From patchwork Wed Sep 29 19:15:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 12526483 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75E9EC433EF for ; Wed, 29 Sep 2021 19:12:08 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (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 53669613D3 for ; Wed, 29 Sep 2021 19:12:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 53669613D3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 616C316DE; Wed, 29 Sep 2021 21:11:15 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 616C316DE DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1632942725; bh=g/8s55Jc9bqt8ZNNteEuzgrzOaKJ/elKL6Rcokeb5XM=; h=Date:From:To:Subject:Cc:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From; b=H7lgY9EoLrpgjsLhc1hJFYeasjKyCxJ/4aBh0V6rw44kcI1cTYAs2UTDKXTJJXy5L DjiJffB2wKDa0Hlesrj1c4JX2We/y+vMTrYrzKe6UE2MfKdduX5zaXTMe8DlXpba1s PJ5Bllr8gM6piwNXkOoJHAibHWG72/w1BNQQm1F8= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id D8D10F801F7; Wed, 29 Sep 2021 21:11:14 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id DB5C5F80227; Wed, 29 Sep 2021 21:11:12 +0200 (CEST) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 43F20F80105 for ; Wed, 29 Sep 2021 21:11:03 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 43F20F80105 Authentication-Results: alsa1.perex.cz; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nXFeiZPS" Received: by mail.kernel.org (Postfix) with ESMTPSA id A4F8461526; Wed, 29 Sep 2021 19:10:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1632942660; bh=g/8s55Jc9bqt8ZNNteEuzgrzOaKJ/elKL6Rcokeb5XM=; h=Date:From:To:Cc:Subject:From; b=nXFeiZPSW79r4UtpWMpAj+sFQtFDItw0Azdkv+bcgqAhlqsNY1rIMFzeJg0E7AOSL GGu092Vwb+B8Zt66Dd9akCOdAQvl3OY6aYceGqV3pxbJuAGIkSdxbV/MNqD2KFhu3T /7NbpFrr3sVtXygweNooeksB8BgKwFl5i9ggQhKmF7iWNj6jC9yjwHkRG/tzHnLdNx K4Xv8A8njMCu+Idbn8Qw3uojter5eeOMewy7T24AH+8FsPdwDK8As8WQalcTgI2CUo dDvWtlydXy2hkheMpF31hBm/d5sop6hyYl6WolfVTVwbkDyYm+995y/SnXJbN4pNh3 ZHTzk8/g/jVpA== Date: Wed, 29 Sep 2021 14:15:04 -0500 From: "Gustavo A. R. Silva" To: Anton Yakovlev , "Michael S. Tsirkin" , Jaroslav Kysela , Takashi Iwai Subject: [PATCH][next] ALSA: virtio: Replace zero-length array with flexible-array member Message-ID: <20210929191504.GA337268@embeddedor> MIME-Version: 1.0 Content-Disposition: inline Cc: alsa-devel@alsa-project.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. Also, make use of the struct_size() helper in kzalloc(). [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/78 Signed-off-by: Gustavo A. R. Silva --- sound/virtio/virtio_pcm_msg.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/sound/virtio/virtio_pcm_msg.c b/sound/virtio/virtio_pcm_msg.c index f88c8f29cbd8..aca2dc1989ba 100644 --- a/sound/virtio/virtio_pcm_msg.c +++ b/sound/virtio/virtio_pcm_msg.c @@ -20,7 +20,7 @@ struct virtio_pcm_msg { struct virtio_snd_pcm_xfer xfer; struct virtio_snd_pcm_status status; size_t length; - struct scatterlist sgs[0]; + struct scatterlist sgs[]; }; /** @@ -146,8 +146,7 @@ int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *vss, int sg_num = virtsnd_pcm_sg_num(data, period_bytes); struct virtio_pcm_msg *msg; - msg = kzalloc(sizeof(*msg) + sizeof(*msg->sgs) * (sg_num + 2), - GFP_KERNEL); + msg = kzalloc(struct_size(msg, sgs, sg_num + 2), GFP_KERNEL); if (!msg) return -ENOMEM;