Re: [PATCH v2 0/4] Improve soundness of bus device abstractions

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Mar 14, 2025 at 05:09:03PM +0100, Danilo Krummrich wrote:
> Currently, when sharing references of bus devices (e.g. ARef<pci::Device>), we
> do not have a way to restrict which functions of a bus device can be called.
> 
> Consequently, it is possible to call all bus device functions concurrently from
> any context. This includes functions, which access fields of the (bus) device,
> which are not protected against concurrent access.
> 
> This is improved by applying an execution context to the bus device in form of a
> generic type.
> 
> For instance, the PCI device reference that is passed to probe() has the type
> pci::Device<Core>, which implements all functions that are only allowed to be
> called from bus callbacks.
> 
> The implementation for the default context (pci::Device) contains all functions
> that are safe to call from any context concurrently.
> 
> The context types can be extended as required, e.g. to limit availability  of
> certain (bus) device functions to probe().
> 
> A branch containing the patches can be found in [1].
> 
> [1] https://web.git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=rust/device
> 
> Changes in v2:
>   - make `DeviceContext` trait sealed
>   - impl From<&pci::Device<device::Core>> for ARef<pci::Device>
>   - impl From<&platform::Device<device::Core>> for ARef<platform::Device>
>   - rebase onto v6.14-rc6
>   - apply RBs
> 
> Danilo Krummrich (4):
>   rust: pci: use to_result() in enable_device_mem()
>   rust: device: implement device context marker
>   rust: pci: fix unrestricted &mut pci::Device
>   rust: platform: fix unrestricted &mut platform::Device
> 
>  rust/kernel/device.rs                |  26 +++++
>  rust/kernel/pci.rs                   | 137 +++++++++++++++++----------
>  rust/kernel/platform.rs              |  95 +++++++++++++------
>  samples/rust/rust_driver_pci.rs      |   8 +-
>  samples/rust/rust_driver_platform.rs |  11 ++-
>  5 files changed, 187 insertions(+), 90 deletions(-)

Thanks for doing this work, looks good to me.  Mind if I suck it into
the driver-core tree now?  Or do you want it to go through a different
tree?

thanks,

greg k-h