If the "clock-frequency" DT property is not found, req_rate is used uninitialized, and the "audio_clkout" clock will be created with an arbitrary clock rate.
This uninitialized kernel stack data may leak to userspace through /sys/kernel/debug/clk/clk_summary, cfr. the value in the "rate" column:
clock enable_cnt prepare_cnt rate accuracy phase -------------------------------------------------------------------- audio_clkout 0 0 4001836240 0 0
Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be --- Should the absence of this property be considered an error?
Documentation/devicetree/bindings/sound/renesas,rsnd.txt states that both "#clock-cells" and "clock-frequency" are required properties, but none of the R-Car Gen1 and Gen2 DTSes seem to have them? --- sound/soc/sh/rcar/adg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/soc/sh/rcar/adg.c b/sound/soc/sh/rcar/adg.c index 2a5b3a293cd243db..b123734f9fbdabd9 100644 --- a/sound/soc/sh/rcar/adg.c +++ b/sound/soc/sh/rcar/adg.c @@ -437,7 +437,7 @@ static void rsnd_adg_get_clkout(struct rsnd_priv *priv, struct device *dev = rsnd_priv_to_dev(priv); struct device_node *np = dev->of_node; u32 ckr, rbgx, rbga, rbgb; - u32 rate, req_rate, div; + u32 rate, req_rate = 0, div; uint32_t count = 0; unsigned long req_48kHz_rate, req_441kHz_rate; int i;