From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nathan Chancellor <natechancellor@gmail.com>,
Sedat Dilek <sedat.dilek@gmail.com>,
Kees Cook <keescook@chromium.org>,
Sami Tolvanen <samitolvanen@google.com>,
Michal Marek <michal.lkml@markovi.net>,
Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Dominik Brodowski <linux@dominikbrodowski.net>,
Nicholas Piggin <npiggin@gmail.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Vasily Gorbik <gor@linux.ibm.com>, Adrian Reber <adrian@lisas.de>,
Richard Guy Briggs <rgb@redhat.com>,
Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 3/4] Makefile: lld: tell clang to use lld
Date: Wed, 13 Feb 2019 23:58:18 +0900 [thread overview]
Message-ID: <CAK7LNATZY-K4g81LLvXpjp=+oMSY8L0wQoVXgHt-Bjrb2WXnNg@mail.gmail.com> (raw)
In-Reply-To: <20190211193008.24101-3-ndesaulniers@google.com>
On Tue, Feb 12, 2019 at 5:42 AM <ndesaulniers@google.com> wrote:
>
> This is needed because clang doesn't select which linker to use based on
> $LD but rather -fuse-ld=lld. This is problematic especially for
> cc-ldoption, which checks for linker flag support via invoking the
> compiler, rather than the linker.
Sorry, please explain what kind of problem
this patch solves.
[1] $(LD) is used to link vmlinux, modules, etc.
[2] $(CC) is used to link vdso, etc.
and -fuse-ld= selects which linker is invoked from $(CC)
Is it a problem to use a different
type of linker for [1] and [2] ?
Thanks.
> Link: https://github.com/ClangBuiltLinux/linux/issues/342
> Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
> Changes V1->V2:
> * add reviewed and tested by tags.
> * move this addition up 2 statments so that it's properly added to
> KBUILD_*FLAGS as per Nathan.
>
> Makefile | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/Makefile b/Makefile
> index d3b65e96d183..00e8e01d23fc 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -500,6 +500,9 @@ ifneq ($(GCC_TOOLCHAIN),)
> CLANG_FLAGS += --gcc-toolchain=$(GCC_TOOLCHAIN)
> endif
> CLANG_FLAGS += -no-integrated-as
> +ifneq ($(shell $(LD) --version 2>&1 | head -n 1 | grep LLD),)
> +CLANG_FLAGS += -fuse-ld=lld
> +endif
> KBUILD_CFLAGS += $(CLANG_FLAGS)
> KBUILD_AFLAGS += $(CLANG_FLAGS)
> export CLANG_FLAGS
> --
> 2.20.1.791.gb4d0f1c61a-goog
>
--
Best Regards
Masahiro Yamada
next prev parent reply other threads:[~2019-02-13 14:59 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-11 19:30 [PATCH v2 1/4] init/Kconfig: add config support for detecting linker ndesaulniers
2019-02-11 19:30 ` [PATCH v2 2/4] Makefile: clang: choose GCC_TOOLCHAIN_DIR not on LD ndesaulniers
2019-02-16 3:02 ` Masahiro Yamada
2019-02-11 19:30 ` [PATCH v2 3/4] Makefile: lld: tell clang to use lld ndesaulniers
2019-02-13 14:58 ` Masahiro Yamada [this message]
2019-02-13 17:41 ` Nick Desaulniers
2019-02-16 3:07 ` Masahiro Yamada
2019-04-02 3:54 ` Nick Desaulniers
2019-04-02 4:49 ` Masahiro Yamada
2019-04-02 7:08 ` [PATCH v3] " Nick Desaulniers
2019-04-02 7:27 ` Nathan Chancellor
2019-04-02 7:33 ` [PATCH v4] " Nick Desaulniers
2019-04-02 7:57 ` Nathan Chancellor
2019-04-02 7:52 ` [PATCH v3] " Sedat Dilek
2019-04-02 7:56 ` Nathan Chancellor
2019-04-05 10:16 ` Masahiro Yamada
2019-04-05 16:11 ` Kees Cook
2019-04-05 16:52 ` Nick Desaulniers
2019-04-07 2:20 ` Masahiro Yamada
2019-02-11 19:30 ` [PATCH v2 4/4] Makefile: lld: set -O2 linker flag when linking with LLD ndesaulniers
2019-02-12 12:22 ` Peter Zijlstra
2019-02-16 2:55 ` Masahiro Yamada
2019-02-11 19:30 ` [PATCH v2 0/4] Improve kernel LLD support ndesaulniers
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