In Rust 1.51.0, Clippy introduced the `ptr_as_ptr` lint [1]:
> Though `as` casts between raw pointers are not terrible,
> `pointer::cast` is safer because it cannot accidentally change the
> pointer's mutability, nor cast the pointer to other types like `usize`.
There are a few classes of changes required:
- Modules generated by bindgen are marked
`#[allow(clippy::ptr_as_ptr)]`.
- Inferred casts (` as _`) are replaced with `.cast()`.
- Ascribed casts (` as *... T`) are replaced with `.cast::<T>()`.
- Multistep casts from references (` as *const _ as *const T`) are
replaced with `core::ptr::from_ref(&x).cast()` with or without `::<T>`
according to the previous rules. The `core::ptr::from_ref` call is
required because `(x as *const _).cast::<T>()` results in inference
failure.
- Native literal C strings are replaced with `c_str!().as_char_ptr()`.
- `*mut *mut T as _` is replaced with `let *mut *const T = (*mut *mut
T)`.cast();` since pointer to pointer can be confusing.
Apply these changes and enable the lint -- no functional change
intended.
Link: https://rust-lang.github.io/rust-clippy/master/index.html#ptr_as_ptr
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-1-f43b024581e8@gmail.com
[ Added `.cast()` for `opp`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
-Wclippy::needless_bitwise_bool \
-Aclippy::needless_lifetimes \
-Wclippy::no_mangle_with_rust_abi \
+ -Wclippy::ptr_as_ptr \
-Wclippy::undocumented_unsafe_blocks \
-Wclippy::unnecessary_safety_comment \
-Wclippy::unnecessary_safety_doc \
)]
#[allow(dead_code)]
+#[allow(clippy::ptr_as_ptr)]
#[allow(clippy::undocumented_unsafe_blocks)]
#[cfg_attr(CONFIG_RUSTC_HAS_UNNECESSARY_TRANSMUTES, allow(unnecessary_transmutes))]
mod bindings_raw {
// SAFETY: Returns either NULL or a pointer to a memory allocation that satisfies or
// exceeds the given size and alignment requirements.
- let dst = unsafe { libc_aligned_alloc(layout.align(), layout.size()) } as *mut u8;
+ let dst = unsafe { libc_aligned_alloc(layout.align(), layout.size()) }.cast::<u8>();
let dst = NonNull::new(dst).ok_or(AllocError)?;
if flags.contains(__GFP_ZERO) {
// - `self.len` is smaller than `self.capacity` by the type invariant and hence, the
// resulting pointer is guaranteed to be part of the same allocated object.
// - `self.len` can not overflow `isize`.
- let ptr = unsafe { self.as_mut_ptr().add(self.len) } as *mut MaybeUninit<T>;
+ let ptr = unsafe { self.as_mut_ptr().add(self.len) }.cast::<MaybeUninit<T>>();
// SAFETY: The memory between `self.len` and `self.capacity` is guaranteed to be allocated
// and valid, but uninitialized.
// - `ptr` points to memory with at least a size of `size_of::<T>() * len`,
// - all elements within `b` are initialized values of `T`,
// - `len` does not exceed `isize::MAX`.
- unsafe { Vec::from_raw_parts(ptr as _, len, len) }
+ unsafe { Vec::from_raw_parts(ptr.cast(), len, len) }
}
}
let data: &Data = unsafe { get_group_data(c_group) };
// SAFETY: By function safety requirements, `page` is writable for `PAGE_SIZE`.
- let ret = O::show(data, unsafe { &mut *(page as *mut [u8; PAGE_SIZE]) });
+ let ret = O::show(data, unsafe { &mut *(page.cast::<[u8; PAGE_SIZE]>()) });
match ret {
Ok(size) => size as isize,
fn set_data<T: ForeignOwnable>(&mut self, data: T) -> Result {
if self.as_ref().driver_data.is_null() {
// Transfer the ownership of the data to the foreign interface.
- self.as_mut_ref().driver_data = <T as ForeignOwnable>::into_foreign(data) as _;
+ self.as_mut_ref().driver_data = <T as ForeignOwnable>::into_foreign(data).cast();
Ok(())
} else {
Err(EBUSY)
#[cfg(CONFIG_PRINTK)]
unsafe {
bindings::_dev_printk(
- klevel as *const _ as *const crate::ffi::c_char,
+ klevel.as_ptr().cast::<crate::ffi::c_char>(),
self.as_raw(),
c_str!("%pA").as_char_ptr(),
- &msg as *const _ as *const crate::ffi::c_void,
+ core::ptr::from_ref(&msg).cast::<crate::ffi::c_void>(),
)
};
}
#[allow(clippy::missing_safety_doc)]
unsafe extern "C" fn devres_callback(ptr: *mut kernel::ffi::c_void) {
- let ptr = ptr as *mut DevresInner<T>;
+ let ptr = ptr.cast::<DevresInner<T>>();
// Devres owned this memory; now that we received the callback, drop the `Arc` and hence the
// reference.
// SAFETY: Safe, since we leaked an `Arc` reference to devm_add_action() in
dev: dev.into(),
dma_handle,
count,
- cpu_addr: ret as *mut T,
+ cpu_addr: ret.cast::<T>(),
dma_attrs,
})
}
bindings::dma_free_attrs(
self.dev.as_raw(),
size,
- self.cpu_addr as _,
+ self.cpu_addr.cast(),
self.dma_handle,
self.dma_attrs.as_raw(),
)
/// Returns the error encoded as a pointer.
pub fn to_ptr<T>(self) -> *mut T {
// SAFETY: `self.0` is a valid error due to its invariant.
- unsafe { bindings::ERR_PTR(self.0.get() as _) as *mut _ }
+ unsafe { bindings::ERR_PTR(self.0.get() as _).cast() }
}
/// Returns a string representing the error, if one exists.
fn request_internal(name: &CStr, dev: &Device, func: FwFunc) -> Result<Self> {
let mut fw: *mut bindings::firmware = core::ptr::null_mut();
let pfw: *mut *mut bindings::firmware = &mut fw;
+ let pfw: *mut *const bindings::firmware = pfw.cast();
// SAFETY: `pfw` is a valid pointer to a NULL initialized `bindings::firmware` pointer.
// `name` and `dev` are valid as by their type invariants.
- let ret = unsafe { func.0(pfw as _, name.as_char_ptr(), dev.as_raw()) };
+ let ret = unsafe { func.0(pfw, name.as_char_ptr(), dev.as_raw()) };
if ret != 0 {
return Err(Error::from_errno(ret));
}
//
// 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 File as *const bindings::file) }
+ unsafe { LocalFile::from_raw_file((self as *const Self).cast()) }
}
}
use crate::prelude::*;
use core::{ffi::c_void, fmt};
+#[cfg(CONFIG_PRINTK)]
+use crate::c_str;
+
/// Prints a KUnit error-level message.
///
/// Public but hidden since it should only be used from KUnit generated code.
#[cfg(CONFIG_PRINTK)]
unsafe {
bindings::_printk(
- c"\x013%pA".as_ptr() as _,
- &args as *const _ as *const c_void,
+ c_str!("\x013%pA").as_char_ptr(),
+ core::ptr::from_ref(&args).cast::<c_void>(),
);
}
}
#[cfg(CONFIG_PRINTK)]
unsafe {
bindings::_printk(
- c"\x016%pA".as_ptr() as _,
- &args as *const _ as *const c_void,
+ c_str!("\x016%pA").as_char_ptr(),
+ core::ptr::from_ref(&args).cast::<c_void>(),
);
}
}
unsafe fn raw_get_list_links(ptr: *mut Self) -> *mut ListLinks<ID> {
// SAFETY: The caller promises that the pointer is valid. The implementer promises that the
// `OFFSET` constant is correct.
- unsafe { (ptr as *mut u8).add(Self::OFFSET) as *mut ListLinks<ID> }
+ unsafe { ptr.cast::<u8>().add(Self::OFFSET).cast() }
}
}
let mut list = KVec::with_capacity(names.len() + 1, GFP_KERNEL)?;
for name in names.iter() {
- list.push(name.as_ptr() as _, GFP_KERNEL)?;
+ list.push(name.as_ptr().cast(), GFP_KERNEL)?;
}
list.push(ptr::null(), GFP_KERNEL)?;
// Let the `struct pci_dev` own a reference of the driver's private data.
// SAFETY: By the type invariant `pdev.as_raw` returns a valid pointer to a
// `struct pci_dev`.
- unsafe { bindings::pci_set_drvdata(pdev.as_raw(), data.into_foreign() as _) };
+ unsafe { bindings::pci_set_drvdata(pdev.as_raw(), data.into_foreign().cast()) };
}
Err(err) => return Error::to_errno(err),
}
// Let the `struct platform_device` own a reference of the driver's private data.
// SAFETY: By the type invariant `pdev.as_raw` returns a valid pointer to a
// `struct platform_device`.
- unsafe { bindings::platform_set_drvdata(pdev.as_raw(), data.into_foreign() as _) };
+ unsafe {
+ bindings::platform_set_drvdata(pdev.as_raw(), data.into_foreign().cast())
+ };
}
Err(err) => return Error::to_errno(err),
}
// SAFETY: The C contract guarantees that `buf` is valid if it's less than `end`.
let mut w = unsafe { RawFormatter::from_ptrs(buf.cast(), end.cast()) };
// SAFETY: TODO.
- let _ = w.write_fmt(unsafe { *(ptr as *const fmt::Arguments<'_>) });
+ let _ = w.write_fmt(unsafe { *ptr.cast::<fmt::Arguments<'_>>() });
w.pos().cast()
}
bindings::_printk(
format_string.as_ptr(),
module_name.as_ptr(),
- &args as *const _ as *const c_void,
+ core::ptr::from_ref(&args).cast::<c_void>(),
);
}
}
unsafe {
bindings::_printk(
format_strings::CONT.as_ptr(),
- &args as *const _ as *const c_void,
+ core::ptr::from_ref(&args).cast::<c_void>(),
);
}
}
bindings::seq_printf(
self.inner.get(),
c_str!("%pA").as_char_ptr(),
- &args as *const _ as *const crate::ffi::c_void,
+ core::ptr::from_ref(&args).cast::<crate::ffi::c_void>(),
);
}
}
// to a `NUL`-terminated C string.
let len = unsafe { bindings::strlen(ptr) } + 1;
// SAFETY: Lifetime guaranteed by the safety precondition.
- let bytes = unsafe { core::slice::from_raw_parts(ptr as _, len) };
+ let bytes = unsafe { core::slice::from_raw_parts(ptr.cast(), len) };
// SAFETY: As `len` is returned by `strlen`, `bytes` does not contain interior `NUL`.
// As we have added 1 to `len`, the last byte is known to be `NUL`.
unsafe { Self::from_bytes_with_nul_unchecked(bytes) }
// be destroyed, the destructor must run. That destructor first removes all waiters,
// and then waits for an rcu grace period. Therefore, `cv.wait_queue_head` is valid for
// long enough.
- unsafe { qproc(file.as_ptr() as _, cv.wait_queue_head.get(), self.0.get()) };
+ unsafe { qproc(file.as_ptr().cast(), cv.wait_queue_head.get(), self.0.get()) };
}
}
}
unsafe extern "C" fn run(ptr: *mut bindings::hrtimer) -> bindings::hrtimer_restart {
// `HrTimer` is `repr(C)`
- let timer_ptr = ptr as *mut HrTimer<T>;
+ let timer_ptr = ptr.cast::<HrTimer<T>>();
// SAFETY: By the safety requirement of this function, `timer_ptr`
// points to a `HrTimer<T>` contained in an `T`.
unsafe extern "C" fn run(ptr: *mut bindings::hrtimer) -> bindings::hrtimer_restart {
// `HrTimer` is `repr(C)`
- let timer_ptr = ptr as *mut HrTimer<T>;
+ let timer_ptr = ptr.cast::<HrTimer<T>>();
// SAFETY: By the safety requirement of this function, `timer_ptr`
// points to a `HrTimer<T>` contained in an `T`.
pub unsafe fn from_raw<'a>(ptr: *const bindings::workqueue_struct) -> &'a Queue {
// SAFETY: The `Queue` type is `#[repr(transparent)]`, so the pointer cast is valid. The
// caller promises that the pointer is not dangling.
- unsafe { &*(ptr as *const Queue) }
+ unsafe { &*ptr.cast::<Queue>() }
}
/// Enqueues a work item.
{
unsafe extern "C" fn run(ptr: *mut bindings::work_struct) {
// The `__enqueue` method always uses a `work_struct` stored in a `Work<T, ID>`.
- let ptr = ptr as *mut Work<T, ID>;
+ let ptr = ptr.cast::<Work<T, ID>>();
// SAFETY: This computes the pointer that `__enqueue` got from `Arc::into_raw`.
let ptr = unsafe { T::work_container_of(ptr) };
// SAFETY: This pointer comes from `Arc::into_raw` and we've been given back ownership.
{
unsafe extern "C" fn run(ptr: *mut bindings::work_struct) {
// The `__enqueue` method always uses a `work_struct` stored in a `Work<T, ID>`.
- let ptr = ptr as *mut Work<T, ID>;
+ let ptr = ptr.cast::<Work<T, ID>>();
// SAFETY: This computes the pointer that `__enqueue` got from `Arc::into_raw`.
let ptr = unsafe { T::work_container_of(ptr) };
// SAFETY: This pointer comes from `Arc::into_raw` and we've been given back ownership.
#![cfg_attr(test, allow(unsafe_op_in_unsafe_fn))]
#![allow(
clippy::all,
+ clippy::ptr_as_ptr,
clippy::undocumented_unsafe_blocks,
dead_code,
missing_docs,