linux-kernel - Re: [PATCH 3/5] driver core: make struct device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Y35ftyYlE8FX8xQO@casper.infradead.org>
Date:   Wed, 23 Nov 2022 18:00:23 +0000
From:   Matthew Wilcox <willy@...radead.org>
To:     Jason Gunthorpe <jgg@...pe.ca>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Maximilian Luz <luzmaximilian@...il.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        linux-kernel@...r.kernel.org, Jens Axboe <axboe@...nel.dk>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Len Brown <lenb@...nel.org>,
        Stefan Richter <stefanr@...6.in-berlin.de>,
        Wolfram Sang <wsa@...nel.org>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Sean Young <sean@...s.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Frank Rowand <frowand.list@...il.com>,
        Hans de Goede <hdegoede@...hat.com>,
        Mark Gross <markgross@...nel.org>,
        Vinod Koul <vkoul@...nel.org>,
        Bard Liao <yung-chuan.liao@...ux.intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        Sanyog Kale <sanyog.r.kale@...el.com>,
        Andreas Noever <andreas.noever@...il.com>,
        Michael Jamet <michael.jamet@...el.com>,
        Mika Westerberg <mika.westerberg@...ux.intel.com>,
        Yehezkel Bernat <YehezkelShB@...il.com>,
        Jiri Slaby <jirislaby@...nel.org>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Chaitanya Kulkarni <kch@...dia.com>,
        Ming Lei <ming.lei@...hat.com>,
        Jilin Yuan <yuanjilin@...rlc.com>,
        Alan Stern <stern@...land.harvard.edu>,
        Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ira Weiny <ira.weiny@...el.com>,
        Dan Williams <dan.j.williams@...el.com>,
        Won Chung <wonchung@...gle.com>, alsa-devel@...a-project.org,
        devicetree@...r.kernel.org, linux-acpi@...r.kernel.org,
        linux-block@...r.kernel.org, linux-i2c@...r.kernel.org,
        linux-i3c@...ts.infradead.org, linux-input@...r.kernel.org,
        linux-media@...r.kernel.org, linux-serial@...r.kernel.org,
        linux-usb@...r.kernel.org, linux1394-devel@...ts.sourceforge.net,
        platform-driver-x86@...r.kernel.org
Subject: Re: [PATCH 3/5] driver core: make struct device_type.uevent() take a
 const *

On Wed, Nov 23, 2022 at 01:55:42PM -0400, Jason Gunthorpe wrote:
> On Wed, Nov 23, 2022 at 05:49:36PM +0000, Matthew Wilcox wrote:
> > On Wed, Nov 23, 2022 at 01:29:56PM -0400, Jason Gunthorpe wrote:
> > > #define generic_container_of(in_type, in, out_type, out_member) \
> > > 	_Generic(in,                                        \
> > >                   const in_type *: ((const out_type *)container_of(in, out_type, out_member)),   \
> > >                   in_type *: ((out_type *)container_of(in, out_type, out_member)) \
> > > 		  )
> > 
> > There's a neat trick I found in seqlock.h:
> > 
> > #define generic_container_of(in_t, in, out_t, m)			\
> > 	_Generic(*(in),							\
> > 		const in_t: ((const out_t *)container_of(in, out_t, m)), \
> > 		in_t: ((out_t *)container_of(in, out_type, m))	\
> > 	)
> >
> > and now it fits in 80 columns ;-)
> 
> Aside from less letters, is their another benifit to using *(in) ?

I don't think so.  It just looks nicer to me than putting the star in
each case.  If I'd thought of it, I would have done it to page_folio(),
but I won't change it now.