linux-kernel - Re: [PATCH v4] rust: Respect HOSTCC when linking for host

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAKwvOdnWc6b9-XwC56ADXx6K2XCzrUPc_VMsAt=syKsp_b6ZSg@mail.gmail.com>
Date:   Fri, 6 Oct 2023 13:39:11 -0700
From:   Nick Desaulniers <ndesaulniers@...gle.com>
To:     Matthew Maurer <mmaurer@...gle.com>
Cc:     Miguel Ojeda <ojeda@...nel.org>,
        Alex Gaynor <alex.gaynor@...il.com>,
        Wedson Almeida Filho <wedsonaf@...il.com>,
        Masahiro Yamada <masahiroy@...nel.org>,
        Nathan Chancellor <nathan@...nel.org>,
        Boqun Feng <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>,
        Björn Roy Baron <bjorn3_gh@...tonmail.com>,
        Benno Lossin <benno.lossin@...ton.me>,
        Andreas Hindborg <a.hindborg@...sung.com>,
        Alice Ryhl <aliceryhl@...gle.com>,
        Nicolas Schier <nicolas@...sle.eu>, Tom Rix <trix@...hat.com>,
        rust-for-linux@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-kbuild@...r.kernel.org, llvm@...ts.linux.dev
Subject: Re: [PATCH v4] rust: Respect HOSTCC when linking for host

On Thu, Oct 5, 2023 at 2:41 PM Matthew Maurer <mmaurer@...gle.com> wrote:
>
> Currently, rustc defaults to invoking `cc`, even if `HOSTCC` is defined,
> resulting in build failures in hermetic environments where `cc` does not
> exist. This includes both hostprogs and proc-macros.
>
> Since we are setting the linker to `HOSTCC`, we set the linker flavor to
> `gcc` explicitly. The linker-flavor selects both which linker to search
> for if the linker is unset, and which kind of linker flags to pass.
> Without this flag, `rustc` would attempt to determine which flags to
> pass based on the name of the binary passed as `HOSTCC`. `gcc` is the
> name of the linker-flavor used by `rustc` for all C compilers, including
> both `gcc` and `clang`.
>
> Signed-off-by: Matthew Maurer <mmaurer@...gle.com>
> ---
>
> Edited to use escsq in both Makefiles, as per Masahiro Yamada's
> suggestion.

That looks better; thanks Matthew!
Reviewed-by: Nick Desaulniers <ndesaulniers@...gle.com>

>
>  rust/Makefile         | 2 ++
>  scripts/Makefile.host | 2 ++
>  2 files changed, 4 insertions(+)
>
> diff --git a/rust/Makefile b/rust/Makefile
> index 87958e864be0..2ddd821d9435 100644
> --- a/rust/Makefile
> +++ b/rust/Makefile
> @@ -383,6 +383,8 @@ $(obj)/exports_kernel_generated.h: $(obj)/kernel.o FORCE
>  quiet_cmd_rustc_procmacro = $(RUSTC_OR_CLIPPY_QUIET) P $@
>        cmd_rustc_procmacro = \
>         $(RUSTC_OR_CLIPPY) $(rust_common_flags) \
> +               -Clinker-flavor=gcc -Clinker=$(HOSTCC) \
> +               -Clink-args='$(call escsq,$(KBUILD_HOSTLDFLAGS))' \
>                 --emit=dep-info=$(depfile) --emit=link=$@ --extern proc_macro \
>                 --crate-type proc-macro \
>                 --crate-name $(patsubst lib%.so,%,$(notdir $@)) $<
> diff --git a/scripts/Makefile.host b/scripts/Makefile.host
> index 8f7f842b54f9..08d83d9db31a 100644
> --- a/scripts/Makefile.host
> +++ b/scripts/Makefile.host
> @@ -91,6 +91,8 @@ hostcxx_flags  = -Wp,-MMD,$(depfile) \
>  # current working directory, which may be not accessible in the out-of-tree
>  # modules case.
>  hostrust_flags = --out-dir $(dir $@) --emit=dep-info=$(depfile) \
> +                -Clinker-flavor=gcc -Clinker=$(HOSTCC) \
> +                -Clink-args='$(call escsq,$(KBUILD_HOSTLDFLAGS))' \
>                   $(KBUILD_HOSTRUSTFLAGS) $(HOST_EXTRARUSTFLAGS) \
>                   $(HOSTRUSTFLAGS_$(target-stem))
>
> --
> 2.42.0.609.gbb76f46606-goog
>


-- 
Thanks,
~Nick Desaulniers