From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5243C4321D for ; Thu, 23 Aug 2018 21:27:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 837BA21557 for ; Thu, 23 Aug 2018 21:27:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 837BA21557 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728206AbeHXA70 (ORCPT ); Thu, 23 Aug 2018 20:59:26 -0400 Received: from mail.bootlin.com ([62.4.15.54]:50640 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727829AbeHXA7Z (ORCPT ); Thu, 23 Aug 2018 20:59:25 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id 1C2B920750; Thu, 23 Aug 2018 23:27:49 +0200 (CEST) Received: from bbrezillon (91-160-177-164.subs.proxad.net [91.160.177.164]) by mail.bootlin.com (Postfix) with ESMTPSA id C18B3204AE; Thu, 23 Aug 2018 23:27:48 +0200 (CEST) Date: Thu, 23 Aug 2018 23:27:47 +0200 From: Boris Brezillon To: "Gustavo A. R. Silva" Cc: Harvey Hunt , Miquel Raynal , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, Kees Cook Subject: Re: [PATCH] mtd: rawnand: jz4780: use struct_size() in devm_kzalloc() Message-ID: <20180823232747.072af43d@bbrezillon> In-Reply-To: <20180823193332.GA31602@embeddedor.com> References: <20180823193332.GA31602@embeddedor.com> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 23 Aug 2018 14:33:32 -0500 "Gustavo A. R. Silva" wrote: > 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; > void *entry[]; > }; > > instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); > > Instead of leaving these open-coded and prone to type mistakes, we can > now use the new struct_size() helper: > > instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL); Oh, I didn't know about that one. That's nice! > > Signed-off-by: Gustavo A. R. Silva Reviewed-by: Boris Brezillon > --- > drivers/mtd/nand/raw/jz4780_nand.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mtd/nand/raw/jz4780_nand.c b/drivers/mtd/nand/raw/jz4780_nand.c > index db4fa60..ac62395 100644 > --- a/drivers/mtd/nand/raw/jz4780_nand.c > +++ b/drivers/mtd/nand/raw/jz4780_nand.c > @@ -352,7 +352,7 @@ static int jz4780_nand_probe(struct platform_device *pdev) > return -ENODEV; > } > > - nfc = devm_kzalloc(dev, sizeof(*nfc) + (sizeof(nfc->cs[0]) * num_banks), GFP_KERNEL); > + nfc = devm_kzalloc(dev, struct_size(nfc, cs, num_banks), GFP_KERNEL); > if (!nfc) > return -ENOMEM; >