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

[Don Dutile]

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