Commit 6bbaa939 authored Oct 21, 2025 by Danilo Krummrich

rust: device: narrow the generic of drvdata_obtain()



Let T be the actual private driver data type without the surrounding
box, as it leaves less room for potential bugs.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

parent 37022410

rust/kernel/auxiliary.rs

+1 −1

Original line number	Diff line number	Diff line
		@@ -85,7 +85,7 @@ extern "C" fn remove_callback(adev: *mut bindings::auxiliary_device) {
		// SAFETY: `remove_callback` is only ever called after a successful call to
		// `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called
		// and stored a `Pin<KBox<T>>`.
		drop(unsafe { adev.as_ref().drvdata_obtain::<Pin<KBox<T>>>() });
		drop(unsafe { adev.as_ref().drvdata_obtain::<T>() });
		}
		}

rust/kernel/device.rs

+2 −2

Original line number	Diff line number	Diff line
		@@ -215,7 +215,7 @@ pub fn set_drvdata<T: 'static>(&self, data: impl PinInit<T, Error>) -> Result {
		/// - Must only be called once after a preceding call to [`Device::set_drvdata`].
		/// - The type `T` must match the type of the `ForeignOwnable` previously stored by
		/// [`Device::set_drvdata`].
		pub unsafe fn drvdata_obtain<T: ForeignOwnable>(&self) -> T {
		pub unsafe fn drvdata_obtain<T: 'static>(&self) -> Pin<KBox<T>> {
		// SAFETY: By the type invariants, `self.as_raw()` is a valid pointer to a `struct device`.
		let ptr = unsafe { bindings::dev_get_drvdata(self.as_raw()) };

		@@ -224,7 +224,7 @@ pub unsafe fn drvdata_obtain<T: ForeignOwnable>(&self) -> T {
		// `into_foreign()`.
		// - `dev_get_drvdata()` guarantees to return the same pointer given to `dev_set_drvdata()`
		// in `into_foreign()`.
		unsafe { T::from_foreign(ptr.cast()) }
		unsafe { Pin::<KBox<T>>::from_foreign(ptr.cast()) }
		}

		/// Borrow the driver's private data bound to this [`Device`].

rust/kernel/pci.rs

+1 −1

Original line number	Diff line number	Diff line
		@@ -94,7 +94,7 @@ extern "C" fn remove_callback(pdev: *mut bindings::pci_dev) {
		// SAFETY: `remove_callback` is only ever called after a successful call to
		// `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called
		// and stored a `Pin<KBox<T>>`.
		let data = unsafe { pdev.as_ref().drvdata_obtain::<Pin<KBox<T>>>() };
		let data = unsafe { pdev.as_ref().drvdata_obtain::<T>() };

		T::unbind(pdev, data.as_ref());
		}

rust/kernel/platform.rs

+1 −1

Original line number	Diff line number	Diff line
		@@ -91,7 +91,7 @@ extern "C" fn remove_callback(pdev: *mut bindings::platform_device) {
		// SAFETY: `remove_callback` is only ever called after a successful call to
		// `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called
		// and stored a `Pin<KBox<T>>`.
		let data = unsafe { pdev.as_ref().drvdata_obtain::<Pin<KBox<T>>>() };
		let data = unsafe { pdev.as_ref().drvdata_obtain::<T>() };

		T::unbind(pdev, data.as_ref());
		}

rust/kernel/usb.rs

+2 −2

Original line number	Diff line number	Diff line
		@@ -87,9 +87,9 @@ extern "C" fn disconnect_callback(intf: *mut bindings::usb_interface) {
		// SAFETY: `disconnect_callback` is only ever called after a successful call to
		// `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called
		// and stored a `Pin<KBox<T>>`.
		let data = unsafe { dev.drvdata_obtain::<Pin<KBox<T>>>() };
		let data = unsafe { dev.drvdata_obtain::<T>() };

		T::disconnect(intf, data.as_ref());
		T::disconnect(intf, data.data());
		}
		}