Re: [PATCH] clk: divider: fix incorrect usage of container_of

From: Sylvain Lemieux
Date: Fri Dec 22 2017 - 08:51:39 EST

For lpc32xx:
Acked-by: Sylvain Lemieux <slemieux.tyco@xxxxxxxxx>

On Fri, Dec 22, 2017 at 5:34 AM, Alexandre Belloni
<alexandre.belloni@xxxxxxxxxxxxxxxxxx> wrote:
> On 21/12/2017 at 17:30:54 +0100, Jerome Brunet wrote:
>> divider_recalc_rate() is an helper function used by clock divider of
>> different types, so the structure containing the 'hw' pointer is not
>> always a 'struct clk_divider'
>>
>> At the following line:
>> > div = _get_div(table, val, flags, divider->width);
>>
>> in several cases, the value of 'divider->width' is garbage as the actual
>> structure behind this memory is not a 'struct clk_divider'
>>
>> Fortunately, this width value is used by _get_val() only when
>> CLK_DIVIDER_MAX_AT_ZERO flag is set. This has never been the case so
>> far when the structure is not a 'struct clk_divider'. This is probably
>> why we did not notice this bug before
>>
>> Fixes: afe76c8fd030 ("clk: allow a clk divider with max divisor when zero")
>> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
>
> For RTC:
> Acked-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
>
>> ---
>> Hi Stephen, Mike,
>>
>> In addition to clock, this patch also touch the rtc and drm directories.
>> As it is changing the API of the helper function, I have this fix in a
>> single commit to avoid breaking bisect.
>>
>> Please let me know if you prefer to do differently.
>>
>> Cheers
>> Jerome
>>
>> drivers/clk/clk-divider.c | 7 +++----
>> drivers/clk/hisilicon/clkdivider-hi6220.c | 2 +-
>> drivers/clk/nxp/clk-lpc32xx.c | 2 +-
>> drivers/clk/qcom/clk-regmap-divider.c | 2 +-
>> drivers/clk/sunxi-ng/ccu_div.c | 2 +-
>> drivers/gpu/drm/msm/dsi/pll/dsi_pll_14nm.c | 2 +-
>> drivers/rtc/rtc-ac100.c | 6 ++++--
>> include/linux/clk-provider.h | 2 +-
>> 8 files changed, 13 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
>> index 4ed516cb7276..b49942b9fe50 100644
>> --- a/drivers/clk/clk-divider.c
>> +++ b/drivers/clk/clk-divider.c
>> @@ -118,12 +118,11 @@ static unsigned int _get_val(const struct clk_div_table *table,
>> unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate,
>> unsigned int val,
>> const struct clk_div_table *table,
>> - unsigned long flags)
>> + unsigned long flags, unsigned long width)
>> {
>> - struct clk_divider *divider = to_clk_divider(hw);
>> unsigned int div;
>>
>> - div = _get_div(table, val, flags, divider->width);
>> + div = _get_div(table, val, flags, width);
>> if (!div) {
>> WARN(!(flags & CLK_DIVIDER_ALLOW_ZERO),
>> "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
>> @@ -145,7 +144,7 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
>> val &= div_mask(divider->width);
>>
>> return divider_recalc_rate(hw, parent_rate, val, divider->table,
>> - divider->flags);
>> + divider->flags, divider->width);
>> }
>>
>> static bool _is_valid_table_div(const struct clk_div_table *table,
>> diff --git a/drivers/clk/hisilicon/clkdivider-hi6220.c b/drivers/clk/hisilicon/clkdivider-hi6220.c
>> index a1c1f684ad58..9f46cf9dcc65 100644
>> --- a/drivers/clk/hisilicon/clkdivider-hi6220.c
>> +++ b/drivers/clk/hisilicon/clkdivider-hi6220.c
>> @@ -56,7 +56,7 @@ static unsigned long hi6220_clkdiv_recalc_rate(struct clk_hw *hw,
>> val &= div_mask(dclk->width);
>>
>> return divider_recalc_rate(hw, parent_rate, val, dclk->table,
>> - CLK_DIVIDER_ROUND_CLOSEST);
>> + CLK_DIVIDER_ROUND_CLOSEST, dclk->width);
>> }
>>
>> static long hi6220_clkdiv_round_rate(struct clk_hw *hw, unsigned long rate,
>> diff --git a/drivers/clk/nxp/clk-lpc32xx.c b/drivers/clk/nxp/clk-lpc32xx.c
>> index b669a5c10fee..f5d815f577e0 100644
>> --- a/drivers/clk/nxp/clk-lpc32xx.c
>> +++ b/drivers/clk/nxp/clk-lpc32xx.c
>> @@ -956,7 +956,7 @@ static unsigned long clk_divider_recalc_rate(struct clk_hw *hw,
>> val &= div_mask(divider->width);
>>
>> return divider_recalc_rate(hw, parent_rate, val, divider->table,
>> - divider->flags);
>> + divider->flags, divider->width);
>> }
>>
>> static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
>> diff --git a/drivers/clk/qcom/clk-regmap-divider.c b/drivers/clk/qcom/clk-regmap-divider.c
>> index 53484912301e..928fcc16ee27 100644
>> --- a/drivers/clk/qcom/clk-regmap-divider.c
>> +++ b/drivers/clk/qcom/clk-regmap-divider.c
>> @@ -59,7 +59,7 @@ static unsigned long div_recalc_rate(struct clk_hw *hw,
>> div &= BIT(divider->width) - 1;
>>
>> return divider_recalc_rate(hw, parent_rate, div, NULL,
>> - CLK_DIVIDER_ROUND_CLOSEST);
>> + CLK_DIVIDER_ROUND_CLOSEST, divider->width);
>> }
>>
>> const struct clk_ops clk_regmap_div_ops = {
>> diff --git a/drivers/clk/sunxi-ng/ccu_div.c b/drivers/clk/sunxi-ng/ccu_div.c
>> index baa3cf96507b..302a18efd39f 100644
>> --- a/drivers/clk/sunxi-ng/ccu_div.c
>> +++ b/drivers/clk/sunxi-ng/ccu_div.c
>> @@ -71,7 +71,7 @@ static unsigned long ccu_div_recalc_rate(struct clk_hw *hw,
>> parent_rate);
>>
>> val = divider_recalc_rate(hw, parent_rate, val, cd->div.table,
>> - cd->div.flags);
>> + cd->div.flags, cd->div.width);
>>
>> if (cd->common.features & CCU_FEATURE_FIXED_POSTDIV)
>> val /= cd->fixed_post_div;
>> diff --git a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_14nm.c b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_14nm.c
>> index fe15aa64086f..71fe60e5f01f 100644
>> --- a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_14nm.c
>> +++ b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_14nm.c
>> @@ -698,7 +698,7 @@ static unsigned long dsi_pll_14nm_postdiv_recalc_rate(struct clk_hw *hw,
>> val &= div_mask(width);
>>
>> return divider_recalc_rate(hw, parent_rate, val, NULL,
>> - postdiv->flags);
>> + postdiv->flags, width);
>> }
>>
>> static long dsi_pll_14nm_postdiv_round_rate(struct clk_hw *hw,
>> diff --git a/drivers/rtc/rtc-ac100.c b/drivers/rtc/rtc-ac100.c
>> index 9e336184491c..0282ccc6181c 100644
>> --- a/drivers/rtc/rtc-ac100.c
>> +++ b/drivers/rtc/rtc-ac100.c
>> @@ -137,13 +137,15 @@ static unsigned long ac100_clkout_recalc_rate(struct clk_hw *hw,
>> div = (reg >> AC100_CLKOUT_PRE_DIV_SHIFT) &
>> ((1 << AC100_CLKOUT_PRE_DIV_WIDTH) - 1);
>> prate = divider_recalc_rate(hw, prate, div,
>> - ac100_clkout_prediv, 0);
>> + ac100_clkout_prediv, 0,
>> + AC100_CLKOUT_PRE_DIV_WIDTH);
>> }
>>
>> div = (reg >> AC100_CLKOUT_DIV_SHIFT) &
>> (BIT(AC100_CLKOUT_DIV_WIDTH) - 1);
>> return divider_recalc_rate(hw, prate, div, NULL,
>> - CLK_DIVIDER_POWER_OF_TWO);
>> + CLK_DIVIDER_POWER_OF_TWO,
>> + AC100_CLKOUT_DIV_WIDTH);
>> }
>>
>> static long ac100_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
>> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
>> index 73ac87f34df9..4c4001086447 100644
>> --- a/include/linux/clk-provider.h
>> +++ b/include/linux/clk-provider.h
>> @@ -412,7 +412,7 @@ extern const struct clk_ops clk_divider_ro_ops;
>>
>> unsigned long divider_recalc_rate(struct clk_hw *hw, unsigned long parent_rate,
>> unsigned int val, const struct clk_div_table *table,
>> - unsigned long flags);
>> + unsigned long flags, unsigned long width);
>> long divider_round_rate_parent(struct clk_hw *hw, struct clk_hw *parent,
>> unsigned long rate, unsigned long *prate,
>> const struct clk_div_table *table,
>> --
>> 2.14.3
>>
>
> --
> Alexandre Belloni, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com