From: Samuel Thibault <samuel.thibault@ens-lyon.org>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: libc-alpha@sourceware.org, Szabolcs Nagy <szabolcs.nagy@arm.com>,
rrh.henry@gmail.com
Subject: Re: RFC: Remove --disable-hidden-plt
Date: Tue, 6 Apr 2021 20:03:38 +0200 [thread overview]
Message-ID: <20210406180338.wh2vwyqqsro7v3d5@begin> (raw)
In-Reply-To: <bfeb43b1-5ffd-84c2-983e-011c21c75252@linaro.org>
Adhemerval Zanella, le mar. 06 avril 2021 14:39:27 -0300, a ecrit:
> On 06/04/2021 14:18, Samuel Thibault wrote:
> > Adhemerval Zanella via Libc-alpha, le mar. 06 avril 2021 14:12:41 -0300, a ecrit:
> >> On 03/04/2021 14:41, H.J. Lu via Libc-alpha wrote:
> >> However it seems it will still need to support it internally for
> >> Hurd
> >
> > Yes, some symbols in ld.so (most of sysdeps/mach/hurd/dl-sysdep.c)
> > *need* to be interposed by the loaded libc.so, because the
> > implementation in ld.so is to be used only at bootstrap of the program,
> > and then overriden by the real full-fledged implementation.
>
> Are these the only ones required to Hurd?
Yes. Previously we were using the NO_HIDDEN hammer, but:
> I wonder if would be simple to instead of have the bit NO_HIDDEN
> hammer, to create a different hidden_def/hidden_proto to be used on
> the required symbols (where default version would map to use non-PLT
> call and Hurd could just reimplement it).
That was already roughly done in
3d1870fa3301c5cd00d5fdab0014c4e22b71fef2
where we made all rtld_hidden_proto respect NO_RTLD_HIDDEN.
I didn't specifically mark the exactly required functions, but the
localplt check exceptions in sysdeps/mach/hurd/i386/localplt.data is
already exactly the list of needed PLTs, so I don't think it's worth
the extra maintenance complexity of special-casing in the headers for
everyone in addition to the rtld implementation in dl-sysdep.c.
Samuel
next prev parent reply other threads:[~2021-04-06 18:03 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-03 17:41 H.J. Lu
2021-04-06 17:12 ` Adhemerval Zanella
2021-04-06 17:18 ` Samuel Thibault
2021-04-06 17:39 ` Adhemerval Zanella
2021-04-06 18:03 ` Samuel Thibault [this message]
2021-04-06 18:15 ` Adhemerval Zanella
2021-04-06 18:43 ` Samuel Thibault
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=20210406180338.wh2vwyqqsro7v3d5@begin \
--to=samuel.thibault@ens-lyon.org \
--cc=adhemerval.zanella@linaro.org \
--cc=libc-alpha@sourceware.org \
--cc=rrh.henry@gmail.com \
--cc=szabolcs.nagy@arm.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).