Re: [PATCH net-next v5 1/5] rust: core abstractions for network PHY drivers

[Benno Lossin <benno.lossin@proton.me>]

On 21.10.23 09:30, FUJITA Tomonori wrote:
> On Sat, 21 Oct 2023 07:25:17 +0000
> Benno Lossin <benno.lossin@proton.me> wrote:
> 
>> On 20.10.23 14:54, FUJITA Tomonori wrote:
>>> On Fri, 20 Oct 2023 09:34:46 +0900 (JST)
>>> FUJITA Tomonori <fujita.tomonori@gmail.com> wrote:
>>>
>>>> On Thu, 19 Oct 2023 15:20:51 +0000
>>>> Benno Lossin <benno.lossin@proton.me> wrote:
>>>>
>>>>> I would like to remove the mutable static variable and simplify
>>>>> the macro.
>>>>
>>>> How about adding DriverVTable array to Registration?
>>>>
>>>> /// Registration structure for a PHY driver.
>>>> ///
>>>> /// # Invariants
>>>> ///
>>>> /// The `drivers` slice are currently registered to the kernel via `phy_drivers_register`.
>>>> pub struct Registration<const N: usize> {
>>>>       drivers: [DriverVTable; N],
>>>> }
>>>>
>>>> impl<const N: usize> Registration<{ N }> {
>>>>       /// Registers a PHY driver.
>>>>       pub fn register(
>>>>           module: &'static crate::ThisModule,
>>>>           drivers: [DriverVTable; N],
>>>>       ) -> Result<Self> {
>>>>           let mut reg = Registration { drivers };
>>>>           let ptr = reg.drivers.as_mut_ptr().cast::<bindings::phy_driver>();
>>>>           // SAFETY: The type invariants of [`DriverVTable`] ensure that all elements of the `drivers` slice
>>>>           // are initialized properly. So an FFI call with a valid pointer.
>>>>           to_result(unsafe {
>>>>               bindings::phy_drivers_register(ptr, reg.drivers.len().try_into()?, module.0)
>>>>           })?;
>>>>           // INVARIANT: The `drivers` slice is successfully registered to the kernel via `phy_drivers_register`.
>>>>           Ok(reg)
>>>>       }
>>>> }
>>>
>>> Scratch this.
>>>
>>> This doesn't work. Also simply putting slice of DriverVTable into
>>> Module strcut doesn't work.
>>
>> Why does it not work? I tried it and it compiled fine for me.
> 
> You can compile but the kernel crashes. The addresses of the callback
> functions are invalid.

Can you please share your setup and the error? For me it booted fine.

-- 
Cheers,
Benno