linux-kernel - [PATCH v2 0/5] Check Rust signatures at compile time

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250228-export-macro-v2-0-569cc7e8926c@google.com>
Date: Fri, 28 Feb 2025 12:39:29 +0000
From: Alice Ryhl <aliceryhl@...gle.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Miguel Ojeda <ojeda@...nel.org>
Cc: Petr Mladek <pmladek@...e.com>, Steven Rostedt <rostedt@...dmis.org>, 
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>, 
	Rasmus Villemoes <linux@...musvillemoes.dk>, Sergey Senozhatsky <senozhatsky@...omium.org>, 
	Andrew Morton <akpm@...ux-foundation.org>, Boqun Feng <boqun.feng@...il.com>, 
	Gary Guo <gary@...yguo.net>, 
	"Björn Roy Baron" <bjorn3_gh@...tonmail.com>, Benno Lossin <benno.lossin@...ton.me>, 
	Andreas Hindborg <a.hindborg@...nel.org>, Trevor Gross <tmgross@...ch.edu>, 
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Maxime Ripard <mripard@...nel.org>, 
	Thomas Zimmermann <tzimmermann@...e.de>, David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
	linux-kernel@...r.kernel.org, rust-for-linux@...r.kernel.org, 
	dri-devel@...ts.freedesktop.org, Alice Ryhl <aliceryhl@...gle.com>
Subject: [PATCH v2 0/5] Check Rust signatures at compile time

Rust has two different tools for generating function declarations to
call across the FFI boundary:

* bindgen. Generates Rust declarations from a C header.
* cbindgen. Generates C headers from Rust declarations.

In the kernel, we only use bindgen. This is because cbindgen assumes a
cargo-based buildsystem, so it is not compatible with the kernel's build
system. This means that when C code calls a Rust function by name, its
signature must be duplicated in both Rust code and a C header, and the
signature needs to be kept in sync manually.

To eliminate this manual checking, introduce a new macro that verifies
at compile time that the two function declarations use the same
signature. The idea is to run the C declaration through bindgen, and
then have rustc verify that the function pointers have the same type.

The main commit of this series is "rust: add #[export] macro". Please
see its commit message for more details.

Signed-off-by: Alice Ryhl <aliceryhl@...gle.com>
---
Changes in v2:
- Various improvements to documentation.
- Split out quote! changes into its own commit.
- Link to v1: https://lore.kernel.org/r/20250227-export-macro-v1-0-948775fc37aa@google.com

---
Alice Ryhl (5):
      rust: fix signature of rust_fmt_argument
      rust: macros: support additional tokens in quote!
      rust: add #[export] macro
      print: use new #[export] macro for rust_fmt_argument
      panic_qr: use new #[export] macro

 drivers/gpu/drm/drm_panic.c     |  5 -----
 drivers/gpu/drm/drm_panic_qr.rs | 15 +++++++++++----
 include/drm/drm_panic.h         |  7 +++++++
 include/linux/sprintf.h         |  3 +++
 lib/vsprintf.c                  |  3 ---
 rust/bindings/bindings_helper.h |  4 ++++
 rust/kernel/prelude.rs          |  2 +-
 rust/kernel/print.rs            | 10 +++++-----
 rust/macros/export.rs           | 28 ++++++++++++++++++++++++++++
 rust/macros/helpers.rs          | 19 ++++++++++++++++++-
 rust/macros/lib.rs              | 24 ++++++++++++++++++++++++
 rust/macros/quote.rs            | 21 +++++++++++++++++++--
 12 files changed, 120 insertions(+), 21 deletions(-)
---
base-commit: a64dcfb451e254085a7daee5fe51bf22959d52d3
change-id: 20250227-export-macro-9aa9f1016d8c

Best regards,
-- 
Alice Ryhl <aliceryhl@...gle.com>