Re: [PATCH modules-next] module: Add debugfs interface to view unloaded tainted modules

From: Aaron Tomlin
Date: Wed Aug 31 2022 - 06:19:18 EST


On Mon 2022-08-29 09:14 +0200, Petr Pavlu wrote:
> On 8/23/22 21:32, Aaron Tomlin wrote:
> > [...]
> > @@ -59,3 +60,68 @@ void print_unloaded_tainted_modules(void)
> > }
> > }
> > }
> > +
> > +#ifdef CONFIG_DEBUG_FS
> > +static void *unloaded_tainted_modules_seq_start(struct seq_file *m, loff_t *pos)
> > +{
> > + mutex_lock(&module_mutex);
> > + return seq_list_start_rcu(&unloaded_tainted_modules, *pos);
> > +}

Hi Petr,

> unloaded_tainted_modules looks to be a proper RCU list which makes me think
> this reader could use just rcu_read_lock() instead of
> mutex_lock(&module_mutex)?

If I understand correctly, yes: the use of rcu_read_lock() and
rcu_read_unlock(), respectively, will be sufficient.

I will send a follow up patch.


Kind regards,

--
Aaron Tomlin