From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id BBE6D3858431 for ; Fri, 3 Feb 2023 18:56:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org BBE6D3858431 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675450596; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=hT7ZM+kXp/yq+uXVaZjmVUyrMQfvac1MbXj3D3N3T6I=; b=gYzAr3Q4Ncy2PnPEB8u5v5HRGjbUuA6AM4TACgXWVTi/rcoSpTo5Wz6wAAfhZAPAl+9MCF bPg2dHi4JbfgUr4O3FQ6X9OMBcLDxe/llr7jn/N8Prg/M8tYp2aOnMkHOLHMZ92tZjapna YzAYQO8wDMHp0s4hKnDCRQXrsvCcgBQ= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-441-957nHsjzOr26Bc7aEE8jug-1; Fri, 03 Feb 2023 13:56:33 -0500 X-MC-Unique: 957nHsjzOr26Bc7aEE8jug-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B6D1D2803613; Fri, 3 Feb 2023 18:56:32 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.194.38]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 93203492C14; Fri, 3 Feb 2023 18:56:31 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Netto Cc: Michael Hudson-Doyle , Sam James via Libc-alpha , Sam James Subject: Re: time64 / Large File Support: 2) default time64 breaks legacy 32bit binaries References: <10857996.18pcnM708K@pinacolada> <7196595.N7aMVyhfb1@pinacolada> <7271eb94-b5d7-69d6-9be0-ca1afda29a50@cs.ucla.edu> <2342ab66-6ac6-17d8-3693-8e2fd93fc8a1@linaro.org> <87bkmdwdv8.fsf@oldenburg.str.redhat.com> Date: Fri, 03 Feb 2023 19:56:29 +0100 In-Reply-To: (Adhemerval Zanella Netto's message of "Fri, 3 Feb 2023 11:17:24 -0300") Message-ID: <87ilgih92a.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-4.9 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: * Adhemerval Zanella Netto: > It is an option, although I am not sure what might really work since afaik > Linux does not support CLOCK_REALTIME on time namespace. Not yet. The pressure isn't there yet, but I totally see it happening. > Not really, there are some idea on how to proceed with 64 time_t promotion: > > 1. Add a configure option to enable LFS and 64 bit time_t support as default. > It is basically promoting the port to a new ABI, although a program can > still build with non LFS or 32 bit time_t by explicit use -D_TIME_BITS=32. > > 2. Make this option the default on a future glibc version, meaning that for > distribution that want to keep the the compatibility mode as default (to > run old binaries) will need to explicit enable it. > > 3. Move the non-LFS and 32 bit time_t symbols compat one, meaning that newer > binaries won't be able to use them and -D_TIME_BITS=32 won't be supported > or just be a no-op. > > The 1 and 2 should not be cause many trouble, even if 2 would make > 32-bit time_t opt-in. At least it would focused on glibc itself, > meaning that a distribution could just ignore the transition by just > adding a configure option on glibc build. I tend to agree, except we'd have to make it clear that 1 (if enabled) & 2 may require extensive porting work across the distribution to maintain a consistent ABI. > The 3. is what might cause i386 (and any 32-bit port where ABI also supports > 64-bit) to wither. I don't have a strong opinion, maybe we should focus on > only the 1. and 2. and see what community things about 3. This still doesn't solve the implicit function declaration/dlsym problem, though, so I don't know how Meanwhile, Ocaml has removed compiler (but not interpreter) support for i386, and Openblas dropped 32-bit support completely. I think it's going to become more and more difficult to offer a general-purpose distribution on i386 well before we hit Y2038 problems. Thanks, Florian