Re: [PATCH 1/2] rust: pci: impl Send + Sync for pci::Device

[Danilo Krummrich <dakr@kernel.org>]

On Wed, Mar 19, 2025 at 12:18:35PM +0100, Andreas Hindborg wrote:
> "Danilo Krummrich" <dakr@kernel.org> writes:
> 
> > Commit 7b948a2af6b5 ("rust: pci: fix unrestricted &mut pci::Device")
> > changed the definition of pci::Device and discarded the implicitly
> > derived Send and Sync traits.
> >
> > This isn't required by upstream code yet, and hence did not cause any
> > issues. However, it is relied on by upcoming drivers, hence add it back
> > in.
> >
> > Signed-off-by: Danilo Krummrich <dakr@kernel.org>
> > ---
> >  rust/kernel/pci.rs | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
> > index 0ac6cef74f81..0d09ae34a64d 100644
> > --- a/rust/kernel/pci.rs
> > +++ b/rust/kernel/pci.rs
> > @@ -465,3 +465,10 @@ fn as_ref(&self) -> &device::Device {
> >          unsafe { device::Device::as_ref(dev) }
> >      }
> >  }
> > +
> > +// SAFETY: A `Device` is always reference-counted and can be released from any thread.
> > +unsafe impl Send for Device {}
> > +
> > +// SAFETY: `Device` can be shared among threads because all methods of `Device`
> > +// (i.e. `Device<Normal>) are thread safe.
> > +unsafe impl Sync for Device {}
> >
> > base-commit: 4d320e30ee04c25c660eca2bb33e846ebb71a79a
> 
> I can't find the base-commit and the patch does not apply clean on v6.14-rc7:
> 
>   patching file rust/kernel/pci.rs
>   Hunk #1 succeeded at 432 with fuzz 1 (offset -33 lines).
> 
> Otherwise looks good. You might want to rebase?

This is intentional, the base commit is from the driver-core tree, where also
commit 7b948a2af6b5 ("rust: pci: fix unrestricted &mut pci::Device") landed.

> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
> 
> 
> Best regards,
> Andreas Hindborg
> 
>