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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 C440BC433ED for ; Sat, 24 Apr 2021 08:28:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 98D6D61466 for ; Sat, 24 Apr 2021 08:28:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232924AbhDXI3e (ORCPT ); Sat, 24 Apr 2021 04:29:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:57948 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235342AbhDXI3P (ORCPT ); Sat, 24 Apr 2021 04:29:15 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9B4D661483; Sat, 24 Apr 2021 08:28:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1619252915; bh=iA6WKyKWLFOpBjgxGfRf5mbNticXYZ5x2t79/LDjV3A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ISzYGw7YSdRIhCqteqqqkjoFe9iKHptvjx9kVcHwiXOBQHWJ+QBTfxBO+EG630IWK B0ZL/LpfM9pX739VZIPmM8X9Ji0HEr7fyvLwQR2F/Xv+DB+16KE6kbjemzynAsMucU aSPqOaSFdWkFyMRTqGFWfuI7UABVPt0t3E1pPf4A= Date: Sat, 24 Apr 2021 10:28:27 +0200 From: Greg Kroah-Hartman To: Ashish Kalra Cc: Joe Perches , Abheek Dhawan , Johannes Weiner , Romain Perier , Waiman Long , Allen Pais , Ivan Safonov , linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] staging: wlan-ng: silence incorrect type in argument 1 (different address spaces) warning Message-ID: References: <20210420090142.GA4086@ashish-NUC8i5BEH> <20210423152619.GA2469@ashish-NUC8i5BEH> <20210424081529.GA1731@ubuntu> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210424081529.GA1731@ubuntu> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 24, 2021 at 01:45:29PM +0530, Ashish Kalra wrote: > On Fri, Apr 23, 2021 at 11:11:05PM -0700, Joe Perches wrote: > > On Sat, 2021-04-24 at 08:00 +0200, Greg Kroah-Hartman wrote: > > > On Fri, Apr 23, 2021 at 08:56:19PM +0530, Ashish Kalra wrote: > > > > On Thu, Apr 22, 2021 at 10:43:13AM +0200, Greg Kroah-Hartman wrote: > > > > > On Tue, Apr 20, 2021 at 02:31:42PM +0530, Ashish Kalra wrote: > > > > > > Upon running sparse, "warning: incorrect type in argument 1 (different address spaces) > > > > > > is brought to notice for this file.let's add correct typecast to make it cleaner and > > > > > > silence the Sparse warning. > > [] > > > >  struct p80211ioctl_req { > > > >         char name[WLAN_DEVNAMELEN_MAX]; > > > > - caddr_t data; > > > > + void __user *data; > > > > > > > > Does this looks ok to you and is there any other check possible if this is ok? > > > > > > Wait, what is "caddr_t"? Try unwinding that mess first... > > > > Might not be that simple. > > > > include/linux/types.h:typedef __kernel_caddr_t caddr_t; > > include/uapi/linux/coda.h:typedef void * caddr_t; > > include/uapi/asm-generic/posix_types.h:typedef char * __kernel_caddr_t; > > > > > data is part of p80211ioctl_req and is used at two places only inside p80211knetdev_do_ioctl > it seems both places it will be used as void __user* only > > msgbuf = memdup_user(req->data, req->len); > > if (result == 0) { > if (copy_to_user > ((void __user *)req->data, msgbuf, req->len)) { > result = -EFAULT; > } > } > > Will it still be problem if we change it from char * to void *.? Why do you want to change it to void *? Never use a void * unless it has to point to unknown data. That does not seem the case here. > is there any way to check how caller of this function will be using it? Look at the code to determine this... thanks, greg k-h