diff options
Diffstat (limited to 'drivers/of/overlay.c')
| -rw-r--r-- | drivers/of/overlay.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c index 791753321ed2..d164f86e5541 100644 --- a/drivers/of/overlay.c +++ b/drivers/of/overlay.c @@ -71,6 +71,28 @@ static int build_changeset_next_level(struct overlay_changeset *ovcs, const struct device_node *overlay_node, bool is_symbols_node); +/* + * of_resolve_phandles() finds the largest phandle in the live tree. + * of_overlay_apply() may add a larger phandle to the live tree. + * Do not allow race between two overlays being applied simultaneously: + * mutex_lock(&of_overlay_phandle_mutex) + * of_resolve_phandles() + * of_overlay_apply() + * mutex_unlock(&of_overlay_phandle_mutex) + */ +static DEFINE_MUTEX(of_overlay_phandle_mutex); + +void of_overlay_mutex_lock(void) +{ + mutex_lock(&of_overlay_phandle_mutex); +} + +void of_overlay_mutex_unlock(void) +{ + mutex_unlock(&of_overlay_phandle_mutex); +} + + static LIST_HEAD(ovcs_list); static DEFINE_IDR(ovcs_idr); @@ -624,6 +646,12 @@ int of_overlay_apply(struct device_node *tree, int *ovcs_id) goto out; } + of_overlay_mutex_lock(); + + ret = of_resolve_phandles(tree); + if (ret) + goto err_overlay_unlock; + mutex_lock(&of_mutex); ret = init_overlay_changeset(ovcs, tree); @@ -669,9 +697,13 @@ int of_overlay_apply(struct device_node *tree, int *ovcs_id) } mutex_unlock(&of_mutex); + of_overlay_mutex_unlock(); goto out; +err_overlay_unlock: + of_overlay_mutex_unlock(); + err_free_overlay_changeset: free_overlay_changeset(ovcs); |