In Rust 1.78.0, Clippy introduced the `ref_as_ptr` lint [1]:
Using `as` casts may result in silently changing mutability or type.
While this doesn't eliminate unchecked `as` conversions, it makes such conversions easier to scrutinize. It also has the slight benefit of removing a degree of freedom on which to bikeshed. Thus apply the changes and enable the lint -- no functional change intended.
Link: https://rust-lang.github.io/rust-clippy/master/index.html#ref_as_ptr [1] Suggested-by: Benno Lossin benno.lossin@proton.me Link: https://lore.kernel.org/all/D8PGG7NTWB6U.3SS3A5LN4XWMN@proton.me/ Reviewed-by: Benno Lossin benno.lossin@proton.me Reviewed-by: Boqun Feng boqun.feng@gmail.com Signed-off-by: Tamir Duberstein tamird@gmail.com --- Makefile | 1 + rust/bindings/lib.rs | 1 + rust/kernel/configfs.rs | 20 ++++++-------------- rust/kernel/device_id.rs | 2 +- rust/kernel/fs/file.rs | 2 +- rust/kernel/str.rs | 4 ++-- rust/kernel/uaccess.rs | 4 ++-- rust/uapi/lib.rs | 1 + 8 files changed, 15 insertions(+), 20 deletions(-)
diff --git a/Makefile b/Makefile index 29cf39be14de..1a855f42a34a 100644 --- a/Makefile +++ b/Makefile @@ -489,6 +489,7 @@ export rust_common_flags := --edition=2021 \ -Wclippy::no_mangle_with_rust_abi \ -Wclippy::ptr_as_ptr \ -Wclippy::ptr_cast_constness \ + -Wclippy::ref_as_ptr \ -Wclippy::undocumented_unsafe_blocks \ -Wclippy::unnecessary_safety_comment \ -Wclippy::unnecessary_safety_doc \ diff --git a/rust/bindings/lib.rs b/rust/bindings/lib.rs index 7631c9f6708d..474cc98c48a3 100644 --- a/rust/bindings/lib.rs +++ b/rust/bindings/lib.rs @@ -27,6 +27,7 @@ #[allow(dead_code)] #[allow(clippy::cast_lossless)] #[allow(clippy::ptr_as_ptr)] +#[allow(clippy::ref_as_ptr)] #[allow(clippy::undocumented_unsafe_blocks)] #[cfg_attr(CONFIG_RUSTC_HAS_UNNECESSARY_TRANSMUTES, allow(unnecessary_transmutes))] mod bindings_raw { diff --git a/rust/kernel/configfs.rs b/rust/kernel/configfs.rs index bc8e15dcec18..1ddac786bd0d 100644 --- a/rust/kernel/configfs.rs +++ b/rust/kernel/configfs.rs @@ -426,7 +426,7 @@ impl<Parent, Child> GroupOperationsVTable<Parent, Child> };
const fn vtable_ptr() -> *const bindings::configfs_group_operations { - &Self::VTABLE as *const bindings::configfs_group_operations + &Self::VTABLE } }
@@ -464,7 +464,7 @@ impl<Data> ItemOperationsVTable<Group<Data>, Data> };
const fn vtable_ptr() -> *const bindings::configfs_item_operations { - &Self::VTABLE as *const bindings::configfs_item_operations + &Self::VTABLE } }
@@ -476,7 +476,7 @@ impl<Data> ItemOperationsVTable<Subsystem<Data>, Data> { };
const fn vtable_ptr() -> *const bindings::configfs_item_operations { - &Self::VTABLE as *const bindings::configfs_item_operations + &Self::VTABLE } }
@@ -717,11 +717,7 @@ impl<const N: usize, Data> AttributeList<N, Data> {
// SAFETY: By function safety requirements, we have exclusive access to // `self` and the reference created below will be exclusive. - unsafe { - (&mut *self.0.get())[I] = (attribute as *const Attribute<ID, O, Data>) - .cast_mut() - .cast() - }; + unsafe { (&mut *self.0.get())[I] = core::ptr::from_ref(attribute).cast_mut().cast() }; } }
@@ -761,9 +757,7 @@ pub const fn new_with_child_ctor<const N: usize, Child>( ct_owner: owner.as_ptr(), ct_group_ops: GroupOperationsVTable::<Data, Child>::vtable_ptr().cast_mut(), ct_item_ops: ItemOperationsVTable::<$tpe, Data>::vtable_ptr().cast_mut(), - ct_attrs: (attributes as *const AttributeList<N, Data>) - .cast_mut() - .cast(), + ct_attrs: core::ptr::from_ref(attributes).cast_mut().cast(), ct_bin_attrs: core::ptr::null_mut(), }), _p: PhantomData, @@ -780,9 +774,7 @@ pub const fn new<const N: usize>( ct_owner: owner.as_ptr(), ct_group_ops: core::ptr::null_mut(), ct_item_ops: ItemOperationsVTable::<$tpe, Data>::vtable_ptr().cast_mut(), - ct_attrs: (attributes as *const AttributeList<N, Data>) - .cast_mut() - .cast(), + ct_attrs: core::ptr::from_ref(attributes).cast_mut().cast(), ct_bin_attrs: core::ptr::null_mut(), }), _p: PhantomData, diff --git a/rust/kernel/device_id.rs b/rust/kernel/device_id.rs index f9d55ac7b9e6..3dc72ca8cfc2 100644 --- a/rust/kernel/device_id.rs +++ b/rust/kernel/device_id.rs @@ -136,7 +136,7 @@ impl<T: RawDeviceId, U, const N: usize> IdTable<T, U> for IdArray<T, U, N> { fn as_ptr(&self) -> *const T::RawType { // This cannot be `self.ids.as_ptr()`, as the return pointer must have correct provenance // to access the sentinel. - (self as *const Self).cast() + core::ptr::from_ref(self).cast() }
fn id(&self, index: usize) -> &T::RawType { diff --git a/rust/kernel/fs/file.rs b/rust/kernel/fs/file.rs index e9bfbad00755..35fd5db35c46 100644 --- a/rust/kernel/fs/file.rs +++ b/rust/kernel/fs/file.rs @@ -366,7 +366,7 @@ fn deref(&self) -> &LocalFile { // // By the type invariants, there are no `fdget_pos` calls that did not take the // `f_pos_lock` mutex. - unsafe { LocalFile::from_raw_file((self as *const Self).cast()) } + unsafe { LocalFile::from_raw_file(core::ptr::from_ref(self).cast()) } } }
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index 43597eb7c5c1..cbc8b459ed41 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -29,7 +29,7 @@ pub const fn is_empty(&self) -> bool { #[inline] pub const fn from_bytes(bytes: &[u8]) -> &Self { // SAFETY: `BStr` is transparent to `[u8]`. - unsafe { &*(bytes as *const [u8] as *const BStr) } + unsafe { &*(core::ptr::from_ref(bytes) as *const BStr) } }
/// Strip a prefix from `self`. Delegates to [`slice::strip_prefix`]. @@ -290,7 +290,7 @@ pub const fn from_bytes_with_nul(bytes: &[u8]) -> Result<&Self, CStrConvertError #[inline] pub unsafe fn from_bytes_with_nul_unchecked_mut(bytes: &mut [u8]) -> &mut CStr { // SAFETY: Properties of `bytes` guaranteed by the safety precondition. - unsafe { &mut *(bytes as *mut [u8] as *mut CStr) } + unsafe { &mut *(core::ptr::from_mut(bytes) as *mut CStr) } }
/// Returns a C pointer to the string. diff --git a/rust/kernel/uaccess.rs b/rust/kernel/uaccess.rs index 6d70edd8086a..4ef13cf13a78 100644 --- a/rust/kernel/uaccess.rs +++ b/rust/kernel/uaccess.rs @@ -240,7 +240,7 @@ pub fn read_raw(&mut self, out: &mut [MaybeUninit<u8>]) -> Result { pub fn read_slice(&mut self, out: &mut [u8]) -> Result { // SAFETY: The types are compatible and `read_raw` doesn't write uninitialized bytes to // `out`. - let out = unsafe { &mut *(out as *mut [u8] as *mut [MaybeUninit<u8>]) }; + let out = unsafe { &mut *(core::ptr::from_mut(out) as *mut [MaybeUninit<u8>]) }; self.read_raw(out) }
@@ -355,7 +355,7 @@ pub fn write<T: AsBytes>(&mut self, value: &T) -> Result { let res = unsafe { bindings::_copy_to_user( self.ptr as *mut c_void, - (value as *const T).cast::<c_void>(), + core::ptr::from_ref(value).cast::<c_void>(), len, ) }; diff --git a/rust/uapi/lib.rs b/rust/uapi/lib.rs index 08e68ebef606..31c2f713313f 100644 --- a/rust/uapi/lib.rs +++ b/rust/uapi/lib.rs @@ -16,6 +16,7 @@ clippy::all, clippy::cast_lossless, clippy::ptr_as_ptr, + clippy::ref_as_ptr, clippy::undocumented_unsafe_blocks, dead_code, missing_docs,