Re: start switching sysfs attributes to expose the seq_file

From: Tejun Heo
Date: Mon Sep 13 2021 - 12:46:18 EST


On Mon, Sep 13, 2021 at 07:41:08AM +0200, Christoph Hellwig wrote:
> Hi all,
>
> Al pointed out multiple times that seq_get_buf is highly dangerous as
> it opens up the tight seq_file abstractions to buffer overflows. The
> last such caller now is sysfs.
>
> This series allows attributes to implement a seq_show method and switch
> the block and XFS code as users that I'm most familiar with to use
> seq_files directly after a few preparatory cleanups. With this series
> "leaf" users of sysfs_ops can be converted one at at a time, after that
> we can move the seq_get_buf into the multiplexers (e.g. kobj, device,
> class attributes) and remove the show method in sysfs_ops and repeat the
> process until all attributes are converted. This will probably take a
> fair amount of time.

The whole series looks good to me. With Greg's sysfs_emit argument aside on
which I don't have any opinion,

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

--
tejun