From patchwork Tue Jan 15 19:41:53 2019 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: 1025384 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=embeddedor.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43fLMD35HVz9s9G for ; Wed, 16 Jan 2019 06:42:00 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389410AbfAOTl6 (ORCPT ); Tue, 15 Jan 2019 14:41:58 -0500 Received: from gateway22.websitewelcome.com ([192.185.47.129]:46769 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389406AbfAOTl6 (ORCPT ); Tue, 15 Jan 2019 14:41:58 -0500 Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway22.websitewelcome.com (Postfix) with ESMTP id 1326D9C51 for ; Tue, 15 Jan 2019 13:41:57 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id jUazgiNNt2qH7jUazgLxeZ; Tue, 15 Jan 2019 13:41:57 -0600 X-Authority-Reason: nr=8 Received: from [189.250.130.205] (port=50320 helo=embeddedor) by gator4166.hostgator.com with esmtpa (Exim 4.91) (envelope-from ) id 1gjUax-000YFc-PO; Tue, 15 Jan 2019 13:41:56 -0600 Date: Tue, 15 Jan 2019 13:41:53 -0600 From: "Gustavo A. R. Silva" To: Ilya Dryomov , "Yan, Zheng" , Sage Weil , "David S. Miller" Cc: ceph-devel@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH net-next] libceph, ceph: use struct_size() in kmalloc() Message-ID: <20190115194153.GA9565@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: 189.250.130.205 X-Source-L: No X-Exim-ID: 1gjUax-000YFc-PO X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.250.130.205]:50320 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 6 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 One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct foo { int stuff; struct boo entry[]; }; instance = kmalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva --- net/ceph/osdmap.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index 98c0ff3d6441..48a31dc9161c 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -495,9 +495,8 @@ static struct crush_map *crush_decode(void *pbyval, void *end) / sizeof(struct crush_rule_step)) goto bad; #endif - r = c->rules[i] = kmalloc(sizeof(*r) + - yes*sizeof(struct crush_rule_step), - GFP_NOFS); + r = kmalloc(struct_size(r, steps, yes), GFP_NOFS); + c->rules[i] = r; if (r == NULL) goto badmem; dout(" rule %d is at %p\n", i, r);