From 903efc553f738030a4ffa23fa03e7f329655c1c2 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Thu, 29 Aug 2013 12:10:51 +0100 Subject: [PATCH] clk: fix new_parent dereference before null check Commit 71472c0 (clk: add support for clock reparent on set_rate) added a dereference of the new_parent pointer in clk_reparent(), but as detected by smatch clk_reparent() later checks whether new_parent is NULL. The dereference was in order to clear the new parent's new_child pointer to avoid duplicate POST_RATE_CHANGE notifications, so clearly isn't necessary if the new parent is NULL, so move it inside the "if (new_parent)" block. Reported-by: Dan Carpenter Signed-off-by: James Hogan Signed-off-by: Mike Turquette --- drivers/clk/clk.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 2db08c01ef51..02e75d4e0a77 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1108,16 +1108,17 @@ static u8 clk_fetch_parent_index(struct clk *clk, struct clk *parent) static void clk_reparent(struct clk *clk, struct clk *new_parent) { - /* avoid duplicate POST_RATE_CHANGE notifications */ - if (new_parent->new_child == clk) - new_parent->new_child = NULL; - hlist_del(&clk->child_node); - if (new_parent) + if (new_parent) { + /* avoid duplicate POST_RATE_CHANGE notifications */ + if (new_parent->new_child == clk) + new_parent->new_child = NULL; + hlist_add_head(&clk->child_node, &new_parent->children); - else + } else { hlist_add_head(&clk->child_node, &clk_orphan_list); + } clk->parent = new_parent; }