Re: [PATCH] clk: st: avoid uninitialized variable use

From: Gabriel Fernandez
Date: Mon Nov 16 2015 - 03:27:59 EST


On 12 November 2015 at 15:24, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> quadfs_pll_fs660c32_round_rate prints a few structure members
> that are never initialized, and also doesn't print the only one
> it cares about. We get a gcc warning about the ones that
> are printed:
>
> clk/st/clkgen-fsyn.c:560:93: warning: 'params.sdiv' may be used uninitialized in this function
> clk/st/clkgen-fsyn.c:560:93: warning: 'params.mdiv' may be used uninitialized in this function
> clk/st/clkgen-fsyn.c:560:93: warning: 'params.pe' may be used uninitialized in this function
> clk/st/clkgen-fsyn.c:560:93: warning: 'params.nsdiv' may be used uninitialized in this function
>
> This changes the code to no longer print uninitialized data, and
> for good measure it also prints the ndiv member that is being
> set.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Fixes: 5f7aa9071e93 ("clk: st: Support for QUADFS inside ClockGenB/C/D/E/F")
>
> diff --git a/drivers/clk/st/clkgen-fsyn.c b/drivers/clk/st/clkgen-fsyn.c
> index 576cd0354d48..ccb324d97160 100644
> --- a/drivers/clk/st/clkgen-fsyn.c
> +++ b/drivers/clk/st/clkgen-fsyn.c
> @@ -549,19 +549,20 @@ static int clk_fs660c32_vco_get_params(unsigned long input,
> return 0;
> }
>
> -static long quadfs_pll_fs660c32_round_rate(struct clk_hw *hw, unsigned long rate
> - , unsigned long *prate)
> +static long quadfs_pll_fs660c32_round_rate(struct clk_hw *hw,
> + unsigned long rate,
> + unsigned long *prate)
> {
> struct stm_fs params;
>
> - if (!clk_fs660c32_vco_get_params(*prate, rate, &params))
> - clk_fs660c32_vco_get_rate(*prate, &params, &rate);
> + if (clk_fs660c32_vco_get_params(*prate, rate, &params))
> + return rate;
>
> - pr_debug("%s: %s new rate %ld [sdiv=0x%x,md=0x%x,pe=0x%x,nsdiv3=%u]\n",
> + clk_fs660c32_vco_get_rate(*prate, &params, &rate);
> +
> + pr_debug("%s: %s new rate %ld [ndiv=%u]\n",
> __func__, clk_hw_get_name(hw),
> - rate, (unsigned int)params.sdiv,
> - (unsigned int)params.mdiv,
> - (unsigned int)params.pe, (unsigned int)params.nsdiv);
> + rate, (unsigned int)params.ndiv);
>
> return rate;
> }
>
>
Acked-by: Gabriel Fernandez <gabriel.fernandez@xxxxxxxxxx>

Thanks
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/