From: Nathan Chancellor <nathan@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
Nick Desaulniers <ndesaulniers@google.com>,
linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm64: Make CPU_BIG_ENDIAN depend on !LD_IS_LLD
Date: Sat, 6 Feb 2021 19:30:41 -0700 [thread overview]
Message-ID: <20210207023041.GA655027@ubuntu-m3-large-x86> (raw)
In-Reply-To: <20210202022441.1451389-1-nathan@kernel.org>
On Mon, Feb 01, 2021 at 07:24:42PM -0700, Nathan Chancellor wrote:
> Similar to commit 28187dc8ebd9 ("ARM: 9025/1: Kconfig: CPU_BIG_ENDIAN
> depends on !LD_IS_LLD"), ld.lld does not support aarch64 big endian,
> leading to the following build error when CONFIG_CPU_BIG_ENDIAN is
> selected:
>
> ld.lld: error: unknown emulation: aarch64linuxb
>
> There are not currently plans to implement big endian support for
> aarch64 in ld.lld but if it should be supported in the future, this
> symbol can depend on the version that first supports it. In the
> meantime, prevent this symbol from being selected to avoid these type
> of build errors.
>
> While we are here, the indentation of this symbol used spaces since its
> introduction in commit a872013d6d03 ("arm64: kconfig: allow
> CPU_BIG_ENDIAN to be selected"). Change it to tabs to be consistent with
> kernel coding style.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/380
> Link: https://github.com/ClangBuiltLinux/linux/issues/1288
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Fangrui has pushed proper aarch64linuxb and elf64-bigaarch64 for ld.lld:
https://reviews.llvm.org/D96211
https://reviews.llvm.org/D96188
This patch is needed for OUTPUT_FORMAT in the vDSO to work properly:
https://reviews.llvm.org/D96214
Once these are all merged into LLVM 13, I will update this to be:
depends on !LD_IS_LLD || LLD_VERSION >= 130000
Cheers,
Nathan
> ---
> arch/arm64/Kconfig | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index f39568b28ec1..5ddf9fe7b4ee 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -952,8 +952,9 @@ choice
> that is selected here.
>
> config CPU_BIG_ENDIAN
> - bool "Build big-endian kernel"
> - help
> + bool "Build big-endian kernel"
> + depends on !LD_IS_LLD
> + help
> Say Y if you plan on running a kernel with a big-endian userspace.
>
> config CPU_LITTLE_ENDIAN
>
> base-commit: 88bb507a74ea7d75fa49edd421eaa710a7d80598
> --
> 2.30.0
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
WARNING: multiple messages have this Message-ID (diff)
From: Nathan Chancellor <nathan@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
clang-built-linux@googlegroups.com,
Nick Desaulniers <ndesaulniers@google.com>,
linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>
Subject: Re: [PATCH] arm64: Make CPU_BIG_ENDIAN depend on !LD_IS_LLD
Date: Sat, 6 Feb 2021 19:30:41 -0700 [thread overview]
Message-ID: <20210207023041.GA655027@ubuntu-m3-large-x86> (raw)
In-Reply-To: <20210202022441.1451389-1-nathan@kernel.org>
On Mon, Feb 01, 2021 at 07:24:42PM -0700, Nathan Chancellor wrote:
> Similar to commit 28187dc8ebd9 ("ARM: 9025/1: Kconfig: CPU_BIG_ENDIAN
> depends on !LD_IS_LLD"), ld.lld does not support aarch64 big endian,
> leading to the following build error when CONFIG_CPU_BIG_ENDIAN is
> selected:
>
> ld.lld: error: unknown emulation: aarch64linuxb
>
> There are not currently plans to implement big endian support for
> aarch64 in ld.lld but if it should be supported in the future, this
> symbol can depend on the version that first supports it. In the
> meantime, prevent this symbol from being selected to avoid these type
> of build errors.
>
> While we are here, the indentation of this symbol used spaces since its
> introduction in commit a872013d6d03 ("arm64: kconfig: allow
> CPU_BIG_ENDIAN to be selected"). Change it to tabs to be consistent with
> kernel coding style.
>
> Link: https://github.com/ClangBuiltLinux/linux/issues/380
> Link: https://github.com/ClangBuiltLinux/linux/issues/1288
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Fangrui has pushed proper aarch64linuxb and elf64-bigaarch64 for ld.lld:
https://reviews.llvm.org/D96211
https://reviews.llvm.org/D96188
This patch is needed for OUTPUT_FORMAT in the vDSO to work properly:
https://reviews.llvm.org/D96214
Once these are all merged into LLVM 13, I will update this to be:
depends on !LD_IS_LLD || LLD_VERSION >= 130000
Cheers,
Nathan
> ---
> arch/arm64/Kconfig | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index f39568b28ec1..5ddf9fe7b4ee 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -952,8 +952,9 @@ choice
> that is selected here.
>
> config CPU_BIG_ENDIAN
> - bool "Build big-endian kernel"
> - help
> + bool "Build big-endian kernel"
> + depends on !LD_IS_LLD
> + help
> Say Y if you plan on running a kernel with a big-endian userspace.
>
> config CPU_LITTLE_ENDIAN
>
> base-commit: 88bb507a74ea7d75fa49edd421eaa710a7d80598
> --
> 2.30.0
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-02-07 2:31 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 2:24 [PATCH] arm64: Make CPU_BIG_ENDIAN depend on !LD_IS_LLD Nathan Chancellor
2021-02-02 2:24 ` Nathan Chancellor
2021-02-02 8:04 ` Arnd Bergmann
2021-02-02 8:04 ` Arnd Bergmann
2021-02-02 19:51 ` Nathan Chancellor
2021-02-02 19:51 ` Nathan Chancellor
2021-02-02 20:43 ` Arnd Bergmann
2021-02-02 20:43 ` Arnd Bergmann
2021-02-03 10:08 ` Peter Smith
2021-02-03 10:08 ` Peter Smith
2021-02-07 2:30 ` Nathan Chancellor [this message]
2021-02-07 2:30 ` Nathan Chancellor
2021-02-09 0:57 ` [PATCH v2] arm64: Make CPU_BIG_ENDIAN depend on ld.bfd or ld.lld 13.0.0+ Nathan Chancellor
2021-02-09 0:57 ` Nathan Chancellor
2021-02-09 1:39 ` Nick Desaulniers
2021-02-09 1:39 ` Nick Desaulniers
2021-02-09 14:35 ` Will Deacon
2021-02-09 14:35 ` Will Deacon
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