Re: [PATCH v7 0/6] rust: DebugFS Bindings

[Dirk Behme <dirk.behme@de.bosch.com>]

On 25/06/2025 01:25, Matthew Maurer wrote:
> This series provides safe DebugFS bindings for Rust, with a sample
> module using them.
> 
> Signed-off-by: Matthew Maurer <mmaurer@google.com>


Same testing done as on v6:

Tested-by: Dirk Behme <dirk.behme@de.bosch.com>

Thanks!

Dirk

> ---
> Changes in v7:
> - Rewrote `entry::Entry` -> `Entry`
> - Use `c_int` and `c_void` from kernel prelude rather than core
> - Removed unnecessary `display_open` cast
> - Switched from `Deref` + an explicit box to `ForeignOwnable` for
>   attaching owned data.
> - Made `&'static` and `&'static mut` implement `ForeignOwnable`
> - Swapped "driver" to "module" in sample code
> - Link to v6: https://lore.kernel.org/r/20250618-debugfs-rust-v6-0-72cae211b133@google.com
> 
> Changes in v6:
> - Replaced explicit lifetimes with children keeping their parents alive.
> - Added support for attaching owned data.
> - Removed recomendation to only keep root handles and handles you want
>   to delete around.
> - Refactored some code into separate files to improve clarity.
> - Link to v5: https://lore.kernel.org/r/20250505-debugfs-rust-v5-0-3e93ce7bb76e@google.com
> 
> Changes in v5:
> - Made Dir + File wrappers around Entry
> - All functions return owning handles. To discard without drop, use
>   `forget`. To keep a handle without drop, use `ManuallyDrop`.
> - Fixed bugs around `not(CONFIG_DEBUG_FS)`
> - Removed unnecessary `addr_of!`
> - Link to v4: https://lore.kernel.org/r/20250502-debugfs-rust-v4-0-788a9c6c2e77@google.com
> 
> Changes in v4:
> - Remove SubDir, replace with type-level constant.
> - Add lifetime to Dir to prevent subdirectories and files from outliving
>   their parents and triggering an Oops when accessed.
> - Split unsafe blocks with two calls into two blocks
> - Access `private` field through direct pointer dereference, avoiding
>   creation of a reference to it.
> - Notably not changed - owning/non-owning handle defaults. The best read
>   I had from the thread was to continue with this mode, but I'm willing
>   to change if need be.
> - Comment changes
>   - More comment markdown
>   - Remove scopes from examples
>   - Put `as_ptr` properties into a `# Guarantees` section.
> - Link to v3: https://lore.kernel.org/r/20250501-debugfs-rust-v3-0-850869fab672@google.com
> 
> Changes in v3:
> - Split `Dir` into `Dir`/`SubDir`/`File` to improve API.
> - Add "." to end of all comments.
> - Convert INVARIANT to # Invariants on types.
> - Add backticks everywhere I found variables/types in my comments.
> - Promoted invariant comment to doc comment.
> - Extended sample commenting to make it clearer what is happening.
> - Link to v2: https://lore.kernel.org/r/20250430-debugfs-rust-v2-0-2e8d3985812b@google.com
> 
> Changes in v2:
> - Drop support for builder / pinned bindings in initial series
> - Remove `ARef` usage to abstract the dentry nature of handles
> - Remove error handling to discourage users from caring whether DebugFS
>   is enabled.
> - Support CONFIG_DEBUG_FS=n while leaving the API available
> - Fixed mistaken decimal/octal mixup
> - Doc/comment cleanup
> - Link to v1: https://lore.kernel.org/r/20250429-debugfs-rust-v1-0-6b6e7cb7929f@google.com
> 
> ---
> Matthew Maurer (6):
>       rust: debugfs: Bind DebugFS directory creation
>       rust: debugfs: Bind file creation for long-lived Display
>       rust: types: Support &'static and &'static mut ForeignOwnable
>       rust: debugfs: Support arbitrary owned backing for File
>       rust: debugfs: Support format hooks
>       rust: samples: Add debugfs sample
> 
>  MAINTAINERS                         |   3 +
>  rust/bindings/bindings_helper.h     |   1 +
>  rust/kernel/debugfs.rs              | 268 ++++++++++++++++++++++++++++++++++++
>  rust/kernel/debugfs/display_file.rs | 155 +++++++++++++++++++++
>  rust/kernel/debugfs/entry.rs        |  66 +++++++++
>  rust/kernel/lib.rs                  |   1 +
>  rust/kernel/types.rs                |  58 ++++++++
>  samples/rust/Kconfig                |  11 ++
>  samples/rust/Makefile               |   1 +
>  samples/rust/rust_debugfs.rs        |  76 ++++++++++
>  10 files changed, 640 insertions(+)
> ---
> base-commit: bd243cb5d922cc6343007a3f3918c8d1970541d2
> change-id: 20250428-debugfs-rust-3cd5c97eb7d1
> 
> Best regards,