In Rust 1.63.0, Clippy introduced the `as_underscore` lint [1]:
The conversion might include lossy conversion or a dangerous cast that might go undetected due to the type being inferred.
The lint is allowed by default as using `_` is less wordy than always specifying the type.
Always specifying the type is especially helpful in function call contexts where the inferred type may change at a distance. Specifying the type also allows Clippy to spot more cases of `useless_conversion`.
The primary downside is the need to specify the type in trivial getters. There are 4 such functions: 3 have become slightly less ergonomic, 1 was revealed to be a `useless_conversion`.
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#as_underscore [1] Reviewed-by: Benno Lossin benno.lossin@proton.me Signed-off-by: Tamir Duberstein tamird@gmail.com --- Makefile | 1 + rust/kernel/block/mq/operations.rs | 2 +- rust/kernel/block/mq/request.rs | 2 +- rust/kernel/device_id.rs | 2 +- rust/kernel/devres.rs | 15 ++++++++------- rust/kernel/dma.rs | 2 +- rust/kernel/error.rs | 2 +- rust/kernel/io.rs | 18 +++++++++--------- rust/kernel/miscdevice.rs | 2 +- rust/kernel/of.rs | 6 +++--- rust/kernel/pci.rs | 9 ++++++--- rust/kernel/str.rs | 8 ++++---- rust/kernel/workqueue.rs | 2 +- 13 files changed, 38 insertions(+), 33 deletions(-)
diff --git a/Makefile b/Makefile index 04a5246171f9..57080a64913f 100644 --- a/Makefile +++ b/Makefile @@ -475,6 +475,7 @@ export rust_common_flags := --edition=2021 \ -Wunreachable_pub \ -Wclippy::all \ -Wclippy::as_ptr_cast_mut \ + -Wclippy::as_underscore \ -Wclippy::ignored_unit_patterns \ -Wclippy::mut_mut \ -Wclippy::needless_bitwise_bool \ diff --git a/rust/kernel/block/mq/operations.rs b/rust/kernel/block/mq/operations.rs index 864ff379dc91..d18ef55490da 100644 --- a/rust/kernel/block/mq/operations.rs +++ b/rust/kernel/block/mq/operations.rs @@ -101,7 +101,7 @@ impl<T: Operations> OperationsVTable<T> { if let Err(e) = ret { e.to_blk_status() } else { - bindings::BLK_STS_OK as _ + bindings::BLK_STS_OK as u8 } }
diff --git a/rust/kernel/block/mq/request.rs b/rust/kernel/block/mq/request.rs index c9f8046af65c..807a72de6455 100644 --- a/rust/kernel/block/mq/request.rs +++ b/rust/kernel/block/mq/request.rs @@ -125,7 +125,7 @@ pub fn end_ok(this: ARef<Self>) -> Result<(), ARef<Self>> { // success of the call to `try_set_end` guarantees that there are no // `ARef`s pointing to this request. Therefore it is safe to hand it // back to the block layer. - unsafe { bindings::blk_mq_end_request(request_ptr, bindings::BLK_STS_OK as _) }; + unsafe { bindings::blk_mq_end_request(request_ptr, bindings::BLK_STS_OK as u8) };
Ok(()) } diff --git a/rust/kernel/device_id.rs b/rust/kernel/device_id.rs index e5859217a579..4063f09d76d9 100644 --- a/rust/kernel/device_id.rs +++ b/rust/kernel/device_id.rs @@ -82,7 +82,7 @@ impl<T: RawDeviceId, U, const N: usize> IdArray<T, U, N> { unsafe { raw_ids[i] .as_mut_ptr() - .byte_offset(T::DRIVER_DATA_OFFSET as _) + .byte_add(T::DRIVER_DATA_OFFSET) .cast::<usize>() .write(i); } diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs index f7e8f5f53622..70d12014e476 100644 --- a/rust/kernel/devres.rs +++ b/rust/kernel/devres.rs @@ -45,7 +45,7 @@ struct DevresInner<T> { /// # Example /// /// ```no_run -/// # use kernel::{bindings, c_str, device::Device, devres::Devres, io::{Io, IoRaw}}; +/// # use kernel::{bindings, c_str, device::Device, devres::Devres, ffi::c_void, io::{Io, IoRaw}}; /// # use core::ops::Deref; /// /// // See also [`pci::Bar`] for a real example. @@ -59,19 +59,19 @@ struct DevresInner<T> { /// unsafe fn new(paddr: usize) -> Result<Self>{ /// // SAFETY: By the safety requirements of this function [`paddr`, `paddr` + `SIZE`) is /// // valid for `ioremap`. -/// let addr = unsafe { bindings::ioremap(paddr as _, SIZE as _) }; +/// let addr = unsafe { bindings::ioremap(paddr as bindings::phys_addr_t, SIZE) }; /// if addr.is_null() { /// return Err(ENOMEM); /// } /// -/// Ok(IoMem(IoRaw::new(addr as _, SIZE)?)) +/// Ok(IoMem(IoRaw::new(addr as usize, SIZE)?)) /// } /// } /// /// impl<const SIZE: usize> Drop for IoMem<SIZE> { /// fn drop(&mut self) { /// // SAFETY: `self.0.addr()` is guaranteed to be properly mapped by `Self::new`. -/// unsafe { bindings::iounmap(self.0.addr() as _); }; +/// unsafe { bindings::iounmap(self.0.addr() as *mut c_void); }; /// } /// } /// @@ -115,8 +115,9 @@ fn new(dev: &Device, data: T, flags: Flags) -> Result<Arc<DevresInner<T>>> {
// SAFETY: `devm_add_action` guarantees to call `Self::devres_callback` once `dev` is // detached. - let ret = - unsafe { bindings::devm_add_action(dev.as_raw(), Some(inner.callback), data as _) }; + let ret = unsafe { + bindings::devm_add_action(dev.as_raw(), Some(inner.callback), data.cast_mut().cast()) + };
if ret != 0 { // SAFETY: We just created another reference to `inner` in order to pass it to @@ -130,7 +131,7 @@ fn new(dev: &Device, data: T, flags: Flags) -> Result<Arc<DevresInner<T>>> { }
fn as_ptr(&self) -> *const Self { - self as _ + self }
fn remove_action(this: &Arc<Self>) { diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs index 43ecf3c2e860..851a6339aa90 100644 --- a/rust/kernel/dma.rs +++ b/rust/kernel/dma.rs @@ -38,7 +38,7 @@ impl Attrs { /// Get the raw representation of this attribute. pub(crate) fn as_raw(self) -> crate::ffi::c_ulong { - self.0 as _ + self.0 as crate::ffi::c_ulong }
/// Check whether `flags` is contained in `self`. diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs index afcb00cb6a75..fd7a8b759437 100644 --- a/rust/kernel/error.rs +++ b/rust/kernel/error.rs @@ -153,7 +153,7 @@ pub(crate) fn to_blk_status(self) -> bindings::blk_status_t { /// 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 _).cast() } + unsafe { bindings::ERR_PTR(self.0.get() as isize).cast() } }
/// Returns a string representing the error, if one exists. diff --git a/rust/kernel/io.rs b/rust/kernel/io.rs index 72d80a6f131e..c08de4121637 100644 --- a/rust/kernel/io.rs +++ b/rust/kernel/io.rs @@ -5,7 +5,7 @@ //! C header: [`include/asm-generic/io.h`](srctree/include/asm-generic/io.h)
use crate::error::{code::EINVAL, Result}; -use crate::{bindings, build_assert}; +use crate::{bindings, build_assert, ffi::c_void};
/// Raw representation of an MMIO region. /// @@ -56,7 +56,7 @@ pub fn maxsize(&self) -> usize { /// # Examples /// /// ```no_run -/// # use kernel::{bindings, io::{Io, IoRaw}}; +/// # use kernel::{bindings, ffi::c_void, io::{Io, IoRaw}}; /// # use core::ops::Deref; /// /// // See also [`pci::Bar`] for a real example. @@ -70,19 +70,19 @@ pub fn maxsize(&self) -> usize { /// unsafe fn new(paddr: usize) -> Result<Self>{ /// // SAFETY: By the safety requirements of this function [`paddr`, `paddr` + `SIZE`) is /// // valid for `ioremap`. -/// let addr = unsafe { bindings::ioremap(paddr as _, SIZE as _) }; +/// let addr = unsafe { bindings::ioremap(paddr as bindings::phys_addr_t, SIZE) }; /// if addr.is_null() { /// return Err(ENOMEM); /// } /// -/// Ok(IoMem(IoRaw::new(addr as _, SIZE)?)) +/// Ok(IoMem(IoRaw::new(addr as usize, SIZE)?)) /// } /// } /// /// impl<const SIZE: usize> Drop for IoMem<SIZE> { /// fn drop(&mut self) { /// // SAFETY: `self.0.addr()` is guaranteed to be properly mapped by `Self::new`. -/// unsafe { bindings::iounmap(self.0.addr() as _); }; +/// unsafe { bindings::iounmap(self.0.addr() as *mut c_void); }; /// } /// } /// @@ -119,7 +119,7 @@ pub fn $name(&self, offset: usize) -> $type_name { let addr = self.io_addr_assert::<$type_name>(offset);
// SAFETY: By the type invariant `addr` is a valid address for MMIO operations. - unsafe { bindings::$c_fn(addr as _) } + unsafe { bindings::$c_fn(addr as *const c_void) } }
/// Read IO data from a given offset. @@ -131,7 +131,7 @@ pub fn $try_name(&self, offset: usize) -> Result<$type_name> { let addr = self.io_addr::<$type_name>(offset)?;
// SAFETY: By the type invariant `addr` is a valid address for MMIO operations. - Ok(unsafe { bindings::$c_fn(addr as _) }) + Ok(unsafe { bindings::$c_fn(addr as *const c_void) }) } }; } @@ -148,7 +148,7 @@ pub fn $name(&self, value: $type_name, offset: usize) { let addr = self.io_addr_assert::<$type_name>(offset);
// SAFETY: By the type invariant `addr` is a valid address for MMIO operations. - unsafe { bindings::$c_fn(value, addr as _, ) } + unsafe { bindings::$c_fn(value, addr as *mut c_void) } }
/// Write IO data from a given offset. @@ -160,7 +160,7 @@ pub fn $try_name(&self, value: $type_name, offset: usize) -> Result { let addr = self.io_addr::<$type_name>(offset)?;
// SAFETY: By the type invariant `addr` is a valid address for MMIO operations. - unsafe { bindings::$c_fn(value, addr as _) } + unsafe { bindings::$c_fn(value, addr as *mut c_void) } Ok(()) } }; diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs index fa9ecc42602a..6f9a7f97b7e5 100644 --- a/rust/kernel/miscdevice.rs +++ b/rust/kernel/miscdevice.rs @@ -33,7 +33,7 @@ impl MiscDeviceOptions { pub const fn into_raw<T: MiscDevice>(self) -> bindings::miscdevice { // SAFETY: All zeros is valid for this C type. let mut result: bindings::miscdevice = unsafe { MaybeUninit::zeroed().assume_init() }; - result.minor = bindings::MISC_DYNAMIC_MINOR as _; + result.minor = bindings::MISC_DYNAMIC_MINOR as i32; result.name = self.name.as_char_ptr(); result.fops = MiscdeviceVTable::<T>::build(); result diff --git a/rust/kernel/of.rs b/rust/kernel/of.rs index 04f2d8ef29cb..40d1bd13682c 100644 --- a/rust/kernel/of.rs +++ b/rust/kernel/of.rs @@ -22,7 +22,7 @@ unsafe impl RawDeviceId for DeviceId { const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::of_device_id, data);
fn index(&self) -> usize { - self.0.data as _ + self.0.data as usize } }
@@ -34,10 +34,10 @@ pub const fn new(compatible: &'static CStr) -> Self { // SAFETY: FFI type is valid to be zero-initialized. let mut of: bindings::of_device_id = unsafe { core::mem::zeroed() };
- // TODO: Use `clone_from_slice` once the corresponding types do match. + // TODO: Use `copy_from_slice` once stabilized for `const`. let mut i = 0; while i < src.len() { - of.compatible[i] = src[i] as _; + of.compatible[i] = src[i]; i += 1; }
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs index 391b4f070b1c..7efbbe5f8f59 100644 --- a/rust/kernel/pci.rs +++ b/rust/kernel/pci.rs @@ -169,7 +169,7 @@ unsafe impl RawDeviceId for DeviceId { const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::pci_device_id, driver_data);
fn index(&self) -> usize { - self.0.driver_data as _ + self.0.driver_data } }
@@ -204,7 +204,10 @@ macro_rules! pci_device_table { /// MODULE_PCI_TABLE, /// <MyDriver as pci::Driver>::IdInfo, /// [ -/// (pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, bindings::PCI_ANY_ID as _), ()) +/// ( +/// pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, bindings::PCI_ANY_ID as u32), +/// (), +/// ) /// ] /// ); /// @@ -327,7 +330,7 @@ unsafe fn do_release(pdev: &Device, ioptr: usize, num: i32) { // `ioptr` is valid by the safety requirements. // `num` is valid by the safety requirements. unsafe { - bindings::pci_iounmap(pdev.as_raw(), ioptr as _); + bindings::pci_iounmap(pdev.as_raw(), ioptr as *mut kernel::ffi::c_void); bindings::pci_release_region(pdev.as_raw(), num); } } diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index 02863c40c21b..40034f77fc2f 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -738,9 +738,9 @@ fn new() -> Self { pub(crate) unsafe fn from_ptrs(pos: *mut u8, end: *mut u8) -> Self { // INVARIANT: The safety requirements guarantee the type invariants. Self { - beg: pos as _, - pos: pos as _, - end: end as _, + beg: pos as usize, + pos: pos as usize, + end: end as usize, } }
@@ -765,7 +765,7 @@ pub(crate) unsafe fn from_buffer(buf: *mut u8, len: usize) -> Self { /// /// N.B. It may point to invalid memory. pub(crate) fn pos(&self) -> *mut u8 { - self.pos as _ + self.pos as *mut u8 }
/// Returns the number of bytes written to the formatter. diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index 223fe5e8ed82..7d3a6e586a1d 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -198,7 +198,7 @@ pub fn enqueue<W, const ID: u64>(&self, w: W) -> W::EnqueueOutput unsafe { w.__enqueue(move |work_ptr| { bindings::queue_work_on( - bindings::wq_misc_consts_WORK_CPU_UNBOUND as _, + bindings::wq_misc_consts_WORK_CPU_UNBOUND as i32, queue_ptr, work_ptr, )