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 X-Spam-Level: X-Spam-Status: No, score=-21.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 E11B4C433E6 for ; Mon, 1 Feb 2021 17:45:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4C3864EA9 for ; Mon, 1 Feb 2021 17:45:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232266AbhBARop (ORCPT ); Mon, 1 Feb 2021 12:44:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:50580 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231287AbhBARoQ (ORCPT ); Mon, 1 Feb 2021 12:44:16 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id DD36664E92; Mon, 1 Feb 2021 17:43:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612201416; bh=6JuMhwiPxB5zwCevxjDcGxnSg7igAiVfttRPt3eGViM=; h=Date:From:To:Cc:Subject:From; b=RzHBn+zcnVxDBGt7mlXIwAfT7kISdYH5yde5MD1mHMHHzUnJCYwEinKiGKenm/oPj 4gNFA30b9y2ujEmDtW5YQx6+2qWOGHUW441BU0QAVYzE59NX54GdVwzJGpDMHW1+CS jzSdNGz1qB89qQ8YCoN4sYtkiTrZqMWtzTVeaI+cKyUCOpRQ/wvNPKhi/vUY3+uqyu Wt9gsJJSJyKk9R0q12r4GD+wtxWaxUOjNSTpdKKwLbjNQ5q8UTL349ir0A4M+4SJYA vHB7/t9hfcSja+Lb8/P5lm8/rlCqx9vIziZXWWMlOk+DJcOleoVH7uLw4CoKTLhNEk d3cD5RMLT/TXQ== Date: Mon, 1 Feb 2021 11:43:34 -0600 From: "Gustavo A. R. Silva" To: "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu Cc: linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] hv: hyperv.h: Replace one-element array with flexible-array in struct icmsg_negotiate Message-ID: <20210201174334.GA171933@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org 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]. Refactor the code according to the use of a flexible-array member in struct icmsg_negotiate, instead of a one-element array. Also, this helps the ongoing efforts to enable -Warray-bounds and fix the following warnings: drivers/hv/channel_mgmt.c:315:23: warning: array subscript 1 is above array bounds of ‘struct ic_version[1]’ [-Warray-bounds] drivers/hv/channel_mgmt.c:316:23: warning: array subscript 1 is above array bounds of ‘struct ic_version[1]’ [-Warray-bounds] [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/109 Signed-off-by: Gustavo A. R. Silva --- include/linux/hyperv.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index f0d48a368f13..7877746f1077 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1528,14 +1528,14 @@ struct icmsg_hdr { #define IC_VERSION_NEGOTIATION_MAX_VER_COUNT 100 #define ICMSG_HDR (sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr)) #define ICMSG_NEGOTIATE_PKT_SIZE(icframe_vercnt, icmsg_vercnt) \ - (ICMSG_HDR + offsetof(struct icmsg_negotiate, icversion_data) + \ + (ICMSG_HDR + sizeof(struct icmsg_negotiate) + \ (((icframe_vercnt) + (icmsg_vercnt)) * sizeof(struct ic_version))) struct icmsg_negotiate { u16 icframe_vercnt; u16 icmsg_vercnt; u32 reserved; - struct ic_version icversion_data[1]; /* any size array */ + struct ic_version icversion_data[]; /* any size array */ } __packed; struct shutdown_msg_data { -- 2.27.0