Re: [Linux-kernel-mentees] [PATCH v2 2/3] PCI: sysfs: Change permissions from symbolic to octal

Don Dutile
2019-08-15T14:37:16Z

On 08/14/2019 01:38 AM, Bjorn Helgaas wrote:
> [+cc Bodong, Don, Greg for permission question]
>
> On Tue, Aug 13, 2019 at 02:45:12PM -0600, Kelsey Skunberg wrote:
>> Symbolic permissions such as "(S_IWUSR | S_IWGRP)" are not
>> preferred and octal permissions should be used instead. Change all
>> symbolic permissions to octal permissions.
>>
>> Example of old:
>>
>> "(S_IWUSR | S_IWGRP)"
>>
>> Example of new:
>>
>> "0220"
>
>
>> static DEVICE_ATTR_RO(sriov_totalvfs);
>> -static DEVICE_ATTR(sriov_numvfs, (S_IRUGO | S_IWUSR | S_IWGRP),
>> - sriov_numvfs_show, sriov_numvfs_store);
>> +static DEVICE_ATTR(sriov_numvfs, 0664, sriov_numvfs_show, sriov_numvfs_store);
>> static DEVICE_ATTR_RO(sriov_offset);
>> static DEVICE_ATTR_RO(sriov_stride);
>> static DEVICE_ATTR_RO(sriov_vf_device);
>> -static DEVICE_ATTR(sriov_drivers_autoprobe, (S_IRUGO | S_IWUSR | S_IWGRP),
>> - sriov_drivers_autoprobe_show, sriov_drivers_autoprobe_store);
>> +static DEVICE_ATTR(sriov_drivers_autoprobe, 0664, sriov_drivers_autoprobe_show,
>> + sriov_drivers_autoprobe_store);
>
> Greg noticed that sriov_numvfs and sriov_drivers_autoprobe have
> "unusual" permissions. These were added by:
>
> 0e7df22401a3 ("PCI: Add sysfs sriov_drivers_autoprobe to control VF driver binding")
> 1789382a72a5 ("PCI: SRIOV control and status via sysfs")
>
> Kelsey's patch correctly preserves the existing permissions, but we
> should double-check that they are the permissions they want, and
> possibly add a comment about why they're different from the rest.
>
> Bjorn
>
The rest being? ... 0644 vs 0664 ?
The file is read & written, thus the (first) 6; I'll have to dig through very old (7 yr) notes to see if the second 6 is needed for libvirt (so it doesn't have to be root to enable).

-dd