netdev - Re: [PATCH v2 04/15] spi: Replace open coded spi_controller_xfer

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]

Date: Tue, 11 Jul 2023 18:30:06 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Mark Brown <broonie@...nel.org>
Cc: Cristian Ciocaltea <cristian.ciocaltea@...labora.com>,
	Yang Yingliang <yangyingliang@...wei.com>,
	Amit Kumar Mahapatra via Alsa-devel <alsa-devel@...a-project.org>,
	Neil Armstrong <neil.armstrong@...aro.org>,
	Tharun Kumar P <tharunkumar.pasumarthi@...rochip.com>,
	Vijaya Krishna Nivarthi <quic_vnivarth@...cinc.com>,
	Uwe Kleine-König <u.kleine-koenig@...gutronix.de>,
	linux-spi@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-amlogic@...ts.infradead.org,
	linux-mediatek@...ts.infradead.org, linux-arm-msm@...r.kernel.org,
	linux-rockchip@...ts.infradead.org, linux-riscv@...ts.infradead.org,
	linux-stm32@...md-mailman.stormreply.com,
	linux-trace-kernel@...r.kernel.org, netdev@...r.kernel.org,
	Sanjay R Mehta <sanju.mehta@....com>,
	Radu Pirea <radu_nicolae.pirea@....ro>,
	Nicolas Ferre <nicolas.ferre@...rochip.com>,
	Alexandre Belloni <alexandre.belloni@...tlin.com>,
	Claudiu Beznea <claudiu.beznea@...rochip.com>,
	Tudor Ambarus <tudor.ambarus@...aro.org>,
	Serge Semin <fancer.lancer@...il.com>,
	Shawn Guo <shawnguo@...nel.org>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Pengutronix Kernel Team <kernel@...gutronix.de>,
	Fabio Estevam <festevam@...il.com>,
	NXP Linux Team <linux-imx@....com>,
	Kevin Hilman <khilman@...libre.com>,
	Jerome Brunet <jbrunet@...libre.com>,
	Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
	Matthias Brugger <matthias.bgg@...il.com>,
	AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
	Andy Gross <agross@...nel.org>,
	Bjorn Andersson <andersson@...nel.org>,
	Konrad Dybcio <konrad.dybcio@...aro.org>,
	Heiko Stuebner <heiko@...ech.de>,
	Palmer Dabbelt <palmer@...belt.com>,
	Paul Walmsley <paul.walmsley@...ive.com>,
	Orson Zhai <orsonzhai@...il.com>,
	Baolin Wang <baolin.wang@...ux.alibaba.com>,
	Chunyan Zhang <zhang.lyra@...il.com>,
	Alain Volmat <alain.volmat@...s.st.com>,
	Maxime Coquelin <mcoquelin.stm32@...il.com>,
	Alexandre Torgue <alexandre.torgue@...s.st.com>,
	Max Filippov <jcmvbkbc@...il.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Masami Hiramatsu <mhiramat@...nel.org>,
	Richard Cochran <richardcochran@...il.com>
Subject: Re: [PATCH v2 04/15] spi: Replace open coded
 spi_controller_xfer_timeout()

On Tue, Jul 11, 2023 at 03:14:54PM +0100, Mark Brown wrote:
> On Tue, Jul 11, 2023 at 02:01:13PM +0300, Andy Shevchenko wrote:
> > On Mon, Jul 10, 2023 at 06:30:32PM +0100, Mark Brown wrote:
> > > On Mon, Jul 10, 2023 at 06:49:21PM +0300, Andy Shevchenko wrote:
> 
> > > > + * Assume speed to be 100 kHz if it's not defined at the time of invocation.
> 
> > > You didn't mention this bit in the changelog, and I'm not 100% convinced
> > > it was the best idea in the first place.  It's going to result in some
> > > very big timeouts if it goes off, and we really should be doing
> > > validation much earlier in the process.
> 
> > Okay, let's drop this change.
> 
> Like I say we *should* be fine with the refactoring without this, or at
> least if it's an issue we should improve the validation.

For the speeds < 1000 Hz, this change will lead to the div by 0 crash.
It seems that the current code which this one removes is better than
the spi_controller_xfer_timeout() provides.

If anything, the spi_controller_xfer_timeout() should be improved first.
So, for now I drop this for sure. Maybe in the future we can come back
to it.

-- 
With Best Regards,
Andy Shevchenko