[PATCH 2/3] nvmem: core: add locking to nvmem_find_cell

[Heiner Kallweit <hkallweit1@gmail.com>]

Adding entries to nvmem_cells and deleting entries from it is
protected by nvmem_cells_mutex. Therefore this mutex should
also protect iterating over the list.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/nvmem/core.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 4e07f3f8..1aa6d25a 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -286,9 +286,15 @@ static struct nvmem_cell *nvmem_find_cell(const char *cell_id)
 {
 	struct nvmem_cell *p;
 
+	mutex_lock(&nvmem_cells_mutex);
+
 	list_for_each_entry(p, &nvmem_cells, node)
-		if (p && !strcmp(p->name, cell_id))
+		if (p && !strcmp(p->name, cell_id)) {
+			mutex_unlock(&nvmem_cells_mutex);
 			return p;
+		}
+
+	mutex_unlock(&nvmem_cells_mutex);
 
 	return NULL;
 }
-- 
2.13.0