Re: [PATCH V10] fixup: audit: implement audit by executable

[Paul Moore <pmoore@redhat.com>]

On Monday, August 10, 2015 01:29:43 PM Richard Guy Briggs wrote:
> On 15/08/10, Paul Moore wrote:
> > On Saturday, August 08, 2015 10:20:25 AM Richard Guy Briggs wrote:
> > > diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
> > > index 1255dbf..656c7e9 100644
> > > --- a/kernel/audit_watch.c
> > > +++ b/kernel/audit_watch.c
> > > @@ -540,8 +540,14 @@ int audit_dupe_exe(struct audit_krule *new, struct
> > > audit_krule *old)
> > > 
> > >  int audit_exe_compare(struct task_struct *tsk, struct
> > >  audit_fsnotify_mark
> > > 
> > > *mark) {
> > > -	unsigned long ino = tsk->mm->exe_file->f_inode->i_ino;
> > > -	dev_t dev = tsk->mm->exe_file->f_inode->i_sb->s_dev;
> > > -
> > > +	struct file *exe_file;
> > > +	unsigned long ino;
> > > +	dev_t dev;
> > > +
> > > +	rcu_read_lock();
> > > +	exe_file = rcu_dereference(tsk->mm->exe_file);
> > 
> > This line is triggering a sparse error on my system:
> >  # make C=1 M=kernel
> >  ...
> >  
> >    CHECK   kernel/audit_watch.c
> >  
> >  kernel/audit_watch.c:548:20: error: incompatible types in comparison
> >  expression (different address spaces)
> 
> That's odd.  I got this complaint when I had forgotten to add the
> rcu_dereference() call, but not in its current state.  Mind you, I get
> swamped with errors and warnings from all over the system (starting with
> ptrace.c, signal.c, exit.c, fork.c, audit.c, ftrace.c,
> selinux/netnode.c, ...) when I add
> "M=kernel" to my build command, so I start to wonder how valid that
> result is or that flag.  Where is M=kernel documented?

I don't remember anymore, it's something I've been using so long that I've 
forgotten where I first learned of it.  The "M=<X>" flag signals that you only 
want to build a specific module/directory, e.g. M=kernel builds everything 
under kernel/ whereas M=security/selinux builds everything under 
security/selinux.

So you don't see this error?

-- 
paul moore
security @ redhat