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From:   Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date:   Tue, 24 Oct 2023 00:15:53 +0200
Message-ID: <CANiq72nTE_qua9w+EeqiPCukst4876Gi7gHeusFLofYZRoJCDw@mail.gmail.com>
Subject: Re: [PATCH 3/4] x86/rust: depend on !RETHUNK
To:     Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Cc:     Miguel Ojeda <ojeda@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Josh Poimboeuf <jpoimboe@kernel.org>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
        =?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>,
        Benno Lossin <benno.lossin@proton.me>,
        Andreas Hindborg <a.hindborg@samsung.com>,
        Alice Ryhl <aliceryhl@google.com>, x86@kernel.org,
        rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
        patches@lists.linux.dev
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On Mon, Oct 23, 2023 at 8:43=E2=80=AFPM Martin Rodriguez Reboredo
<yakoyoku@gmail.com> wrote:
>
> I'll mention that I've tested boots, both in bare metal and QEMU, with
> `RUST=3Dy` and `RETHUNK=3Dy` and they were alright regardless of `objtool=
`
> warnings. Although, if you had an issue in the past then I'd like to know
> about it.

These are mitigations -- things do functionally work if they are not
applied, but you would be vulnerable.

In other words, it is not like e.g. IBT where you could have noticed
it breaking by running it normally if you happened to have a supported
platform.

Cheers,
Miguel