Re: [PATCH 3/3] bus: mhi: replace snprintf in show functions with sysfs_emit

[Manivannan Sadhasivam]

On Sat, Oct 16, 2021 at 09:37:50AM +0200, Greg KH wrote:
> On Sat, Oct 16, 2021 at 12:27:34PM +0530, Manivannan Sadhasivam wrote:
> > From: Qing Wang <wangqing@xxxxxxxx>
> > 
> > coccicheck complains about the use of snprintf() in sysfs show functions.
> > 
> > Fix the following coccicheck warning:
> > drivers/bus/mhi/core/init.c:97:8-16: WARNING: use scnprintf or sprintf.
> > 
> > Use sysfs_emit instead of scnprintf or sprintf makes more sense.
> > 
> > Signed-off-by: Qing Wang <wangqing@xxxxxxxx>
> > Reviewed-by: Hemant Kumar <hemantk@xxxxxxxxxxxxxx>
> > Reviewed-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> > Link: https://lore.kernel.org/r/1634095550-3978-1-git-send-email-wangqing@xxxxxxxx
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> >  drivers/bus/mhi/core/init.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> > index 5aaca6d0f52b..a5a5c722731e 100644
> > --- a/drivers/bus/mhi/core/init.c
> > +++ b/drivers/bus/mhi/core/init.c
> > @@ -94,7 +94,7 @@ static ssize_t serial_number_show(struct device *dev,
> >  	struct mhi_device *mhi_dev = to_mhi_device(dev);
> >  	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
> >  
> > -	return snprintf(buf, PAGE_SIZE, "Serial Number: %u\n",
> > +	return sysfs_emit(buf, "Serial Number: %u\n",
> >  			mhi_cntrl->serial_number);
> 
> The text "Serial Number: " should not be in here, right?  It's obvious
> this is a serial number, that's what the documentation and file name
> says.  Userspace should not have to parse sysfs files.
> 

Right, somehow missed it :/

> And why is only one sysfs entry being changed in this file?  Either they
> all should be, or none, no need to do this one-patch-per-entry, right?
> 
> Note, I have rejected Qing's patches like this for other subsystems
> already because they are not complete, this is something they are well
> aware of by now...
> 

Oh, I'm not aware of this.

Qing: Please modify the other instance of snprintf also.

Thanks,
Mani

> thanks,
> 
> greg k-h