From patchwork Mon May 4 20:12:24 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: 11527611 X-Patchwork-Delegate: kvalo@adurom.com 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 A3FC6913 for ; Mon, 4 May 2020 20:31:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8413D206A5 for ; Mon, 4 May 2020 20:31:02 +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="YvBiONp6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726482AbgEDUbB (ORCPT ); Mon, 4 May 2020 16:31:01 -0400 Received: from gateway20.websitewelcome.com ([192.185.53.25]:49591 "EHLO gateway20.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726338AbgEDUbB (ORCPT ); Mon, 4 May 2020 16:31:01 -0400 X-Greylist: delayed 1382 seconds by postgrey-1.27 at vger.kernel.org; Mon, 04 May 2020 16:31:01 EDT Received: from cm16.websitewelcome.com (cm16.websitewelcome.com [100.42.49.19]) by gateway20.websitewelcome.com (Postfix) with ESMTP id C88B0400C7A36 for ; Mon, 4 May 2020 13:50:07 -0500 (CDT) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id VhNejiwUn8vkBVhNejRMoo; Mon, 04 May 2020 15:07:58 -0500 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=QQwjaZedmAfrFU0rWpB+oFfnyoC2Vh8dMVpNEp+/1a8=; b=YvBiONp6QYSQAI1G8z08SM7g/Z B1dlFOOIF+orc6+l7/Ci3y/6MAJXtWyEM+aX8APnapsdo/7pjDIgs/wXikNBb4r6j62iTrQJbfJrU kPmAp/Xd3Kqd3hIxiLrnOMjZkJfPOxw+3gtGMsXh3Dr5wPi+95QmHtFjJ0HrlsWdTuJW0OLvHPdyV 3qGUbetw4jTRK/I0JuP75NMN7XUzMRhlvsLQYVIwLXy5klCeJRO4l13ND/MZfSBLgS7I/7N3t28zs wdCwdqBUiFIo0noLla95CJrJ4qZLw4/SBUscQrxJ0Bi5DXdH+V6I6eA4ZKUvJMWU7wIxbJ9ykgjhZ h3xqyYHQ==; Received: from [189.207.59.248] (port=58770 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1jVhNd-002HS1-SC; Mon, 04 May 2020 15:07:57 -0500 Date: Mon, 4 May 2020 15:12:24 -0500 From: "Gustavo A. R. Silva" To: Kalle Valo , "David S. Miller" Cc: ath11k@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] ath11k: Replace zero-length array with flexible-array Message-ID: <20200504201224.GA32282@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: 189.207.59.248 X-Source-L: No X-Exim-ID: 1jVhNd-002HS1-SC X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.207.59.248]:58770 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 15 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] 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/net/wireless/ath/ath11k/debug.h | 4 ++-- drivers/net/wireless/ath/ath11k/debug_htt_stats.h | 8 ++++---- drivers/net/wireless/ath/ath11k/hal_desc.h | 4 ++-- drivers/net/wireless/ath/ath11k/hal_rx.h | 2 +- drivers/net/wireless/ath/ath11k/hw.h | 2 +- drivers/net/wireless/ath/ath11k/wmi.h | 2 +- 6 files changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/net/wireless/ath/ath11k/debug.h b/drivers/net/wireless/ath/ath11k/debug.h index 97e7306c506d..c7edf946ff5c 100644 --- a/drivers/net/wireless/ath/ath11k/debug.h +++ b/drivers/net/wireless/ath/ath11k/debug.h @@ -67,7 +67,7 @@ struct debug_htt_stats_req { u8 peer_addr[ETH_ALEN]; struct completion cmpln; u32 buf_len; - u8 buf[0]; + u8 buf[]; }; struct ath_pktlog_hdr { @@ -77,7 +77,7 @@ struct ath_pktlog_hdr { u16 size; u32 timestamp; u32 type_specific_data; - u8 payload[0]; + u8 payload[]; }; #define ATH11K_HTT_STATS_BUF_SIZE (1024 * 512) diff --git a/drivers/net/wireless/ath/ath11k/debug_htt_stats.h b/drivers/net/wireless/ath/ath11k/debug_htt_stats.h index 23a6baa9e95a..682a6ff222bd 100644 --- a/drivers/net/wireless/ath/ath11k/debug_htt_stats.h +++ b/drivers/net/wireless/ath/ath11k/debug_htt_stats.h @@ -239,7 +239,7 @@ struct htt_tx_pdev_stats_tx_ppdu_stats_tlv_v { */ struct htt_tx_pdev_stats_tried_mpdu_cnt_hist_tlv_v { u32 hist_bin_size; - u32 tried_mpdu_cnt_hist[0]; /* HTT_TX_PDEV_TRIED_MPDU_CNT_HIST */ + u32 tried_mpdu_cnt_hist[]; /* HTT_TX_PDEV_TRIED_MPDU_CNT_HIST */ }; /* == SOC ERROR STATS == */ @@ -550,7 +550,7 @@ struct htt_tx_hwq_stats_cmn_tlv { struct htt_tx_hwq_difs_latency_stats_tlv_v { u32 hist_intvl; /* histogram of ppdu post to hwsch - > cmd status received */ - u32 difs_latency_hist[0]; /* HTT_TX_HWQ_MAX_DIFS_LATENCY_BINS */ + u32 difs_latency_hist[]; /* HTT_TX_HWQ_MAX_DIFS_LATENCY_BINS */ }; /* NOTE: Variable length TLV, use length spec to infer array size */ @@ -586,7 +586,7 @@ struct htt_tx_hwq_fes_result_stats_tlv_v { struct htt_tx_hwq_tried_mpdu_cnt_hist_tlv_v { u32 hist_bin_size; /* Histogram of number of mpdus on tried mpdu */ - u32 tried_mpdu_cnt_hist[0]; /* HTT_TX_HWQ_TRIED_MPDU_CNT_HIST */ + u32 tried_mpdu_cnt_hist[]; /* HTT_TX_HWQ_TRIED_MPDU_CNT_HIST */ }; /* NOTE: Variable length TLV, use length spec to infer array size @@ -1584,7 +1584,7 @@ struct htt_pdev_stats_twt_session_tlv { struct htt_pdev_stats_twt_sessions_tlv { u32 pdev_id; u32 num_sessions; - struct htt_pdev_stats_twt_session_tlv twt_session[0]; + struct htt_pdev_stats_twt_session_tlv twt_session[]; }; enum htt_rx_reo_resource_sample_id_enum { diff --git a/drivers/net/wireless/ath/ath11k/hal_desc.h b/drivers/net/wireless/ath/ath11k/hal_desc.h index 5e200380cca4..a1f747c1c44d 100644 --- a/drivers/net/wireless/ath/ath11k/hal_desc.h +++ b/drivers/net/wireless/ath/ath11k/hal_desc.h @@ -477,7 +477,7 @@ enum hal_tlv_tag { struct hal_tlv_hdr { u32 tl; - u8 value[0]; + u8 value[]; } __packed; #define RX_MPDU_DESC_INFO0_MSDU_COUNT GENMASK(7, 0) @@ -1972,7 +1972,7 @@ struct hal_rx_reo_queue { u32 processed_total_bytes; u32 info5; u32 rsvd[3]; - struct hal_rx_reo_queue_ext ext_desc[0]; + struct hal_rx_reo_queue_ext ext_desc[]; } __packed; /* hal_rx_reo_queue diff --git a/drivers/net/wireless/ath/ath11k/hal_rx.h b/drivers/net/wireless/ath/ath11k/hal_rx.h index e863e4abfcc1..c436191ae1e8 100644 --- a/drivers/net/wireless/ath/ath11k/hal_rx.h +++ b/drivers/net/wireless/ath/ath11k/hal_rx.h @@ -23,7 +23,7 @@ struct hal_rx_wbm_rel_info { struct hal_rx_mon_status_tlv_hdr { u32 hdr; - u8 value[0]; + u8 value[]; }; enum hal_rx_su_mu_coding { diff --git a/drivers/net/wireless/ath/ath11k/hw.h b/drivers/net/wireless/ath/ath11k/hw.h index 9973477ae373..cdec95644758 100644 --- a/drivers/net/wireless/ath/ath11k/hw.h +++ b/drivers/net/wireless/ath/ath11k/hw.h @@ -111,7 +111,7 @@ struct ath11k_hw_params { struct ath11k_fw_ie { __le32 id; __le32 len; - u8 data[0]; + u8 data[]; }; enum ath11k_bd_ie_board_type { diff --git a/drivers/net/wireless/ath/ath11k/wmi.h b/drivers/net/wireless/ath/ath11k/wmi.h index 510f9c6bc1d7..717e87db91cb 100644 --- a/drivers/net/wireless/ath/ath11k/wmi.h +++ b/drivers/net/wireless/ath/ath11k/wmi.h @@ -39,7 +39,7 @@ struct wmi_cmd_hdr { struct wmi_tlv { u32 header; - u8 value[0]; + u8 value[]; } __packed; #define WMI_TLV_LEN GENMASK(15, 0)