Re: [PATCH 2/2] drivers/base/node.c: use bin_attribute to avoid buff overflow

[Greg KH]

On Tue, Jun 01, 2021 at 10:56:50AM +0800, Tian Tao wrote:
> Reading sys/devices/system/cpu/cpuX/nodeX/ returns cpumap and cpulist.
> However, the size of this file is limited to PAGE_SIZE because of the
> limitation for sysfs attribute. so we use bin_attribute instead of
> attribute to avoid NR_CPUS too big to cause buff overflow.
> 
> Signed-off-by: Tian Tao <tiantao6@xxxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> ---
>  drivers/base/node.c | 49 +++++++++++++++++++++++++++++++------------------
>  1 file changed, 31 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/base/node.c b/drivers/base/node.c
> index f449dbb..a19be64 100644
> --- a/drivers/base/node.c
> +++ b/drivers/base/node.c
> @@ -27,42 +27,42 @@ static struct bus_type node_subsys = {
>  };
>  
>  
> -static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)
> +static ssize_t node_read_cpumap(struct kobject *kobj, bool list,

Why not stick with the dev pointer here?  These are devices, please use
them.

thanks,

greg k-h