From patchwork Sat Feb 8 08:01:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andi Kleen X-Patchwork-Id: 3609751 Return-Path: X-Original-To: patchwork-linux-kbuild@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 19D69BF418 for ; Sat, 8 Feb 2014 08:06:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5ABDD20172 for ; Sat, 8 Feb 2014 08:06:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 74B8720103 for ; Sat, 8 Feb 2014 08:06:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751707AbaBHIGs (ORCPT ); Sat, 8 Feb 2014 03:06:48 -0500 Received: from mga01.intel.com ([192.55.52.88]:35074 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751199AbaBHICG (ORCPT ); Sat, 8 Feb 2014 03:02:06 -0500 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 08 Feb 2014 00:02:05 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.95,805,1384329600"; d="scan'208";a="477990123" Received: from laut.jf.intel.com (HELO localhost) ([10.23.232.94]) by fmsmga002.fm.intel.com with ESMTP; 08 Feb 2014 00:02:05 -0800 Received: by localhost (Postfix, from userid 1000) id 56D22124ACD; Sat, 8 Feb 2014 09:01:27 +0100 (CET) From: Andi Kleen To: linux-kernel@vger.kernel.org Cc: linux-kbuild@vger.kernel.org, x86@kernel.org, Joe Mario , rusty@rustcorp.com.au, Andi Kleen Subject: [PATCH 05/17] lto: Handle LTO common symbols in module loader Date: Sat, 8 Feb 2014 09:01:09 +0100 Message-Id: <1391846481-31491-5-git-send-email-ak@linux.intel.com> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1391846481-31491-1-git-send-email-ak@linux.intel.com> References: <1391846481-31491-1-git-send-email-ak@linux.intel.com> Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Acked-by: Rusty Russell --- kernel/module.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/module.c b/kernel/module.c index d24fcf2..b99e801 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1948,6 +1948,10 @@ 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);