From patchwork Thu May 7 19:25:35 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: 11534795 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 09FCE1392 for ; Thu, 7 May 2020 19:21:16 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DC9FF21835 for ; Thu, 7 May 2020 19:21:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sbWa/NGs"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="juFTsTqe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DC9FF21835 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Subject:To:From :Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=UuOslO/5BAtFRhW3/u0/vgKjARBqRGFpB3gHldNxCfI=; b=sbWa/NGsUJF7iu 2/S56nscE+GpTxkRaIEJs5fuNiUN7eY+zMeFu4mqPm/QXdxgIwDvenjtlTwY5MuMSs1ZP3ByP/iFi 53gHaE3JIoRVS/7zCgwR7JoB0+opWfNeibHgh4395q5ntMjMRTeSkPZqi9+MwPW4tHq+gPsK56IyI fH8XxBOnRCG3sSQYXH97JcSS50NkO3bqVlZs3tdr6aIgnjfuZHlgTFX07YG326+oqsGj0eZZofI4f lcxC2UBLuh0zTpCaA9q0fUlrvcPc52MiHE83kOZc5Og9X4OoncLH0iOeW7dZ4KcyzwIdmfHlWdREi 2Q7lJQewsmQFEChZidcg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWm51-0003jj-Jz; Thu, 07 May 2020 19:21:11 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWm4y-0003j8-Ma for linux-arm-kernel@lists.infradead.org; Thu, 07 May 2020 19:21:10 +0000 Received: from embeddedor (unknown [189.207.59.248]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 163A521835; Thu, 7 May 2020 19:21:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588879268; bh=qh1j1EPgFp9gEO4yUol6TFAoaToJnGzXm0ToAUgd8vA=; h=Date:From:To:Cc:Subject:From; b=juFTsTqegvq3Bv4Q2LiuA8DtFUy8o/PXwJhVFoG153XAwDnoyikkW75jBlGZ+d+3i SXYGKQVIOEPhhnUxU7c8JHjgnxHDcQ5yn74TK1z4ZjBNJ41QTvPbw64yHFwFtQ7lhs 6NmDIyesKEngYmbeZtxRFwUKpa+PiBIRYDPhtPC0= Date: Thu, 7 May 2020 14:25:35 -0500 From: "Gustavo A. R. Silva" To: Santosh Shilimkar Subject: [PATCH] soc: ti: Replace zero-length array with flexible-array Message-ID: <20200507192535.GA16622@embeddedor> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200507_122108_755845_D1940CA9 X-CRM114-Status: GOOD ( 13.81 ) X-Spam-Score: -5.2 (-----) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-5.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [198.145.29.99 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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 inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. 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/soc/ti/knav_qmss.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/soc/ti/knav_qmss.h b/drivers/soc/ti/knav_qmss.h index 038aec352df7..a01eda720bf6 100644 --- a/drivers/soc/ti/knav_qmss.h +++ b/drivers/soc/ti/knav_qmss.h @@ -67,7 +67,7 @@ struct knav_reg_config { u32 link_ram_size0; u32 link_ram_base1; u32 __pad2[2]; - u32 starvation[0]; + u32 starvation[]; }; struct knav_reg_region {