[PATCH 11/17] rust: export generated symbols

From: Miguel Ojeda <ojeda@kernel.org>

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.

Co-developed-by: Alex Gaynor <redacted>
Signed-off-by: Alex Gaynor <redacted>
Co-developed-by: Geoffrey Thomas <redacted>
Signed-off-by: Geoffrey Thomas <redacted>
Co-developed-by: Finn Behrens <redacted>
Signed-off-by: Finn Behrens <redacted>
Co-developed-by: Adam Bratschi-Kaye <redacted>
Signed-off-by: Adam Bratschi-Kaye <redacted>
Co-developed-by: Wedson Almeida Filho <redacted>
Signed-off-by: Wedson Almeida Filho <redacted>
Co-developed-by: Boqun Feng <redacted>
Signed-off-by: Boqun Feng <redacted>
Co-developed-by: Sumera Priyadarsini <redacted>
Signed-off-by: Sumera Priyadarsini <redacted>
Co-developed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Co-developed-by: Sven Van Asbroeck <redacted>
Signed-off-by: Sven Van Asbroeck <redacted>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boris-Chengbiao Zhou <redacted>
Signed-off-by: Boris-Chengbiao Zhou <redacted>
Co-developed-by: Fox Chen <redacted>
Signed-off-by: Fox Chen <redacted>
Co-developed-by: Ayaan Zaidi <redacted>
Signed-off-by: Ayaan Zaidi <redacted>
Co-developed-by: Douglas Su <redacted>
Signed-off-by: Douglas Su <redacted>
Co-developed-by: Yuki Okushi <redacted>
Signed-off-by: Yuki Okushi <redacted>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 rust/exports.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 rust/exports.c

diff --git a/rust/exports.c b/rust/exports.c
new file mode 100644
index 00000000000..d7dff1b3b91
--- /dev/null
+++ b/rust/exports.c

@@ -0,0 +1,16 @@
+// 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).
+
+#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_kernel_generated.h"

-- 
2.32.0