From patchwork Thu Feb 13 18:37:15 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: 11381047 X-Patchwork-Delegate: jgg@ziepe.ca 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 39162139A for ; Thu, 13 Feb 2020 18:59:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 17A0D217F4 for ; Thu, 13 Feb 2020 18:59:12 +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="gtG1qJTt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726968AbgBMS7L (ORCPT ); Thu, 13 Feb 2020 13:59:11 -0500 Received: from gateway24.websitewelcome.com ([192.185.51.202]:36908 "EHLO gateway24.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726780AbgBMS7L (ORCPT ); Thu, 13 Feb 2020 13:59:11 -0500 X-Greylist: delayed 1465 seconds by postgrey-1.27 at vger.kernel.org; Thu, 13 Feb 2020 13:59:10 EST Received: from cm11.websitewelcome.com (cm11.websitewelcome.com [100.42.49.5]) by gateway24.websitewelcome.com (Postfix) with ESMTP id 60E2312C2B7 for ; Thu, 13 Feb 2020 12:34:45 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id 2JK0j1NvQSl8q2JK1jjpCr; Thu, 13 Feb 2020 12:34:45 -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=+18p4uN9DK6dRKJWk5cR9EvFxREWiKNZQXUu8xY4YP0=; b=gtG1qJTtH1YieKQThWW4u0Ri6p YtfZtnun87pbLIu1YGRozG6O2Ubk4vVKRNAgnex4QoyFI974320vwKGYZ+NuQzPxpBgrOnqwUqDOE ZihyrJ9j1tQlatdhd3LdpoAYahtOuHlCqzR5Tocg+Ylgxo0FbSK1Ev/PPUA73bMX8OZzUX6i8/Fgz NKJG1CCMMyIfEjYGT7SG8FPVWZlSvutvMhNLI2X/rWvauQhXQl6kJTUBTwNAllBT43cR3rbUXDrqc Krc9c0qhe8ImxnjOgqL1kdTNUpMVQM1KqQEcis4UmssbPg1LI7g3FSFKlXvzJ3kSY9u9kvCVGsYC6 Xc5Rk97A==; Received: from [200.68.140.15] (port=6289 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.92) (envelope-from ) id 1j2JJv-000X97-0B; Thu, 13 Feb 2020 12:34:39 -0600 Date: Thu, 13 Feb 2020 12:37:15 -0600 From: "Gustavo A. R. Silva" To: Doug Ledford , Jason Gunthorpe Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] IB/core: Replace zero-length array with flexible-array member Message-ID: <20200213183715.GA19636@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: 200.68.140.15 X-Source-L: No X-Exim-ID: 1j2JJv-000X97-0B X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [200.68.140.15]:6289 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 7 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@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/infiniband/core/cache.c | 2 +- drivers/infiniband/core/cm.c | 4 ++-- drivers/infiniband/core/multicast.c | 2 +- drivers/infiniband/core/sa_query.c | 2 +- 4 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c index 17bfedd24cc3..dedfbe27916f 100644 --- a/drivers/infiniband/core/cache.c +++ b/drivers/infiniband/core/cache.c @@ -46,7 +46,7 @@ struct ib_pkey_cache { int table_len; - u16 table[0]; + u16 table[]; }; struct ib_update_work { diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c index 68cc1b2d6824..8424abe83607 100644 --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -197,7 +197,7 @@ struct cm_device { struct ib_device *ib_device; u8 ack_delay; int going_down; - struct cm_port *port[0]; + struct cm_port *port[]; }; struct cm_av { @@ -216,7 +216,7 @@ struct cm_work { __be32 local_id; /* Established / timewait */ __be32 remote_id; struct ib_cm_event cm_event; - struct sa_path_rec path[0]; + struct sa_path_rec path[]; }; struct cm_timewait_info { diff --git a/drivers/infiniband/core/multicast.c b/drivers/infiniband/core/multicast.c index cd338ddc4a39..9c2d8b7f1af9 100644 --- a/drivers/infiniband/core/multicast.c +++ b/drivers/infiniband/core/multicast.c @@ -71,7 +71,7 @@ struct mcast_device { struct ib_event_handler event_handler; int start_port; int end_port; - struct mcast_port port[0]; + struct mcast_port port[]; }; enum mcast_state { diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c index 30d4c126a2db..74e0058fcf9e 100644 --- a/drivers/infiniband/core/sa_query.c +++ b/drivers/infiniband/core/sa_query.c @@ -101,7 +101,7 @@ struct ib_sa_port { struct ib_sa_device { int start_port, end_port; struct ib_event_handler event_handler; - struct ib_sa_port port[0]; + struct ib_sa_port port[]; }; struct ib_sa_query {