[PATCH 1/8] rust: device: narrow the generic of drvdata_obtain()

Danilo Krummrich
2025-10-20T22:35:38Z

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

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
rust/kernel/auxiliary.rs | 2 +-
rust/kernel/device.rs | 4 ++--
rust/kernel/pci.rs | 2 +-
rust/kernel/platform.rs | 2 +-
rust/kernel/usb.rs | 4 ++--
5 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/rust/kernel/auxiliary.rs b/rust/kernel/auxiliary.rs
index e12f78734606..a6a2b23befce 100644
--- a/rust/kernel/auxiliary.rs
+++ b/rust/kernel/auxiliary.rs
@@ -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>() });
}
}

diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index 343996027c89..106aa57a6385 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -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`].
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 83e19bcec46e..e90b13aebac8 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -148,7 +148,7 @@ 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());
}
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 043721fdb6d8..8f7522c4cf89 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -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());
}
diff --git a/rust/kernel/usb.rs b/rust/kernel/usb.rs
index 9238b96c2185..05eed3f4f73e 100644
--- a/rust/kernel/usb.rs
+++ b/rust/kernel/usb.rs
@@ -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());
}
}

--
2.51.0