From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 130927 invoked by alias); 31 Mar 2016 13:27:09 -0000 Mailing-List: contact binutils-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: binutils-owner@sourceware.org Received: (qmail 130910 invoked by uid 89); 31 Mar 2016 13:27:08 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.6 required=5.0 tests=BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:1327 X-HELO: mail-lf0-f68.google.com Received: from mail-lf0-f68.google.com (HELO mail-lf0-f68.google.com) (209.85.215.68) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Thu, 31 Mar 2016 13:26:58 +0000 Received: by mail-lf0-f68.google.com with SMTP id v198so8018908lfd.0 for ; Thu, 31 Mar 2016 06:26:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc; bh=2micrLUefKpLNhUPm95tdwFATruRb/qdXQEJ+h3gBWE=; b=hI0RG3/KKeRD0tBu1jBaau2U1Oh2CFapZIyqDchBCJLQFH1+trrIogsC2B0iuTfw5f Iof0BHHFQ6Ix4hRQiVVThD6X6P13p53zBl0r+PmUXcX4jHSnSU41J6P3nJEMLRhvr5MZ tKWrU9B3kmLTu3Kn/C7N5Ffw5kdssF55eGzjm3Hev2iaSInGUBqfx5+EGICbL58t6Njq j4xUz3QF2d4ml+zUXLRplfWE70yHiOeSGH9hacDCk7q5OjAo49peI8elZ3rcYzvLglQ0 olOntD6IUzIpAIX6rU6QZhPEcyoEblDPV7w629/QaCktBwRxV9upkQj93UYGKTczdG9A CkDg== X-Gm-Message-State: AD7BkJIg9ReilK/Mm5bW+qtWMImE5AhzNV2OcT0uo7lMgNuvfKe34CXGNATSU/GSxH8eEdjp3iPxgqn9tSqTRw== MIME-Version: 1.0 X-Received: by 10.25.151.75 with SMTP id z72mr5647878lfd.122.1459430814485; Thu, 31 Mar 2016 06:26:54 -0700 (PDT) Received: by 10.114.23.38 with HTTP; Thu, 31 Mar 2016 06:26:54 -0700 (PDT) In-Reply-To: <56FC74E7.1000700@redhat.com> References: <983472E1-A1BC-4970-9CF9-0138A6BAD16D@apple.com> <6AAD87D2-90F9-4AD7-A195-AC91B76EA6AE@apple.com> <56FB5061.9010303@redhat.com> <56FC74E7.1000700@redhat.com> Date: Thu, 31 Mar 2016 13:27:00 -0000 Message-ID: Subject: Re: Preventing preemption of 'protected' symbols in GNU ld 2.26 From: Ramana Radhakrishnan To: Jeff Law Cc: Cary Coutant , "H.J. Lu" , Joe Groff , Alan Modra , Binutils , Szabolcs Nagy Content-Type: text/plain; charset=UTF-8 X-IsSubscribed: yes X-SW-Source: 2016-03/txt/msg00459.txt.bz2 On Thu, Mar 31, 2016 at 1:52 AM, Jeff Law wrote: > On 03/30/2016 06:40 PM, Cary Coutant wrote: >>> >>> It would help me immensely on the GCC side if things if you and Alan >>> could >>> easily summarize correct behavior and the impact if we were to just >>> revert >>> HJ's change. A testcase would be amazingly helpful too. >> >> >> It looks like it's not just the one change. There's this patch: >> >> https://gcc.gnu.org/ml/gcc-patches/2015-07/msg01871.html >> >> which took the idea that protected can still be pre-empted by a COPY >> relocation and extended it to three more targets that use COPY >> relocations. >> >> I wonder how many other patches have been based on the same >> misunderstanding? > > I don't think it was many -- I certainly recall the arm/aarch64 variant. > There may have been one other varasm.c change in this space or I might be > conflating it with the arm/aarch64 change. Tracking those down is naturally > part of this work. The glibc tests elf/tst-protected1{a,b}.c also need to be reviewed at the same time. IIUC, the reason the patch above went in were to fix failures on arm / aarch64 with those tests. I haven't yet worked out whether all this is the same issue. CC'ing Szabolcs. Thanks, Ramana > > jeff