From patchwork Tue Feb 11 20:49:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 209171 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=-13.1 required=3.0 tests=DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_SANE_1 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 88C6EC35242 for ; Tue, 11 Feb 2020 21:10:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F8AB20708 for ; Tue, 11 Feb 2020 21:10:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=embeddedor.com header.i=@embeddedor.com header.b="MeMsZ2Kz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728917AbgBKVKB (ORCPT ); Tue, 11 Feb 2020 16:10:01 -0500 Received: from gateway32.websitewelcome.com ([192.185.145.18]:49489 "EHLO gateway32.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728894AbgBKVKB (ORCPT ); Tue, 11 Feb 2020 16:10:01 -0500 X-Greylist: delayed 1398 seconds by postgrey-1.27 at vger.kernel.org; Tue, 11 Feb 2020 16:10:01 EST Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway32.websitewelcome.com (Postfix) with ESMTP id 23A41B75C5D for ; Tue, 11 Feb 2020 14:46:43 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 1cQdjVjIS8vkB1cQdjTtvJ; Tue, 11 Feb 2020 14:46:43 -0600 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Type:MIME-Version:Message-ID:Subject: Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=/FMhIrq5BpFrUC9zx3anUJVmYnzfBgatLaHuFwJIoQM=; b=MeMsZ2Kz3+N22ONp7xJJdeIa3c TxzeaBvytZxe5lZsUU7/PRh09m6PN0rMSD+AXcx0W7Zw+K/HZplH4dLiv7vjHaGVL/wnURlRmfqsb SmfsnDz6wgCM8nMQPbOfPOc58DUAIMMfABDj+Ep72V3HfCe5PL6KMXLIRLNZk2mQexLZHuYYRtP2G hxwTVAeNlqdtV2hqsr0Yh4llaW8LyiByO4IlxKfEBF0Mv4+FtAyUlYT2tyaoPctuuWrwqA8Ei0TZI /Jqe7hX6d5xGmGawyZmWc3cHqiKCx1Wza2MIFBQ5zeFhGz+D2QhSfLCV1gHKa5h8R6RvSYAIETlT0 /XxWW/Jw==; Received: from [200.68.140.36] (port=18749 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j1cQb-001uRh-MN; Tue, 11 Feb 2020 14:46:41 -0600 Date: Tue, 11 Feb 2020 14:49:16 -0600 From: "Gustavo A. R. Silva" To: Jacek Anaszewski , Pavel Machek Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] leds: pwm: Replace zero-length array with flexible-array member Message-ID: <20200211204916.GA20344@embeddedor> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 200.68.140.36 X-Source-L: No X-Exim-ID: 1j1cQb-001uRh-MN X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [200.68.140.36]:18749 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 36 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-leds-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva --- drivers/leds/leds-pwm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/leds/leds-pwm.c b/drivers/leds/leds-pwm.c index af08bcdc4fd8..904a74ebbe6a 100644 --- a/drivers/leds/leds-pwm.c +++ b/drivers/leds/leds-pwm.c @@ -32,7 +32,7 @@ struct led_pwm_data { struct led_pwm_priv { int num_leds; - struct led_pwm_data leds[0]; + struct led_pwm_data leds[]; }; static void __led_pwm_set(struct led_pwm_data *led_dat)