From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail26.static.mailgun.info ([104.130.122.26]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jGR2N-0005LT-UA for ath11k@lists.infradead.org; Mon, 23 Mar 2020 17:38:59 +0000 MIME-Version: 1.0 Subject: Re: [PATCH][next] ath: Replace zero-length array with flexible-array member From: Kalle Valo In-Reply-To: <20200224165952.GA9377@embeddedor> References: <20200224165952.GA9377@embeddedor> Message-Id: <20200323173848.56CBFC432C2@smtp.codeaurora.org> Date: Mon, 23 Mar 2020 17:38:48 +0000 (UTC) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath11k" Errors-To: ath11k-bounces+kvalo=adurom.com@lists.infradead.org To: "Gustavo A. R. Silva" Cc: Maya Erez , Alexandre Torgue , netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, ath10k@lists.infradead.org, ath11k@lists.infradead.org, wil6210@qti.qualcomm.com, Maxime Coquelin , Christian Lamparter , wcn36xx@lists.infradead.org, "David S. Miller" , linux-arm-kernel@lists.infradead.org "Gustavo A. R. Silva" wrote: > 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 detected 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 Fails to apply, please rebase on top of my ath.git master branch. error: patch failed: drivers/net/wireless/ath/ath10k/core.h:1223 error: drivers/net/wireless/ath/ath10k/core.h: patch does not apply error: patch failed: drivers/net/wireless/ath/ath11k/debug.h:65 error: drivers/net/wireless/ath/ath11k/debug.h: patch does not apply error: patch failed: drivers/net/wireless/ath/ath11k/rx_desc.h:1206 error: drivers/net/wireless/ath/ath11k/rx_desc.h: patch does not apply stg import: Diff does not apply cleanly Patch set to Changes Requested. -- https://patchwork.kernel.org/patch/11401227/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches _______________________________________________ ath11k mailing list ath11k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath11k