On 6/6/19 11:11 AM, pmkellly(a)frontier.com wrote:
On 6/6/19 13:45, Adam Williamson wrote:
> On Thu, 2019-06-06 at 11:15 -0600, Chris Murphy wrote:
>> On Thu, Jun 6, 2019 at 9:49 AM Richard Ryniker <ryniker(a)alum.mit.edu>
>> wrote:
>>> I think you will find the file is not truly empty. /sys is not an
>>> actual
>>> file system, merely an interface to kernel information. There is no
>>> directory structure that records the length or other attributes of a
>>> file,
>>> as is the case for data on real media such as disks.
>>>
>>> If you read the /sys/kernel/debug/usb/devices file, you should find the
>>> data you seek.
>>
>> [root@fmac ~]# ls -l /sys/kernel/debug/usb/devices
>> -r--r--r--. 1 root root 0 Jun 6 10:11 /sys/kernel/debug/usb/devices
>> [root@fmac ~]# cat /sys/kernel/debug/usb/devices
>> cat: /sys/kernel/debug/usb/devices: Operation not permitted
>> [root@fmac ~]#
>>
>> 5.2.0-0.rc3.git1.1.fc31.x86_64
>
> Try it with enforcing=0 ?
>
I just tried permissive mode with the same result. I've just looked
through of the "files" in debug and they are all empty; so I'm guessing
that the kernel folks turned this off.
By empty, do you mean there's no content, or that you get a permission
error as above?