Re: [PATCH 1/7] comedi: Convert snprintf() to scnprintf()

[Ian Abbott]

On 27/09/2022 07:06, Greg KH wrote:
> On Mon, Sep 26, 2022 at 07:37:37PM +0100, Jules Irenge wrote:
> > Coccinnelle reports a warning
> > Warning: Use scnprintf or sprintf
> > Adding to that, there has been a slow migration from snprintf to scnprintf.
> > This LWN article explains the rationale for this change
> > https: //lwn.net/Articles/69419/
> > Ie. snprintf() returns what *would* be the resulting length,
> > while scnprintf() returns the actual length.
> >
> > Signed-off-by: Jules Irenge <jbi.octave@xxxxxxxxx>
> > ---
> >   drivers/comedi/comedi_fops.c | 8 ++++----
> >   1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c
> > index 55a0cae04b8d..e8a0142d5894 100644
> > --- a/drivers/comedi/comedi_fops.c
> > +++ b/drivers/comedi/comedi_fops.c
> > @@ -396,7 +396,7 @@ static ssize_t max_read_buffer_kb_show(struct device *csdev,
> >   	mutex_unlock(&dev->mutex);
> >   
> >   	comedi_dev_put(dev);
> > -	return snprintf(buf, PAGE_SIZE, "%u\n", size);
> > +	return scnprintf(buf, PAGE_SIZE, "%u\n", size);
>
> Ick, no, you should use sysfs_emit() if you really want to change these
> functions to "do the right thing".

There was a patch to do that by Xuezhi Zhang.  It got to PATCH v4.  I 
should have replied with a "Reviewed-By" tag, but I'd already done that 
for the earlier versions.

https://lore.kernel.org/lkml/20220901013423.418464-1-zhangxuezhi3@xxxxxxxxx/

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