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: 10765073 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BD8C714E5 for ; Tue, 15 Jan 2019 20:05:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AA6E72B8CB for ; Tue, 15 Jan 2019 20:05:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9D4B02BD6E; Tue, 15 Jan 2019 20:05:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 491F32B8CB for ; Tue, 15 Jan 2019 20:05:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389640AbfAOUF4 (ORCPT ); Tue, 15 Jan 2019 15:05:56 -0500 Received: from gateway22.websitewelcome.com ([192.185.47.129]:20209 "EHLO gateway22.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730062AbfAOUF4 (ORCPT ); Tue, 15 Jan 2019 15:05:56 -0500 X-Greylist: delayed 1439 seconds by postgrey-1.27 at vger.kernel.org; Tue, 15 Jan 2019 15:05:56 EST Received: from cm17.websitewelcome.com (cm17.websitewelcome.com [100.42.49.20]) by gateway22.websitewelcome.com (Postfix) with ESMTP id 140B5A6A8 for ; Tue, 15 Jan 2019 13:41:57 -0600 (CST) Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with SMTP id jUazggjQu90onjUazg9Zst; 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: 5 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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);