Hi all,

Today's linux-next merge of the rust-pin-init tree got a conflict in:

  rust/kernel/devres.rs

between commit:

  75a7b151e808 ("rust: devres: fix leaking call to devm_add_action()")

from Linus' tree and commit:

  42415d163e5d ("rust: pin-init: add references to previously initialized fields")

from the rust-pin-init tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

-- 
Cheers,
Stephen Rothwell

diff --cc rust/kernel/devres.rs
index 132545962218,91dbf3f4b166..000000000000
--- a/rust/kernel/devres.rs
+++ b/rust/kernel/devres.rs
@@@ -135,21 -134,11 +135,19 @@@ impl<T: Send> Devres<T> 
          T: 'a,
          Error: From<E>,
      {
-         let callback = Self::devres_callback;
- 
          try_pin_init!(&this in Self {
              dev: dev.into(),
-             callback,
+             callback: Self::devres_callback,
              // INVARIANT: `inner` is properly initialized.
 -            inner <- {
 +            inner <- Opaque::pin_init(try_pin_init!(Inner {
 +                    devm <- Completion::new(),
 +                    revoke <- Completion::new(),
 +                    data <- Revocable::new(data),
 +            })),
 +            // TODO: Replace with "initializer code blocks" [1] once available.
 +            //
 +            // [1] https://github.com/Rust-for-Linux/pin-init/pull/69
 +            _add_action: {
                  // SAFETY: `this` is a valid pointer to uninitialized memory.
                  let inner = unsafe { &raw mut (*this.as_ptr()).inner };
  
@@@ -160,14 -149,14 +158,14 @@@
                  //    properly initialized, because we require `dev` (i.e. the *bound* device) to
                  //    live at least as long as the returned `impl PinInit<Self, Error>`.
                  to_result(unsafe {
-                     bindings::devm_add_action(dev.as_raw(), Some(callback), inner.cast())
+                     bindings::devm_add_action(dev.as_raw(), Some(*callback), inner.cast())
 -                })?;
 +                }).inspect_err(|_| {
 +                    let inner = Opaque::cast_into(inner);
  
 -                Opaque::pin_init(try_pin_init!(Inner {
 -                    devm <- Completion::new(),
 -                    revoke <- Completion::new(),
 -                    data <- Revocable::new(data),
 -                }))
 +                    // SAFETY: `inner` is a valid pointer to an `Inner<T>` and valid for both reads
 +                    // and writes.
 +                    unsafe { core::ptr::drop_in_place(inner) };
 +                })?;
              },
          })
      }

On 9/12/25 5:51 AM, Stephen Rothwell wrote:
> diff --cc rust/kernel/devres.rs
> index 132545962218,91dbf3f4b166..000000000000
> --- a/rust/kernel/devres.rs
> +++ b/rust/kernel/devres.rs
> @@@ -135,21 -134,11 +135,19 @@@ impl<T: Send> Devres<T> 
>           T: 'a,
>           Error: From<E>,
>       {
> -         let callback = Self::devres_callback;
> - 
>           try_pin_init!(&this in Self {
>               dev: dev.into(),
> -             callback,
> +             callback: Self::devres_callback,
>               // INVARIANT: `inner` is properly initialized.
>  -            inner <- {
>  +            inner <- Opaque::pin_init(try_pin_init!(Inner {
>  +                    devm <- Completion::new(),
>  +                    revoke <- Completion::new(),
>  +                    data <- Revocable::new(data),
>  +            })),
>  +            // TODO: Replace with "initializer code blocks" [1] once available.
>  +            //
>  +            // [1] https://github.com/Rust-for-Linux/pin-init/pull/69
>  +            _add_action: {
>                   // SAFETY: `this` is a valid pointer to uninitialized memory.
>                   let inner = unsafe { &raw mut (*this.as_ptr()).inner };
>   
> @@@ -160,14 -149,14 +158,14 @@@
>                   //    properly initialized, because we require `dev` (i.e. the *bound* device) to
>                   //    live at least as long as the returned `impl PinInit<Self, Error>`.
>                   to_result(unsafe {
> -                     bindings::devm_add_action(dev.as_raw(), Some(callback), inner.cast())
> +                     bindings::devm_add_action(dev.as_raw(), Some(*callback), inner.cast())
>  -                })?;
>  +                }).inspect_err(|_| {
>  +                    let inner = Opaque::cast_into(inner);
>   
>  -                Opaque::pin_init(try_pin_init!(Inner {
>  -                    devm <- Completion::new(),
>  -                    revoke <- Completion::new(),
>  -                    data <- Revocable::new(data),
>  -                }))
>  +                    // SAFETY: `inner` is a valid pointer to an `Inner<T>` and valid for both reads
>  +                    // and writes.
>  +                    unsafe { core::ptr::drop_in_place(inner) };
>  +                })?;
>               },
>           })
>       }

Looks good, thanks!