On Thu, 2020-08-27 at 22:03 +0000, David Laight wrote:
> From: Joe Perches
> > Sent: 27 August 2020 21:30
> ...
> > Perhaps what's necessary is to find any
> > appropriate .show function and change
> > any use of strcpy/sprintf within those
> > function to some other name.
> >
> > For instance:
> >
> > drivers/isdn/mISDN/core.c-static ssize_t name_show(struct device *dev,
> > drivers/isdn/mISDN/core.c- struct device_attribute *attr, char *buf)
> > drivers/isdn/mISDN/core.c-{
> > drivers/isdn/mISDN/core.c: strcpy(buf, dev_name(dev));
> > drivers/isdn/mISDN/core.c- return strlen(buf);
> > drivers/isdn/mISDN/core.c-}
> > drivers/isdn/mISDN/core.c-static DEVICE_ATTR_RO(name);
>
> That form ends up calculating the string length twice.
> Better would be:
> len = strlen(msg);
> memcpy(buf, msg, len);
> return len;
or given clang's requirement for stpcpy
return stpcpy(buf, dev_name(dev)) - buf;
(I do not advocate for this ;)
