Commit 903efc55 authored Aug 29, 2013 by James Hogan Committed by Mike Turquette Aug 30, 2013

clk: fix new_parent dereference before null check



Commit 71472c0c (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 <dan.carpenter@oracle.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

parent 08442ce9

drivers/clk/clk.c

+7 −6

Original line number	Diff line number	Diff line
		@@ -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)
		{
		hlist_del(&clk->child_node);

		if (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)
		hlist_add_head(&clk->child_node, &new_parent->children);
		else
		} else {
		hlist_add_head(&clk->child_node, &clk_orphan_list);
		}

		clk->parent = new_parent;
		}

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