From patchwork Mon Jul 24 13:17:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Clark X-Patchwork-Id: 13324774 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 BC916C001B0 for ; Mon, 24 Jul 2023 13:18:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230083AbjGXNSs (ORCPT ); Mon, 24 Jul 2023 09:18:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230076AbjGXNSr (ORCPT ); Mon, 24 Jul 2023 09:18:47 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BE55DDA; Mon, 24 Jul 2023 06:18:46 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9AA09FEC; Mon, 24 Jul 2023 06:19:29 -0700 (PDT) Received: from e127643.arm.com (unknown [10.57.2.52]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7DD9C3F67D; Mon, 24 Jul 2023 06:18:44 -0700 (PDT) From: James Clark To: linux-kbuild@vger.kernel.org, masahiroy@kernel.org Cc: linux-kernel@vger.kernel.org, James Clark , Kees Cook , Greg Kroah-Hartman , Zhen Lei , Miguel Ojeda , Boqun Feng , Arnd Bergmann , Nicolas Schier Subject: [PATCH] scripts/kallsyms: Fix build failure by setting errno before calling getline() Date: Mon, 24 Jul 2023 14:17:40 +0100 Message-Id: <20230724131741.954624-1-james.clark@arm.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org getline() returns -1 at EOF as well as on error. It also doesn't set errno to 0 on success, so initialize it to 0 before using errno to check for an error condition. See the paragraph here [1]: For some system calls and library functions (e.g., getpriority(2)), -1 is a valid return on success. In such cases, a successful return can be distinguished from an error return by setting errno to zero before the call, and then, if the call returns a status that indicates that an error may have occurred, checking to see if errno has a nonzero value. This fixes the following build failure if scripts/kallsyms launches with a non-zero errno value: $ make ... LD .tmp_vmlinux.kallsyms1 NM .tmp_vmlinux.kallsyms1.syms KSYMS .tmp_vmlinux.kallsyms1.S read_symbol: Invalid argument [1]: https://linux.die.net/man/3/errno Fixes: 1c975da56a6f ("scripts/kallsyms: remove KSYM_NAME_LEN_BUFFER") Signed-off-by: James Clark --- scripts/kallsyms.c | 1 + 1 file changed, 1 insertion(+) diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index 16c87938b316..653b92f6d4c8 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -129,6 +129,7 @@ static struct sym_entry *read_symbol(FILE *in, char **buf, size_t *buf_len) ssize_t readlen; struct sym_entry *sym; + errno = 0; readlen = getline(buf, buf_len, in); if (readlen < 0) { if (errno) {