On Thu, 14 Jul 2022 20:04:22 -0700
ira.weiny@xxxxxxxxx wrote:
> From: Ira Weiny <ira.weiny@xxxxxxxxx>
>
> Many binary attributes need to limit access to CAP_SYS_ADMIN only; ie
> many binary attributes specify is_visible with 0400 or 0600.
>
> Make setting the permissions of such attributes more explicit by
> defining BIN_ATTR_ADMIN_{RO,RW}.
>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> Suggested-by: Krzysztof Wilczyński <kw@xxxxxxxxx>
> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Seems sensible.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
>
> ---
> Changes from V12:
> Pick up review tag
> Bjorn:
> NOTE: this has a lot of similarities to
> https://lore.kernel.org/all/20210416205856.3234481-7-kw@xxxxxxxxx/
> I'm not sure why that patch was not picked up. But I've
> added Krzysztof as a suggested by if that is ok?
>
> Changes from V11:
> New Patch
> ---
> include/linux/sysfs.h | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
> index e3f1e8ac1f85..fd3fe5c8c17f 100644
> --- a/include/linux/sysfs.h
> +++ b/include/linux/sysfs.h
> @@ -235,6 +235,22 @@ struct bin_attribute bin_attr_##_name = __BIN_ATTR_WO(_name, _size)
> #define BIN_ATTR_RW(_name, _size) \
> struct bin_attribute bin_attr_##_name = __BIN_ATTR_RW(_name, _size)
>
> +
> +#define __BIN_ATTR_ADMIN_RO(_name, _size) { \
> + .attr = { .name = __stringify(_name), .mode = 0400 }, \
> + .read = _name##_read, \
> + .size = _size, \
> +}
> +
> +#define __BIN_ATTR_ADMIN_RW(_name, _size) \
> + __BIN_ATTR(_name, 0600, _name##_read, _name##_write, _size)
> +
> +#define BIN_ATTR_ADMIN_RO(_name, _size) \
> +struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RO(_name, _size)
> +
> +#define BIN_ATTR_ADMIN_RW(_name, _size) \
> +struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RW(_name, _size)
> +
> struct sysfs_ops {
> ssize_t (*show)(struct kobject *, struct attribute *, char *);
> ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t);
