From: "H.J. Lu" <hjl.tools@gmail.com>
To: "Carlos O'Donell" <carlos@redhat.com>
Cc: Fangrui Song <maskray@google.com>,
GNU C Library <libc-alpha@sourceware.org>,
Binutils <binutils@sourceware.org>
Subject: Re: [PATCH v2] elf: Support DT_RELR relative relocation format [BZ #27924]
Date: Fri, 29 Oct 2021 11:36:53 -0700 [thread overview]
Message-ID: <CAMe9rOqiFJhPzi98j-WNkiHDKTGD+Hxss4+u8-c1-dxo7SLEOg@mail.gmail.com> (raw)
In-Reply-To: <1763c6f4-dfb9-e102-84d6-892ee2a3208a@redhat.com>
On Fri, Oct 29, 2021 at 11:22 AM Carlos O'Donell via Binutils
<binutils@sourceware.org> wrote:
>
> On 10/16/21 20:50, Fangrui Song via Binutils wrote:
> > PIE and shared objects usually have many relative relocations. In
> > 2017/2018, SHT_RELR/DT_RELR was proposed on
> > https://groups.google.com/g/generic-abi/c/bX460iggiKg/m/GxjM0L-PBAAJ
> > ("Proposal for a new section type SHT_RELR") and is a pre-standard. RELR
> > usually takes 3% or smaller space than R_*_RELATIVE relocations. The
> > virtual memory size of a mostly statically linked PIE is typically 5~10%
> > smaller.
>
> We've been going over this patch on the weekly Monday patch queue review.
>
> I took a note to point out that one of the blockers here is that it is difficult
> to immediately test this work because it requires a working glibc build using
> ldd (which has support for DT_RELR).
>
> What is the status of the lld support patches for glibc?
>
> If we made progress on the lld support then we'd be able to more easily review
> a testable configuration and keep the review going forward.
>
I raised the mysterious crash issue:
https://groups.google.com/g/generic-abi/c/bX460iggiKg
We need an updated proposal without mysterious crashes. One option is
that the linker should bump EI_ABIVERSION when generating DT_RELR.
After this issue is resolved, I can look into the bfd linker support.
--
H.J.
next prev parent reply other threads:[~2021-10-29 18:37 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-17 0:50 Fangrui Song
2021-10-18 14:42 ` H.J. Lu
2021-10-18 16:16 ` Fāng-ruì Sòng
2021-10-18 17:28 ` H.J. Lu
2021-10-18 18:15 ` Fāng-ruì Sòng
2021-10-18 18:27 ` H.J. Lu
2021-10-18 19:19 ` Fāng-ruì Sòng
2021-10-18 19:44 ` H.J. Lu
2021-10-18 20:11 ` Fāng-ruì Sòng
2021-10-18 21:10 ` Joseph Myers
2021-10-18 22:27 ` H.J. Lu
2021-10-18 22:30 ` Joseph Myers
2021-10-18 22:42 ` H.J. Lu
2021-10-18 23:00 ` Joseph Myers
2021-10-18 23:36 ` H.J. Lu
2021-10-18 23:44 ` Joseph Myers
2021-10-19 1:05 ` H.J. Lu
2021-10-18 19:21 ` Joseph Myers
2021-10-18 19:45 ` H.J. Lu
2021-10-29 18:21 ` Carlos O'Donell
2021-10-29 18:36 ` H.J. Lu [this message]
2021-10-29 19:15 ` Fangrui Song
2021-10-29 18:38 ` Fāng-ruì Sòng
2021-10-29 19:35 ` Carlos O'Donell
2021-10-29 19:53 ` Adhemerval Zanella
2021-11-01 4:50 ` Fāng-ruì Sòng
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=CAMe9rOqiFJhPzi98j-WNkiHDKTGD+Hxss4+u8-c1-dxo7SLEOg@mail.gmail.com \
--to=hjl.tools@gmail.com \
--cc=binutils@sourceware.org \
--cc=carlos@redhat.com \
--cc=libc-alpha@sourceware.org \
--cc=maskray@google.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 read-only IMAP folder(s) and NNTP newsgroup(s).