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=-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,USER_AGENT_SANE_1 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 0A416C4BA29 for ; Wed, 26 Feb 2020 21:17:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D2A5624656 for ; Wed, 26 Feb 2020 21:17:15 +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="fidh2amC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727673AbgBZVRP (ORCPT ); Wed, 26 Feb 2020 16:17:15 -0500 Received: from gateway22.websitewelcome.com ([192.185.46.187]:45476 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727591AbgBZVRN (ORCPT ); Wed, 26 Feb 2020 16:17:13 -0500 Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway22.websitewelcome.com (Postfix) with ESMTP id 2FFC36B76 for ; Wed, 26 Feb 2020 15:17:11 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 743LjeMuKAGTX743LjndPt; Wed, 26 Feb 2020 15:17:11 -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=hcbL3GZL7zsDbcF7idZFTlF2lQ3OpBjxU8cd/6ijrTg=; b=fidh2amCT9uWl2kffO/euzuGBx UEBpTxuFfCFq9WZOVARghIAnVfVkv1j7SzqN9AecVch+6Kz4jZNxnkm/cu+48NfjSQM5ZSlVNlnjD FYoTTlQUiSDLDoaSNBn7sx1nZZpkK+cm0MvhXpdJGS60/05Y7520Y71IIv0lVO8eg4/dVbFsjXo/G uRyPUFUr3miIoqER1U7tKfo2yAKSqeEBhLvTMe/mtIb+KBRNQlMAenN7h6iHaKmmKAg7TXqKF6koG MtJEK9hLR/migrGJdxeMq949dFojySxzONPVMxCEzT4RsappO8FJmP6jJao1Vv6QTgv075YdDUq1P kE62bZeQ==; Received: from [201.162.161.213] (port=47606 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j743J-000kNj-0S; Wed, 26 Feb 2020 15:17:09 -0600 Date: Wed, 26 Feb 2020 15:20:00 -0600 From: "Gustavo A. R. Silva" To: "David S. Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH][next] NFC: Replace zero-length array with flexible-array member Message-ID: <20200226212000.GA32231@embeddedor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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: 201.162.161.213 X-Source-L: No X-Exim-ID: 1j743J-000kNj-0S X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [201.162.161.213]:47606 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 10 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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/nfc/fdp/fdp.c | 2 +- drivers/nfc/st21nfca/dep.c | 4 ++-- include/net/nfc/nci.h | 14 +++++++------- include/net/nfc/nfc.h | 2 +- 4 files changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/nfc/fdp/fdp.c b/drivers/nfc/fdp/fdp.c index 062535c8251b..d4ff9e6056c2 100644 --- a/drivers/nfc/fdp/fdp.c +++ b/drivers/nfc/fdp/fdp.c @@ -76,7 +76,7 @@ static u8 nci_core_get_config_otp_ram_version[5] = { struct nci_core_get_config_rsp { u8 status; u8 count; - u8 data[0]; + u8 data[]; }; static int fdp_nci_create_conn(struct nci_dev *ndev) diff --git a/drivers/nfc/st21nfca/dep.c b/drivers/nfc/st21nfca/dep.c index 137eb3f7dabd..98e73e047e02 100644 --- a/drivers/nfc/st21nfca/dep.c +++ b/drivers/nfc/st21nfca/dep.c @@ -66,7 +66,7 @@ struct st21nfca_atr_req { u8 bsi; u8 bri; u8 ppi; - u8 gbi[0]; + u8 gbi[]; } __packed; struct st21nfca_atr_res { @@ -79,7 +79,7 @@ struct st21nfca_atr_res { u8 bri; u8 to; u8 ppi; - u8 gbi[0]; + u8 gbi[]; } __packed; struct st21nfca_psl_req { diff --git a/include/net/nfc/nci.h b/include/net/nfc/nci.h index 6ab5a83f597c..0550e0380b8d 100644 --- a/include/net/nfc/nci.h +++ b/include/net/nfc/nci.h @@ -244,13 +244,13 @@ struct dest_spec_params { struct core_conn_create_dest_spec_params { __u8 type; __u8 length; - __u8 value[0]; + __u8 value[]; } __packed; struct nci_core_conn_create_cmd { __u8 destination_type; __u8 number_destination_params; - struct core_conn_create_dest_spec_params params[0]; + struct core_conn_create_dest_spec_params params[]; } __packed; #define NCI_OP_CORE_CONN_CLOSE_CMD nci_opcode_pack(NCI_GID_CORE, 0x05) @@ -321,7 +321,7 @@ struct nci_core_init_rsp_1 { __u8 status; __le32 nfcc_features; __u8 num_supported_rf_interfaces; - __u8 supported_rf_interfaces[0]; /* variable size array */ + __u8 supported_rf_interfaces[]; /* variable size array */ /* continuted in nci_core_init_rsp_2 */ } __packed; @@ -338,7 +338,7 @@ struct nci_core_init_rsp_2 { struct nci_core_set_config_rsp { __u8 status; __u8 num_params; - __u8 params_id[0]; /* variable size array */ + __u8 params_id[]; /* variable size array */ } __packed; #define NCI_OP_CORE_CONN_CREATE_RSP nci_opcode_pack(NCI_GID_CORE, 0x04) @@ -501,18 +501,18 @@ struct nci_rf_nfcee_action_ntf { __u8 nfcee_id; __u8 trigger; __u8 supported_data_length; - __u8 supported_data[0]; + __u8 supported_data[]; } __packed; #define NCI_OP_NFCEE_DISCOVER_NTF nci_opcode_pack(NCI_GID_NFCEE_MGMT, 0x00) struct nci_nfcee_supported_protocol { __u8 num_protocol; - __u8 supported_protocol[0]; + __u8 supported_protocol[]; } __packed; struct nci_nfcee_information_tlv { __u8 num_tlv; - __u8 information_tlv[0]; + __u8 information_tlv[]; } __packed; struct nci_nfcee_discover_ntf { diff --git a/include/net/nfc/nfc.h b/include/net/nfc/nfc.h index 5d277d68fd8d..2cd3a261bcbc 100644 --- a/include/net/nfc/nfc.h +++ b/include/net/nfc/nfc.h @@ -146,7 +146,7 @@ struct nfc_evt_transaction { u32 aid_len; u8 aid[NFC_MAX_AID_LENGTH]; u8 params_len; - u8 params[0]; + u8 params[]; } __packed; struct nfc_genl_data { -- 2.25.0