From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88235C18E5B for ; Mon, 16 Mar 2020 12:33:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 67BA220663 for ; Mon, 16 Mar 2020 12:33:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731028AbgCPMdm (ORCPT ); Mon, 16 Mar 2020 08:33:42 -0400 Received: from mail.cn.fujitsu.com ([183.91.158.132]:22833 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730878AbgCPMdk (ORCPT ); Mon, 16 Mar 2020 08:33:40 -0400 X-IronPort-AV: E=Sophos;i="5.70,560,1574092800"; d="scan'208";a="86408493" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 16 Mar 2020 20:33:36 +0800 Received: from G08CNEXMBPEKD06.g08.fujitsu.local (unknown [10.167.33.206]) by cn.fujitsu.com (Postfix) with ESMTP id 9FD3E50A9967; Mon, 16 Mar 2020 20:23:29 +0800 (CST) Received: from G08CNEXCHPEKD03.g08.fujitsu.local (10.167.33.85) by G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 16 Mar 2020 20:33:32 +0800 Received: from Fedora-30.g08.fujitsu.local (10.167.220.106) by G08CNEXCHPEKD03.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server id 14.3.439.0; Mon, 16 Mar 2020 20:33:32 +0800 From: Xiao Yang To: , CC: , , Xiao Yang Subject: [PATCH] modpost: Get proper section index by get_secindex() instead of st_shndx Date: Mon, 16 Mar 2020 20:28:20 +0800 Message-ID: <20200316122820.11032-1-yangx.jy@cn.fujitsu.com> X-Mailer: git-send-email 2.21.0 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-yoursite-MailScanner-ID: 9FD3E50A9967.AA9D8 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: yangx.jy@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (uint16_t) st_shndx is limited to 65535(i.e. SHN_XINDEX) so sym_get_data() gets wrong section index by st_shndx if object file(e.g. vmlinux.o) has more than 65535 sessions. In this case, we need to get proper section index by .symtab_shndx section. Module.symvers generated by building kernel with "-ffunction-sections -fdata-sections" shows the issue(i.e. cannot get 89902 by st_shndx): ------------------------------------------------------------------- [root@Fedora-30 linux]# file Module.symvers Module.symvers: data [root@Fedora-30 linux]# head -n1 Module.symvers 0x5caf3011 ipv6_chk_custom_prefix ▒▒▒▒▒▒▒▒ vmlinux EXPORT_SYMBOL ... [root@Fedora-30 linux]# readelf -s -W vmlinux.o | grep __kstrtabns_ipv6_chk_custom_prefix 199174: 0000000000032578 1 OBJECT LOCAL DEFAULT 89902 __kstrtabns_ipv6_chk_custom_prefix [root@Fedora-30 linux]# readelf -S -W vmlinux.o | grep 89902 [89902] __ksymtab_strings PROGBITS 0000000000000000 a94e00 0345a2 00 A 0 0 1 ------------------------------------------------------------------- Fixes: afa0459daa7b ("modpost: add a helper to get data pointed by a symbol") Fixes: 5545322c86d9 ("modpost: refactor namespace_from_kstrtabns() to not hard-code section name") Signed-off-by: Xiao Yang --- scripts/mod/modpost.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index d9418c58a8c0..c1fec8cac257 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -310,7 +310,8 @@ static const char *sec_name(struct elf_info *elf, int secindex) static void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym) { - Elf_Shdr *sechdr = &info->sechdrs[sym->st_shndx]; + unsigned int secindex = get_secindex(info, sym); + Elf_Shdr *sechdr = &info->sechdrs[secindex]; unsigned long offset; offset = sym->st_value; -- 2.21.0