[PATCH] staging: iio: adc: ad7280a: check for devm_kasprint() failure
dan.carpenter at oracle.com
Mon Nov 26 13:26:13 UTC 2018
On Mon, Nov 26, 2018 at 02:10:09PM +0100, Nicholas Mc Guire wrote:
> On Mon, Nov 26, 2018 at 04:00:32PM +0300, Dan Carpenter wrote:
> > On Mon, Nov 26, 2018 at 10:39:04AM +0100, Nicholas Mc Guire wrote:
> > > devm_kasprintf() may return NULL on failure of internal allocation thus
> > > the assignments to attr.name are not safe if not checked. On error
> > > ad7280_attr_init() returns a negative return so -ENOMEM should be
> > > OK here (passed on as return value of the probe function).
> > >
> > > Signed-off-by: Nicholas Mc Guire <hofrat at osadl.org>
> > > Fixes: 2051f25d2a26 ("iio: adc: New driver for AD7280A Lithium Ion Battery Monitoring System2")
> > > ---
> > >
> > > Problem located with an experimental coccinelle script
> > >
> > > As using if(!st->iio_attr[cnt].dev_attr.attr.name) seamed quite
> > > unreadable in this case the (var == NULL) variant was used. Not
> > ^^
> > Why two spaces?
> just a typo
> > > sure if there are objections against this (checkpatch.pl issues
> > > a CHECK on this).
> > >
> > You should just follow checkpatch rules here. If you don't, someone
> > else will just send a patch to make it checkpatch compliant. One thing
> > you could do is at the start of the loop do:
> > struct iio_dev_attr *attr = &st->iio_attr[cnt];
> > Then it becomes:
> > if (!attr->dev_attr.attr.name)
> > It's slightly more readable that way. Keep in mind that we increment
> > cnt++ in the middle of the loop so you'll have to update attr as well.
> My understanding was that CHECK: notes are not strict rules but
> those that may vary from case to case.
Checkpatch is just a script. It's not a genius or the king of the
world. Sometimes checkpatch compliant code is clearly worse than
breaking the rules. But fighting against checkpatch is a huge hassle so
you should avoid it if you can.
I actually agree with checkpatch on this one but it's a minor thing.
Sometimes a maintainer will get obsessed with minor things. You have to
be a bit obsessed to be a good kernel maintainer. Anyway, they have
their fights with checkpatch and it creates a small thread every time a
newbie sends a patch. And everyone on the CC list has to endure it as
Btw, when I get annoyed with checkpatch, I feel like it's pretty obvious
I am correct. I'm not like other kernel developers who have debatable
style preferences... ;)
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