From: Nick Desaulniers <ndesaulniers@google.com>
To: Masahiro Yamada <yamada.masahiro@socionext.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 09:41:52 -0800 [thread overview]
Message-ID: <CAKwvOdmyNFsV=67eLQtETSDJJyDZ8aEJY1+LHuoP4OtpdQOdWQ@mail.gmail.com> (raw)
In-Reply-To: <CAK7LNATZY-K4g81LLvXpjp=+oMSY8L0wQoVXgHt-Bjrb2WXnNg@mail.gmail.com>
On Wed, Feb 13, 2019 at 6:59 AM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
>
> 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)
It solves case 2.
>
>
> Is it a problem to use a different
> type of linker for [1] and [2] ?
Ideally, no, but I can think of at least one case where it might be
problematic to mix linkers like that:
You might be mixing linker flags added via ld-option from one linker
that aren't actually supported by the other linker.
--
Thanks,
~Nick Desaulniers
next prev parent reply other threads:[~2019-02-13 17:42 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
2019-02-13 17:41 ` Nick Desaulniers [this message]
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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