linux-kbuild.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Nick Desaulniers <ndesaulniers@google.com>
To: "Björn Töpel" <bjorn@kernel.org>
Cc: Alexandre Ghiti <alex@ghiti.fr>,
	Alexandre Ghiti <alexghiti@rivosinc.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Nicholas Piggin <npiggin@gmail.com>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	linux-riscv@lists.infradead.org, nathan@kernel.org,
	linux-kbuild@vger.kernel.org, llvm@lists.linux.dev
Subject: Re: [PATCH v8 1/3] riscv: Introduce CONFIG_RELOCATABLE
Date: Wed, 22 Mar 2023 11:25:45 -0700	[thread overview]
Message-ID: <CAKwvOdk0Lr-9gt0xAKvkcwA53+Wy8oeYQo1RJ7XH-LKCCURQCQ@mail.gmail.com> (raw)
In-Reply-To: <877cw7dphf.fsf@all.your.base.are.belong.to.us>

On Fri, Feb 24, 2023 at 7:58 AM Björn Töpel <bjorn@kernel.org> wrote:
>
> Alexandre Ghiti <alex@ghiti.fr> writes:
>
> > +cc linux-kbuild, llvm, Nathan, Nick
> >
> > On 2/15/23 15:36, Alexandre Ghiti wrote:
> >> From: Alexandre Ghiti <alex@ghiti.fr>
> >>
> > I tried a lot of things, but I struggle to understand, does anyone have
> > any idea? FYI, the same problem happens with LLVM.

Off the top of my head, no idea.

(Maybe as a follow up to this series, I wonder if pursuing
ARCH_HAS_RELR for ARCH=riscv is worthwhile?)

>
> Don't ask me *why*, but adding --emit-relocs to your linker flags solves
> "the NULL .rela.dyn" both for GCC and LLVM.
>
> The downside is that you end up with a bunch of .rela cruft in your
> vmlinux.

There was a patch just this week to use $(OBJCOPY) to strip these from
vmlinux (for x86). Looks like x86 uses --emit-relocs for KASLR:
https://lore.kernel.org/lkml/20230320121006.4863-1-petr.pavlu@suse.com/
-- 
Thanks,
~Nick Desaulniers

  reply	other threads:[~2023-03-22 18:26 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20230215143626.453491-1-alexghiti@rivosinc.com>
     [not found] ` <20230215143626.453491-2-alexghiti@rivosinc.com>
2023-02-22 12:29   ` [PATCH v8 1/3] riscv: Introduce CONFIG_RELOCATABLE Alexandre Ghiti
2023-02-24 15:58     ` Björn Töpel
2023-03-22 18:25       ` Nick Desaulniers [this message]
2023-03-23 20:01         ` Fangrui Song
2023-03-24 10:34         ` Alexandre Ghiti
2023-03-22 13:38     ` Alexandre Ghiti

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAKwvOdk0Lr-9gt0xAKvkcwA53+Wy8oeYQo1RJ7XH-LKCCURQCQ@mail.gmail.com \
    --to=ndesaulniers@google.com \
    --cc=alex@ghiti.fr \
    --cc=alexghiti@rivosinc.com \
    --cc=aou@eecs.berkeley.edu \
    --cc=bjorn@kernel.org \
    --cc=christophe.leroy@csgroup.eu \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=llvm@lists.linux.dev \
    --cc=mpe@ellerman.id.au \
    --cc=nathan@kernel.org \
    --cc=npiggin@gmail.com \
    --cc=palmer@dabbelt.com \
    --cc=paul.walmsley@sifive.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).