Adding a security parameter to VFS functions

[Andreas Gruenbacher]

On Wednesday 15 August 2007 18:23, Casey Schaufler wrote:
> > Hi Linus, Al,
> > 
> > Would you object greatly to functions like vfs_mkdir() gaining a security
> > parameter?
> 
> Could you describe how this compares to the proposal that the
> AppArmor developers suggested recently? I expect that we can 
> reduce the amount of discussion required, and maybe avoid some
> confusion if you could do that.

That's from one of those patches:

-int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+int vfs_mkdir(struct inode *dir, struct dentry *dentry, struct vfsmount *mnt,
+             int mode)

We need the vfsmount in the LSM hooks in addition to the dentry in order to 
figure out where in the filesystem namespace we are. The various vfs_ 
functions are the ones calling the LSM hooks. (The same could be achieved 
passing a struct path instead.)

-- Andreas