Commit bbe98f4f authored by Danilo Krummrich's avatar Danilo Krummrich Committed by Greg Kroah-Hartman
Browse files

firmware: rust: improve safety comments 



Improve the wording of safety comments to be more explicit about what
exactly is guaranteed to be valid.

Suggested-by: default avatarBenno Lossin <benno.lossin@proton.me>
Signed-off-by: default avatarDanilo Krummrich <dakr@redhat.com>
Link: https://lore.kernel.org/r/20240619132029.59296-1-dakr@redhat.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 269e974e

rust/kernel/firmware.rs

+6 −7
Original line number Diff line number Diff line
@@ -22,8 +22,7 @@ 
///

/// The pointer is valid, and has ownership over the instance of `struct firmware`.

///

/// Once requested, the `Firmware` backing buffer is not modified until it is freed when `Firmware`

/// is dropped.

/// The `Firmware`'s backing buffer is not modified.

///

/// # Examples

///
@@ -72,22 +71,22 @@ fn as_raw(&self) -> *mut bindings::firmware { 


    /// Returns the size of the requested firmware in bytes.

    pub fn size(&self) -> usize {

        // SAFETY: Safe by the type invariant.

        // SAFETY: `self.as_raw()` is valid by the type invariant.

        unsafe { (*self.as_raw()).size }

    }



    /// Returns the requested firmware as `&[u8]`.

    pub fn data(&self) -> &[u8] {

        // SAFETY: Safe by the type invariant. Additionally, `bindings::firmware` guarantees, if

        // successfully requested, that `bindings::firmware::data` has a size of

        // `bindings::firmware::size` bytes.

        // SAFETY: `self.as_raw()` is valid by the type invariant. Additionally,

        // `bindings::firmware` guarantees, if successfully requested, that

        // `bindings::firmware::data` has a size of `bindings::firmware::size` bytes.

        unsafe { core::slice::from_raw_parts((*self.as_raw()).data, self.size()) }

    }

}



impl Drop for Firmware {

    fn drop(&mut self) {

        // SAFETY: Safe by the type invariant.

        // SAFETY: `self.as_raw()` is valid by the type invariant.

        unsafe { bindings::release_firmware(self.as_raw()) };

    }

}