[PATCH 2/2] rust/faux: Add missing parent argument to Registration::new()

Lyude Paul
2025-02-25T21:31:52Z

A little late in the review of the faux device interface, we added the
ability to specify a parent device when creating new faux devices - but
this never got ported over to the rust bindings. So, let's add the missing
argument now so we don't have to convert other users later down the line.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
rust/kernel/faux.rs | 10 ++++++++--
samples/rust/rust_driver_faux.rs | 2 +-
2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/rust/kernel/faux.rs b/rust/kernel/faux.rs
index 41751403cd868..ae99ea3d114ef 100644
--- a/rust/kernel/faux.rs
+++ b/rust/kernel/faux.rs
@@ -23,11 +23,17 @@

impl Registration {
/// Create and register a new faux device with the given name.
- pub fn new(name: &CStr) -> Result<Self> {
+ pub fn new(name: &CStr, parent: Option<&device::Device>) -> Result<Self> {
// SAFETY:
// - `name` is copied by this function into its own storage
// - `faux_ops` is safe to leave NULL according to the C API
- let dev = unsafe { bindings::faux_device_create(name.as_char_ptr(), null_mut(), null()) };
+ let dev = unsafe {
+ bindings::faux_device_create(
+ name.as_char_ptr(),
+ parent.map_or(null_mut(), |p| p.as_raw()),
+ null(),
+ )
+ };

// The above function will return either a valid device, or NULL on failure
// INVARIANT: The device will remain registered until faux_device_destroy() is called, which
diff --git a/samples/rust/rust_driver_faux.rs b/samples/rust/rust_driver_faux.rs
index 048c6cb98b29a..58a3a94121bff 100644
--- a/samples/rust/rust_driver_faux.rs
+++ b/samples/rust/rust_driver_faux.rs
@@ -20,7 +20,7 @@ impl Module for SampleModule {
fn init(_module: &'static ThisModule) -> Result<Self> {
pr_info!("Initialising Rust Faux Device Sample\n");

- let reg = faux::Registration::new(c_str!("rust-faux-sample-device"))?;
+ let reg = faux::Registration::new(c_str!("rust-faux-sample-device"), None)?;

dev_info!(reg.as_ref(), "Hello from faux device!\n");

--
2.48.1