clk: check ->determine/round_rate() return value in clk_calc_new_rates (03bc10ab) · Commits · 戴 / test

->determine_rate() and ->round_rate() can return the closest rate to the requested one or an error code. clk_calc_new_rates is assuming these functions can't return a negative value, which leads to a undefined behavior when the clk implementation returns such an error code. Fix this by returning NULL in case ->determine_rate() or ->round_rate() returned an error code. Signed-off-by:

Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by:

Michael Turquette <mturquette@linaro.org>

drivers/clk/clk.c

+16 −7

Original line number	Diff line number	Diff line
		@@ -1618,6 +1618,7 @@ static struct clk_core clk_calc_new_rates(struct clk_core clk,
		unsigned long min_rate;
		unsigned long max_rate;
		int p_index = 0;
		long ret;

		/* sanity */
		if (IS_ERR_OR_NULL(clk))
		@@ -1633,15 +1634,23 @@ static struct clk_core clk_calc_new_rates(struct clk_core clk,
		/* find the closest rate and parent clk/rate */
		if (clk->ops->determine_rate) {
		parent_hw = parent ? parent->hw : NULL;
		new_rate = clk->ops->determine_rate(clk->hw, rate,
		ret = clk->ops->determine_rate(clk->hw, rate,
		min_rate,
		max_rate,
		&best_parent_rate,
		&parent_hw);
		if (ret < 0)
		return NULL;

		new_rate = ret;
		parent = parent_hw ? parent_hw->core : NULL;
		} else if (clk->ops->round_rate) {
		new_rate = clk->ops->round_rate(clk->hw, rate,
		ret = clk->ops->round_rate(clk->hw, rate,
		&best_parent_rate);
		if (ret < 0)
		return NULL;

		new_rate = ret;
		if (new_rate < min_rate \|\| new_rate > max_rate)
		return NULL;
		} else if (!parent \|\| !(clk->flags & CLK_SET_RATE_PARENT)) {

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