Re: [PATCH v11 08/13] rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>`

[Andreas Hindborg <a.hindborg@kernel.org>]

"Benno Lossin" <benno.lossin@proton.me> writes:

> On Fri Mar 7, 2025 at 10:38 PM CET, Andreas Hindborg wrote:
>> Allow pinned mutable references to structs that contain a `HrTimer` node to
>> be scheduled with the `hrtimer` subsystem.
>>
>> Acked-by: Frederic Weisbecker <frederic@kernel.org>
>> Reviewed-by: Lyude Paul <lyude@redhat.com>
>> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
>
> One problem below, with that fixed:
>
> Reviewed-by: Benno Lossin <benno.lossin@proton.me>

Thanks, will fix.

>
>> ---
>>  rust/kernel/time/hrtimer.rs         |   2 +
>>  rust/kernel/time/hrtimer/pin_mut.rs | 110 ++++++++++++++++++++++++++++++++++++
>>  2 files changed, 112 insertions(+)
>>
>> diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs
>> index fee8e44447ee..ab0950a964e8 100644
>> --- a/rust/kernel/time/hrtimer.rs
>> +++ b/rust/kernel/time/hrtimer.rs
>> @@ -433,3 +433,5 @@ unsafe fn timer_container_of(
>>  pub use arc::ArcHrTimerHandle;
>>  mod pin;
>>  pub use pin::PinHrTimerHandle;
>> +mod pin_mut;
>> +pub use pin_mut::PinMutHrTimerHandle;
>> diff --git a/rust/kernel/time/hrtimer/pin_mut.rs b/rust/kernel/time/hrtimer/pin_mut.rs
>> new file mode 100644
>> index 000000000000..007f47d26df6
>> --- /dev/null
>> +++ b/rust/kernel/time/hrtimer/pin_mut.rs
>> @@ -0,0 +1,110 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +
>> +use super::{
>> +    HasHrTimer, HrTimer, HrTimerCallback, HrTimerHandle, RawHrTimerCallback, UnsafeHrTimerPointer,
>> +};
>> +use crate::time::Ktime;
>> +use core::{marker::PhantomData, pin::Pin, ptr::NonNull};
>> +
>> +/// A handle for a `Pin<&mut HasHrTimer>`. When the handle exists, the timer might
>> +/// be running.
>> +pub struct PinMutHrTimerHandle<'a, T>
>> +where
>> +    T: HasHrTimer<T>,
>> +{
>> +    pub(crate) inner: NonNull<T>,
>> +    _p: PhantomData<&'a T>,
>
> This should be `PhantomData<&'a mut T>`.

Nice catch!



Best regards,
Andreas Hindborg