From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-x634.google.com (mail-pl1-x634.google.com [IPv6:2607:f8b0:4864:20::634]) by sourceware.org (Postfix) with ESMTPS id CF8003858D3C for ; Sat, 20 Nov 2021 02:56:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org CF8003858D3C Received: by mail-pl1-x634.google.com with SMTP id m24so9520546pls.10 for ; Fri, 19 Nov 2021 18:56:24 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=1fdJ+7EOZnMTga0xwgiN6xDt19CNqapTRzxwTZRmJ8I=; b=3+DDQP2IoCCsHzelDS+lZPECFsMqqfAKplCcuxSUrY1Lk0Y/DBvGUaSylAUHRBmWY9 nowIf1rlLIAXtAzJVqbVgreYjOzNG3SeIXglodEfTIfagEj7yO6TAeV+H3IppKKEXi0O st0+gfw0XaZupGVVko2vnIiEY9SEk5nzVYU6QfdfiAXVwam86wTDlA2yQJ7ipL7WpzFa A9tDWEkhAs5+84agzXNB1GhBZdo3rziorRG+ET3NrDedEo0RvSmY0oqojCOPwULkvF+B 6k2aM9vYXHuXVVPTfLYTM8Otx7hl/blk5K9KDxpK6ZcuvCGPZVAaC3FKr2kwnC1zackO NEQA== X-Gm-Message-State: AOAM530wUF0Pll20fGqG5/T5Db7ip/0vyZuLuswMZpmQyqx3tPXE1p9Z NQKhAkyxHBCUOFDe15rf4lpS0o6BWHs0kuW4kdk= X-Google-Smtp-Source: ABdhPJy3hw0J6PTJ39ZKXwSS8G3IqvAJlswbcjM5vLRxFn9gC1IfLJfr9llEXbb94WYhVh7VVvec0yjcPw+W+wuhTaY= X-Received: by 2002:a17:902:ced1:b0:141:e15d:49e0 with SMTP id d17-20020a170902ced100b00141e15d49e0mr83748635plg.27.1637376983701; Fri, 19 Nov 2021 18:56:23 -0800 (PST) MIME-Version: 1.0 References: <20211119152655.121201-1-hjl.tools@gmail.com> <87zgq0b1t4.fsf@oldenburg.str.redhat.com> <878rxj930y.fsf@oldenburg.str.redhat.com> In-Reply-To: <878rxj930y.fsf@oldenburg.str.redhat.com> From: "H.J. Lu" Date: Fri, 19 Nov 2021 18:55:47 -0800 Message-ID: Subject: Re: [PATCH] Add GLIBC_PRIVATE_RELR as proxy for DT_RELR To: Florian Weimer Cc: GNU C Library , Adhemerval Zanella Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-3022.6 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Nov 2021 02:56:26 -0000 On Fri, Nov 19, 2021 at 2:47 PM Florian Weimer wrote: > > * H. J. Lu: > > > On Fri, Nov 19, 2021 at 7:30 AM Florian Weimer wrote: > >> > >> * H. J. Lu: > >> > >> > Executables with DT_RELR will crash mysteriously with glibc binaries > >> > without DT_RELR support. Bump EI_ABIVERSION won't prevent crash since > >> > the Linux kernel loader doesn't check EI_ABIVERSION on executables. > >> > Adding a glibc version dependency on the first glibc version with > >> > DT_RELR support will prevent backporting DT_RELR support to released > >> > glibc branches. > >> > > >> > Add a GLIBC_PRIVATE_RELR version as a proxy for DT_RELR support in glibc. > >> > Linker should add the GLIBC_PRIVATE_RELR version dependency on binaries > >> > with DT_RELR. GLIBC_PRIVATE_RELR should be backported together when > >> > backporting DT_RELR support. > >> > >> I don't like it. What's wrong about EI_ABIVERSION? > > > > Bumping EI_ABIVERSION on executables doesn't prevent crashes > > with existing ld.so binaries. > > Oh, right, I keep forgetting that. What is wrong with GLIBC_PRIVATE_RELR? > If we do not intend to backport features that require an EI_ABIVERSION > bump back further than glibc 2.34, we can rely on the __libc_start_main > switch to the GLIBC_2.34 symbol version. > GLIBC_2.34 is no better than GLIBC_PRIVATE_RELR. -- H.J.