From dc35ddcf97e99b18559d0855071030e664aae44d Mon Sep 17 00:00:00 2001 From: Tamir Duberstein Date: Sun, 15 Jun 2025 16:55:10 -0400 Subject: [PATCH] rust: enable `clippy::ref_as_ptr` lint 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 Link: https://lore.kernel.org/all/D8PGG7NTWB6U.3SS3A5LN4XWMN@proton.me/ Reviewed-by: Benno Lossin Reviewed-by: Boqun Feng Signed-off-by: Tamir Duberstein Acked-by: Danilo Krummrich Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-6-f43b024581e8@gmail.com Signed-off-by: Miguel Ojeda --- 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 a95000adf2613..31268acb0d22b 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 7631c9f6708d5..474cc98c48a32 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 bc8e15dcec181..1ddac786bd0dd 100644 --- a/rust/kernel/configfs.rs +++ b/rust/kernel/configfs.rs @@ -426,7 +426,7 @@ where }; const fn vtable_ptr() -> *const bindings::configfs_group_operations { - &Self::VTABLE as *const bindings::configfs_group_operations + &Self::VTABLE } } @@ -464,7 +464,7 @@ where }; const fn vtable_ptr() -> *const bindings::configfs_item_operations { - &Self::VTABLE as *const bindings::configfs_item_operations + &Self::VTABLE } } @@ -476,7 +476,7 @@ impl ItemOperationsVTable, 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 AttributeList { // 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) - .cast_mut() - .cast() - }; + unsafe { (&mut *self.0.get())[I] = core::ptr::from_ref(attribute).cast_mut().cast() }; } } @@ -761,9 +757,7 @@ macro_rules! impl_item_type { ct_owner: owner.as_ptr(), ct_group_ops: GroupOperationsVTable::::vtable_ptr().cast_mut(), ct_item_ops: ItemOperationsVTable::<$tpe, Data>::vtable_ptr().cast_mut(), - ct_attrs: (attributes as *const AttributeList) - .cast_mut() - .cast(), + ct_attrs: core::ptr::from_ref(attributes).cast_mut().cast(), ct_bin_attrs: core::ptr::null_mut(), }), _p: PhantomData, @@ -780,9 +774,7 @@ macro_rules! impl_item_type { ct_owner: owner.as_ptr(), ct_group_ops: core::ptr::null_mut(), ct_item_ops: ItemOperationsVTable::<$tpe, Data>::vtable_ptr().cast_mut(), - ct_attrs: (attributes as *const AttributeList) - .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 f9d55ac7b9e67..3dc72ca8cfc26 100644 --- a/rust/kernel/device_id.rs +++ b/rust/kernel/device_id.rs @@ -136,7 +136,7 @@ impl IdTable for IdArray { 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 e9bfbad007553..35fd5db35c465 100644 --- a/rust/kernel/fs/file.rs +++ b/rust/kernel/fs/file.rs @@ -366,7 +366,7 @@ impl core::ops::Deref for File { // // 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 43597eb7c5c1a..cbc8b459ed416 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -29,7 +29,7 @@ impl BStr { #[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 @@ impl CStr { #[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 6d70edd8086a9..4ef13cf13a78f 100644 --- a/rust/kernel/uaccess.rs +++ b/rust/kernel/uaccess.rs @@ -240,7 +240,7 @@ impl UserSliceReader { 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]) }; + let out = unsafe { &mut *(core::ptr::from_mut(out) as *mut [MaybeUninit]) }; self.read_raw(out) } @@ -355,7 +355,7 @@ impl UserSliceWriter { let res = unsafe { bindings::_copy_to_user( self.ptr as *mut c_void, - (value as *const T).cast::(), + core::ptr::from_ref(value).cast::(), len, ) }; diff --git a/rust/uapi/lib.rs b/rust/uapi/lib.rs index 08e68ebef6062..31c2f713313fe 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, -- 2.47.2