On Sun, Jun 15, 2025 at 4:55 PM Tamir Duberstein <tam...@gmail.com> wrote: > > 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.los...@proton.me> > Reviewed-by: Boqun Feng <boqun.f...@gmail.com> > Signed-off-by: Tamir Duberstein <tam...@gmail.com>
@Danilo Krummrich could you please have a look for nova? > --- > Makefile | 1 + > drivers/gpu/nova-core/driver.rs | 2 +- > rust/kernel/block/mq/operations.rs | 2 +- > rust/kernel/block/mq/request.rs | 7 ++++- > rust/kernel/device_id.rs | 2 +- > rust/kernel/devres.rs | 13 +++++----- > rust/kernel/dma.rs | 2 +- > rust/kernel/drm/device.rs | 2 +- > rust/kernel/error.rs | 2 +- > rust/kernel/io.rs | 18 ++++++------- > rust/kernel/miscdevice.rs | 2 +- > rust/kernel/mm/virt.rs | 52 > +++++++++++++++++++------------------- > rust/kernel/of.rs | 6 ++--- > rust/kernel/pci.rs | 9 ++++--- > rust/kernel/str.rs | 8 +++--- > rust/kernel/workqueue.rs | 2 +- > 16 files changed, 70 insertions(+), 60 deletions(-) > > diff --git a/Makefile b/Makefile > index bb33023f87c3..0ba22c361de8 100644 > --- a/Makefile > +++ b/Makefile > @@ -480,6 +480,7 @@ 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/drivers/gpu/nova-core/driver.rs b/drivers/gpu/nova-core/driver.rs > index 8c86101c26cb..a0e435dc4656 100644 > --- a/drivers/gpu/nova-core/driver.rs > +++ b/drivers/gpu/nova-core/driver.rs > @@ -19,7 +19,7 @@ pub(crate) struct NovaCore { > MODULE_PCI_TABLE, > <NovaCore as pci::Driver>::IdInfo, > [( > - pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_NVIDIA, > bindings::PCI_ANY_ID as _), > + pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_NVIDIA, > bindings::PCI_ANY_ID as u32), > () > )] > ); > diff --git a/rust/kernel/block/mq/operations.rs > b/rust/kernel/block/mq/operations.rs > index 864ff379dc91..c2b98f507bcb 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 bindings::blk_status_t > } > } > > diff --git a/rust/kernel/block/mq/request.rs b/rust/kernel/block/mq/request.rs > index af5c9ac94f36..fefd394f064a 100644 > --- a/rust/kernel/block/mq/request.rs > +++ b/rust/kernel/block/mq/request.rs > @@ -125,7 +125,12 @@ 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 bindings::blk_status_t, > + ) > + }; > > Ok(()) > } > diff --git a/rust/kernel/device_id.rs b/rust/kernel/device_id.rs > index 0a4eb56d98f2..f9d55ac7b9e6 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 237182446db3..1e44d70687a8 100644 > --- a/rust/kernel/devres.rs > +++ b/rust/kernel/devres.rs > @@ -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); }; > /// } > /// } > /// > @@ -112,8 +112,9 @@ fn new(dev: &Device<Bound>, 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 > @@ -127,7 +128,7 @@ fn new(dev: &Device<Bound>, 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 666bf2d64f9a..8e317005decd 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/drm/device.rs b/rust/kernel/drm/device.rs > index ef66deb7ce23..b7ee3c464a12 100644 > --- a/rust/kernel/drm/device.rs > +++ b/rust/kernel/drm/device.rs > @@ -89,7 +89,7 @@ impl<T: drm::Driver> Device<T> { > driver_features: drm::driver::FEAT_GEM, > ioctls: T::IOCTLS.as_ptr(), > num_ioctls: T::IOCTLS.len() as i32, > - fops: &Self::GEM_FOPS as _, > + fops: &Self::GEM_FOPS, > }; > > const GEM_FOPS: bindings::file_operations = drm::gem::create_fops(); > 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 939278bc7b03..288f40e79906 100644 > --- a/rust/kernel/miscdevice.rs > +++ b/rust/kernel/miscdevice.rs > @@ -34,7 +34,7 @@ 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 ffi::c_int; > result.name = self.name.as_char_ptr(); > result.fops = MiscdeviceVTable::<T>::build(); > result > diff --git a/rust/kernel/mm/virt.rs b/rust/kernel/mm/virt.rs > index 31803674aecc..6086ca981b06 100644 > --- a/rust/kernel/mm/virt.rs > +++ b/rust/kernel/mm/virt.rs > @@ -392,80 +392,80 @@ pub mod flags { > use crate::bindings; > > /// No flags are set. > - pub const NONE: vm_flags_t = bindings::VM_NONE as _; > + pub const NONE: vm_flags_t = bindings::VM_NONE as vm_flags_t; > > /// Mapping allows reads. > - pub const READ: vm_flags_t = bindings::VM_READ as _; > + pub const READ: vm_flags_t = bindings::VM_READ as vm_flags_t; > > /// Mapping allows writes. > - pub const WRITE: vm_flags_t = bindings::VM_WRITE as _; > + pub const WRITE: vm_flags_t = bindings::VM_WRITE as vm_flags_t; > > /// Mapping allows execution. > - pub const EXEC: vm_flags_t = bindings::VM_EXEC as _; > + pub const EXEC: vm_flags_t = bindings::VM_EXEC as vm_flags_t; > > /// Mapping is shared. > - pub const SHARED: vm_flags_t = bindings::VM_SHARED as _; > + pub const SHARED: vm_flags_t = bindings::VM_SHARED as vm_flags_t; > > /// Mapping may be updated to allow reads. > - pub const MAYREAD: vm_flags_t = bindings::VM_MAYREAD as _; > + pub const MAYREAD: vm_flags_t = bindings::VM_MAYREAD as vm_flags_t; > > /// Mapping may be updated to allow writes. > - pub const MAYWRITE: vm_flags_t = bindings::VM_MAYWRITE as _; > + pub const MAYWRITE: vm_flags_t = bindings::VM_MAYWRITE as vm_flags_t; > > /// Mapping may be updated to allow execution. > - pub const MAYEXEC: vm_flags_t = bindings::VM_MAYEXEC as _; > + pub const MAYEXEC: vm_flags_t = bindings::VM_MAYEXEC as vm_flags_t; > > /// Mapping may be updated to be shared. > - pub const MAYSHARE: vm_flags_t = bindings::VM_MAYSHARE as _; > + pub const MAYSHARE: vm_flags_t = bindings::VM_MAYSHARE as vm_flags_t; > > /// Page-ranges managed without `struct page`, just pure PFN. > - pub const PFNMAP: vm_flags_t = bindings::VM_PFNMAP as _; > + pub const PFNMAP: vm_flags_t = bindings::VM_PFNMAP as vm_flags_t; > > /// Memory mapped I/O or similar. > - pub const IO: vm_flags_t = bindings::VM_IO as _; > + pub const IO: vm_flags_t = bindings::VM_IO as vm_flags_t; > > /// Do not copy this vma on fork. > - pub const DONTCOPY: vm_flags_t = bindings::VM_DONTCOPY as _; > + pub const DONTCOPY: vm_flags_t = bindings::VM_DONTCOPY as vm_flags_t; > > /// Cannot expand with mremap(). > - pub const DONTEXPAND: vm_flags_t = bindings::VM_DONTEXPAND as _; > + pub const DONTEXPAND: vm_flags_t = bindings::VM_DONTEXPAND as vm_flags_t; > > /// Lock the pages covered when they are faulted in. > - pub const LOCKONFAULT: vm_flags_t = bindings::VM_LOCKONFAULT as _; > + pub const LOCKONFAULT: vm_flags_t = bindings::VM_LOCKONFAULT as > vm_flags_t; > > /// Is a VM accounted object. > - pub const ACCOUNT: vm_flags_t = bindings::VM_ACCOUNT as _; > + pub const ACCOUNT: vm_flags_t = bindings::VM_ACCOUNT as vm_flags_t; > > /// Should the VM suppress accounting. > - pub const NORESERVE: vm_flags_t = bindings::VM_NORESERVE as _; > + pub const NORESERVE: vm_flags_t = bindings::VM_NORESERVE as vm_flags_t; > > /// Huge TLB Page VM. > - pub const HUGETLB: vm_flags_t = bindings::VM_HUGETLB as _; > + pub const HUGETLB: vm_flags_t = bindings::VM_HUGETLB as vm_flags_t; > > /// Synchronous page faults. (DAX-specific) > - pub const SYNC: vm_flags_t = bindings::VM_SYNC as _; > + pub const SYNC: vm_flags_t = bindings::VM_SYNC as vm_flags_t; > > /// Architecture-specific flag. > - pub const ARCH_1: vm_flags_t = bindings::VM_ARCH_1 as _; > + pub const ARCH_1: vm_flags_t = bindings::VM_ARCH_1 as vm_flags_t; > > /// Wipe VMA contents in child on fork. > - pub const WIPEONFORK: vm_flags_t = bindings::VM_WIPEONFORK as _; > + pub const WIPEONFORK: vm_flags_t = bindings::VM_WIPEONFORK as vm_flags_t; > > /// Do not include in the core dump. > - pub const DONTDUMP: vm_flags_t = bindings::VM_DONTDUMP as _; > + pub const DONTDUMP: vm_flags_t = bindings::VM_DONTDUMP as vm_flags_t; > > /// Not soft dirty clean area. > - pub const SOFTDIRTY: vm_flags_t = bindings::VM_SOFTDIRTY as _; > + pub const SOFTDIRTY: vm_flags_t = bindings::VM_SOFTDIRTY as vm_flags_t; > > /// Can contain `struct page` and pure PFN pages. > - pub const MIXEDMAP: vm_flags_t = bindings::VM_MIXEDMAP as _; > + pub const MIXEDMAP: vm_flags_t = bindings::VM_MIXEDMAP as vm_flags_t; > > /// MADV_HUGEPAGE marked this vma. > - pub const HUGEPAGE: vm_flags_t = bindings::VM_HUGEPAGE as _; > + pub const HUGEPAGE: vm_flags_t = bindings::VM_HUGEPAGE as vm_flags_t; > > /// MADV_NOHUGEPAGE marked this vma. > - pub const NOHUGEPAGE: vm_flags_t = bindings::VM_NOHUGEPAGE as _; > + pub const NOHUGEPAGE: vm_flags_t = bindings::VM_NOHUGEPAGE as vm_flags_t; > > /// KSM may merge identical pages. > - pub const MERGEABLE: vm_flags_t = bindings::VM_MERGEABLE as _; > + pub const MERGEABLE: vm_flags_t = bindings::VM_MERGEABLE as vm_flags_t; > } > 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 33ae0bdc433d..f6b19764ad17 100644 > --- a/rust/kernel/pci.rs > +++ b/rust/kernel/pci.rs > @@ -171,7 +171,7 @@ 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 > } > } > > @@ -206,7 +206,10 @@ 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), > +/// (), > +/// ) > /// ] > /// ); > /// > @@ -330,7 +333,7 @@ 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 6a3cb607b332..43597eb7c5c1 100644 > --- a/rust/kernel/str.rs > +++ b/rust/kernel/str.rs > @@ -728,9 +728,9 @@ 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, > } > } > > @@ -755,7 +755,7 @@ 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 de61374e36bd..89e5c2560eec 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 ffi::c_int, > queue_ptr, > work_ptr, > ) > > -- > 2.49.0 >