2022-03-14 06:47:12

by Christian Marangi

Subject: [PATCH 07/16] clk: qcom: clk-krait: add hw_parent check for div2_round_rate

Check if hw_parent is present before calculating the round_rate to
prevent kernel panic.

Signed-off-by: Ansuel Smith <[email protected]>
---
drivers/clk/qcom/clk-krait.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c
index e447fcc3806d..d8af281eba0e 100644
--- a/drivers/clk/qcom/clk-krait.c
+++ b/drivers/clk/qcom/clk-krait.c
@@ -80,7 +80,12 @@ EXPORT_SYMBOL_GPL(krait_mux_clk_ops);
static long krait_div2_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
- *parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), rate * 2);
+ struct clk_hw *hw_parent = clk_hw_get_parent(hw);
+
+ if (!hw_parent)
+ return -1;
+
+ *parent_rate = clk_hw_round_rate(hw_parent, rate * 2);
return DIV_ROUND_UP(*parent_rate, 2);
}

--
2.34.1

2022-03-17 03:35:04

by Stephen Boyd

Subject: Re: [PATCH 07/16] clk: qcom: clk-krait: add hw_parent check for div2_round_rate

Quoting Ansuel Smith (2022-03-13 12:04:10)
> Check if hw_parent is present before calculating the round_rate to
> prevent kernel panic.
>
> Signed-off-by: Ansuel Smith <[email protected]>
> ---
> drivers/clk/qcom/clk-krait.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c
> index e447fcc3806d..d8af281eba0e 100644
> --- a/drivers/clk/qcom/clk-krait.c
> +++ b/drivers/clk/qcom/clk-krait.c
> @@ -80,7 +80,12 @@ EXPORT_SYMBOL_GPL(krait_mux_clk_ops);
> static long krait_div2_round_rate(struct clk_hw *hw, unsigned long rate,
> unsigned long *parent_rate)
> {
> - *parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), rate * 2);
> + struct clk_hw *hw_parent = clk_hw_get_parent(hw);
> +
> + if (!hw_parent)
> + return -1;

Use -EINVAL or some proper error code, not just -1

> +
> + *parent_rate = clk_hw_round_rate(hw_parent, rate * 2);
> return DIV_ROUND_UP(*parent_rate, 2);
> }
>
> --
> 2.34.1
>