From: Guilherme Giacomo Simoes trintaeoitogc@gmail.com
[ Upstream commit cc4332afb5631b0e9d2ce5699b7f4b7caf743526 ]
The function Device::from_raw() increments a refcount by a call to bindings::get_device(ptr). This can be confused because usually from_raw() functions don't increment a refcount. Hence, rename Device::from_raw() to avoid confuion with other "from_raw" semantics.
The new name of function should be "get_device" to be consistent with the function get_device() already exist in .c files.
This function body also changed, because the `into()` will convert the `&'a Device` into `ARef<Device>` and also call `inc_ref` from the `AlwaysRefCounted` trait implemented for Device.
Signed-off-by: Guilherme Giacomo Simoes trintaeoitogc@gmail.com Acked-by: Danilo Krummrich dakr@kernel.org Closes: https://github.com/Rust-for-Linux/linux/issues/1088 Reviewed-by: Boqun Feng boqun.feng@gmail.com Link: https://lore.kernel.org/r/20241001205603.106278-1-trintaeoitogc@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- rust/kernel/device.rs | 15 +++------------ rust/kernel/firmware.rs | 2 +- 2 files changed, 4 insertions(+), 13 deletions(-)
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index 851018eef885e..c8199ee079eff 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -51,18 +51,9 @@ impl Device { /// /// It must also be ensured that `bindings::device::release` can be called from any thread. /// While not officially documented, this should be the case for any `struct device`. - pub unsafe fn from_raw(ptr: *mut bindings::device) -> ARef<Self> { - // SAFETY: By the safety requirements, ptr is valid. - // Initially increase the reference count by one to compensate for the final decrement once - // this newly created `ARef<Device>` instance is dropped. - unsafe { bindings::get_device(ptr) }; - - // CAST: `Self` is a `repr(transparent)` wrapper around `bindings::device`. - let ptr = ptr.cast::<Self>(); - - // SAFETY: `ptr` is valid by the safety requirements of this function. By the above call to - // `bindings::get_device` we also own a reference to the underlying `struct device`. - unsafe { ARef::from_raw(ptr::NonNull::new_unchecked(ptr)) } + pub unsafe fn get_device(ptr: *mut bindings::device) -> ARef<Self> { + // SAFETY: By the safety requirements ptr is valid + unsafe { Self::as_ref(ptr) }.into() }
/// Obtain the raw `struct device *`. diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs index dee5b4b18aec4..13a374a5cdb74 100644 --- a/rust/kernel/firmware.rs +++ b/rust/kernel/firmware.rs @@ -44,7 +44,7 @@ fn request_nowarn() -> Self { /// /// # fn no_run() -> Result<(), Error> { /// # // SAFETY: *NOT* safe, just for the example to get an `ARef<Device>` instance -/// # let dev = unsafe { Device::from_raw(core::ptr::null_mut()) }; +/// # let dev = unsafe { Device::get_device(core::ptr::null_mut()) }; /// /// let fw = Firmware::request(c_str!("path/to/firmware.bin"), &dev)?; /// let blob = fw.data();