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Commit bf47b4fd authored by Pawel Moll's avatar Pawel Moll Committed by Mike Turquette
Browse files

clk: Check parent for NULL in clk_change_rate 



clk_change_rate() is accessing parent's rate without checking
if the parent exists at all. In case of root clocks this will
cause NULL pointer dereference.

This patch follows what clk_calc_new_rates() does in such
situation.

Signed-off-by: default avatarPawel Moll <pawel.moll@arm.com>
Signed-off-by: default avatarMike Turquette <mturquette@linaro.org>
Cc: stable@kernel.org
parent 7975059d

drivers/clk/clk.c

+7 −4
Original line number Diff line number Diff line
@@ -850,18 +850,21 @@ static void clk_change_rate(struct clk *clk) 
{

	struct clk *child;

	unsigned long old_rate;

	unsigned long best_parent_rate = 0;

	struct hlist_node *tmp;



	old_rate = clk->rate;



	if (clk->parent)

		best_parent_rate = clk->parent->rate;



	if (clk->ops->set_rate)

		clk->ops->set_rate(clk->hw, clk->new_rate, clk->parent->rate);

		clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);



	if (clk->ops->recalc_rate)

		clk->rate = clk->ops->recalc_rate(clk->hw,

				clk->parent->rate);

		clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate);

	else

		clk->rate = clk->parent->rate;

		clk->rate = best_parent_rate;



	if (clk->notifier_count && old_rate != clk->rate)

		__clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);