On Thu, 2021-02-11 at 10:11 +0300, Dan Carpenter wrote:
> On Wed, Feb 10, 2021 at 02:28:54PM -0800, Drew Fustini wrote:
> > + ret = strncpy_from_user(buf, user_buf, PINMUX_MAX_NAME * 2);
> > + if (ret < 0) {
> > + dev_err(pctldev->dev, "failed to copy buffer from userspace");
> > + goto free_gname;
> > + }
> > + buf[len-1] = '\0';
> > +
> > + ret = sscanf(buf, "%s %s", fname, gname);
> > + if (ret != 2) {
> > + dev_err(pctldev->dev, "expected format: <function-name>
> > <group-name>");
> > + goto free_gname;
>
> We need a "ret = -EINVAL;" before the goto. sscanf doesn't return error
> codes. Normally we would write it like so:
>
> if (sscanf(buf, "%s %s", fname, gname) != 2) {
> dev_err(pctldev->dev, "expected format: <function-name>
> <group-name>");
> ret = -EINVAL;
> goto free_gname;
> }
>
> I'm going to write a Smatch check for this today.
It's a pretty frequently used style:
$ git grep -P '\w+\s*=\s+sscanf\b' | wc -l
327
A grep with -A5 seems to show most use some additional error assignment
when checking the return value.
$ git grep -P -A5 '\w+\s*=\s+sscanf\b' | grep -P '(?:return|=)\s*\-E' | wc -l
174
