clk: make sure parent is not NULL in clk_fetch_parent_index()

If parent is given with NULL, clk_fetch_parent_index() could return
a positive index value.

Currently, parent is checked by the callers of this function, but
it would be safer to do it in this function.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 0382046..da7c9a5 100644 (file)
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1066,6 +1066,9 @@ static int clk_fetch_parent_index(struct clk_core *core,
 {
        int i;
 
+       if (!parent)
+               return -EINVAL;
+
        /*
         * find index of new parent clock using cached parent ptrs,
         * or if not yet cached, use string name comparison and cache