Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757615AbdLVKe1 (ORCPT ); Fri, 22 Dec 2017 05:34:27 -0500 Received: from mail.free-electrons.com ([62.4.15.54]:46019 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756678AbdLVKeV (ORCPT ); Fri, 22 Dec 2017 05:34:21 -0500 Date: Fri, 22 Dec 2017 11:34:19 +0100 From: Alexandre Belloni To: Jerome Brunet Cc: Michael Turquette , Stephen Boyd , Vladimir Zapolskiy , Sylvain Lemieux , Andy Gross , David Brown , Maxime Ripard , Chen-Yu Tsai , Rob Clark , Alessandro Zummo , linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.or, linux-rtc@vger.kernel.org Subject: Re: [PATCH] clk: divider: fix incorrect usage of container_of Message-ID: <20171222103419.GB18255@piout.net> References: <20171221163054.13600-1-jbrunet@baylibre.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171221163054.13600-1-jbrunet@baylibre.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7311 Lines: 180 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 For RTC: Acked-by: Alexandre Belloni > --- > 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