From patchwork Mon Jun 18 18:06:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej W. Rozycki" X-Patchwork-Id: 931123 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=sourceware.org (client-ip=209.132.180.131; helo=sourceware.org; envelope-from=libc-alpha-return-93355-incoming=patchwork.ozlabs.org@sourceware.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=mips.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=sourceware.org header.i=@sourceware.org header.b="TkvIO6qX"; dkim-atps=neutral Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 418fDb02NBz9s31 for ; Tue, 19 Jun 2018 04:06:38 +1000 (AEST) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:subject:message-id :mime-version:content-type; q=dns; s=default; b=r5sjQ6q0diKEsDOO f1+Qu/rPaG9T7SIAbHCOSlYGa9nL3ePxQn9Ljfu/OJm6x8+MzZ8mavaJF6As/9HV jZyxhL3HLXzIMkUC5H+WK4mmX6VCfGsg4ZoPyGAAXi9VCT+t2nd/ItQ557Km6Jrl k9WRIihay59hM+Wt0H3RFV5dPIQ= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:subject:message-id :mime-version:content-type; s=default; bh=XlgwWeD36DLlja4SWWIEaT HMB5Q=; b=TkvIO6qXgpw6llMpE3jXCzwpHs3ofSu9JacKHlrp3/HE0wb6IKagUH dPQqb0dPfd8lQjeEATHVUxVq2rSJKYKhme1e5yrwSwJv/wrHyhUsA4If21hyJBFY PnCtqbzqcycdCCead0scbwzLtes6C0fOkKT3uzvv1TeO8Ufd85cEw= Received: (qmail 95202 invoked by alias); 18 Jun 2018 18:06:33 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 95188 invoked by uid 89); 18 Jun 2018 18:06:32 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.5 required=5.0 tests=AWL, BAYES_00, SPF_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:769, consequently, H*r:0700 X-HELO: 9pmail.ess.barracuda.com Date: Mon, 18 Jun 2018 19:06:16 +0100 From: "Maciej W. Rozycki" To: CC: Alan Modra Subject: [PATCH 0/2] Accept absolute symbols whose value is zero [BZ #23307] Message-ID: User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 X-ClientProxiedBy: mipsdag02.mipstec.com (10.20.40.47) To mipsdag02.mipstec.com (10.20.40.47) X-BESS-ID: 1529345186-637137-17636-106557-1 X-BESS-VER: 2018.7-r1806151722 X-BESS-Apparent-Source-IP: 12.201.5.32 X-BESS-Envelope-From: Maciej.Rozycki@mips.com X-BESS-Outbound-Spam-Score: 0.00 X-BESS-Outbound-Spam-Status: SCORE=0.00 using account:ESS59374 scores of KILL_LEVEL=7.0 tests=BSF_BESS_OUTBOUND X-BESS-Orig-Rcpt: libc-alpha@sourceware.org,amodra@gmail.com X-BESS-BRTS-Status: 1 Hi, With a prototype fix for PR ld/21375 I have triggered another issue with the dynamic loader, where symbols whose `st_value' is zero are silently ignored in lookup. Consequently references to a global absolute symbol whose value is zero cannot be resolved. I have created a small patch series to address this problem. The first part is the actual fix. The second part is an ABI bump, so that the linker can set the minimum ABI required for an absolute symbol created to address the issue covered in PR ld/21375 and make old dynamic loaders fail with "ELF file ABI version invalid" rather than confusing "undefined symbol". See the individual patch descriptions for further details. Maciej