscDevice> VtableHelper<T> {
> };
>
> // SAFETY: The open call of a file owns the private data.
> - unsafe { (*file).private_data = ptr.into_foreign().cast_mut() };
> + unsafe { (*file).private_data = ptr.into_foreign() };
>
> 0
> }
> diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
> index a11f267ce5d40b987f1f3c459271e5317ea0bae8..01d85da799d77127fc99a9b270b8a7b1ef435b6f 100644
> --- a/rust/kernel/sync/arc.rs
> +++ b/rust/kernel/sync/arc.rs
> @@ -333,24 +333,24 @@ pub fn into_unique_or_drop(self) -> Option<Pin<UniqueArc<T>>> {
> impl<T: 'static> ForeignOwnable for Arc<T> {
> type Borrowed<'a> = ArcBorrow<'a, T>;
>
> - fn into_foreign(self) -> *const crate::ffi::c_void {
> + fn into_foreign(self) -> *mut crate::ffi::c_void {
> ManuallyDrop::new(self).ptr.as_ptr().cast()
> }
>
> - unsafe fn borrow<'a>(ptr: *const crate::ffi::c_void) -> ArcBorrow<'a, T> {
> + unsafe fn borrow<'a>(ptr: *mut crate::ffi::c_void) -> ArcBorrow<'a, T> {
> // SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
> // call to `Self::into_foreign`.
> - let inner = unsafe { NonNull::new_unchecked(ptr.cast_mut().cast::<ArcInner<T>>()) };
> + let inner = unsafe { NonNull::new_unchecked(ptr.cast::<ArcInner<T>>()) };
>
> // SAFETY: The safety requirements of `from_foreign` ensure that the object remains alive
> // for the lifetime of the returned value.
> unsafe { ArcBorrow::new(inner) }
> }
>
> - unsafe fn from_foreign(ptr: *const crate::ffi::c_void) -> Self {
> + unsafe fn from_foreign(ptr: *mut crate::ffi::c_void) -> Self {
> // SAFETY: The safety requirements of this function ensure that `ptr` comes from a previous
> // call to `Self::into_foreign`.
> - let inner = unsafe { NonNull::new_unchecked(ptr.cast_mut().cast::<ArcInner<T>>()) };
> + let inner = unsafe { NonNull::new_unchecked(ptr.cast::<ArcInner<T>>()) };
>
> // SAFETY: By the safety requirement of this function, we know that `ptr` came from
> // a previous call to `Arc::into_foreign`, which guarantees that `ptr` is valid and
> diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
> index 318d2140470a90568100f86fd8c6d8084031f556..f9b398ee31fd5303f0224995f51d314a0c4ecbf2 100644
> --- a/rust/kernel/types.rs
> +++ b/rust/kernel/types.rs
> @@ -29,7 +29,7 @@ pub trait ForeignOwnable: Sized {
> /// For example, it might be invalid, dangling or pointing to uninitialized memory. Using it in
> /// any way except for [`ForeignOwnable::from_foreign`], [`ForeignOwnable::borrow`],
> /// [`ForeignOwnable::try_from_foreign`] can result in undefined behavior.
> - fn into_foreign(self) -> *const crate::ffi::c_void;
> + fn into_foreign(self) -> *mut crate::ffi::c_void;
>
> /// Borrows a foreign-owned object.
> ///
> @@ -37,7 +37,7 @@ pub trait ForeignOwnable: Sized {
> ///
> /// `ptr` must have been returned by a previous call to [`ForeignOwnable::into_foreign`] for
> /// which a previous matching [`ForeignOwnable::from_foreign`] hasn't been called yet.
> - unsafe fn borrow<'a>(ptr: *const crate::ffi::c_void) -> Self::Borrowed<'a>;
> + unsafe fn borrow<'a>(ptr: *mut crate::ffi::c_void) -> Self::Borrowed<'a>;
>
> /// Converts a foreign-owned object back to a Rust-owned one.
> ///
> @@ -47,7 +47,7 @@ pub trait ForeignOwnable: Sized {
> /// which a previous matching [`ForeignOwnable::from_foreign`] hasn't been called yet.
> /// Additionally, all instances (if any) of values returned by [`ForeignOwnable::borrow`] for
> /// this object must have been dropped.
> - unsafe fn from_foreign(ptr: *const crate::ffi::c_void) -> Self;
> + unsafe fn from_foreign(ptr: *mut crate::ffi::c_void) -> Self;
>
> /// Tries to convert a foreign-owned object back to a Rust-owned one.
> ///
> @@ -58,7 +58,7 @@ pub trait ForeignOwnable: Sized {
> ///
> /// `ptr` must either be null or satisfy the safety requirements for
> /// [`ForeignOwnable::from_foreign`].
> - unsafe fn try_from_foreign(ptr: *const crate::ffi::c_void) -> Option<Self> {
> + unsafe fn try_from_foreign(ptr: *mut crate::ffi::c_void) -> Option<Self> {
> if ptr.is_null() {
> None
> } else {
> @@ -72,13 +72,13 @@ unsafe fn try_from_foreign(ptr: *const crate::ffi::c_void) -> Option<Self> {
> impl ForeignOwnable for () {
> type Borrowed<'a> = ();
>
> - fn into_foreign(self) -> *const crate::ffi::c_void {
> + fn into_foreign(self) -> *mut crate::ffi::c_void {
> core::ptr::NonNull::dangling().as_ptr()
> }
>
> - unsafe fn borrow<'a>(_: *const crate::ffi::c_void) -> Self::Borrowed<'a> {}
> + unsafe fn borrow<'a>(_: *mut crate::ffi::c_void) -> Self::Borrowed<'a> {}
>
> - unsafe fn from_foreign(_: *const crate::ffi::c_void) -> Self {}
> + unsafe fn from_foreign(_: *mut crate::ffi::c_void) -> Self {}
> }
>
> /// Runs a cleanup function/closure when dropped.
>
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