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From: David Laight <David.Laight@ACULAB.COM>
To: 'Heiko Carstens' <hca@linux.ibm.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	"linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>
Subject: RE: [PATCH v1 1/1] s390: Use string_upper() instead of open coded variant
Date: Tue, 12 Oct 2021 08:04:58 +0000	[thread overview]
Message-ID: <985bbceb3ee046bbbee6199efcf7c90c@AcuMS.aculab.com> (raw)
In-Reply-To: <YWQNZb25R3SjsQAL@osiris>

From: Heiko Carstens
> Sent: 11 October 2021 11:10
> 
> On Mon, Oct 11, 2021 at 08:21:15AM +0000, David Laight wrote:
> > ...
> > > > +	 * This snprintf() call does two things:
> > > > +	 * - makes a NUL-terminated copy of the input string
> > > > +	 * - pads it with spaces
> > > > +	 */
> > > > +	snprintf(tmp, sizeof(tmp), "%s        ", name);
> > >
> > > I can't say I like code where I have to count spaces in order to
> > > verify if the code is actually correct.
> >
> > What it wrong with "%-8.8s" ?
> 
> There's nothing wrong with it, except lack of imagination on my side ;)
> Andy, care to to send a separate patch just for extmem.c?

Are any of the snprintf() versions actually correct at all?
The implication of the comment is that the input string might
not be NUL terminated - in which case it shouldn't be passed
to snprintf().
I don't think you can assume that the format processing doesn't
do a strlen() of any %s argument - even if a maximum field
width is given.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


  reply	other threads:[~2021-10-12  8:05 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-01 13:02 [PATCH v1 1/1] s390: Use string_upper() instead of open coded variant Andy Shevchenko
2021-10-04 20:31 ` Heiko Carstens
2021-10-05  8:18   ` Andy Shevchenko
2021-10-05  8:54     ` Heiko Carstens
2021-10-05 12:09       ` Andy Shevchenko
2021-10-11  8:21   ` David Laight
2021-10-11 10:09     ` Heiko Carstens
2021-10-12  8:04       ` David Laight [this message]
2021-10-12  9:12         ` Heiko Carstens
2021-10-07 18:07 ` Heiko Carstens

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