From patchwork Wed May 31 01:25:24 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zack Weinberg X-Patchwork-Id: 20647 Received: (qmail 46748 invoked by alias); 31 May 2017 01:25:29 -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 46714 invoked by uid 89); 31 May 2017 01:25:26 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-24.1 required=5.0 tests=AWL, BAYES_00, FREEMAIL_FROM, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM, SPF_PASS autolearn=ham version=3.3.2 spammy=gonna, clever X-HELO: mail-qk0-f195.google.com X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=8YUbbh9tTkEXbussJXO5lr56wn22HRZfRoZv3vtXQz4=; b=eawXwMKc83HoCBhcaT3fssC6I4bg1OMJJgBbpaSB1PRMdphuTEC7UqJEmqPNNG1ZuP cVB5WnYgMBQquC4YGT/I1Bg9Hu+HdtAmPlZ3auVu1G1iwVZ/lHpkKjuhAI5lqO1Lhf1a doyq8qJmT+WtA4nNkqTBsQVhqOtwAtN0vCvQCI0hCFDmEMzuTvyBtZ3IEuuFn9aCyE/p O66XJn0mJkrR/mGkMUAwAUwha4zv9Jq6tFr2B/+8ZxCeVFBFF8+H5/PoXEUekCYzuuIL zsyp9bKOofzrtG0SaC8r9Q4trW9trCZSrd4xk8cQIuZQzW68XUfNgNjVIv72Arkf+Nmg saGQ== X-Gm-Message-State: AODbwcC/M/mbmUJAsMVwXeY9Sk1l/RVCrvcF0WiUEaCfa9UMLnCWHaon gtbwjgZE0XSgHQTukA8= X-Received: by 10.55.125.65 with SMTP id y62mr23611354qkc.143.1496193926016; Tue, 30 May 2017 18:25:26 -0700 (PDT) Subject: Avoid linker bug on Microblaze (was Re: Default build-many-glibcs.py to GCC 7 branch [committed]) To: Joseph Myers References: Cc: GNU C Library From: Zack Weinberg Message-ID: Date: Tue, 30 May 2017 21:25:24 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: On 05/10/2017 09:16 AM, Joseph Myers wrote: > That said, > > seems to have a plausible explanation of the problem (alias to undefined > __libc_vfork, apparently triggering a linker bug). I'd prefer making > MicroBlaze follow the same symbol handling as other architectures (so > defining __libc_vfork and then defining other symbols as aliases to it) > over the approach in that patch of a MicroBlaze-specific pt-vfork.S. Indeed, this fixes the problem. Is this roughly what you had in mind? I'm probably gonna go ahead and check it in if I don't hear objections in, like, 24 hours or so. zw diff --git a/sysdeps/unix/sysv/linux/microblaze/localplt.data b/sysdeps/unix/sysv/linux/microblaze/localplt.data index a61b94dfb8..ca476bedd8 100644 --- a/sysdeps/unix/sysv/linux/microblaze/localplt.data +++ b/sysdeps/unix/sysv/linux/microblaze/localplt.data @@ -5,7 +5,6 @@ libc.so: malloc libc.so: memalign libc.so: realloc libm.so: matherr -libpthread.so: __errno_location # The dynamic loader needs __tls_get_addr for TLS. ld.so: __tls_get_addr ? # The main malloc is interposed into the dynamic linker, for diff --git a/sysdeps/unix/sysv/linux/microblaze/pt-vfork.S b/sysdeps/unix/sysv/linux/microblaze/pt-vfork.S index 65cc3823ac..f201f0429f 100644 --- a/sysdeps/unix/sysv/linux/microblaze/pt-vfork.S +++ b/sysdeps/unix/sysv/linux/microblaze/pt-vfork.S @@ -1 +1,49 @@ -#include +/* vfork ABI-compatibility entry points for libpthread. + Copyright (C) 2014-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include + +/* libpthread used to have its own vfork implementation that differed + from libc's only in having a pointless micro-optimization. There + is no longer any use to having a separate copy in libpthread, but + the historical ABI requires it. For static linking, there is no + need to provide anything here--the libc version will be linked in. + For shared library ABI compatibility, there must be __vfork and + vfork symbols in libpthread.so. + + As of GCC 7, microblaze can *not* rely on the compiler to generate + a tail call from this vfork to __libc_vfork. */ + +#if (SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) \ + || SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20)) + +ENTRY (vfork_compat) + bri __libc_vfork +END (vfork_compat) + +#endif + +#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) +compat_symbol (libpthread, vfork_compat, vfork, GLIBC_2_0) +#endif + +#if SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20) +strong_alias (vfork_compat, vfork_compat2) +compat_symbol (libpthread, vfork_compat2, __vfork, GLIBC_2_1_2) +#endif diff --git a/sysdeps/unix/sysv/linux/microblaze/vfork.S b/sysdeps/unix/sysv/linux/microblaze/vfork.S index 1ad86229a9..f1e4508d20 100644 --- a/sysdeps/unix/sysv/linux/microblaze/vfork.S +++ b/sysdeps/unix/sysv/linux/microblaze/vfork.S @@ -43,3 +43,4 @@ PSEUDO_END (__vfork) libc_hidden_def (__vfork) weak_alias (__vfork, vfork) +strong_alias (__vfork, __libc_vfork)