Re: [PATCH V2] sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output

[Greg Kroah-Hartman]

On Sat, Aug 29, 2020 at 05:43:58PM -0700, Joe Perches wrote:
> On Sat, 2020-08-29 at 16:48 -0700, Joe Perches wrote:
> > Output defects can exist in sysfs content using sprintf and snprintf.
> > 
> > sprintf does not know the PAGE_SIZE maximum of the temporary buffer
> > used for outputting sysfs content and it's possible to overrun the
> > PAGE_SIZE buffer length.
> > 
> > Add a generic sysfs_emit function that knows that the size of the
> > temporary buffer and ensures that no overrun is done.
> > 
> > Add a generic sysfs_emit_at function that can be used in multiple
> > call situations that also ensures that no overrun is done.
> 
> This preliminary coccinelle script converts ~5000 instances treewide.
> There are still many remaining instances that could be converted.
> 
> $ git grep -w sysfs_emit -- '*.[ch]'|wc -l
> 4702
> $ git grep -w sysfs_emit_at -- '*.[ch]'|wc -l
> 229

Can you send a patch that would at least convert the driver core code
(drivers/base/*) to use these new helpers so we have an in-tree user
when applying the first patch?

thanks,

greg k-h