Adding a security parameter to VFS functions

[Andreas Gruenbacher]

On Wednesday 15 August 2007 13:40, David Howells wrote:
> 
> Hi Linus, Al,
> 
> Would you object greatly to functions like vfs_mkdir() gaining a security
> parameter?  What I'm thinking of is this:
> 
> 	int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode,
> 		      struct security *security)
> 
> Where the security context is the state of the context at the time the call
> was issued:
> 
> 	struct security {
> 		uid_t			fsuid;
> 		git_t			fsgid;
> 		struct group_info	*group_info;
> 		void			*security;
> 		struct key		*session_keyring;
> 		struct key		*process_keyring;
> 		struct key		*thread_keyring;
> 
> And perhaps:
> 
> 		struct audit_context	*audit_context;
> 		seccomp_t		seccomp;
> 	};
> 
> This would, for the most part, be a temporary affair, being set up by such
> as sys_mkdir()/sys_mkdirat() from data held in task_struct.

That's additional setup work unless that struct can be embedded in 
task_struct. We would be complicating the common / fast / local case to 
simplify the not-so-common case or cases.

-- Andreas