[PATCH v5 1/5] pinctrl: mediatek: Check gpio pin number and use binary search in mtk_hw_pin_field_lookup()

Light Hsieh
2019-09-18T02:39:04Z

1. Check if gpio pin number is in valid range to prevent from get invalid
pointer 'desc' in the following code:
desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];

2. Use binary search in mtk_hw_pin_field_lookup()
Modify mtk_hw_pin_field_lookup() to use binary search for accelerating
search.

---
drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c | 24 +++++++++++++++++++-----
drivers/pinctrl/mediatek/pinctrl-paris.c | 19 +++++++++++++++++++
2 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
index 20e1c89..4687f63 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
@@ -68,7 +68,7 @@ static int mtk_hw_pin_field_lookup(struct mtk_pinctrl *hw,
{
const struct mtk_pin_field_calc *c, *e;
const struct mtk_pin_reg_calc *rc;
- u32 bits;
+ u32 bits, start = 0, end, found = 0, check;

if (hw->soc->reg_cal && hw->soc->reg_cal[field].range) {
rc = &hw->soc->reg_cal[field];
@@ -79,21 +79,32 @@ static int mtk_hw_pin_field_lookup(struct mtk_pinctrl *hw,
return -ENOTSUPP;
}

+ end = rc->nranges - 1;
c = rc->range;
e = c + rc->nranges;

- while (c < e) {
- if (desc->number >= c->s_pin && desc->number <= c->e_pin)
+ while (start <= end) {
+ check = (start + end) >> 1;
+ if (desc->number >= rc->range[check].s_pin
+ && desc->number <= rc->range[check].e_pin) {
+ found = 1;
break;
- c++;
+ } else if (start == end)
+ break;
+ else if (desc->number < rc->range[check].s_pin)
+ end = check - 1;
+ else
+ start = check + 1;
}

- if (c >= e) {
+ if (!found) {
dev_dbg(hw->dev, "Not support field %d for pin = %d (%s)\n",
field, desc->number, desc->name);
return -ENOTSUPP;
}

+ c = rc->range + check;
+
if (c->i_base > hw->nbase - 1) {
dev_err(hw->dev,
"Invalid base for field %d for pin = %d (%s)\n",
@@ -182,6 +193,9 @@ int mtk_hw_set_value(struct mtk_pinctrl *hw, const struct mtk_pin_desc *desc,
if (err)
return err;

+ if (value < 0 || value > pf.mask)
+ return -EINVAL;
+
if (!pf.next)
mtk_rmw(hw, pf.index, pf.offset, pf.mask << pf.bitpos,
(value & pf.mask) << pf.bitpos);
diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
index 923264d..28b4951 100644
--- a/drivers/pinctrl/mediatek/pinctrl-paris.c
+++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
@@ -693,6 +693,9 @@ static int mtk_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
const struct mtk_pin_desc *desc;
int value, err;

+ if (gpio > hw->soc->npins)
+ return -EINVAL;
+
desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];

err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DIR, &value);
@@ -708,6 +711,9 @@ static int mtk_gpio_get(struct gpio_chip *chip, unsigned int gpio)
const struct mtk_pin_desc *desc;
int value, err;

+ if (gpio > hw->soc->npins)
+ return -EINVAL;
+
desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];

err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DI, &value);
@@ -722,6 +728,9 @@ static void mtk_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
struct mtk_pinctrl *hw = gpiochip_get_data(chip);
const struct mtk_pin_desc *desc;

+ if (gpio > hw->soc->npins)
+ return;
+
desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];

mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DO, !!value);
@@ -729,12 +738,22 @@ static void mtk_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)

static int mtk_gpio_direction_input(struct gpio_chip *chip, unsigned int gpio)
{
+ struct mtk_pinctrl *hw = gpiochip_get_data(chip);
+
+ if (gpio > hw->soc->npins)
+ return -EINVAL;
+
return pinctrl_gpio_direction_input(chip->base + gpio);
}

static int mtk_gpio_direction_output(struct gpio_chip *chip, unsigned int gpio,
int value)
{
+ struct mtk_pinctrl *hw = gpiochip_get_data(chip);
+
+ if (gpio > hw->soc->npins)
+ return -EINVAL;
+
mtk_gpio_set(chip, gpio, value);

return pinctrl_gpio_direction_output(chip->base + gpio);
--
1.8.1.1.dirty