qlcnic binary sysfs file abuse

qlcnic binary sysfs file abuse

[Greg KH]

Hi all,

I was doing a kernel-wide audit on all of the binary sysfs files, and
noticed a metric ton of them in the qlcnic driver.

The rules about binary sysfs files are that they can not be touched by
the kernel at all, they are "pass-through" directly to the hardware, and
it seems that this driver is not doing that properly.

It also seems that almost all of these files are merely "debugging"
files, but as I can't seem to find the relevant Documentation/ABI/
documentation for them, I can't be sure.

So, any objection to me just deleting these entirely?  Or, if they
really are needed, can I just move them to debugfs, which is where I
think they should have been from the beginning?

Oh, and I'm pretty sure that the creation of these is totally racy, so I
really doubt that anyone is using them otherwise they would have noticed
this already.

thanks,

greg k-h

RE: qlcnic binary sysfs file abuse

[Sony Chacko]

> -----Original Message-----
> From: Greg KH [mailto:gregkh@linuxfoundation.org]
> Sent: Saturday, July 06, 2013 5:30 PM
> To: Rajesh Borundia; Shahed Shaikh; Jitendra Kalsaria; Sony Chacko; Dept-Eng
> Linux Driver
> Cc: netdev; linux-kernel
> Subject: qlcnic binary sysfs file abuse
> 
> I was doing a kernel-wide audit on all of the binary sysfs files, and noticed a
> metric ton of them in the qlcnic driver.
> 
> So, any objection to me just deleting these entirely?  Or, if they really are
> needed, can I just move them to debugfs, which is where I think they should
> have been from the beginning?

Some applications are using these files, please move them to debugfs.

Thanks,
Sony

Re: qlcnic binary sysfs file abuse

[Greg KH]

On Thu, Jul 25, 2013 at 07:37:46PM +0000, Sony Chacko wrote:
> > -----Original Message-----
> > From: Greg KH [mailto:gregkh@linuxfoundation.org]
> > Sent: Saturday, July 06, 2013 5:30 PM
> > To: Rajesh Borundia; Shahed Shaikh; Jitendra Kalsaria; Sony Chacko; Dept-Eng
> > Linux Driver
> > Cc: netdev; linux-kernel
> > Subject: qlcnic binary sysfs file abuse
> > 
> > I was doing a kernel-wide audit on all of the binary sysfs files, and noticed a
> > metric ton of them in the qlcnic driver.
> > 
> > So, any objection to me just deleting these entirely?  Or, if they really are
> > needed, can I just move them to debugfs, which is where I think they should
> > have been from the beginning?
> 
> Some applications are using these files, please move them to debugfs.

What applications care about the internal data structures of the kernel
driver?  What can those applications do with that information?  What
happens when you have a 64bit kernel on a 32bit userspace?  How about
endian issues on different processor types?  That sounds like a
nightmare to even consider getting correct...

Anyway, I'll move them to debugfs, thanks.

greg k-h

Re: qlcnic binary sysfs file abuse

[David Miller]

From: Sony Chacko <sony.chacko@qlogic.com>
Date: Thu, 25 Jul 2013 19:37:46 +0000

>> -----Original Message-----
>> From: Greg KH [mailto:gregkh@linuxfoundation.org]
>> Sent: Saturday, July 06, 2013 5:30 PM
>> To: Rajesh Borundia; Shahed Shaikh; Jitendra Kalsaria; Sony Chacko; Dept-Eng
>> Linux Driver
>> Cc: netdev; linux-kernel
>> Subject: qlcnic binary sysfs file abuse
>> 
>> I was doing a kernel-wide audit on all of the binary sysfs files, and noticed a
>> metric ton of them in the qlcnic driver.
>> 
>> So, any objection to me just deleting these entirely?  Or, if they really are
>> needed, can I just move them to debugfs, which is where I think they should
>> have been from the beginning?
> 
> Some applications are using these files, please move them to debugfs.

This is quite a mess, and I've complained about all of the crazy
files created by qlcnic in the past.

debugfs is for things that do not create a ABI which the kernel has to
maintain forever.