From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f179.google.com (mail-pf1-f179.google.com [209.85.210.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 17C5E72 for ; Tue, 27 Apr 2021 12:23:39 +0000 (UTC) Received: by mail-pf1-f179.google.com with SMTP id y62so8609164pfg.4 for ; Tue, 27 Apr 2021 05:23:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=oIH8WYIkB/ztyv6SBr4INOuz26sOP+Zv7q5JUrWt5S8=; b=vh8IqGRq8Sq5pPjUyHXRnecANmNmrskCeP5WRIHL8932dVb8+07Vfg+D8d6+gS9Br5 WSuLY6wi16zCyeba0dAwEnQzEO4Vexq4RFxiq6lELPEmfHHC3yooTUFzG3tCjn0kvVry PcWuG7OyqHnSWAn8X3iHnuyLc4tcEI2Riz7+kkaFUFz5DnqqCJKkGO1mZHWpgTxfaxYe 1ke+gztJKXZKnjzmAOor/Nob/X8j2t9D2zDVRMVEf5zXukVH+WF9N//8A7+uvXNWgcKu 8YI6xb2CaMZ6rqA8cRGIW549UzkP3FfKFKg2Ad4NgRBRlqi7GOcUwh+VXroFbLHh/Nqn vYuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=oIH8WYIkB/ztyv6SBr4INOuz26sOP+Zv7q5JUrWt5S8=; b=ugU6BLU+uINEnWSsxk8vqySA2xIrjFSOFHyLVqmn+lQno/gOU3xONnUu60vIzVpmxn finXtVg3GJSdlBKd0LFbrRkfE5fk3Ew86WWSyyLfmqROwJ2rPpccXoGgEwUez7020rYg ucp15v2Qap/+kMIc8Hdib/7hq+CWMufFckK/3AvHDcuWQMTyNKk34sc5Zol2hn1k/cHh 5HPhHeDyvkB2iZV1cdfba/pT0YsTtRfcOZhIsHjPNXOF+4p7/bxvEOJDXiSbogEwyEk8 qsVwq1SGHuM+znMC4jMlvI32tzQzIi2KS43QGnucXeVLeAEiloct2BjraQ5LTrvEWhNL Lz3Q== X-Gm-Message-State: AOAM530Kj3uZj4vxpW2ale5mCiL+9IbfAn0PVB3JApcdf0Z5Bt9v64uK wxxstX22DXJNsH5WhJBjsu0= X-Google-Smtp-Source: ABdhPJx20lR4SNDF+cm5Avx5zJyQMAHpmnv+dL6KMGctS63n9+BFqdat8Zmwu3RXnlq4jMvuMrvHfA== X-Received: by 2002:a63:540b:: with SMTP id i11mr4719813pgb.44.1619526218307; Tue, 27 Apr 2021 05:23:38 -0700 (PDT) Received: from ashish-NUC8i5BEH ([182.77.14.23]) by smtp.gmail.com with ESMTPSA id b21sm2576751pji.39.2021.04.27.05.23.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Apr 2021 05:23:37 -0700 (PDT) From: ashish X-Google-Original-From: ashish Date: Tue, 27 Apr 2021 17:53:30 +0530 To: Greg Kroah-Hartman Cc: Ashish Kalra , 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> X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Sat, Apr 24, 2021 at 10:28:27AM +0200, Greg Kroah-Hartman wrote: > 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 Thanks Greg and Joe I have found that adding __user to data is also fixing this warning, It should be fine logically to make this change Please share your opinion and will post v2 for this patch --- a/drivers/staging/wlan-ng/p80211ioctl.h +++ b/drivers/staging/wlan-ng/p80211ioctl.h @@ -81,7 +81,7 @@ struct p80211ioctl_req { char name[WLAN_DEVNAMELEN_MAX]; - caddr_t data; + char __user *data; u32 magic; u16 len; u32 result; -- 2.30.2