From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <hjl.tools@gmail.com>
Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com
 [IPv6:2607:f8b0:4864:20::102d])
 by sourceware.org (Postfix) with ESMTPS id 9F904385740E
 for <libc-alpha@sourceware.org>; Mon,  9 Aug 2021 14:33:02 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 9F904385740E
Received: by mail-pj1-x102d.google.com with SMTP id
 mq2-20020a17090b3802b0290178911d298bso186948pjb.1
 for <libc-alpha@sourceware.org>; Mon, 09 Aug 2021 07:33:02 -0700 (PDT)
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20161025;
 h=x-gm-message-state:mime-version:references:in-reply-to:from:date
 :message-id:subject:to:cc;
 bh=7s/34lmB/f3EWb80XIXLCetAs/yd+xfAdgRVDGsYMPM=;
 b=PXTN17T+FFAeRoTt95TV5e5p+JwlSUWZnSyTvEDiOpRQ3XgIXnDjxiFSJUYD/Qczpw
 cNx/q9vWRM+krnYvje/ZGoO5biidPClpOFKzBnO9tSDNnJZxmm14KF0uCDtCpWefjxsd
 cjzAu5gUx+NC80xR4hZ52vHwUGwfyOOSZradKKNXu0YKdSBNQ8uDcIZtYpfyGzcVu6y1
 9ADbDfm8vi7lNnI9RXmFF5Vzm5oIFLw76XEM7F4/LZhv9XLYXfj2o2WSP0LGOnxEAIFh
 DL1tN90c3FHMH3hAFdko/ERr3NrdTN+tqSwT72hRbOI10Gv8lH2+1YKz3fjNUhRNWMne
 dHZg==
X-Gm-Message-State: AOAM531J9Nzg4LPXqz+t1C3AGsuRIP3RtdOr9ORShIW68izWue9K975a
 gyQtCZvMdjNlCvhpSSZoc1WKthleTYpvxOCCFu8=
X-Google-Smtp-Source: ABdhPJyHiV76Hwryu4+xfln38jco/RaUGe8Jid2vNdZiYUmd2S6Rvu5QXmctO9Z/8jxbbFPps/RkYF6klkCH1k1q4KY=
X-Received: by 2002:a62:87c5:0:b029:3b5:f90f:c2eb with SMTP id
 i188-20020a6287c50000b02903b5f90fc2ebmr24732471pfe.28.1628519581697; Mon, 09
 Aug 2021 07:33:01 -0700 (PDT)
MIME-Version: 1.0
References: <20210727173958.GB1633923@zorba>
 <CAMe9rOqUvLEz14VS7e_DhwRNjuENuz8F2PBQSD0fh5a696EFAw@mail.gmail.com>
 <CAMe9rOqMOJmxtSLKFTMdQvBwQbdoi_u3j=nXM_5rhneLwdhh6Q@mail.gmail.com>
 <20210728154408.GF1633923@zorba>
 <CAMe9rOqQj9hFjQijUS8aJ9z8gOTs0GTh80W2th3zFgYZ4TVtZg@mail.gmail.com>
 <20210728190211.GJ1633923@zorba>
 <CAMe9rOoVCWg+9c1nq9+HeA9uBkb8Hdu-kamczBHjaF+wciq5fw@mail.gmail.com>
 <CAMe9rOpyFWJeX1db_6iNqQBAOzqywy4Nw2QhLjE=mWH_bZykTg@mail.gmail.com>
 <87o8agto7v.fsf@oldenburg.str.redhat.com>
 <CAMe9rOqDYcVg4ngo4qP_mVZp7WPtG9mjb6H0pR7osMLAOk7OGQ@mail.gmail.com>
 <20210803163917.GU1633923@zorba> <87mtpyfldl.fsf@oldenburg.str.redhat.com>
 <CAMe9rOouBMpx064pRAaS6XyD8BS2E2XgZi5_JsuikJK-heynUg@mail.gmail.com>
 <87pmuue175.fsf@oldenburg.str.redhat.com>
 <CAMe9rOrGcwcOZd_ofi9mbRxZS7ntLypJyiGRvbw4JohRM7pzcg@mail.gmail.com>
In-Reply-To: <CAMe9rOrGcwcOZd_ofi9mbRxZS7ntLypJyiGRvbw4JohRM7pzcg@mail.gmail.com>
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Mon, 9 Aug 2021 07:32:26 -0700
Message-ID: <CAMe9rOoPuJiv2=n=56QVZuiv4EedsDaniRRV2TyNWR4b3H0Rsw@mail.gmail.com>
Subject: RFC: 2 choices of DT_XXX for dlmopen
To: Florian Weimer <fweimer@redhat.com>
Cc: Daniel Walker <danielwa@cisco.com>, "Metzger,
 Markus T" <markus.t.metzger@intel.com>, 
 "Carlos O'Donell via Libc-alpha" <libc-alpha@sourceware.org>,
 Pedro Alves <palves@redhat.com>, 
 Conan C Huang <conhuang@cisco.com>, Jeremy Stenglein <jstengle@cisco.com>, 
 "xe-linux-external(mailer list)" <xe-linux-external@cisco.com>
Content-Type: text/plain; charset="UTF-8"
X-Spam-Status: No, score=-3025.4 required=5.0 tests=BAYES_00, DKIM_SIGNED,
 DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,
 SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on
 server2.sourceware.org
X-BeenThere: libc-alpha@sourceware.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Libc-alpha mailing list <libc-alpha.sourceware.org>
List-Unsubscribe: <https://sourceware.org/mailman/options/libc-alpha>,
 <mailto:libc-alpha-request@sourceware.org?subject=unsubscribe>
List-Archive: <https://sourceware.org/pipermail/libc-alpha/>
List-Post: <mailto:libc-alpha@sourceware.org>
List-Help: <mailto:libc-alpha-request@sourceware.org?subject=help>
List-Subscribe: <https://sourceware.org/mailman/listinfo/libc-alpha>,
 <mailto:libc-alpha-request@sourceware.org?subject=subscribe>
X-List-Received-Date: Mon, 09 Aug 2021 14:33:03 -0000

We need a new DT_XXX to support dlmopen.  We have 2 choices:

1. Similar to DT_DEBUG.  Linker will allocate a new DT_XXX and
ld.so will fill it with the address of the new debug data structure for
dlmopen.
2. Similar to DT_MIPS_RLD_MAP_REL/DT_MIPS_RLD_MAP.
Linker will allocate a space for a pointer, a new DT_XXX and fill
the DT_XXX entry with the address of the pointer.   ld.so will update
the pointer with the address of the new debug data structure for
dlmopen.

#1 is the most straightforward to implement.  #2 is compatible with
the current MIPS implementation.

Does anyone have any preferences?

-- 
H.J.