Re: [PATCH v2] rust: macros: fix soundness issue in `module!` macro

[Miguel Ojeda]

On Mon, Apr 1, 2024 at 8:53 PM Benno Lossin <benno.lossin@xxxxxxxxx> wrote:
>
> The `module!` macro creates glue code that are called by C to initialize
> the Rust modules using the `Module::init` function. Part of this glue
> code are the local functions `__init` and `__exit` that are used to
> initialize/destroy the Rust module.
> These functions are safe and also visible to the Rust mod in which the
> `module!` macro is invoked. This means that they can be called by other
> safe Rust code. But since they contain `unsafe` blocks that rely on only
> being called at the right time, this is a soundness issue.
>
> Wrap these generated functions inside of two private modules, this
> guarantees that the public functions cannot be called from the outside.
> Make the safe functions `unsafe` and add SAFETY comments.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Closes: https://github.com/Rust-for-Linux/linux/issues/629
> Fixes: 1fbde52bde73 ("rust: add `macros` crate")
> Signed-off-by: Benno Lossin <benno.lossin@xxxxxxxxx>

[ Capitalized comments, avoided newline in non-list SAFETY comments
  and reworded to add Reported-by and newline. ]

Applied to `rust-fixes` -- thanks everyone!

Cheers,
Miguel