From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jvPpX-0005n6-Ca for barebox@lists.infradead.org; Tue, 14 Jul 2020 18:39:04 +0000 Date: Tue, 14 Jul 2020 20:39:01 +0200 From: Sascha Hauer Message-ID: <20200714183901.GY15485@pengutronix.de> References: <20200707160124.3188793-1-enrico.scholz@sigma-chemnitz.de> <9c7cf1e5-baf1-65b0-ddef-e651f6f21e2d@pengutronix.de> <20200711050719.GP15485@pengutronix.de> <6525ec7f-c391-4394-4eef-6777459b94da@pengutronix.de> <20200711052007.GR15485@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] net:fec: fixed unaligned access and stack corruption To: Ahmad Fatoum Cc: Enrico Scholz , barebox@lists.infradead.org On Sat, Jul 11, 2020 at 07:28:58AM +0200, Ahmad Fatoum wrote: > Hi, > > On 7/11/20 7:20 AM, Sascha Hauer wrote: > > On Sat, Jul 11, 2020 at 07:13:11AM +0200, Ahmad Fatoum wrote: > >> > >> > >> On 7/11/20 7:07 AM, Sascha Hauer wrote: > >>> On Tue, Jul 07, 2020 at 07:11:31PM +0200, Ahmad Fatoum wrote: > >>>> On 7/7/20 6:01 PM, Enrico Scholz wrote: > >>>>> on 64 bit architectures, the 'enum fec_type' might not be aligned and > >>>>> large enough to hold a pointer. > >>>> > >>>> I am wondering if we couldn't just adopt the Linux prototype: > >>>> void *dev_get_drvdata(const struct device_d *dev); > >>>> > >>>> and do away with the error code and most of the casts. > >>>> Users won't be able to differentiate between NULL from id table > >>>> and NULL due to lack of drvdata, but I don't think this is > >>>> that much of a downside, compared with not having casts obscure > >>>> the more common pitfall (besides fec_imx.c, lm75.c, apbh_dma.c and nand_mxs.c > >>>> are affected as well of which probably only the first is an issue.) > >>> > >>> Sounds good. When we change this we should rename the function > >>> alongside, because dev_get_drvdata() does something different in Linux. > >> > >> Does it? I thought it does the same, with the difference that it can > >> be set with dev_set_drvdata as well. At the cost of one extra pointer > >> per device_d, we could have both of them. > > > > dev_set_drvdata() in Linux allows you to store a pointer to private > > driver data in struct device. We don't have a function for that in > > barebox and use dev->priv instead. > > dev_get_drvdata() in barebox gets you the device type data (or however > > we want to call it). There's no function for that in Linux and we have > > to first find out if we probe from platform data or from device tree > > to pick the right function to get the data. > > Ah, I thought the drvdata is pre-populated in Linux. I would rename > the new function to device_get_match_data then for alignment with > Linux, with the difference that it returns either platform data or > device tree driver_data as appropriate. Sounds good. Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox