linux-kernel - Re: [PATCH v1 2/4] leds: trigger: gpio: Convert to use kstrtox()

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Message-ID: <20231123144735.GB1354538@google.com>
Date:   Thu, 23 Nov 2023 14:47:35 +0000
From:   Lee Jones <lee@...nel.org>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        linux-leds@...r.kernel.org, linux-kernel@...r.kernel.org,
        Pavel Machek <pavel@....cz>
Subject: Re: [PATCH v1 2/4] leds: trigger: gpio: Convert to use kstrtox()

On Thu, 23 Nov 2023, Andy Shevchenko wrote:

> On Thu, Nov 23, 2023 at 11:05:38AM +0000, Lee Jones wrote:
> > On Fri, 03 Nov 2023, Andy Shevchenko wrote:
> 
> ...
> 
> > > -	ret = sscanf(buf, "%u", &desired_brightness);
> 
> "%u" (see man sscanf() for the details)
> 
> ...
> 
> > > +	ret = kstrtou8(buf, 10, &desired_brightness);
> > 
> > Where does 10 come from?
> 
> See above.

Hmmm ...

I see that this is generally accepted.  Although is looks like a recipe
for bugs to me.  It's a shame we don't have something that can take a
variable, derives its type, then calculates the maximum length if
converted to a string.

Anyway, I'm probably babbling now ...

-- 
Lee Jones [李琼斯]