From patchwork Sun Aug 19 02:56:55 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andi Kleen X-Patchwork-Id: 1343821 Return-Path: X-Original-To: patchwork-linux-kbuild@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 8653CDF25A for ; Sun, 19 Aug 2012 03:15:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754294Ab2HSC6b (ORCPT ); Sat, 18 Aug 2012 22:58:31 -0400 Received: from mga03.intel.com ([143.182.124.21]:17805 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753209Ab2HSC52 (ORCPT ); Sat, 18 Aug 2012 22:57:28 -0400 Received: from azsmga001.ch.intel.com ([10.2.17.19]) by azsmga101.ch.intel.com with ESMTP; 18 Aug 2012 19:57:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.77,792,1336374000"; d="scan'208";a="182675628" Received: from tassilo.jf.intel.com ([10.7.201.151]) by azsmga001.ch.intel.com with ESMTP; 18 Aug 2012 19:57:26 -0700 Received: by tassilo.jf.intel.com (Postfix, from userid 501) id 11C9B2419B6; Sat, 18 Aug 2012 19:57:26 -0700 (PDT) From: Andi Kleen To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, mmarek@suse.cz, linux-kbuild@vger.kernel.org, JBeulich@suse.com, akpm@linux-foundation.org, Joe Mario , rusty@rustcorp.com.au, Andi Kleen Subject: [PATCH 59/74] lto: Handle LTO common symbols in module loader Date: Sat, 18 Aug 2012 19:56:55 -0700 Message-Id: <1345345030-22211-60-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1345345030-22211-1-git-send-email-andi@firstfloor.org> References: <1345345030-22211-1-git-send-email-andi@firstfloor.org> Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org From: Joe Mario Here is the workaround I made for having the kernel not reject modules built with -flto. The clean solution would be to get the compiler to not emit the symbol. Or if it has to emit the symbol, then emit it as initialized data but put it into a comdat/linkonce section. Minor tweaks by AK over Joe's patch. Cc: rusty@rustcorp.com.au Signed-off-by: Andi Kleen --- kernel/module.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index c00565a..2cbbae3 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1904,6 +1904,10 @@ static int simplify_symbols(struct module *mod, const struct load_info *info) switch (sym[i].st_shndx) { case SHN_COMMON: + /* Ignore common symbols */ + if (!strncmp(name, "__gnu_lto", 9)) + break; + /* We compiled with -fno-common. These are not supposed to happen. */ pr_debug("Common symbol: %s\n", name);