4.15-stable review patch. If anyone has any objections, please let me know.
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From: Jerome Brunet jbrunet@baylibre.com
[ Upstream commit 12a26c298d2a8b1cab498533fa65198e49e3afd3 ]
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@baylibre.com Acked-by: Alexandre Belloni alexandre.belloni@free-electrons.com Acked-by: Sylvain Lemieux slemieux.tyco@gmail.com Signed-off-by: Stephen Boyd sboyd@codeaurora.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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(-)
--- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -118,12 +118,11 @@ static unsigned int _get_val(const struc 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_ 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, --- a/drivers/clk/hisilicon/clkdivider-hi6220.c +++ b/drivers/clk/hisilicon/clkdivider-hi6220.c @@ -56,7 +56,7 @@ static unsigned long hi6220_clkdiv_recal 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, --- a/drivers/clk/nxp/clk-lpc32xx.c +++ b/drivers/clk/nxp/clk-lpc32xx.c @@ -956,7 +956,7 @@ static unsigned long clk_divider_recalc_ 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, --- 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(str 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 = { --- 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 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; --- 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_postdi 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, --- a/drivers/rtc/rtc-ac100.c +++ b/drivers/rtc/rtc-ac100.c @@ -137,13 +137,15 @@ static unsigned long ac100_clkout_recalc 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, --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -412,7 +412,7 @@ extern const struct clk_ops clk_divider_
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,