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References: <20230718055235.1050223-1-ojeda@kernel.org>
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From:   Masahiro Yamada <masahiroy@kernel.org>
Date:   Fri, 21 Jul 2023 02:17:55 +0900
Message-ID: <CAK7LNAQ-hjW_19fjA+E-bQCrXcVPdN4-GvzAnEnYzna5KRVXew@mail.gmail.com>
Subject: Re: [PATCH] kbuild: rust: avoid creating temporary files
To:     Miguel Ojeda <ojeda@kernel.org>
Cc:     Wedson Almeida Filho <wedsonaf@gmail.com>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Nicolas Schier <nicolas@fjasle.eu>,
        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>,
        Alice Ryhl <aliceryhl@google.com>,
        Andreas Hindborg <a.hindborg@samsung.com>,
        linux-kbuild@vger.kernel.org, rust-for-linux@vger.kernel.org,
        linux-kernel@vger.kernel.org, patches@lists.linux.dev,
        Raphael Nestler <raphael.nestler@gmail.com>,
        Andrea Righi <andrea.righi@canonical.com>,
        stable@vger.kernel.org
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On Tue, Jul 18, 2023 at 2:52=E2=80=AFPM Miguel Ojeda <ojeda@kernel.org> wro=
te:
>
> `rustc` outputs by default the temporary files (i.e. the ones saved
> by `-Csave-temps`, such as `*.rcgu*` files) in the current working
> directory when `-o` and `--out-dir` are not given (even if
> `--emit=3Dx=3Dpath` is given, i.e. it does not use those for temporaries)=
.
>
> Since out-of-tree modules are compiled from the `linux` tree,
> `rustc` then tries to create them there, which may not be accessible.
>
> Thus pass `--out-dir` explicitly, even if it is just for the temporary
> files.
>
> Reported-by: Raphael Nestler <raphael.nestler@gmail.com>
> Closes: https://github.com/Rust-for-Linux/linux/issues/1015
> Reported-by: Andrea Righi <andrea.righi@canonical.com>
> Tested-by: Raphael Nestler <raphael.nestler@gmail.com>
> Tested-by: Andrea Righi <andrea.righi@canonical.com>
> Cc: stable@vger.kernel.org
> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
> ---


Applied to linux-kbuild/fixes. Thanks.

I believe this is a fix, so I will include it
in my next pull request.


>  scripts/Makefile.build | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/scripts/Makefile.build b/scripts/Makefile.build
> index 6413342a03f4..82e3fb19fdaf 100644
> --- a/scripts/Makefile.build
> +++ b/scripts/Makefile.build
> @@ -264,6 +264,9 @@ $(obj)/%.lst: $(src)/%.c FORCE
>
>  rust_allowed_features :=3D new_uninit
>
> +# `--out-dir` is required to avoid temporaries being created by `rustc` =
in the
> +# current working directory, which may be not accessible in the out-of-t=
ree
> +# modules case.
>  rust_common_cmd =3D \
>         RUST_MODFILE=3D$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
>         -Zallow-features=3D$(rust_allowed_features) \
> @@ -272,7 +275,7 @@ rust_common_cmd =3D \
>         --extern alloc --extern kernel \
>         --crate-type rlib -L $(objtree)/rust/ \
>         --crate-name $(basename $(notdir $@)) \
> -       --emit=3Ddep-info=3D$(depfile)
> +       --out-dir $(dir $@) --emit=3Ddep-info=3D$(depfile)
>
>  # `--emit=3Dobj`, `--emit=3Dasm` and `--emit=3Dllvm-ir` imply a single c=
odegen unit
>  # will be used. We explicitly request `-Ccodegen-units=3D1` in any case,=
 and
>
> base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5
> --
> 2.41.0
>


--=20
Best Regards
Masahiro Yamada