Re: rust compile failure in next-20260730

[Luna Jernberg]

Noticed this too

Den fre 31 juli 2026 kl 15:21 skrev Thorsten Leemhuis <linux@xxxxxxxxxxxxx>:
>
> On 7/31/26 14:28, Bert Karwatzki wrote:
> > With next-20260730 building a kernel with CONFIG_RUST=y fails with
> > the following error:
>
> Ran into this, too. Fixing this is discussed in this thread:
> https://lore.kernel.org/all/20260731075644.20215-1-ojeda@xxxxxxxxxx/
>
> >  RUSTC L rust/kernel.o
> > error[E0308]: mismatched types
> >      --> rust/kernel/sync/poll.rs:175:44
> >       |
> >   175 |         unsafe { bindings::kvfree_call_rcu((*ptr).rcu.get(), ptr.cast::<ffi::c_void>()) };
> >       |                  ------------------------- ^^^^^^^^^^^^^^^^ expected `*mut kvfree_rcu_head`, found `*mut callback_head`
> >       |                  |
> >       |                  arguments to this function are incorrect
> >       |
> >       = note: expected raw pointer `*mut bindings::kvfree_rcu_head`
> >                  found raw pointer `*mut bindings::callback_head`
> > note: function defined here
> >      --> /mnt/data/linux-forest/linux-next/rust/bindings/bindings_generated.rs:73708:12
> >       |
> > 73708 |     pub fn kvfree_call_rcu(head: *mut kvfree_rcu_head, ptr: *mut ffi::c_void);
> >       |            ^^^^^^^^^^^^^^^
> >
> > error: aborting due to 1 previous error
> >
> > For more information about this error, try `rustc --explain E0308`.
> > make[5]: *** [rust/Makefile:781: rust/kernel.o] Fehler 1
> > make[4]: *** [Makefile:1420: prepare] Fehler 2
> > make[3]: *** [debian/rules:80: build-arch] Fehler 2
> >
> > Reverting the following commits:
> > ef32a74f8f6a ("mm/slab: introduce kfree_rcu_nolock()")
> > bdd0cc9f0ffc ("mm/slab: introduce struct kvfree_rcu_head for kvfree_rcu batching")
> >
> > make the compilation work again.
> >
> > Bert Karwatzki
>
>