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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5454C43217 for ; Wed, 9 Feb 2022 19:00:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241985AbiBITAp (ORCPT ); Wed, 9 Feb 2022 14:00:45 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:37984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241909AbiBITAj (ORCPT ); Wed, 9 Feb 2022 14:00:39 -0500 Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65597C0045B7; Wed, 9 Feb 2022 10:59:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1644433158; x=1675969158; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=++X99Su9CmcwEyMn/TkpPbeHGo1khXP+bvcbF0jf6Kk=; b=PESZ/2mi3/yq8NDCBQDN1XqWjcvcBEhQq0asKgTk2GBEx5D3SoXZ7uwA GA9DKfq56pE2pXCMTpV0ZVuVn1pKEn0eZ+r1R1OOIvf1movzCXnebOLJm S0TyCT0DoXo078ZCTQE+zFrq4mf0bXNj7KRCjcD8Buq/Kd1rSP/HXoye1 TSrqcFa3NiTBVNf+qyERfy0yd6OTR/3L8vWJ0L0BL9gJnxjpEgKfRvc8u ObB+qcf0XjVZ8/ksYWNsSpu44tcwHCwkSHgIoB7p9QGWqt/lcKbT0m236 PLMTW/qA+W/NvFjxvyYoG6isMV9dvSaGJH+f9R7JU2tz2uIXOqupHz7se Q==; X-IronPort-AV: E=McAfee;i="6200,9189,10253"; a="310047636" X-IronPort-AV: E=Sophos;i="5.88,356,1635231600"; d="scan'208";a="310047636" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Feb 2022 10:58:58 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,356,1635231600"; d="scan'208";a="629389815" Received: from irvmail001.ir.intel.com ([10.43.11.63]) by fmsmga002.fm.intel.com with ESMTP; 09 Feb 2022 10:58:50 -0800 Received: from newjersey.igk.intel.com (newjersey.igk.intel.com [10.102.20.203]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id 219IwjQO031082; Wed, 9 Feb 2022 18:58:47 GMT From: Alexander Lobakin To: linux-hardening@vger.kernel.org, x86@kernel.org Cc: Alexander Lobakin , Borislav Petkov , Jesse Brandeburg , Kristen Carlson Accardi , Kees Cook , Miklos Szeredi , Ard Biesheuvel , Tony Luck , Bruce Schlobohm , Jessica Yu , kernel test robot , Miroslav Benes , Evgenii Shatokhin , Jonathan Corbet , Masahiro Yamada , Michal Marek , Nick Desaulniers , Herbert Xu , "David S. Miller" , Thomas Gleixner , Will Deacon , Ingo Molnar , Christoph Hellwig , Dave Hansen , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Arnd Bergmann , Josh Poimboeuf , Nathan Chancellor , Masami Hiramatsu , Marios Pomonis , Sami Tolvanen , "H.J. Lu" , Nicolas Pitre , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, live-patching@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH v10 01/15] modpost: fix removing numeric suffixes Date: Wed, 9 Feb 2022 19:57:38 +0100 Message-Id: <20220209185752.1226407-2-alexandr.lobakin@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220209185752.1226407-1-alexandr.lobakin@intel.com> References: <20220209185752.1226407-1-alexandr.lobakin@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org `-z unique-symbol` linker flag which is planned to use with FG-KASLR to simplify livepatching (hopefully globally later on) triggers the following: ERROR: modpost: "param_set_uint.0" [vmlinux] is a static EXPORT_SYMBOL The reason is that for now the condition from remove_dot(): if (m && (s[n + m] == '.' || s[n + m] == 0)) which was designed to test if it's a dot or a '\0' after the suffix is never satisfied. This is due to that `s[n + m]` always points to the last digit of a numeric suffix, not on the symbol next to it (from a custom debug print added to modpost): param_set_uint.0, s[n + m] is '0', s[n + m + 1] is '\0' So it's off-by-one and was like that since 2014. Fix this for the sake of upcoming features, but don't bother stable-backporting, as it's well hidden -- apart from that LD flag, can be triggered only by GCC LTO which never landed upstream. Fixes: fcd38ed0ff26 ("scripts: modpost: fix compilation warning") Signed-off-by: Alexander Lobakin --- scripts/mod/modpost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 6bfa33217914..4648b7afe5cc 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1986,7 +1986,7 @@ static char *remove_dot(char *s) if (n && s[n]) { size_t m = strspn(s + n + 1, "0123456789"); - if (m && (s[n + m] == '.' || s[n + m] == 0)) + if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0)) s[n] = 0; /* strip trailing .lto */ -- 2.34.1