Re: [PATCH v10 13/27] rust: export generated symbols

[Greg Kroah-Hartman]

On Tue, Sep 27, 2022 at 03:14:44PM +0200, Miguel Ojeda wrote:
> All symbols are reexported reusing the `EXPORT_SYMBOL_GPL` macro
> from C. The lists of symbols are generated on the fly.
> 
> There are three main sets of symbols to distinguish:
> 
>   - The ones from the `core` and `alloc` crates (from the Rust
>     standard library). The code is licensed as Apache/MIT.
> 
>   - The ones from our abstractions in the `kernel` crate.
> 
>   - The helpers (already exported since they are not generated).
> 
> We export everything as GPL. This ensures we do not mistakenly
> expose GPL kernel symbols/features as non-GPL, even indirectly.
> 
> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
> Co-developed-by: Alex Gaynor <alex.gaynor@xxxxxxxxx>
> Signed-off-by: Alex Gaynor <alex.gaynor@xxxxxxxxx>
> Co-developed-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxxx>
> Signed-off-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxxx>
> Co-developed-by: Björn Roy Baron <bjorn3_gh@xxxxxxxxxxxxxx>
> Signed-off-by: Björn Roy Baron <bjorn3_gh@xxxxxxxxxxxxxx>
> Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
> ---
>  rust/exports.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>  create mode 100644 rust/exports.c
> 
> diff --git a/rust/exports.c b/rust/exports.c
> new file mode 100644
> index 000000000000..bb7cc64cecd0
> --- /dev/null
> +++ b/rust/exports.c
> @@ -0,0 +1,21 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * A hack to export Rust symbols for loadable modules without having to redo
> + * the entire `include/linux/export.h` logic in Rust.
> + *
> + * This requires the Rust's new/future `v0` mangling scheme because the default
> + * one ("legacy") uses invalid characters for C identifiers (thus we cannot use
> + * the `EXPORT_SYMBOL_*` macros).
> + *
> + * All symbols are exported as GPL-only to guarantee no GPL-only feature is
> + * accidentally exposed.
> + */
> +
> +#include <linux/module.h>
> +
> +#define EXPORT_SYMBOL_RUST_GPL(sym) extern int sym; EXPORT_SYMBOL_GPL(sym)
> +
> +#include "exports_core_generated.h"
> +#include "exports_alloc_generated.h"
> +#include "exports_bindings_generated.h"
> +#include "exports_kernel_generated.h"
> -- 
> 2.37.3

Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>