Re: [PATCH v3 0/6] Rust: support `CPU_MITIGATIONS` and enable `objtool`

[Miguel Ojeda]

On Thu, Jul 25, 2024 at 8:35 PM Miguel Ojeda <ojeda@xxxxxxxxxx> wrote:
>
> Miguel Ojeda (6):
>   rust: module: add static pointer to `{init,cleanup}_module()`
>   x86/rust: support MITIGATION_RETPOLINE
>   x86/rust: support MITIGATION_RETHUNK
>   x86/rust: support MITIGATION_SLS
>   objtool/rust: list `noreturn` Rust functions
>   objtool/kbuild/rust: enable objtool for Rust
>
>  arch/x86/Makefile               |  7 ++++-
>  rust/Makefile                   | 22 +++++++++------
>  rust/macros/module.rs           | 12 +++++++++
>  scripts/Makefile.build          |  9 +++++--
>  scripts/generate_rust_target.rs | 15 +++++++++++
>  tools/objtool/check.c           | 48 ++++++++++++++++++++++++++++++++-
>  tools/objtool/noreturns.h       |  2 ++
>  7 files changed, 103 insertions(+), 12 deletions(-)

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

In the `noreturn` patch:

    [ Kees agrees this should be automated and Peter says:

        So it would be fairly simple to make objtool consume a magic section
        emitted by the compiler.. I think we've asked the compiler folks
        for that at some point even, but I don't have clear recollections.

      We will ask upstream Rust about it. And if they agree, then perhaps
      we can get Clang/GCC to implement something similar too -- for this
      sort of thing we can take advantage of the shorter cycles of `rustc`
      as well as their unstable features concept to experiment.

      Gary proposed using DWARF (though it would need to be available), and
      wrote a proof of concept script using the `object` and `gimli` crates:
      https://gist.github.com/nbdd0121/449692570622c2f46a29ad9f47c3379a

        - Miguel ]

    [ Added `len_mismatch_fail` symbol for new `kernel` crate code merged
      since then as well as 3 more `core::panicking` symbols that appear
      in `RUST_DEBUG_ASSERTIONS=y` builds.  - Miguel ]

Cheers,
Miguel