From patchwork Tue Feb 18 14:28:43 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andi Kleen X-Patchwork-Id: 3671631 Return-Path: X-Original-To: patchwork-linux-kbuild@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 1B87A9F370 for ; Tue, 18 Feb 2014 14:39:10 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 47403201FE for ; Tue, 18 Feb 2014 14:39:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5FE29201F7 for ; Tue, 18 Feb 2014 14:39:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932134AbaBROiv (ORCPT ); Tue, 18 Feb 2014 09:38:51 -0500 Received: from mga02.intel.com ([134.134.136.20]:27315 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755989AbaBRO3t (ORCPT ); Tue, 18 Feb 2014 09:29:49 -0500 Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 18 Feb 2014 06:29:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,502,1389772800"; d="scan'208";a="485209689" Received: from laut.jf.intel.com (HELO localhost) ([10.23.232.94]) by orsmga002.jf.intel.com with ESMTP; 18 Feb 2014 06:29:47 -0800 Received: by localhost (Postfix, from userid 1000) id 0BCE21249CB; Tue, 18 Feb 2014 15:29:06 +0100 (CET) From: Andi Kleen To: linux-kernel@vger.kernel.org Cc: sam@ravnborg.org, x86@kernel.org, linux-kbuild@vger.kernel.org, Joe Mario , rusty@rustcorp.com.au, Andi Kleen Subject: [PATCH 05/20] lto: Handle LTO common symbols in module loader Date: Tue, 18 Feb 2014 15:28:43 +0100 Message-Id: <1392733738-8290-6-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1392733738-8290-1-git-send-email-andi@firstfloor.org> References: <1392733738-8290-1-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 X-Spam-Status: No, score=-7.5 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 --- 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);