linux-kernel - Re: [PATCH 01/20] bitfield: introduce HWORD

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 for Android: free password hash cracker in your pocket

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

Message-ID: <aEs0PVkwFN9uRgU0@yury>
Date: Thu, 12 Jun 2025 16:10:37 -0400
From: Yury Norov <yury.norov@...il.com>
To: Nicolas Frattaroli <nicolas.frattaroli@...labora.com>
Cc: Jakub Kicinski <kuba@...nel.org>,
	Rasmus Villemoes <linux@...musvillemoes.dk>,
	Jaehoon Chung <jh80.chung@...sung.com>,
	Ulf Hansson <ulf.hansson@...aro.org>,
	Heiko Stuebner <heiko@...ech.de>,
	Shreeya Patel <shreeya.patel@...labora.com>,
	Mauro Carvalho Chehab <mchehab@...nel.org>,
	Sandy Huang <hjc@...k-chips.com>,
	Andy Yan <andy.yan@...k-chips.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>,
	Vinod Koul <vkoul@...nel.org>,
	Kishon Vijay Abraham I <kishon@...nel.org>,
	Nicolas Frattaroli <frattaroli.nicolas@...il.com>,
	Liam Girdwood <lgirdwood@...il.com>,
	Mark Brown <broonie@...nel.org>, Jaroslav Kysela <perex@...ex.cz>,
	Takashi Iwai <tiwai@...e.com>, Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>, Paolo Abeni <pabeni@...hat.com>,
	Maxime Coquelin <mcoquelin.stm32@...il.com>,
	Alexandre Torgue <alexandre.torgue@...s.st.com>,
	Shawn Lin <shawn.lin@...k-chips.com>,
	Lorenzo Pieralisi <lpieralisi@...nel.org>,
	Krzysztof Wilczyński <kwilczynski@...nel.org>,
	Manivannan Sadhasivam <mani@...nel.org>,
	Rob Herring <robh@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>,
	Chanwoo Choi <cw00.choi@...sung.com>,
	MyungJoo Ham <myungjoo.ham@...sung.com>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	Qin Jian <qinjian@...lus1.com>,
	Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...nel.org>,
	Nathan Chancellor <nathan@...nel.org>,
	Nick Desaulniers <nick.desaulniers+lkml@...il.com>,
	Bill Wendling <morbo@...gle.com>,
	Justin Stitt <justinstitt@...gle.com>, kernel@...labora.com,
	linux-kernel@...r.kernel.org, linux-mmc@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-rockchip@...ts.infradead.org, linux-media@...r.kernel.org,
	dri-devel@...ts.freedesktop.org, linux-phy@...ts.infradead.org,
	linux-sound@...r.kernel.org, netdev@...r.kernel.org,
	linux-stm32@...md-mailman.stormreply.com, linux-pci@...r.kernel.org,
	linux-pm@...r.kernel.org, linux-clk@...r.kernel.org,
	llvm@...ts.linux.dev
Subject: Re: [PATCH 01/20] bitfield: introduce HWORD_UPDATE bitfield macros

On Thu, Jun 12, 2025 at 09:50:12PM +0200, Nicolas Frattaroli wrote:
> On Thursday, 12 June 2025 21:44:15 Central European Summer Time Jakub Kicinski wrote:
> > On Thu, 12 Jun 2025 20:56:03 +0200 Nicolas Frattaroli wrote:
> > > Hardware of various vendors, but very notably Rockchip, often uses
> > > 32-bit registers where the upper 16-bit half of the register is a
> > > write-enable mask for the lower half.
> > 
> > Please limit the spread of this weirdness to a rockchip or "hiword"
> > specific header. To a normal reader of bitfield.h these macros will
> > be equally confusing and useless.
> > 
> 
> That is how this change started out, and then a different maintainer told
> me that this is a commonly used thing (see: the sunplus patch), and
> Rockchip just happens to have a lot of these with consistent naming.

That other maintainer was me, and the macro is indeed not used by rockchip
weirdness solely:

$ git grep HIWORD | grep -v rockchip | wc -l
326

I don't think that that having HWORD_UPDATE() in bitfield.h is a wrong
thing. Jakub, if you do, we can just create a new header for it.

Thanks,
Yury