From patchwork Tue Feb 25 01:14:15 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: 216423 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 719B8C35DEA for ; Tue, 25 Feb 2020 01:11:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A8D6218AC for ; Tue, 25 Feb 2020 01:11:30 +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="ZP4B0m1M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728516AbgBYBL3 (ORCPT ); Mon, 24 Feb 2020 20:11:29 -0500 Received: from gateway32.websitewelcome.com ([192.185.145.178]:11873 "EHLO gateway32.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728011AbgBYBL3 (ORCPT ); Mon, 24 Feb 2020 20:11:29 -0500 Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway32.websitewelcome.com (Postfix) with ESMTP id 36BA51BB089 for ; Mon, 24 Feb 2020 19:11:28 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 6OkyjPc0CXVkQ6OkyjlD6J; Mon, 24 Feb 2020 19:11:28 -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=rzMLcS2/ZUpYVpdJI43BRpgzSfEuuyjXrY5HzICY5lU=; b=ZP4B0m1M6tm079nzgpmYt0ILyG 5Pybfw+yRZIJ15oHp4SO0AwAHczetoTrQ48NxdpDGb6sL/+/GdP9UJ5HQYEDaNT91J4/DHIlPVnyq GAZqMVydJBxNvDSVxxWkiKhhtzPnmFdxoQkrIc3/Rj0wPBz4y0zuufu+yCqDA9UYhr/nOEw09VkyJ H2Wnpt/2NW10dEU2hH1bBcMb0CinWZAYChiW88tyGTLFYTof+Kyfy92pbzJBB1dkYI9IZIUlYDntt 7YtgeVjuUbU0Jlg6798SX21xl+tSImTvq6oTVXnhwVLVgMjYxM+YPozm0IbjOXf93w0O9UReeVO09 0PBXnLSA==; Received: from [201.166.191.54] (port=58506 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j6Okw-002sYf-D4; Mon, 24 Feb 2020 19:11:26 -0600 Date: Mon, 24 Feb 2020 19:14:15 -0600 From: "Gustavo A. R. Silva" To: Kalle Valo , "David S. Miller" Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH][next] orinoco: Replace zero-length array with flexible-array member Message-ID: <20200225011415.GA31868@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: 201.166.191.54 X-Source-L: No X-Exim-ID: 1j6Okw-002sYf-D4 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.166.191.54]:58506 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 9 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@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 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] 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/net/wireless/intersil/orinoco/fw.c | 2 +- drivers/net/wireless/intersil/orinoco/hermes.h | 2 +- drivers/net/wireless/intersil/orinoco/hermes_dld.c | 6 +++--- drivers/net/wireless/intersil/orinoco/orinoco_usb.c | 2 +- 4 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/intersil/orinoco/fw.c b/drivers/net/wireless/intersil/orinoco/fw.c index 400a35217644..015af782881b 100644 --- a/drivers/net/wireless/intersil/orinoco/fw.c +++ b/drivers/net/wireless/intersil/orinoco/fw.c @@ -49,7 +49,7 @@ struct orinoco_fw_header { __le32 pdr_offset; /* Offset to PDR data from eof header */ __le32 pri_offset; /* Offset to primary plug data */ __le32 compat_offset; /* Offset to compatibility data*/ - char signature[0]; /* FW signature length headersize-20 */ + char signature[]; /* FW signature length headersize-20 */ } __packed; /* Check the range of various header entries. Return a pointer to a diff --git a/drivers/net/wireless/intersil/orinoco/hermes.h b/drivers/net/wireless/intersil/orinoco/hermes.h index 121fdd8e5da2..9f668185b7d2 100644 --- a/drivers/net/wireless/intersil/orinoco/hermes.h +++ b/drivers/net/wireless/intersil/orinoco/hermes.h @@ -341,7 +341,7 @@ struct agere_ext_scan_info { __le64 timestamp; __le16 beacon_interval; __le16 capabilities; - u8 data[0]; + u8 data[]; } __packed; #define HERMES_LINKSTATUS_NOT_CONNECTED (0x0000) diff --git a/drivers/net/wireless/intersil/orinoco/hermes_dld.c b/drivers/net/wireless/intersil/orinoco/hermes_dld.c index 4a10b7aca043..dbeadfcfefe2 100644 --- a/drivers/net/wireless/intersil/orinoco/hermes_dld.c +++ b/drivers/net/wireless/intersil/orinoco/hermes_dld.c @@ -64,7 +64,7 @@ struct dblock { __le32 addr; /* adapter address where to write the block */ __le16 len; /* length of the data only, in bytes */ - char data[0]; /* data to be written */ + char data[]; /* data to be written */ } __packed; /* @@ -76,7 +76,7 @@ struct pdr { __le32 id; /* record ID */ __le32 addr; /* adapter address where to write the data */ __le32 len; /* expected length of the data, in bytes */ - char next[0]; /* next PDR starts here */ + char next[]; /* next PDR starts here */ } __packed; /* @@ -87,7 +87,7 @@ struct pdr { struct pdi { __le16 len; /* length of ID and data, in words */ __le16 id; /* record ID */ - char data[0]; /* plug data */ + char data[]; /* plug data */ } __packed; /*** FW data block access functions ***/ diff --git a/drivers/net/wireless/intersil/orinoco/orinoco_usb.c b/drivers/net/wireless/intersil/orinoco/orinoco_usb.c index e753f43e0162..a77bbcd544d6 100644 --- a/drivers/net/wireless/intersil/orinoco/orinoco_usb.c +++ b/drivers/net/wireless/intersil/orinoco/orinoco_usb.c @@ -202,7 +202,7 @@ struct ezusb_packet { __le16 crc; /* CRC up to here */ __le16 hermes_len; __le16 hermes_rid; - u8 data[0]; + u8 data[]; } __packed; /* Table of devices that work or may work with this driver */