Re: [PATCH v8 5/6] rust: ww_mutex: add Mutex, AcquireCtx and MutexGuard

["Onur Özkan" <work@onurozkan.dev>]

On Tue, 2 Dec 2025 09:49:34 +0800
kernel test robot <lkp@intel.com> wrote:

> Hi Onur,
> 
> kernel test robot noticed the following build errors:
> 
> [auto build test ERROR on tip/locking/core]
> [also build test ERROR on rust/rust-next linus/master v6.18
> next-20251201] [If your patch is applied to the wrong git tree,
> kindly drop us a note. And when submitting patch, we suggest to use
> '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:
> https://github.com/intel-lab-lkp/linux/commits/Onur-zkan/rust-add-C-wrappers-for-ww_mutex-inline-functions/20251201-184152
> base:   tip/locking/core patch link:
> https://lore.kernel.org/r/20251201102855.4413-6-work%40onurozkan.dev
> patch subject: [PATCH v8 5/6] rust: ww_mutex: add Mutex, AcquireCtx
> and MutexGuard config: arm64-randconfig-001-20251202
> (https://download.01.org/0day-ci/archive/20251202/202512020943.whFrDsXx-lkp@intel.com/config)
> compiler: clang version 22.0.0git
> (https://github.com/llvm/llvm-project
> b3428bb966f1de8aa48375ffee0eba04ede133b7) rustc: rustc 1.88.0
> (6b00bc388 2025-06-23) reproduce (this is a W=1 build):
> (https://download.01.org/0day-ci/archive/20251202/202512020943.whFrDsXx-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new
> version of the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes:
> https://lore.kernel.org/oe-kbuild-all/202512020943.whFrDsXx-lkp@intel.com/
> 
> All errors (new ones prefixed by >>):
> 
> >> error[E0609]: no field `ww_class` on type `ww_acquire_ctx`
>    --> rust/kernel/sync/lock/ww_mutex/acquire_ctx.rs:110:41
>    |
>    110 |         let class_ptr = unsafe { (*ctx).ww_class };
>    |                                         ^^^^^^^^ unknown field
>    |
>    = note: available field is: `_address`
> --
> >> error[E0609]: no field `ww_class` on type `ww_acquire_ctx`
>    --> rust/kernel/sync/lock/ww_mutex.rs:252:49
>    |
>    252 |             let ctx_class = unsafe { (*ctx_ptr).ww_class };
>    |                                                 ^^^^^^^^ unknown
> field |
>    = note: available field is: `_address`
> 

I got a different error:

  CLIPPY L rust/kernel.o
error[E0583]: file not found for module `lock_set`
  --> rust/kernel/sync/lock/ww_mutex.rs:27:1
   |
27 | mod lock_set;
   | ^^^^^^^^^^^^^
   |
   = help: to create the module `lock_set`, create file
  "rust/kernel/sync/lock/ww_mutex/lock_set.rs" or
  "rust/kernel/sync/lock/ww_mutex/lock_set/mod.rs" = note: if there is
  a `mod lock_set` elsewhere in the crate already, import it with `use
  crate::...` instead

I will fix this in the next version. It only appears in the 5th
patch of the series.

But I have no idea about the "no field `ww_class`" error yet. We have
this [1] change so I assume something didn't work properly with the
bindgen generation? I will look more into that later.

[1]: https://github.com/intel-lab-lkp/linux/commit/23ba7e6a3f593455a

-Onur