Re: [PATCH v3 3/3] drivers/base/node.c: use bin_attribute to avoid buff overflow

From: Andy Shevchenko
Date: Thu Jun 03 2021 - 05:53:26 EST


On Thu, Jun 03, 2021 at 05:22:42PM +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.

...

> }
>
> -static DEVICE_ATTR_RO(cpumap);
>
> -static inline ssize_t cpulist_show(struct device *dev,
> - struct device_attribute *attr,
> - char *buf)
> +static BIN_ATTR_RO(cpumap, 0);

So, you will have 2 blank lines in a row after this. Why one is not enough?
Same question for other similar cases, if any.

--
With Best Regards,
Andy Shevchenko