Re: [PATCH] kernel/module.c: Free lock-classes if parse_args failed

From: Ingo Molnar
Date: Thu Feb 19 2015 - 07:24:12 EST



* Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> > indeed ...
>
> How about something like so? It would fix this particular
> issue and lays the groundwork for maybe reusing some of
> the resources we now leak.

> @@ -3916,6 +3926,20 @@ void lockdep_free_key_range(void *start, unsigned long size)
> if (locked)
> graph_unlock();
> raw_local_irq_restore(flags);
> +
> + /*
> + * Wait for any possible iterators from look_up_lock_class() to pass
> + * before continuing to free the memory they refer to.
> + *
> + * sync_sched() is sufficient because the read-side is IRQ disable.
> + */
> + synchronize_sched();

> + /* Free lock-classes; relies on the preceding sync_rcu(). */
> lockdep_free_key_range(mod->module_core, mod->core_size);

> free_module:
> + /* Free lock-classes; relies on the preceding sync_rcu() */
> + lockdep_free_key_range(mod->module_core, mod->core_size);

Yeah. Looks good to me in principle, without having tested
it that is as I don't use modules on devel boxes:

Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>

Thanks,

Ingo
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