From: Lee Jones <lee.jones@linaro.org>
To: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
Nicolas Ferre <nicolas.ferre@microchip.com>,
Ludovic Desroches <ludovic.desroches@microchip.com>,
Boris Brezillon <boris.brezillon@free-electrons.com>
Subject: Re: [PATCH 08/10] mfd: atmel-smc: Silence comparison of unsigned expression < 0 is always false warning (W=1)
Date: Tue, 30 Jun 2020 13:10:23 +0100 [thread overview]
Message-ID: <20200630121023.GL1179328@dell> (raw)
In-Reply-To: <20200626205627.GU131826@piout.net>
On Fri, 26 Jun 2020, Alexandre Belloni wrote:
> Hi,
>
> On 25/06/2020 07:46:17+0100, Lee Jones wrote:
> > GENMASK and it's callees conduct checking to ensure the passed
> > parameters are valid. One of those checks is for '< 0'. So if an
> > unsigned value is passed, in an invalid comparison takes place.
> >
> > Judging from the current code, it looks as though 'unsigned int'
> > is the correct type to use, so simply cast these small values
> > with no chance of being false negative to signed int for
> > comparison/error checking purposes.
> >
>
> I've been thinking about that one but shouldn't the proper fix be in
> GENMASK? My understanding is that this happens because l is 0 and I
> don't think GENMASK would ever expect negative number. What about simply
> checking that h != l when l is 0?
Looks like Rikard Falkeborn recently submitted a patch to 'fix' this
issue. However, Linus slammed it, decrying that it's the warning
that's wrong, not the code. Looks like the type-limits warning might
be getting downgraded to W=2 instead (although I don't see a patch
yet).
I'm going to drop this patch.
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
next prev parent reply other threads:[~2020-06-30 12:10 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-25 6:46 [PATCH 00/10] Fix a bunch more W=1 warnings in MFD Lee Jones
2020-06-25 6:46 ` [PATCH 01/10] mfd: wm8350-core: Supply description wm8350_reg_{un}lock args Lee Jones
2020-06-25 6:56 ` Greg KH
2020-06-25 7:13 ` Lee Jones
2020-06-25 9:45 ` Greg KH
2020-06-25 13:34 ` Lee Jones
2020-06-25 13:24 ` Jonathan Corbet
2020-06-25 13:38 ` Lee Jones
2020-06-25 6:46 ` [PATCH 02/10] mfd: mfd-core: Complete kerneldoc header for devm_mfd_add_devices() Lee Jones
2020-07-01 19:33 ` Sasha Levin
2020-07-02 6:36 ` Lee Jones
2020-07-10 14:02 ` Sasha Levin
2020-06-25 6:46 ` [PATCH 03/10] mfd: db8500-prcmu: Add description for 'reset_reason' in kerneldoc Lee Jones
2020-07-07 12:39 ` Linus Walleij
2020-06-25 6:46 ` [PATCH 04/10] mfd: db8500-prcmu: Remove incorrect function header from .probe() function Lee Jones
2020-07-07 12:39 ` Linus Walleij
2020-06-25 6:46 ` [PATCH 05/10] mfd: omap-usb-host: Remove invalid use of kerneldoc syntax Lee Jones
2020-06-25 6:46 ` [PATCH 06/10] mfd: omap-usb-host: Provide description for 'pdev' argument to .probe() Lee Jones
2020-06-25 6:46 ` [PATCH 07/10] mfd: omap-usb-tll: " Lee Jones
2020-06-25 6:46 ` [PATCH 08/10] mfd: atmel-smc: Silence comparison of unsigned expression < 0 is always false warning (W=1) Lee Jones
2020-06-26 20:56 ` Alexandre Belloni
2020-06-30 12:10 ` Lee Jones [this message]
2020-06-25 6:46 ` [PATCH 09/10] mfd: atmel-smc: Add missing colon(s) for 'conf' arguments Lee Jones
2020-06-25 6:55 ` Greg KH
2020-06-26 20:56 ` Alexandre Belloni
2020-07-01 19:33 ` Sasha Levin
2020-07-02 6:36 ` Lee Jones
2020-07-10 14:02 ` Sasha Levin
2020-06-25 6:46 ` [PATCH 10/10] mfd: altera-sysmgr: Supply descriptions for 'np' and 'property' function args Lee Jones
2020-07-01 19:33 ` Sasha Levin
2020-07-02 6:35 ` Lee Jones
2020-07-10 14:02 ` Sasha Levin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200630121023.GL1179328@dell \
--to=lee.jones@linaro.org \
--cc=alexandre.belloni@bootlin.com \
--cc=boris.brezillon@free-electrons.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ludovic.desroches@microchip.com \
--cc=nicolas.ferre@microchip.com \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).