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From: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Date: Wed, 12 Jun 2024 00:08:30 +0200
Message-ID: <CANiq72mXWERtFSqQRtcgP28aLokwZmXaBiqcrn_zoASawjfdsQ@mail.gmail.com>
Subject: Re: [PATCH] arch: um: rust: Use the generated target.json again
To: David Gow <davidgow@google.com>
Cc: Rae Moar <rmoar@google.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, 
	Miguel Ojeda <ojeda@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>, Masahiro Yamada <masahiroy@kernel.org>, 
	Jamie Cunliffe <Jamie.Cunliffe@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, 
	Richard Weinberger <richard@nod.at>, Anton Ivanov <anton.ivanov@cambridgegreys.com>, 
	Johannes Berg <johannes@sipsolutions.net>, kunit-dev@googlegroups.com, 
	linux-kernel@vger.kernel.org, linux-um@lists.infradead.org, 
	rust-for-linux@vger.kernel.org, x86@kernel.org, 
	Wedson Almeida Filho <wedsonaf@gmail.com>, Borislav Petkov <bp@alien8.de>, 
	Dave Hansen <dave.hansen@linux.intel.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>
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On Wed, May 29, 2024 at 11:33=E2=80=AFAM David Gow <davidgow@google.com> wr=
ote:
>
> The Rust compiler can take a target config from 'target.json', which is
> generated by scripts/generate_rust_target.rs. It used to be that all
> Linux architectures used this to generate a target.json, but now
> architectures must opt-in to this, or they will default to the Rust
> compiler's built-in target definition.
>
> This is mostly okay for (64-bit) x86 and UML, except that it can
> generate SSE instructions, which we can't use in the kernel. So
> re-instate the custom target.json, which disables SSE (and generally
> enables the 'soft-float' feature). This fixes the following compile
> error:
>
> error: <unknown>:0:0: in function _RNvMNtCs5QSdWC790r4_4core3f32f7next_up=
 float (float): SSE register return with SSE disabled
>
> Fixes: f82811e22b48 ("rust: Refactor the build target to allow the use of=
 builtin targets")
> Signed-off-by: David Gow <davidgow@google.com>

I guess this should go through UML, but please let me know otherwise
(I don't see it in next).

Tested-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>

Should this have a

Cc: stable@vger.kernel.org

too?

Thanks!

Cheers,
Miguel