Re: [PATCH v3 02/25] ima: Align ima_post_path_mknod() definition with LSM infrastructure

[Mimi Zohar <zohar@linux.ibm.com>]

> > > > > We need to make sure that ima_post_path_mknod() has the same parameters
> > > > > as the LSM hook at the time we register it to the LSM infrastructure.
> > > > 
> > > > I'm trying to understand why the pre hook parameters and the missing
> > > > IMA parameter are used, as opposed to just defining the new
> > > > post_path_mknod hook like IMA.
> > > 
> > > As an empyrical rule, I pass the same parameters as the corresponding
> > > pre hook (plus idmap, in this case). This is similar to the
> > > inode_setxattr hook. But I can be wrong, if desired I can reduce.
> > 
> > The inode_setxattr hook change example is legitimate, as EVM includes
> > idmap, while IMA doesn't. 
> > 
> > Unless there is a good reason for the additional parameters, I'm not
> > sure that adding them makes sense.  Not modifying the parameter list
> > will reduce the size of this patch set.
> 
> The hook is going to be used by any LSM. Without knowing all the
> possible use cases, maybe it is better to include more information now,
> than modifying the hook and respective implementations later.
> 
> (again, no problem to reduce)

Unless there is a known use case for a specific parameter, please
minimize them.   Additional parameters can be added later as needed. 

-- 
thanks,

Mimi