Re: [PATCH v3] driver-staging: vsoc.c: Add sysfs support for examining the permissions of regions.

[Greg Kroah-Hartman <greg@kroah.com>]

On Thu, Nov 08, 2018 at 08:49:41AM +0800, wahahab wrote:
> 
> > On 7 Nov 2018, at 5:15 PM, Greg Kroah-Hartman <greg@kroah.com> wrote:
> > 
> > On Wed, Nov 07, 2018 at 10:30:43AM +0800, Jerry Lin wrote:
> >> Add a attribute called permissions under vsoc device node for examining
> >> current granted permissions in vsoc_device.
> >> 
> >> This file will display permissions in following format:
> >> begin_offset  end_offset  owner_offset  owned_value
> >>           %x          %x            %x           %x
> >> 
> >> Signed-off-by: Jerry Lin <wahahab11@gmail.com>
> >> ---
> >> drivers/staging/android/vsoc.c | 48 +++++++++++++++++++++++++++++++++++++++---
> >> 1 file changed, 45 insertions(+), 3 deletions(-)
> > 
> > What changed from v2?  And where was v2?  What about v1?
> > 
> > You need a change log here of what you did different from the previous
> > patches.
> 
> Sorry for the mistakes I made, I shall read the document about patches more carefully.
> Here is the change logs:
> 
> Changes in v2:
> 	- Display permissions information in sysfs insureds of debufs.
> Changes in v3:
> 	- Remove unnecessary null terminator after snprintf.
> 
> > 
> > And why ignore my response saying that this type of sysfs file is not ok
> > at all?
> > 
> 
> I didn’t mean to ignore it but I haven’t receive the response you described,
> May you send the response to me again so I can do further revision as well as
> change logs and resubmit the patch again?

You can not have multiple values in a single sysfs file.  sysfs is "one
value per file".  This needs to be individual files, if you really need
this.  And never a "header" for a sysfs file, that's never something
that should ever be in a sysfs file.

And finally, you need a Documentation/ABI/ update for any sysfs file
changes.

thanks,

greg k-h