Re: [PATCH -next v2] staging: greybus: camera: Switch to memdup_user_nul()

[Dan Carpenter <dan.carpenter@oracle.com>]

On Thu, Apr 01, 2021 at 10:43:32AM +0300, Dan Carpenter wrote:
> On Thu, Apr 01, 2021 at 11:17:52AM +0800, Yang Yingliang wrote:
> > Use memdup_user_nul() helper instead of open-coding to
> > simplify the code.
> > 
> > Reported-by: Hulk Robot <hulkci@huawei.com>
> > Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
> > ---
> >  drivers/staging/greybus/camera.c | 13 +++----------
> >  1 file changed, 3 insertions(+), 10 deletions(-)
> > 
> > diff --git a/drivers/staging/greybus/camera.c b/drivers/staging/greybus/camera.c
> > index b570e13394ac..2ecdc1bc5092 100644
> > --- a/drivers/staging/greybus/camera.c
> > +++ b/drivers/staging/greybus/camera.c
> > @@ -1120,16 +1120,9 @@ static ssize_t gb_camera_debugfs_write(struct file *file,
> >  	if (len > 1024)
> >  		return -EINVAL;
> >  
> > -	kbuf = kmalloc(len + 1, GFP_KERNEL);
> > -	if (!kbuf)
> > -		return -ENOMEM;
> > -
> > -	if (copy_from_user(kbuf, buf, len)) {
> > -		ret = -EFAULT;
> > -		goto done;
> > -	}
> > -
> > -	kbuf[len] = '\0';
> > +	kbuf = memdup_user_nul(buf, len);
> > +	if (IS_ERR(kbuf))
> > +		return PTR_ERR(kbuf);;
>                                     ^^
> There is an extra semi-colon here.  Checkpatch actually catches this
> sort of typo.

So when someone makes a typo like this, my response is:

1) Let's add this to checkpatch (turns out it was already done)
2) Let's grep the kernel and fix the other instances.  The command would
be something like: git grep ';;$' | grep '\.c:'

regards,
dan carpenter