Re: [PATCH V12 5/9] driver-core: Introduce BIN_ATTR_ADMIN_{RO,RW}

Bjorn Helgaas
2022-06-29T01:11:03Z

[+cc Krzysztof]

On Mon, Jun 27, 2022 at 09:15:23PM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
>
> 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

FWIW, this looks a lot like this previous patch:
https://lore.kernel.org/all/20210416205856.3234481-7-kw@linux.com/

> ---
> 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);
> --
> 2.35.3
>