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=-9.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 DE2AAC43387 for ; Fri, 4 Jan 2019 18:14:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9A3D218DE for ; Fri, 4 Jan 2019 18:14:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546625668; bh=yl70YXMnOZY6TSWDtyNoEOT2T8HudqSdL5M+ycZzo4k=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=g76FM96bj5Cx6yhml2FMd/n4RUy/jIaRiQP7X+OpgJW7QeB3JJ2eBcpqraCs4fwjQ jUVJq+NbjqqQmhdf9pqZ5a/LJsG92v/3jSbnj46PpUgzgQiBZPEx1yFMPwMFHOUQIC 6PZ1vQoKK581QZ3cBTPhbfKc82ItH/0HwQm/w/sk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727771AbfADSO1 (ORCPT ); Fri, 4 Jan 2019 13:14:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:46118 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725958AbfADSO1 (ORCPT ); Fri, 4 Jan 2019 13:14:27 -0500 Received: from bbrezillon (91-160-177-164.subs.proxad.net [91.160.177.164]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9A32F218CD; Fri, 4 Jan 2019 18:14:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546625666; bh=yl70YXMnOZY6TSWDtyNoEOT2T8HudqSdL5M+ycZzo4k=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=jeYfp4Ho0q+FsMu0WoOzLu7YvbSENGHAKm+xB0VKXFzxsC9HABESIKaFqUKil4Dpu hZxGPuLZn6CmiIm/ANuld9kef8WTWlPqogSo8GgkB4iHqX1zIlCO2DE8bARPPZ91nB YYk2Uc5tBCJNAU+XM23zZUtHJfiMzRoR/HpK+j4c= Date: Fri, 4 Jan 2019 19:14:15 +0100 From: Boris Brezillon To: "Gustavo A. R. Silva" Cc: Miquel Raynal , Richard Weinberger , David Woodhouse , Brian Norris , Marek Vasut , Maxime Ripard , Chen-Yu Tsai , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] mtd: rawnand: sunxi: Use struct_size() in devm_kzalloc() Message-ID: <20190104191415.126e4a07@bbrezillon> In-Reply-To: <20190104172637.GA28084@embeddedor> References: <20190104172637.GA28084@embeddedor> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; 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 Hi Gustavo, On Fri, 4 Jan 2019 11:26:37 -0600 "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); > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva > --- > drivers/mtd/nand/raw/sunxi_nand.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c > index e828ee50a201..f66fffe663bf 100644 > --- a/drivers/mtd/nand/raw/sunxi_nand.c > +++ b/drivers/mtd/nand/raw/sunxi_nand.c > @@ -1870,10 +1870,7 @@ static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc, > return -EINVAL; > } > > - chip = devm_kzalloc(dev, > - sizeof(*chip) + > - (nsels * sizeof(struct sunxi_nand_chip_sel)), > - GFP_KERNEL); > + chip = devm_kzalloc(dev, struct_size(chip, sels, nsels), GFP_KERNEL); > if (!chip) { > dev_err(dev, "could not allocate chip\n"); > return -ENOMEM; I posted the same patch a few days back [1]. [1]http://patchwork.ozlabs.org/patch/1013855/