On So, 2024-09-29 at 12:45 +0200, Markus Elfring wrote:
> > Use guard(mutex) to automatically unlock mutexes when going out of
> > scope. Simplify error paths by removing a goto and manual mutex
> > unlocking in multiple places.
> …
> > +++ b/drivers/reset/core.c
> …
> @@ -1041,29 +1036,27 @@ __of_reset_control_get(struct device_node
> *node, const char *id, int index,
> }
> }
>
> - mutex_lock(&reset_list_mutex);
> + guard(mutex)(&reset_list_mutex);
> rcdev = __reset_find_rcdev(&args, gpio_fallback);
> …
> rstc = __reset_control_get_internal(rcdev, rstc_id, shared,
> acquired);
>
> -out_unlock:
> - mutex_unlock(&reset_list_mutex);
> out_put:
> of_node_put(args.np);
> …
>
> Would you like to preserve the same lock scope (which ended before
> this function call)?
Thank you for pointing this out. Yes, and this should have alerted me
to the issue with goto out_put from before the locked region.
> @@ -1098,7 +1091,7 @@ __reset_control_get_from_lookup(struct device
> *dev, const char *con_id,
> const char *dev_id = dev_name(dev);
> struct reset_control *rstc = NULL;
>
> - mutex_lock(&reset_lookup_mutex);
> + guard(mutex)(&reset_lookup_mutex);
>
> list_for_each_entry(lookup, &reset_lookup_list, list) {
> …
> break;
> }
> }
>
> - mutex_unlock(&reset_lookup_mutex);
> -
> if (!rstc)
> return optional ? NULL : ERR_PTR(-ENOENT);
> …
>
> Would you really like to increase the lock scope here?
I don't think this would have been a problem.
regards
Philipp
