From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 111246 invoked by alias); 19 Apr 2016 08:20:37 -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 111215 invoked by uid 89); 19 Apr 2016 08:20:36 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:1289 X-HELO: mail-wm0-f52.google.com Received: from mail-wm0-f52.google.com (HELO mail-wm0-f52.google.com) (74.125.82.52) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Tue, 19 Apr 2016 08:20:26 +0000 Received: by mail-wm0-f52.google.com with SMTP id 127so3074464wmz.0 for ; Tue, 19 Apr 2016 01:20:26 -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=PMfJKQXD2iJxdxqMjHzDs+TfbqMPuKMY86MKefym5Ow=; b=L4+20/FY17MxKMGKwLjEhXbaBB3IrhlIQRfxMbg++s7ixilm3XKvvfYP05uvdhYUDs NYmgHOBYQPGA5ov1N+0nd+l1V50649uBZCQTWN+INX3TSjsajuRo7csUQ98ijaxeuBbp 7D3XwDArpWel0U2yOvRwyFNW1kMwgOt80ANqNPfkJ48VxVC7Idlu5w0Cq+e2KL2JI92r Bw3z1FznqAh/qlVPkd0HvvzGItfA4/PFsrlRsxUi8rWT6HF895v/z44WgSLXBM4GxIsW 2nGV5p68cj2sx2sxgPO8ArjwqLzhvFZJLG1+iPbYPCGPEN7XAP+yCNW5P/D6sH6peOwJ VmPA== X-Gm-Message-State: AOPr4FVKvEZzM7l9ax+ZwgcfZY3AOIZbmQcOr8gR2O4Ont7YSfw9NG0jcgVJq93kGww3mtYP7JitOeoyl1+R4w== MIME-Version: 1.0 X-Received: by 10.28.148.135 with SMTP id w129mr2366930wmd.29.1461054023738; Tue, 19 Apr 2016 01:20:23 -0700 (PDT) Received: by 10.194.113.102 with HTTP; Tue, 19 Apr 2016 01:20:23 -0700 (PDT) In-Reply-To: <20160419050805.GI15088@bubble.grove.modra.org> References: <6AAD87D2-90F9-4AD7-A195-AC91B76EA6AE@apple.com> <56FB5061.9010303@redhat.com> <20160330143421.GM15812@bubble.grove.modra.org> <571161D0.10601@redhat.com> <20160418144911.GG15088@bubble.grove.modra.org> <20160419050805.GI15088@bubble.grove.modra.org> Date: Tue, 19 Apr 2016 08:20:00 -0000 Message-ID: Subject: Re: Preventing preemption of 'protected' symbols in GNU ld 2.26 [aka should we revert the fix for 65248] From: Richard Biener To: Alan Modra Cc: "H.J. Lu" , Jeff Law , Cary Coutant , Joe Groff , Binutils , GCC Content-Type: text/plain; charset=UTF-8 X-SW-Source: 2016-04/txt/msg00291.txt.bz2 On Tue, Apr 19, 2016 at 7:08 AM, Alan Modra wrote: > On Mon, Apr 18, 2016 at 07:59:50AM -0700, H.J. Lu wrote: >> On Mon, Apr 18, 2016 at 7:49 AM, Alan Modra wrote: >> > On Mon, Apr 18, 2016 at 11:01:48AM +0200, Richard Biener wrote: >> >> To summarize: there is currently no testcase for a wrong-code issue >> >> because there is no wrong-code issue. > > I've added a testcase at > https://sourceware.org/bugzilla/show_bug.cgi?id=19965#c3 > that shows the address problem (&x != x) with older gcc *or* older > glibc, and shows the program behaviour problem with current > binutils+gcc+glibc. Thanks. So with all this it sounds that current protected visibility is just broken and we should forgo with it, making it equal to default visibility? At least I couldn't decipher a solution that solves all of the issues with protected visibility apart from trying to error at link-time (or runtime?) for the cases that are tricky (impossible?) to solve. glibc uses "protected visibility" via its using of local aliases, correct? But it doesn't use anything like that for data symbols? Richard. > -- > Alan Modra > Australia Development Lab, IBM