Re: [PATCH] clk: gemini: Variable "val" in function gemini_clk_probe() could be uninitialized

From: Stephen Boyd
Date: Wed Feb 06 2019 - 14:23:23 EST


Quoting Yizhuo (2019-01-26 21:10:12)
> In function gemini_clk_probe(), local variable "val" could
> be uninitialized if function regmap_read() returns -EINVAL.
> However, it will be used as index in the later context, which
> could potentially be unsafe.

Ok. How did you find this? Any pointers?

>
> Signed-off-by: Yizhuo <yzhai003@xxxxxxx>
> ---
> drivers/clk/clk-gemini.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)

There are other locations in this file where 'val' is used even if
regmap_read() fails. For example gemini_pci_recalc_rate() does this. Can
you fix all the callers in this file? Presumably nobody cares that this
API could fail in this driver because it's a thin wrapper around mmio
read that never fails. Maybe we could have a comment instead that this
is the case and then ignore this patch entirely.