Re: [PATCH v3] rust: make mutually exclusive with CFI_CLANG

From: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
To: Conor Dooley <conor@kernel.org>
Cc: linux-riscv@lists.infradead.org,
	Conor Dooley <conor.dooley@microchip.com>,
	 stable@vger.kernel.org, Miguel Ojeda <ojeda@kernel.org>,
	 Alex Gaynor <alex.gaynor@gmail.com>,
	Wedson Almeida Filho <wedsonaf@gmail.com>,
	linux-kernel@vger.kernel.org,  rust-for-linux@vger.kernel.org,
	Sami Tolvanen <samitolvanen@google.com>,
	 Kees Cook <keescook@chromium.org>,
	Nathan Chancellor <nathan@kernel.org>,
	llvm@lists.linux.dev
Subject: Re: [PATCH v3] rust: make mutually exclusive with CFI_CLANG
Date: Sun, 7 Apr 2024 22:02:46 +0200	[thread overview]
Message-ID: <CANiq72mUGAXj+ajfojfMgOD7S22Q0Y0Y4QCTxNLoNxwCSpksdg@mail.gmail.com> (raw)
In-Reply-To: <20240404-providing-emporium-e652e359c711@spud>

On Thu, Apr 4, 2024 at 4:17 PM Conor Dooley <conor@kernel.org> wrote:
>
> From: Conor Dooley <conor.dooley@microchip.com>
>
> On RISC-V and arm64, and presumably x86, if CFI_CLANG is enabled,
> loading a rust module will trigger a kernel panic. Support for
> sanitisers, including kcfi (CFI_CLANG), is in the works, but for now
> they're nightly-only options in rustc. Make RUST depend on !CFI_CLANG
> to prevent configuring a kernel without symmetrical support for kfi.
>
> Fixes: 2f7ab1267dc9 ("Kbuild: add Rust support")
> cc: stable@vger.kernel.org
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

[ Matthew Maurer writes [1]:

    This patch is fine by me - the last patch needed for KCFI to be
    functional in Rust just landed upstream last night, so we should
    revisit this (in the form of enabling it) once we move to
    `rustc-1.79.0` or later.

  Ramon de C Valle also gave feedback [2] on the status of KCFI for
  Rust and created a tracking issue [3] in upstream Rust.   - Miguel ]

[ Added feedback from the list, links, and used Cc for the tag. ]

Applied to `rust-fixes` -- thanks everyone! Please feel free to send
more tags for this one.

Cheers,
Miguel