On 09/21, Andrzej Hajda wrote:
> With unsigned values underflow in loops can occur resulting in
> theoretically infinite loops.
>
> The problem has been detected using proposed semantic patch
> scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].
>
> [1]: http://permalink.gmane.org/gmane.linux.kernel/2038576
>
> Signed-off-by: Andrzej Hajda <[email protected]>
> ---
> drivers/clk/clk-vt8500.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/clk-vt8500.c b/drivers/clk/clk-vt8500.c
> index 37e9288..098e9fa 100644
> --- a/drivers/clk/clk-vt8500.c
> +++ b/drivers/clk/clk-vt8500.c
> @@ -384,7 +384,7 @@ static void vt8500_find_pll_bits(unsigned long rate,
> unsigned long parent_rate,
> static void wm8650_find_pll_bits(unsigned long rate, unsigned long
> parent_rate,
> u32 *multiplier, u32 *divisor1, u32 *divisor2)
> {
> - u32 mul, div1, div2;
> + int mul, div1, div2;
Only div2 seems to need the treatment here.
> u32 best_mul, best_div1, best_div2;
> unsigned long tclk, rate_err, best_err;
>
> @@ -452,7 +452,7 @@ static u32 wm8750_get_filter(u32 parent_rate, u32
> divisor1)
> static void wm8750_find_pll_bits(unsigned long rate, unsigned long
> parent_rate,
> u32 *filter, u32 *multiplier, u32 *divisor1,
> u32 *divisor2)
> {
> - u32 mul, div1, div2;
> + int mul, div1, div2;
And here div1 and div2 are the only ones.
> u32 best_mul, best_div1, best_div2;
> unsigned long tclk, rate_err, best_err;
>
> @@ -496,7 +496,7 @@ static void wm8750_find_pll_bits(unsigned long rate,
> unsigned long parent_rate,
> static void wm8850_find_pll_bits(unsigned long rate, unsigned long
> parent_rate,
> u32 *multiplier, u32 *divisor1, u32 *divisor2)
> {
> - u32 mul, div1, div2;
> + int mul, div1, div2;
And div1 and div2 here.
Can we focus the changes on the actual problematic variables? I
suppose this has never mattered because we break out of these
loops.
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